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WO2009147165A1 - Novel ep4 receptor agonist compounds - Google Patents

Novel ep4 receptor agonist compounds Download PDF

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Publication number
WO2009147165A1
WO2009147165A1 PCT/EP2009/056789 EP2009056789W WO2009147165A1 WO 2009147165 A1 WO2009147165 A1 WO 2009147165A1 EP 2009056789 W EP2009056789 W EP 2009056789W WO 2009147165 A1 WO2009147165 A1 WO 2009147165A1
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WO
WIPO (PCT)
Prior art keywords
phenyl
chloro
amino
carbonyl
oxy
Prior art date
Application number
PCT/EP2009/056789
Other languages
French (fr)
Inventor
Alessandra Gaiba
Mark Patrick Healy
Helen Susanne Price
Steven James Stanway
Martin Edward Swarbrick
Original Assignee
Glaxo Group Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Glaxo Group Limited filed Critical Glaxo Group Limited
Publication of WO2009147165A1 publication Critical patent/WO2009147165A1/en

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C235/00—Carboxylic acid amides, the carbon skeleton of the acid part being further substituted by oxygen atoms
    • C07C235/42—Carboxylic acid amides, the carbon skeleton of the acid part being further substituted by oxygen atoms having carbon atoms of carboxamide groups bound to carbon atoms of six-membered aromatic rings and singly-bound oxygen atoms bound to the same carbon skeleton
    • C07C235/44—Carboxylic acid amides, the carbon skeleton of the acid part being further substituted by oxygen atoms having carbon atoms of carboxamide groups bound to carbon atoms of six-membered aromatic rings and singly-bound oxygen atoms bound to the same carbon skeleton with carbon atoms of carboxamide groups and singly-bound oxygen atoms bound to carbon atoms of the same non-condensed six-membered aromatic ring
    • C07C235/58—Carboxylic acid amides, the carbon skeleton of the acid part being further substituted by oxygen atoms having carbon atoms of carboxamide groups bound to carbon atoms of six-membered aromatic rings and singly-bound oxygen atoms bound to the same carbon skeleton with carbon atoms of carboxamide groups and singly-bound oxygen atoms bound to carbon atoms of the same non-condensed six-membered aromatic ring with carbon atoms of carboxamide groups and singly-bound oxygen atoms, bound in ortho-position to carbon atoms of the same non-condensed six-membered aromatic ring
    • C07C235/64—Carboxylic acid amides, the carbon skeleton of the acid part being further substituted by oxygen atoms having carbon atoms of carboxamide groups bound to carbon atoms of six-membered aromatic rings and singly-bound oxygen atoms bound to the same carbon skeleton with carbon atoms of carboxamide groups and singly-bound oxygen atoms bound to carbon atoms of the same non-condensed six-membered aromatic ring with carbon atoms of carboxamide groups and singly-bound oxygen atoms, bound in ortho-position to carbon atoms of the same non-condensed six-membered aromatic ring having the nitrogen atom of at least one of the carboxamide groups bound to a carbon atom of a six-membered aromatic ring
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P19/00—Drugs for skeletal disorders
    • A61P19/08—Drugs for skeletal disorders for bone diseases, e.g. rachitism, Paget's disease
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C237/00—Carboxylic acid amides, the carbon skeleton of the acid part being further substituted by amino groups
    • C07C237/28—Carboxylic acid amides, the carbon skeleton of the acid part being further substituted by amino groups having the carbon atom of at least one of the carboxamide groups bound to a carbon atom of a non-condensed six-membered aromatic ring of the carbon skeleton
    • C07C237/40—Carboxylic acid amides, the carbon skeleton of the acid part being further substituted by amino groups having the carbon atom of at least one of the carboxamide groups bound to a carbon atom of a non-condensed six-membered aromatic ring of the carbon skeleton having the nitrogen atom of the carboxamide group bound to a carbon atom of a six-membered aromatic ring

Definitions

  • This invention relates to benzamide derivatives, to processes for their preparation, to pharmaceutical compositions containing them and to their use in medicine.
  • the compounds of the present invention are EP 4 receptor agonists.
  • the EP 4 receptor is a 7-transmembrane receptor and its natural ligand is the prostaglandin PGE 2 .
  • PGE 2 also has affinity for the other EP receptors (types EP 1 , EP 2 and EP 3 ).
  • the prostanoid EP 4 receptor falls into a group of receptors normally associated with elevation of intracellular cyclic adenosine monophosphate (cAMP) levels.
  • the EP 4 receptor is associated with smooth muscle relaxation, intraocular pressure, pain (in particular inflammatory, neuropathic and visceral pain), inflammation, neuroprotection, lymphocyte differentiation, bone metabolic processes, allergic activities, promotion of sleep, renal regulation, gastric or enteric mucus secretion and duodenal bicarbonate secretion.
  • EP 4 receptor agonists may be useful for the treatment of pain, inflammation and other conditions associated with the EP 4 receptor.
  • the EP 4 receptor also plays an important role in closure of the ductus arteriosus, vasodepression, inflammation and bone remodeling as reviewed by Narumiya in Prostaglandins & Other Lipid Mediators 2002, 68-69 557-73.
  • indoprofen such as [4-(1-oxo-1 ,3-dihydro-2H-benzo[f]isoindol-2- yl)phenyl]-2-propionic acid, sodium salt have been described by Rufer et. al. in Eur. J. Med. Chem. - Chimica Therapeutica, 1978, 13, 193.
  • the present invention provides a compound selected from the group consisting of: (3-chloro-4- ⁇ [(5-chloro-2- ⁇ [(2- chlorophenyl)methyl]oxy ⁇ phenyl)carbonyl]amino ⁇ phenyl)acetic acid;
  • pharmaceutically acceptable derivative any pharmaceutically acceptable salt or ester, or salt of such ester of the compounds of the invention, or any other compound which upon administration to the recipient is capable of providing (directly or indirectly) a compound of the invention or an active metabolite or residue thereof.
  • salts referred to above will be the pharmaceutically acceptable salts, but other salts may find use, for example in the preparation of compounds of the invention and the pharmaceutically acceptable salts thereof.
  • Pharmaceutically acceptable salts include those described by Berge, Bighley and Monkhouse, J. Pharm. Sci., 1977, 66, 1-19.
  • pharmaceutically acceptable salts refers to salts prepared from pharmaceutically acceptable bases including inorganic bases and organic bases.
  • Salts derived from inorganic bases include aluminum, ammonium, calcium, copper, ferric, ferrous, lithium, magnesium, manganic salts, manganous, potassium, sodium, zinc, and the like.
  • Salts derived from pharmaceutically acceptable organic bases include salts of primary, secondary, and tertiary amines; substituted amines including naturally occurring substituted amines; and cyclic amines.
  • Particular pharmaceutically acceptable organic bases include arginine, betaine, caffeine, choline, N,N'-dibenzylethylenediamine, diethylamine, 2-diethylaminoethanol, 2- dimethylaminoethanol, ethanolamine, ethylenediamine, N-ethyl-morpholine, N- ethylpiperidine, glucamine, glucosamine, histidine, hydrabamine, isopropylamine, lysine, methylglucamine, morpholine, piperazine, piperidine, procaine, purines, theobromine, triethylamine, trimethylamine, tripropyl amine, tris(hydroxymethyl)aminomethane, and the like. Salts may also be formed from basic ion exchange resins, for example polyamine resins.
  • the compounds of the invention may be produced in vivo by metabolism of a suitable prodrug.
  • suitable prodrug may be for example physiologically acceptable metabolically labile esters of compounds of the invention. These may be formed by esterification of the carboxylic acid group in the parent compound of the invention with, where appropriate, prior protection of any other reactive groups present in the molecule followed by deprotection if required.
  • metabolically labile esters include C 1-4 alkyl esters e.g. methyl ethyl or t-butyl esters esters, C 3 . 6 alkenyl esters e.g. allyl substituted or unsubstituted aminoalkyl esters (e.g.
  • pivaloyloxymethyl 1-pivaloyloxyethyl, acetoxymethyl, 1- acetoxyethyl,1-(1-methoxy-1 - methyl)ethylcarbonyloxyethyl, 1 - benzoyloxyethyl, isopropoxycarbonyloxymethyl, 1- isopropoxycarbonyloxyethyl, cyclohexylcarbonyloxymethyl, 1- cyclohexylcarbonyloxyethyl ester, cyclohexyloxycarbonyloxymethyl, 1- cyclohexyloxycarbonyloxyethyl, 1-(4-tetrahydropyranyloxy)carbonyloxyethyl or 1-(4- tetrahydropyranyl)carbonyloxyethyl.
  • the present invention encompasses all isomers of the compounds of the invention and their pharmaceutically acceptable derivatives, including all geometric, tautomeric and optical forms, and mixtures thereof (e.g. racemic mixtures).
  • the compounds of the invention are intended for use in pharmaceutical compositions, it will be understood that they are each provided in substantially pure form, for example at least 50% pure, more suitably at least 75% pure and preferably at least 95% pure (% are on a wt/wt basis). Impure preparations of the compounds of the invention may be used for preparing the more pure forms used in the pharmaceutical compositions. Although the purity of intermediate compounds of the present invention is less critical, it will be readily understood that the substantially pure form is preferred as for the compounds of the invention. Preferably, whenever possible, the compounds of the present invention are obtained in crystalline form.
  • solvent of crystallisation may be present in the crystalline product.
  • This invention includes within its scope such solvates, including solvates of the free acid molecule and solvates of salts derived from the free acid molecule.
  • some of the compounds of this invention may be crystallised or recrystallised from solvents containing water. In such cases water of hydration may be formed.
  • This invention includes within its scope stoichiometric hydrates as well as compounds containing variable amounts of water that may be produced by processes such as lyophilisation.
  • different crystallisation conditions may lead to the formation of different polymorphic forms of crystalline products.
  • This invention includes within its scope all polymorphic forms of the compounds of the invention.
  • the present invention also includes within its scope all isotopically-labelled compounds of the invention. Such compounds are identical to those recited above except that one or more atoms therein are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number usually found in nature.
  • isotopes that can be incorporated into compounds of the invention and pharmaceutically acceptable salts thereof include isotopes of hydrogen, carbon, nitrogen, oxygen, chlorine and fluorine, such as 2H, 3H, 11 C, 13C, 14C, 15N, 170, 180, 36Cl and 18F.
  • Isotopically-labelled compounds of the invention for example those into which radioactive isotopes such as 3H, 14C are incorporated, are useful in drug and/or substrate tissue distribution assays. Tritiated, i.e., 3H, and carbon-14, i.e., 14C, isotopes are particularly preferred for their ease of preparation and detectability. 1 1 C and 18F isotopes are particularly useful in PET (positron emission tomography), and are useful in brain imaging.
  • lsotopically labelled compounds of the invention may be prepared by carrying out the synthetic procedures disclosed in the Schemes and/or in the Examples below, by substituting a readily available isotopically labelled reagent for a non-isotopically labelled reagent.
  • the compounds of the invention are EP 4 receptor agonists and may therefore be useful in treating EP 4 receptor mediated diseases. These diseases include those mediated by the action, or loss of action, of PGE 2 at EP 4 receptors.
  • the compounds of the invention may be useful in the treatment of pain, for example, chronic articular pain (e.g. rheumatoid arthritis, osteoarthritis, rheumatoid spondylitis, gouty arthritis and juvenile arthritis) including the property of disease modification and joint structure preservation; musculoskeletal pain; lower back and neck pain; sprains and strains; neuropathic pain; sympathetically maintained pain; myositis; pain associated with cancer and fibromyalgia; pain associated with migraine; pain associated with influenza or other viral infections, such as the common cold; rheumatic fever; pain associated with functional bowel disorders such as non-ulcer dyspepsia, non-cardiac chest pain and irritable bowel syndrome; pain associated with myocardial ischemia; post operative pain; headache; toothache; and dysmenorrhea.
  • chronic articular pain e.g. rheumatoid arthritis, osteoarthritis, rheumatoid
  • the compounds of the invention may be particularly useful in the treatment of neuropathic pain and symptoms associated therewith.
  • Neuropathic pain syndromes include: diabetic neuropathy; sciatica; non-specific lower back pain; multiple sclerosis pain; fibromyalgia; HIV-related neuropathy; post-herpetic neuralgia; trigeminal neuralgia; and pain resulting from physical trauma, amputation, cancer, toxins or chronic inflammatory conditions.
  • Symptoms of neuropathic pain include spontaneous shooting and lancinating pain, or ongoing, burning pain.
  • pain associated with normally non-painful sensations such as "pins and needles” (paraesthesias and dysesthesias), increased sensitivity to touch (hyperesthesia), painful sensation following innocuous stimulation (dynamic, static or thermal allodynia), increased sensitivity to noxious stimuli (thermal, cold, mechanical hyperalgesia), continuing pain sensation after removal of the stimulation
  • hypoalgesia or an absence of or deficit in selective sensory pathways (hypoalgesia).
  • the compounds of the invention may also be useful in the treatment of inflammation, for example in the treatment of skin conditions (e.g. sunburn, burns, eczema, dermatitis, psoriasis); ophthalmic diseases such as glaucoma, retinitis, retinopathies, uveitis and of acute injury to the eye tissue (e.g. conjunctivitis); lung disorders (e.g. asthma, bronchitis, emphysema, allergic rhinitis, respiratory distress syndrome, pigeon fancier's disease, farmer's lung, COPD; gastrointestinal tract disorders (e.g.
  • an inflammatory component such as vascular disease, migraine, periarteritis nod
  • the compounds of the invention may also be useful in the treatment of immunological diseases such as autoimmune diseases, immunological deficiency diseases or organ transplantation.
  • immunological diseases such as autoimmune diseases, immunological deficiency diseases or organ transplantation.
  • the compounds of the invention may also be effective in increasing the latency of HIV infection.
  • the compounds of the invention may also be useful in the treatment of diseases of excessive or unwanted platelet activation such as intermittent claudication, unstable angina, stroke, and acute coronary syndrome (e.g. occlusive vascular diseases).
  • the compounds of the invention may also be useful as a drug with diuretic action, or may be useful to treat overactive bladder syndrome.
  • the compounds of the invention may also be useful in the treatment of impotence or erectile dysfunction.
  • the compounds of formula (I) may also be useful in the treatment of various Bone Disorders as hereinbelow defined, which includes the treatment of bone fractures, bone injury or bone defects.
  • the compounds of the invention may be useful in enhancement of bone formation i.e. osteogenesis, such as increasing bone mass, bone volume, osteoblast number or osteoblast survival.
  • the compounds of formula (I) may therefore be useful in the treatment of bone disease, including genetic disorders, that are characterised by abnormal bone metabolism or resorption such as osteoporosis (especially postmenopausal osteoporosis, glucocorticoid induced osteoporosis, hyperthyroidism-induced osteoporosis, immobilisation-induced osteoporosis, heparin-induced osteoporosis and immunosuppressive-induced osteoporosis as well as long term complications of osteoporosis such as curvature of the spine, loss of height and prosthetic surgery), abnormally increased bone turnover, hyper-calcemia (including humoral hypercalcemia), hyperparathyroidism, Paget's bone diseases, osteolysis (including periprosthetic osteolysis), hypercalcemia of malignancy with or without bone metastases, hypercalcemia of fracture healing, rheumatoid arthritis, osteoarthritis (including disease modifying in osteoarthristis such as cartilage/bone repair), ostealgia, osteo
  • the compounds of formula (I) may also be useful in bone remodelling and/or promoting bone generation and/or promoting fracture healing.
  • the compounds of the present invention may be useful in fracture healing e.g. long bone fractures and fractures of other bones.
  • the compounds of the present invention may also be useful in healing fractures of the head, face and neck caused e.g. by injury.
  • the compounds of the present invention may also be useful in bone grafting including replacing bone graft surgery entirely, enhancing the rate of successful bone grafts, bone healing following facial reconstruction, maxillary reconstruction, mandibular reconstruction, craniofacial reconstruction e.g. of craniofacial defects such as orofacial defects at birth (including orofacial clefts such as cleft palate), prosthetic ingrowth, vertebral synostosis, long bone extension, spinal fusion, and sternotomy.
  • the compounds of the invention may also be useful in treating bone defects that might evolve around defects that occur during war.
  • the compounds of the invention may also be useful in periodontal indications such as periodontal disease (periodontitis), tooth loss, and peridontal augmentation e.g. in preparation for tooth implants.
  • the compounds of the present invention may also be useful in facilitating joint fusion, facilitating tendon and ligament repair, reducing the occurrence of secondary fracture, treating avascular necrosis, facilitating cartilage repair, facilitating bone healing after limb transplantation and repairing damage caused by metastatic bone disease.
  • the compounds of the invention may also be useful for attenuating the hemodynamic side effects of NSAIDs and COX-2 inhibitors.
  • the compounds of the invention may also be useful in the treatment of cardiovascular diseases such as hypertension or myocardial ischemia; functional or organic venous insufficiency; varicose therapy; haemorrhoids; and shock states associated with a marked drop in arterial pressure (e.g. septic shock).
  • cardiovascular diseases such as hypertension or myocardial ischemia; functional or organic venous insufficiency; varicose therapy; haemorrhoids; and shock states associated with a marked drop in arterial pressure (e.g. septic shock).
  • the compounds of the invention may also be useful in the treatment of neurodegenerative diseases and neurodegeneration such as dementia, particularly degenerative dementia (including senile dementia, Alzheimer's disease, Pick's disease, Huntingdon's chorea, Parkinson's disease and Creutzfeldt-Jakob disease, ALS, motor neuron disease); vascular dementia (including multi-infarct dementia); as well as dementia associated with intracranial space occupying lesions; trauma; infections and related conditions (including HIV infection); metabolism; toxins; anoxia and vitamin deficiency; and mild cognitive impairment associated with ageing, particularly Age Associated Memory Impairment.
  • dementia particularly degenerative dementia (including senile dementia, Alzheimer's disease, Pick's disease, Huntingdon's chorea, Parkinson's disease and Creutzfeldt-Jakob disease, ALS, motor neuron disease); vascular dementia (including multi-infarct dementia); as well as dementia associated with intracranial space occupying lesions; trauma; infections and related conditions (including HIV infection); metabolism; toxins;
  • the compounds of the invention may also be useful in the treatment of neurological disorders and may be useful as neuroprotecting agents.
  • the compounds of the invention may also be useful in the treatment of neurodegeneration following stroke, cardiac arrest, pulmonary bypass, traumatic brain injury, spinal cord injury or the like.
  • the compounds of the invention may also be useful in the treatment of complications of Type 1 diabetes (e.g. diabetic microangiopathy, diabetic retinopathy, diabetic nephropathy, macular degeneration, glaucoma), nephrotic syndrome, aplastic anaemia, uveitis, Kawasaki disease and sarcoidosis.
  • Type 1 diabetes e.g. diabetic microangiopathy, diabetic retinopathy, diabetic nephropathy, macular degeneration, glaucoma
  • nephrotic syndrome e.g. diabetic microangiopathy, diabetic retinopathy, diabetic nephropathy, macular degeneration, glaucoma
  • nephrotic syndrome e.g. diabetic microangiopathy, diabetic retinopathy, diabetic nephropathy, macular degeneration, glaucoma
  • nephrotic syndrome e.g. diabetic microangiopathy, diabetic retinopathy, diabetic nephropathy
  • the compounds of the invention may also be useful in the treatment of kidney dysfunction (nephritis, particularly mesangial proliferative glomerulonephritis, nephritic syndrome), liver dysfunction (hepatitis, cirrhosis) and gastrointestinal dysfunction (diarrhoea).
  • kidney dysfunction nephritis, particularly mesangial proliferative glomerulonephritis, nephritic syndrome
  • liver dysfunction hepatitis, cirrhosis
  • gastrointestinal dysfunction diarrhoea
  • any reference to treatment includes both treatment of established symptoms and prophylactic treatment.
  • a compound of the invention or a pharmaceutically acceptable derivative thereof for use in human or veterinary medicine.
  • a compound of the invention or a pharmaceutically acceptable derivative thereof for use in the treatment of a Bone Disorder there is provided a compound of the invention or a pharmaceutically acceptable derivative thereof for use in the treatment of a Bone Disorder.
  • a method of treating a human or animal subject suffering from a condition which is mediated by the action, or by loss of action, of PGE 2 at EP 4 receptors which comprises administering to said subject an effective amount of a compound of the invention or a pharmaceutically acceptable derivative thereof.
  • a method of treating a human or animal subject suffering from a Bone Disorder which comprises administering to said subject an effective amount of a compound of the invention or a pharmaceutically acceptable derivative thereof.
  • a method of treating a human or animal subject suffering from a pain, or an inflammatory, immunological, neurodegenerative or renal disorder comprises administering to said subject an effective amount of a compound of the invention or a pharmaceutically acceptable derivative thereof.
  • a compound of the invention or a pharmaceutically acceptable derivative thereof for the manufacture of a medicament for the treatment of a condition which is mediated by the action, or loss of action, of PGE 2 at EP 4 receptors.
  • a compound of the invention or a pharmaceutically acceptable derivative thereof for the manufacture of a medicament for the treatment of a Bone Disorder.
  • a compound of the invention or a pharmaceutically acceptable derivative thereof for the manufacture of a medicament for the treatment or prevention of a condition such as a pain, or an inflammatory, immunological, neurodegenerative or renal disorder.
  • compositions are conveniently administered in the form of pharmaceutical compositions.
  • Such compositions may conveniently be presented for use in conventional manner in admixture with one or more physiologically acceptable carriers or diluents.
  • a pharmaceutical composition comprising a compound of the invention or a pharmaceutically acceptable derivative thereof adapted for use in human or veterinary medicine. While it is possible for the compounds of the invention or a pharmaceutically acceptable derivative thereof to be administered as the raw chemical, it is preferable to present it as a pharmaceutical formulation.
  • the formulations of the present invention comprise the compounds of the invention or a pharmaceutically acceptable derivative thereof together with one or more acceptable carriers or diluents therefore and optionally other therapeutic ingredients.
  • the carrier(s) must be "acceptable” in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient thereof.
  • the invention provides a pharmaceutical composition comprising a compound of the invention or a pharmaceutically acceptable derivative thereof and a pharmaceutically acceptable carrier or diluent therefore.
  • Administration of the compounds of this invention can be via any method which delivers a compound of this invention systemically and/or locally.
  • the formulations include those suitable for oral, parenteral (including subcutaneous e.g. by injection or by depot, intradermal, intrathecal, intracapsular, intraspinal, intrasternal, intraarticular, intramuscular e.g. by depot, intravenous and intranasal), rectal and topical (including dermal, buccal and sublingual) administration although the most suitable route may depend upon for example the condition and disorder of the recipient.
  • the formulations may conveniently be presented in unit dosage form and may be prepared by any of the methods well known in the art of pharmacy (see for example methods disclosed in 'Remington - The Science and Practice of Pharmacy', 21 st Edition, Lippincott, Williams & Wilkins, USA, 2005 and references therein). All methods include the step of bringing into association the active ingredient with the carrier which constitutes one or more accessory ingredients. In general the formulations are prepared by uniformly and intimately bringing into association the active ingredient with liquid carriers or finely divided solid carriers or both and then, if necessary, shaping the product into the desired formulation.
  • Formulations of the present invention suitable for oral administration may be presented as discrete units such as capsules, cachets or tablets (e.g. chewable tablets in particular for paediatric administration) each containing a predetermined amount of the active ingredient; as a powder or granules; as a solution or a suspension in an aqueous liquid or a non-aqueous liquid; or as an oil-in-water liquid emulsion or a water-in-oil liquid emulsion.
  • the active ingredient may also be presented as a bolus, electuary or paste.
  • a tablet may be made by compression or moulding, optionally with one or more accessory ingredients.
  • Compressed tablets may be prepared by compressing in a suitable machine the active ingredient in a free-flowing form such as a powder or granules, optionally mixed with a binder, lubricant, inert diluent, lubricating, surface active or dispersing agent.
  • Moulded tablets may be made by moulding in a suitable machine a mixture of the powdered compound moistened with an inert liquid diluent.
  • the tablets may optionally be coated or scored and may be formulated so as to provide slow or controlled release of the active ingredient therein.
  • Formulations for parenteral administration include aqueous and non-aqueous sterile injection solutions which may contain anti-oxidants, buffers, bacteriostats and solutes which render the formulation isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents.
  • the formulations may be presented in unit-dose or multi-dose containers, for example sealed ampoules and vials, and may be stored in a freeze-dried (lyophilised) condition requiring only the addition of a sterile liquid carrier, for example, water-for-injection, immediately prior to use.
  • Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tablets of the kind previously described.
  • Formulations for rectal administration may be presented as a suppository with the usual carriers such as cocoa butter, hard fat or polyethylene glycol.
  • Formulations for topical administration in the mouth include lozenges comprising the active ingredient in a flavoured basis such as sucrose and acacia or tragacanth, and pastilles comprising the active ingredient in a basis such as gelatin and glycerin or sucrose and acacia.
  • the compounds may also be formulated as depot preparations. Such long acting formulations may be administered by implantation (for example subcutaneously or intramuscularly) or by injection (for example intramuscular or intra-articular injection).
  • the compounds may be formulated with suitable polymeric or hydrophobic materials (for example as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt.
  • Local application e.g., to the site of bone fracture, intra-articular
  • local application may be achieved by applying a solution or dispersion of the compound in a suitable carrier or diluent onto the surface of, or incorporating it into, solid or semisolid implants conventionally used in orthopedic surgery.
  • the present invention can also be administered using an injectable, flowable composition that provides sustained release at the local site of the injection by forming a biodegradable solid or gel depot, matrix or implant.
  • formulations may include other agents conventional in the art having regard to the type of formulation in question, for example those suitable for oral administration may include flavouring agents.
  • COX-2 inhibitors such as celecoxib, rofecoxib, valdecoxib or parecoxib
  • 5-lipoxygenase inhibitors such as paracetamol
  • NSAI D's such as diclofenac, indomethacin, nabumetone, naproxen or ibuprofen
  • leukotriene receptor antagonists leukotriene receptor antagonists
  • DMARD's such as methotrexate
  • sodium channel blockers such as lamotrigine
  • N-type calcium channel antagonists such as NMDA receptor modulators, such as glycine receptor antagonists
  • gabapentin, pregabalin and related compounds tricyclic antidepressants such as amitriptyline
  • neurone stabilising antiepileptic drugs such as venlafaxine
  • opioid analgesics such as venlafaxine
  • 5HT 1 agonists such as tript
  • the compounds of the invention may also be used in combination with known agents useful for treating or preventing the bone disorders described above.
  • the present invention therefore includes combinations of the presently disclosed compounds with other agents including the following: Progestins (such as algestone acetophenide, altrenogest, amadinone acetate, anagestone acetate, chlormadinone acetate, cingestol, clogestone acetate, clomegestone acetate, delmadinone acetate, desogestrel, dimethisterone, dydrogesterone, ethynerone, ethynodiol diacetate, etonogestrel, flurogestone acetate, gestaclone, gestodene, gestonorone caproate, gestrinone, haloprogesterone, hydroxyprogesterone caproate, levonorgestrel, lynestrenol, medrogestone, medroxyproge
  • the invention thus provides, in a further embodiment, a combination comprising a compound of the invention or a pharmaceutically acceptable derivative thereof together with a further therapeutic agent or agents.
  • a combination comprising an EP 4 receptor agonist of the invention or a pharmaceutically acceptable derivative thereof and paracetamol.
  • compositions comprising a combination as defined above together with a pharmaceutically acceptable carrier or diluent comprise a further aspect of the invention.
  • the individual components of such combinations may be administered either sequentially or simultaneously in separate or combined pharmaceutical formulations.
  • the dose of each compound may differ from that when the compound is used alone. Appropriate doses will be readily appreciated by those skilled in the art.
  • a method of treating a human or animal subject suffering from a condition which is mediated by the action, or by loss of action, of PGE 2 at EP 4 receptors which comprises administering to said subject an effective amount of a compound of the invention or a pharmaceutically acceptable derivative thereof and paracetamol.
  • a method of treating a human or animal subject suffering from a Bone Disorder which comprises administering to said subject an effective amount of a compound of the invention or a pharmaceutically acceptable derivative thereof and paracetamol.
  • a proposed daily dosage of compounds of the invention or their pharmaceutically acceptable salts for the treatment of man is from 0.001 to 30 mg/kg body weight per day and more particularly 0.1 to 3 mg/kg body weight per day, calculated as the free acid, which may be administered as a single or divided dose, for example one to four times per day.
  • the dose range for adult human beings is generally from 0.1 to 1000 mg/day, such as from 10 to 800 mg/day, preferably 10 to 200 mg/day, calculated as the free acid.
  • a suitable daily dosage of paracetamol is up to 4000 mg per day.
  • Suitable unit doses include 200, 400, 500 and 1000 mg, one, two, three or four times per day.
  • the precise amount of the compounds of the invention administered to a host, particularly a human patient, will be the responsibility of the attendant physician. However, the dose employed will depend on a number of factors including the age and sex of the patient, the precise condition being treated and its severity, the route of administration, and any possible combination therapy that may be being undertaken.
  • ester intermediates of the compounds of the invention are novel and form an aspect of the invention.
  • the ester intermediates are: Ethyl (3-chloro-4- ⁇ [(5-chloro-2- ⁇ [(3- chloropheny ⁇ methyljoxyjpheny ⁇ carbonyljaminojpheny ⁇ acetate, ethyl ⁇ 4-[( ⁇ 5-chloro-2-[(phenylmethyl)oxy]phenyl ⁇ carbonyl)amino]phenyl ⁇ acetate, ethyl ⁇ 3-chloro-4-[( ⁇ 5-chloro-2-
  • the present invention provides processes for the preparation of the compounds of the invention and pharmaceutically acceptable derivatives thereof.
  • a process for preparing a compound of the invention comprising reacting an ester intermediate with a suitable base, such as sodium hydroxide, and optionally thereafter forming a pharmaceutically acceptable derivative of the compound so formed, and/or converting one compound of formula (I) to another.
  • the above-mentioned reaction comprising an ester intermediate is performed in a suitable solvent, such as ethanol, under reflux.
  • the following examples illustrate the preparation of the compounds the invention.
  • the examples show the preparation of intermediates ("Intermediates") and compounds of the invention ("Examples").
  • the starting material for the preparation of intermediates may not necessarily have been prepared from the batch referred to unless expressly indicated.
  • the intermediates for the preparation of the examples may not necessarily have been prepared from the batch referred to unless expressly indicated.
  • Chromatographic methods include column chromatography, flash chromatography, HPLC (high performance liquid chromatography), SFC (supercritical fluid chromatography), SCX (strong cation exchange chromatography) and MDAP (mass directed autopreparation).
  • Biotage when used herein refers to commercially available pre-packed silica gel cartridges.
  • Aqueous solvent Water + 0.1% Formic Acid
  • Runtime 13.5 minutes, comprising 10-minute gradient followed by a 3.5 minute column flush and re-equilibration step.
  • Runtime 13.5 minutes, comprising 6-minute gradient followed by a 7.5 minute column flush and re-equilibration step.
  • methyl 5- chloro-2-hydroxybenzoate, ethyl 4-aminophenylacetate, 2- [(phenylmethyl)oxy]benzoic acid and methyl 2-hydroxybenzoate may be obtained from Alfa Aesar; 5-chlorosalicylic acid, methyl 2-amino-5-chlorobenzoate and 6- chloro-2H-3,1-benzoxazine-2,4(1 H)-dione may be obtained from Aldrich; 2-amino-6- (methyloxy)benzoic acid may be obtained from Fluorochem.
  • N-chlorosuccinimide (1 eq, 7.45g, 55.8mmol) was added to a solution of ethyl A- aminophenylacetate (10g, 55.8mmol) in chloroform (20OmIs). The reaction mixture was stirred at room temperature, under argon, for 15 minutes.
  • Example 1 (3-chloro-4- ⁇ [(5-chloro-2- ⁇ [(3- chlorophenyl)methyl]oxy ⁇ phenyl)carbonyl]amino ⁇ phenyl)acetic acid
  • Step 1
  • Benzyl bromide (2.79ml, 23.5mmol) and potassium carbonate (4.87g, 35.3mmol) were added to 5-chlorosalicylic acid (2.03g, 1 1.8mmol) in DMF (20ml) and stirred at room temperature for 16 hours.
  • LCMS indicated a mixture of mono and dialkylated material.
  • the mixture was then heated at 6O 0 C for 1 hour giving a ratio of 10:1 , dkmono alkylated product.
  • the mixture was cooled, diluted with water (150ml) and extracted with EtOAc (x3). The organics were washed with water (x2), brine, dried (MgSO 4 ) and concentrated in vacuo to yield a yellow oil that was used immediately in the next step.
  • Example 8 ⁇ 4-[( ⁇ 5-chloro-2- [(phenylmethyljaminojpheny ⁇ carbonyljaminolpheny ⁇ acetic acid
  • Example 10 (4- ⁇ [(5-chloro-2- ⁇ [(3- chlorophenyl)methyl]amino ⁇ phenyl)carbonyl]amino ⁇ phenyl)acetic acid.
  • Lithium hydroxide monohydate (25mg, 0.599mmol) was added to a solution of ethyl ⁇ 4-[( ⁇ 2-chloro-6-[(phenylmethyl)oxy]phenyl ⁇ carbonyl)amino]phenyl ⁇ acetate (169mg, 0.399mmol) in dioxane (4ml) and water (2ml) and the reaction was stirred at room temperature for 2 hrs. The solvent was evaporated and the residue dissolved in water. Acidification (cone. HCI, pH ⁇ 1 ) afforded a colourless solid which was collected by filtration and dried invacuo to give the title compound (154mg, 98%). MS (ES+) m/z 396 [M+H + ] (C 22 H 18 35 CINO 4 ).
  • Example 13 (4- ⁇ [(2-chloro-6- ⁇ [(3- chlorophenyl)methyl]oxy ⁇ phenyl)carbonyl]amino ⁇ phenyl)acetic acid.
  • Lithium hydroxide monohydate (27mg, 0.64mmol) was added to a solution of ethyl (4- ⁇ [(2-chloro-6- ⁇ [(3-chlorophenyl)methyl]oxy ⁇ phenyl)carbonyl]amino ⁇ phenyl)acetate (194mg, 0.424mmol) in dioxane (4ml) and water (2ml) and the reaction was stirred at room temperature for 18 hrs. The solvent was evaporated and the residue dissolved in water. Acidification (cone. HCI, pH ⁇ 1 ) afforded a colourless solid which was collected by filtration and dried invacuo to give the title compound (180mg, 99%).
  • HEK-293(T) cells expressing the recombinant human prostanoid EP 4 receptor were grown as a monolayer culture in DMEM-F12/F12 containing glutamax IITM (a source of L-Glutamine) (Gibco) and supplemented with 10% foetal bovine serum (Gibco) and 0.4mg.ml-1 G418.
  • HEK- EP 4 cells were pre-treated 24hr and 30mins prior to the experiment with 10 ⁇ M indomethacin and harvested using VerseneTM (EDTA) containing 10 ⁇ M indomethacin.
  • the cells were resuspended in assay buffer (DMEM:F12, 10 ⁇ M indomethacin and 200 ⁇ M IBMX) at 1 ⁇ 10 6 cells per ml and incubated for 20min at 37 0 C. Thereafter, 50 ⁇ l of cells were added to 50 ⁇ l test compound (compound of the invention) and incubated at 37°C for 4 minutes before stopping reactions with 10O ⁇ l of 1 % Triton ® X-100 (non-ionic surfactant). cAMP levels in the cell lysates were determined using a competition binding assay.
  • assay buffer DMEM:F12, 10 ⁇ M indomethacin and 200 ⁇ M IBMX
  • the Examples of the present invention were tested in the above-mentioned assay and exhibited average pEC 50 values of 6.0 or higher, and average intrinsic activities of 20% or higher.

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Abstract

A compound selected from the group consisting of: (3-chloro-4-{[(5-chloro-2-{[(2- chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetic acid; {4-[({5-chloro-2-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid; {3-chloro-4-[({5-chloro-2-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid; (3-chloro-4-{[(5-chloro-2-{[(3- chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetic acid; {4-[({2-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid; (4-{[(5-chloro-2-{[(3-chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}-2- fluorophenyl)acetic acid; {3-chloro-4-[({2-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid; (3-chloro-4-{[(2-{[(3-chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetic acid; {4-[({2-chloro-6-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid; (4-{[(2-chloro-6-{[(3-chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetic acid; {4-[({5-chloro-2-[(phenylmethyl)amino]phenyl}carbonyl)amino]phenyl}acetic acid; (4-{[(5-chloro-2-{[(3-chlorophenyl)methyl]amino}phenyl)carbonyl]amino}phenyl)acetic acid; and (4-{[(5-chloro-2-{[(2-chlorophenyl)methyl]amino}phenyl)carbonyl]amino}phenyl)acetic acid, or pharmaceutically acceptable salts thereof, pharmaceutical compositions comprising such compounds and the use of such compounds in medicine.

Description

Novel EP4 Receptor Agonist Compounds
This invention relates to benzamide derivatives, to processes for their preparation, to pharmaceutical compositions containing them and to their use in medicine.
The compounds of the present invention are EP4 receptor agonists.
A number of review articles describe the characterization and therapeutic relevance of the prostanoid receptors as well as the most commonly used selective agonists and antagonists: Eicosanoids; From Biotechnology to Therapeutic Applications, Folco,
Samuelsson, Maclouf, and VeIo eds, Plenum Press, New York, 1996, chap. 14, 137-154 and Journal of Lipid Mediators and Cell Signalling, 1996, 14, 83-87 and Prostanoid Receptors, Structure, Properties and Function, S Narumiya et al, Physiological Reviews 1999, 79(4), 1193-126.
The EP4 receptor is a 7-transmembrane receptor and its natural ligand is the prostaglandin PGE2. PGE2 also has affinity for the other EP receptors (types EP1, EP2 and EP3). The prostanoid EP4 receptor falls into a group of receptors normally associated with elevation of intracellular cyclic adenosine monophosphate (cAMP) levels. The EP4 receptor is associated with smooth muscle relaxation, intraocular pressure, pain (in particular inflammatory, neuropathic and visceral pain), inflammation, neuroprotection, lymphocyte differentiation, bone metabolic processes, allergic activities, promotion of sleep, renal regulation, gastric or enteric mucus secretion and duodenal bicarbonate secretion. Therefore EP4 receptor agonists may be useful for the treatment of pain, inflammation and other conditions associated with the EP4 receptor. The EP4 receptor also plays an important role in closure of the ductus arteriosus, vasodepression, inflammation and bone remodeling as reviewed by Narumiya in Prostaglandins & Other Lipid Mediators 2002, 68-69 557-73.
A number of publications have demonstrated that PGE2 acting through the EP4 receptor subtype, and EP4 agonists alone, can regulate inflammatory cytokines after an inflammatory stimulus. Takayama et al in the Journal of Biological Chemistry 2002, 277(46), 44147-54 showed PGE2 modulates inflammation during inflammatory diseases by suppressing macrophage derived chemokine production via the EP4 receptor. In Bioorganic & Medicinal Chemistry 2002, 10(7), 2103-2110, Maruyama et al demonstrate the selective EP4 receptor agonist (ONO-AE1-437) suppresses LPS induced TNF-α in human whole blood whilst increasing the levels of IL-10. An article from Anesthesiology, 2002, 97,170-176 suggests that a selective EP4 receptor agonist (ONO-AE1-329) effectively inhibited mechanical and thermal hyperalgesia and inflammatory reactions in acute and chronic monoarthritis.
Two independent articles from Sakuma et al in Journal of Bone and Mineral Research 2000, 15(2), 218-227 and Miyaura et a/ in Journal of Biological Chemistry 2000, 275(26), 19819-23, report impaired osteoclast formation in cells cultured from EP4 receptor knock-out mice. Yoshida et al in Proceedings of the National Academy of Sciences of the United States of America 2002, 99(7), 4580-4585, by use of mice lacking each of the PGE2 receptor EP subtypes, identified EP4 as the receptor that mediates bone formation in response to PGE2 administration. They also demonstrated a selective EP4 receptor agonist (ONO-4819) consistently induces bone formation in wild type mice. Additionally, Terai et al in Bone 2005, 37(4), 555-562 have shown the presence of a selective EP4 receptor agonist (ONO-4819) enhanced the bone-inducing capacity of rhBMP-2, a therapeutic cytokine that can induce bone formation.
Further research by Larsen et al shows the effects of PGE2 on secretion in the second part of the human duodenum is mediated through the EP4 receptor (Acta. Physiol. Scand. 2005, 185, 133-140). Also, it has been shown a selective EP4 receptor agonist (ONO-AE1-329) can protect against colitis in rats (Nitta et al in Scandinavian Journal of Immunology 2002, 56(1 ), 66-75).
Dore et al in The European Journal of Neuroscience 2005, 22(9), 2199-206 have shown that PGE2 can protect neurons against amyloid beta peptide toxicity by acting on EP2 and EP4 receptors. Furthermore Dore has demonstrated in Brain Research 2005, 1066(1-2), 71-77 that an EP4 receptor agonist (ONO-AE1-329) protects against neurotoxicity in an acute model of excitotoxicity in the brain.
Woodward et a/ in Journal of Lipid Mediators 1993, 6(1-3), 545-53 found intraocular pressure could be lowered using selective prostanoid agonists. Two papers in Investigative Ophthalmology & Visual Science have shown the prostanoid EP4 receptor is expressed in human lens epithelial cells (Mukhopadhyay et al 1999, 40(1 ), 105-12), and suggest a physiological role for the prostanoid EP4 receptor in modulation of flow in the trabecular framework of the eye (Hoyng et al 1999, 40(1 1 ), 2622-6). Compounds exhibiting EP4 receptor binding activity have been described in, for example, WO98/55468, WO00/18744, WO00/03980, WO00/15608, WO0016760, WO00/21532, EP0855389, EP0985663, WO02/50031 , WO02/50032, WO02/50033, WO02/064564, WO03/103604, WO03/077910, WO03/086371 , WO04/037813, WO04/067524, WO04/085430, US2004142969, WO05/021508, WO05/105733, WO05/105732, WO05/080367, WO05/037812, WO05/1 16010, WO06/122403, WO2007/088189, WO2007/088190, WO2008/012344, WO2008/046798, WO2008/012347, WO2008/020055, WO2008/071736 and WO2009/019281.
Derivatives of indoprofen such as [4-(1-oxo-1 ,3-dihydro-2H-benzo[f]isoindol-2- yl)phenyl]-2-propionic acid, sodium salt have been described by Rufer et. al. in Eur. J. Med. Chem. - Chimica Therapeutica, 1978, 13, 193.
The present invention provides a compound selected from the group consisting of: (3-chloro-4-{[(5-chloro-2-{[(2- chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetic acid;
{4-[({5-chloro-2-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid;
{3-chloro-4-[({5-chloro-2-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid; (3-chloro-4-{[(5-chloro-2-{[(3- chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetic acid;
{4-[({2-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid;
(4-{[(5-chloro-2-{[(3-chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}-2- fluorophenyl)acetic acid; {3-chloro-4-[({2-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid;
(3-chloro-4-{[(2-{[(3-chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetic acid;
{4-[({2-chloro-6-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid;
(4-{[(2-chloro-6-{[(3-chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetic acid;
{4-[({5-chloro-2-[(phenylmethyl)amino]phenyl}carbonyl)amino]phenyl}acetic acid;
(4-{[(5-chloro-2-{[(3-chlorophenyl)methyl]amino}phenyl)carbonyl]amino}phenyl)acetic acid; and
(4-{[(5-chloro-2-{[(2-chlorophenyl)methyl]amino}phenyl)carbonyl]amino}phenyl)acetic acid, and pharmaceutically acceptable derivatives thereof. By pharmaceutically acceptable derivative is meant any pharmaceutically acceptable salt or ester, or salt of such ester of the compounds of the invention, or any other compound which upon administration to the recipient is capable of providing (directly or indirectly) a compound of the invention or an active metabolite or residue thereof.
It will be appreciated that, for pharmaceutical use, the salts referred to above will be the pharmaceutically acceptable salts, but other salts may find use, for example in the preparation of compounds of the invention and the pharmaceutically acceptable salts thereof.
Pharmaceutically acceptable salts include those described by Berge, Bighley and Monkhouse, J. Pharm. Sci., 1977, 66, 1-19. The term "pharmaceutically acceptable salts" refers to salts prepared from pharmaceutically acceptable bases including inorganic bases and organic bases. Salts derived from inorganic bases include aluminum, ammonium, calcium, copper, ferric, ferrous, lithium, magnesium, manganic salts, manganous, potassium, sodium, zinc, and the like. Salts derived from pharmaceutically acceptable organic bases include salts of primary, secondary, and tertiary amines; substituted amines including naturally occurring substituted amines; and cyclic amines. Particular pharmaceutically acceptable organic bases include arginine, betaine, caffeine, choline, N,N'-dibenzylethylenediamine, diethylamine, 2-diethylaminoethanol, 2- dimethylaminoethanol, ethanolamine, ethylenediamine, N-ethyl-morpholine, N- ethylpiperidine, glucamine, glucosamine, histidine, hydrabamine, isopropylamine, lysine, methylglucamine, morpholine, piperazine, piperidine, procaine, purines, theobromine, triethylamine, trimethylamine, tripropyl amine, tris(hydroxymethyl)aminomethane, and the like. Salts may also be formed from basic ion exchange resins, for example polyamine resins.
It will be appreciated that the compounds of the invention may be produced in vivo by metabolism of a suitable prodrug. Such prodrugs may be for example physiologically acceptable metabolically labile esters of compounds of the invention. These may be formed by esterification of the carboxylic acid group in the parent compound of the invention with, where appropriate, prior protection of any other reactive groups present in the molecule followed by deprotection if required. Examples of such metabolically labile esters include C1-4alkyl esters e.g. methyl ethyl or t-butyl esters esters, C3.6 alkenyl esters e.g. allyl substituted or unsubstituted aminoalkyl esters (e.g. aminoethyl, 2-(N, N- diethylamino) ethyl, or 2-(4-morpholino)ethyl esters or acyloxyalkyl esters such as, acyloxymethyl or 1-acyloxyethyl e.g. pivaloyloxymethyl, 1-pivaloyloxyethyl, acetoxymethyl, 1- acetoxyethyl,1-(1-methoxy-1 - methyl)ethylcarbonyloxyethyl, 1 - benzoyloxyethyl, isopropoxycarbonyloxymethyl, 1- isopropoxycarbonyloxyethyl, cyclohexylcarbonyloxymethyl, 1- cyclohexylcarbonyloxyethyl ester, cyclohexyloxycarbonyloxymethyl, 1- cyclohexyloxycarbonyloxyethyl, 1-(4-tetrahydropyranyloxy)carbonyloxyethyl or 1-(4- tetrahydropyranyl)carbonyloxyethyl.
It is to be understood that the present invention encompasses all isomers of the compounds of the invention and their pharmaceutically acceptable derivatives, including all geometric, tautomeric and optical forms, and mixtures thereof (e.g. racemic mixtures).
Since the compounds of the invention are intended for use in pharmaceutical compositions, it will be understood that they are each provided in substantially pure form, for example at least 50% pure, more suitably at least 75% pure and preferably at least 95% pure (% are on a wt/wt basis). Impure preparations of the compounds of the invention may be used for preparing the more pure forms used in the pharmaceutical compositions. Although the purity of intermediate compounds of the present invention is less critical, it will be readily understood that the substantially pure form is preferred as for the compounds of the invention. Preferably, whenever possible, the compounds of the present invention are obtained in crystalline form.
When some of the compounds of this invention are allowed to crystallise or are recrystallised from organic solvents, solvent of crystallisation may be present in the crystalline product. This invention includes within its scope such solvates, including solvates of the free acid molecule and solvates of salts derived from the free acid molecule. Similarly, some of the compounds of this invention may be crystallised or recrystallised from solvents containing water. In such cases water of hydration may be formed. This invention includes within its scope stoichiometric hydrates as well as compounds containing variable amounts of water that may be produced by processes such as lyophilisation. In addition, different crystallisation conditions may lead to the formation of different polymorphic forms of crystalline products. This invention includes within its scope all polymorphic forms of the compounds of the invention. The present invention also includes within its scope all isotopically-labelled compounds of the invention. Such compounds are identical to those recited above except that one or more atoms therein are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes that can be incorporated into compounds of the invention and pharmaceutically acceptable salts thereof include isotopes of hydrogen, carbon, nitrogen, oxygen, chlorine and fluorine, such as 2H, 3H, 11 C, 13C, 14C, 15N, 170, 180, 36Cl and 18F.
Isotopically-labelled compounds of the invention, for example those into which radioactive isotopes such as 3H, 14C are incorporated, are useful in drug and/or substrate tissue distribution assays. Tritiated, i.e., 3H, and carbon-14, i.e., 14C, isotopes are particularly preferred for their ease of preparation and detectability. 1 1 C and 18F isotopes are particularly useful in PET (positron emission tomography), and are useful in brain imaging. Further substitution with heavier isotopes such as deuterium, i.e., 2H, can afford certain therapeutic advantages resulting from greater metabolic stability, for example increased in vivo half-life or reduced dosage requirements and, hence, may be preferred in some circumstances, lsotopically labelled compounds of the invention may be prepared by carrying out the synthetic procedures disclosed in the Schemes and/or in the Examples below, by substituting a readily available isotopically labelled reagent for a non-isotopically labelled reagent.
The compounds of the invention are EP4 receptor agonists and may therefore be useful in treating EP4 receptor mediated diseases. These diseases include those mediated by the action, or loss of action, of PGE2 at EP4 receptors.
In particular the compounds of the invention may be useful in the treatment of pain, for example, chronic articular pain (e.g. rheumatoid arthritis, osteoarthritis, rheumatoid spondylitis, gouty arthritis and juvenile arthritis) including the property of disease modification and joint structure preservation; musculoskeletal pain; lower back and neck pain; sprains and strains; neuropathic pain; sympathetically maintained pain; myositis; pain associated with cancer and fibromyalgia; pain associated with migraine; pain associated with influenza or other viral infections, such as the common cold; rheumatic fever; pain associated with functional bowel disorders such as non-ulcer dyspepsia, non-cardiac chest pain and irritable bowel syndrome; pain associated with myocardial ischemia; post operative pain; headache; toothache; and dysmenorrhea.
The compounds of the invention may be particularly useful in the treatment of neuropathic pain and symptoms associated therewith. Neuropathic pain syndromes include: diabetic neuropathy; sciatica; non-specific lower back pain; multiple sclerosis pain; fibromyalgia; HIV-related neuropathy; post-herpetic neuralgia; trigeminal neuralgia; and pain resulting from physical trauma, amputation, cancer, toxins or chronic inflammatory conditions. Symptoms of neuropathic pain include spontaneous shooting and lancinating pain, or ongoing, burning pain. In addition, there is included pain associated with normally non-painful sensations such as "pins and needles" (paraesthesias and dysesthesias), increased sensitivity to touch (hyperesthesia), painful sensation following innocuous stimulation (dynamic, static or thermal allodynia), increased sensitivity to noxious stimuli (thermal, cold, mechanical hyperalgesia), continuing pain sensation after removal of the stimulation
(hyperpathia) or an absence of or deficit in selective sensory pathways (hypoalgesia).
The compounds of the invention may also be useful in the treatment of inflammation, for example in the treatment of skin conditions (e.g. sunburn, burns, eczema, dermatitis, psoriasis); ophthalmic diseases such as glaucoma, retinitis, retinopathies, uveitis and of acute injury to the eye tissue (e.g. conjunctivitis); lung disorders (e.g. asthma, bronchitis, emphysema, allergic rhinitis, respiratory distress syndrome, pigeon fancier's disease, farmer's lung, COPD; gastrointestinal tract disorders (e.g. aphthous ulcer, Crohn's disease, atopic gastritis, gastritis varialoforme, ulcerative colitis, coeliac disease, regional ileitis, irritable bowel syndrome, inflammatory bowel disease, gastrointestinal reflux disease, diarrhoea, constipation); organ transplantation; other conditions with an inflammatory component such as vascular disease, migraine, periarteritis nodosa, thyroiditis, aplastic anaemia, Hodgkin's disease, sclerodoma, myaesthenia gravis, multiple sclerosis, sorcoidosis, nephrotic syndrome, Bechet's syndrome, polymyositis, gingivitis, myocardial ischemia, pyrexia, systemic lupus erythematosus, polymyositis, tendinitis, bursitis, and Sjogren's syndrome.
The compounds of the invention may also be useful in the treatment of immunological diseases such as autoimmune diseases, immunological deficiency diseases or organ transplantation. The compounds of the invention may also be effective in increasing the latency of HIV infection. The compounds of the invention may also be useful in the treatment of diseases of excessive or unwanted platelet activation such as intermittent claudication, unstable angina, stroke, and acute coronary syndrome (e.g. occlusive vascular diseases).
The compounds of the invention may also be useful as a drug with diuretic action, or may be useful to treat overactive bladder syndrome.
The compounds of the invention may also be useful in the treatment of impotence or erectile dysfunction.
The compounds of formula (I) may also be useful in the treatment of various Bone Disorders as hereinbelow defined, which includes the treatment of bone fractures, bone injury or bone defects.
For example, the compounds of the invention may be useful in enhancement of bone formation i.e. osteogenesis, such as increasing bone mass, bone volume, osteoblast number or osteoblast survival.
The compounds of formula (I) may therefore be useful in the treatment of bone disease, including genetic disorders, that are characterised by abnormal bone metabolism or resorption such as osteoporosis (especially postmenopausal osteoporosis, glucocorticoid induced osteoporosis, hyperthyroidism-induced osteoporosis, immobilisation-induced osteoporosis, heparin-induced osteoporosis and immunosuppressive-induced osteoporosis as well as long term complications of osteoporosis such as curvature of the spine, loss of height and prosthetic surgery), abnormally increased bone turnover, hyper-calcemia (including humoral hypercalcemia), hyperparathyroidism, Paget's bone diseases, osteolysis (including periprosthetic osteolysis), hypercalcemia of malignancy with or without bone metastases, hypercalcemia of fracture healing, rheumatoid arthritis, osteoarthritis (including disease modifying in osteoarthristis such as cartilage/bone repair), ostealgia, osteopenia, calculosis, lithiasis (especially urolithiasis), gout and ankylosing spondylitis, tendonitis, bursitis, malignant bone tumour e.g. osteosarcoma, osteogenesis imperfecta, metastatic bone disease, alveolar bone loss, post-osteomy and childhood idiopathic bone loss. The compounds of formula (I) may also be useful in bone remodelling and/or promoting bone generation and/or promoting fracture healing. For example, the compounds of the present invention may be useful in fracture healing e.g. long bone fractures and fractures of other bones. The compounds of the present invention may also be useful in healing fractures of the head, face and neck caused e.g. by injury. The compounds of the present invention may also be useful in bone grafting including replacing bone graft surgery entirely, enhancing the rate of successful bone grafts, bone healing following facial reconstruction, maxillary reconstruction, mandibular reconstruction, craniofacial reconstruction e.g. of craniofacial defects such as orofacial defects at birth (including orofacial clefts such as cleft palate), prosthetic ingrowth, vertebral synostosis, long bone extension, spinal fusion, and sternotomy. The compounds of the invention may also be useful in treating bone defects that might evolve around defects that occur during war.
The compounds of the invention may also be useful in periodontal indications such as periodontal disease (periodontitis), tooth loss, and peridontal augmentation e.g. in preparation for tooth implants.
The compounds of the present invention may also be useful in facilitating joint fusion, facilitating tendon and ligament repair, reducing the occurrence of secondary fracture, treating avascular necrosis, facilitating cartilage repair, facilitating bone healing after limb transplantation and repairing damage caused by metastatic bone disease.
The compounds of the invention may also be useful for attenuating the hemodynamic side effects of NSAIDs and COX-2 inhibitors.
The compounds of the invention may also be useful in the treatment of cardiovascular diseases such as hypertension or myocardial ischemia; functional or organic venous insufficiency; varicose therapy; haemorrhoids; and shock states associated with a marked drop in arterial pressure (e.g. septic shock).
The compounds of the invention may also be useful in the treatment of neurodegenerative diseases and neurodegeneration such as dementia, particularly degenerative dementia (including senile dementia, Alzheimer's disease, Pick's disease, Huntingdon's chorea, Parkinson's disease and Creutzfeldt-Jakob disease, ALS, motor neuron disease); vascular dementia (including multi-infarct dementia); as well as dementia associated with intracranial space occupying lesions; trauma; infections and related conditions (including HIV infection); metabolism; toxins; anoxia and vitamin deficiency; and mild cognitive impairment associated with ageing, particularly Age Associated Memory Impairment.
The compounds of the invention may also be useful in the treatment of neurological disorders and may be useful as neuroprotecting agents. The compounds of the invention may also be useful in the treatment of neurodegeneration following stroke, cardiac arrest, pulmonary bypass, traumatic brain injury, spinal cord injury or the like.
The compounds of the invention may also be useful in the treatment of complications of Type 1 diabetes (e.g. diabetic microangiopathy, diabetic retinopathy, diabetic nephropathy, macular degeneration, glaucoma), nephrotic syndrome, aplastic anaemia, uveitis, Kawasaki disease and sarcoidosis.
The compounds of the invention may also be useful in the treatment of kidney dysfunction (nephritis, particularly mesangial proliferative glomerulonephritis, nephritic syndrome), liver dysfunction (hepatitis, cirrhosis) and gastrointestinal dysfunction (diarrhoea).
It is to be understood that as used herein any reference to treatment includes both treatment of established symptoms and prophylactic treatment.
According to a further embodiment the invention, there is provided a compound of the invention or a pharmaceutically acceptable derivative thereof for use in human or veterinary medicine.
According to another embodiment of the invention, there is provided a compound of the invention or a pharmaceutically acceptable derivative thereof for use in the treatment of a condition which is mediated by the action, or loss of action, of PGE2 at EP4 receptors. According to another embodiment of the invention, there is provided a compound of the invention or a pharmaceutically acceptable derivative thereof for use in the treatment of a Bone Disorder.
According to a further embodiment of the invention, there is provided a method of treating a human or animal subject suffering from a condition which is mediated by the action, or by loss of action, of PGE2 at EP4 receptors which comprises administering to said subject an effective amount of a compound of the invention or a pharmaceutically acceptable derivative thereof. According to a further embodiment of the invention, there is provided a method of treating a human or animal subject suffering from a Bone Disorder which comprises administering to said subject an effective amount of a compound of the invention or a pharmaceutically acceptable derivative thereof.
According to a further embodiment of the invention there is provided a method of treating a human or animal subject suffering from a pain, or an inflammatory, immunological, neurodegenerative or renal disorder, which method comprises administering to said subject an effective amount of a compound of the invention or a pharmaceutically acceptable derivative thereof.
According to another embodiment of the invention, there is provided the use of a compound of the invention or a pharmaceutically acceptable derivative thereof for the manufacture of a medicament for the treatment of a condition which is mediated by the action, or loss of action, of PGE2 at EP4 receptors. According to another embodiment of the invention, there is provided the use of a compound of the invention or a pharmaceutically acceptable derivative thereof for the manufacture of a medicament for the treatment of a Bone Disorder.
According to another embodiment of the invention there is provided the use of a compound of the invention or a pharmaceutically acceptable derivative thereof for the manufacture of a medicament for the treatment or prevention of a condition such as a pain, or an inflammatory, immunological, neurodegenerative or renal disorder.
The compounds of the invention and their pharmaceutically acceptable derivatives are conveniently administered in the form of pharmaceutical compositions. Such compositions may conveniently be presented for use in conventional manner in admixture with one or more physiologically acceptable carriers or diluents.
Thus, in another aspect of the invention, there is provided a pharmaceutical composition comprising a compound of the invention or a pharmaceutically acceptable derivative thereof adapted for use in human or veterinary medicine. While it is possible for the compounds of the invention or a pharmaceutically acceptable derivative thereof to be administered as the raw chemical, it is preferable to present it as a pharmaceutical formulation. The formulations of the present invention comprise the compounds of the invention or a pharmaceutically acceptable derivative thereof together with one or more acceptable carriers or diluents therefore and optionally other therapeutic ingredients. The carrier(s) must be "acceptable" in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient thereof. Thus, in one embodiment the invention provides a pharmaceutical composition comprising a compound of the invention or a pharmaceutically acceptable derivative thereof and a pharmaceutically acceptable carrier or diluent therefore.
Administration of the compounds of this invention can be via any method which delivers a compound of this invention systemically and/or locally. The formulations include those suitable for oral, parenteral (including subcutaneous e.g. by injection or by depot, intradermal, intrathecal, intracapsular, intraspinal, intrasternal, intraarticular, intramuscular e.g. by depot, intravenous and intranasal), rectal and topical (including dermal, buccal and sublingual) administration although the most suitable route may depend upon for example the condition and disorder of the recipient. The formulations may conveniently be presented in unit dosage form and may be prepared by any of the methods well known in the art of pharmacy (see for example methods disclosed in 'Remington - The Science and Practice of Pharmacy', 21st Edition, Lippincott, Williams & Wilkins, USA, 2005 and references therein). All methods include the step of bringing into association the active ingredient with the carrier which constitutes one or more accessory ingredients. In general the formulations are prepared by uniformly and intimately bringing into association the active ingredient with liquid carriers or finely divided solid carriers or both and then, if necessary, shaping the product into the desired formulation.
Formulations of the present invention suitable for oral administration may be presented as discrete units such as capsules, cachets or tablets (e.g. chewable tablets in particular for paediatric administration) each containing a predetermined amount of the active ingredient; as a powder or granules; as a solution or a suspension in an aqueous liquid or a non-aqueous liquid; or as an oil-in-water liquid emulsion or a water-in-oil liquid emulsion. The active ingredient may also be presented as a bolus, electuary or paste. A tablet may be made by compression or moulding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine the active ingredient in a free-flowing form such as a powder or granules, optionally mixed with a binder, lubricant, inert diluent, lubricating, surface active or dispersing agent. Moulded tablets may be made by moulding in a suitable machine a mixture of the powdered compound moistened with an inert liquid diluent. The tablets may optionally be coated or scored and may be formulated so as to provide slow or controlled release of the active ingredient therein.
Formulations for parenteral administration include aqueous and non-aqueous sterile injection solutions which may contain anti-oxidants, buffers, bacteriostats and solutes which render the formulation isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents. The formulations may be presented in unit-dose or multi-dose containers, for example sealed ampoules and vials, and may be stored in a freeze-dried (lyophilised) condition requiring only the addition of a sterile liquid carrier, for example, water-for-injection, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tablets of the kind previously described.
Formulations for rectal administration may be presented as a suppository with the usual carriers such as cocoa butter, hard fat or polyethylene glycol.
Formulations for topical administration in the mouth, for example buccally or sublingually, include lozenges comprising the active ingredient in a flavoured basis such as sucrose and acacia or tragacanth, and pastilles comprising the active ingredient in a basis such as gelatin and glycerin or sucrose and acacia.
The compounds may also be formulated as depot preparations. Such long acting formulations may be administered by implantation (for example subcutaneously or intramuscularly) or by injection (for example intramuscular or intra-articular injection). Thus, for example, the compounds may be formulated with suitable polymeric or hydrophobic materials (for example as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt. Local application (e.g., to the site of bone fracture, intra-articular) may be achieved by injection of the compound in a suitable solvent or, in cases of open surgery, by local application thereto of such compounds in a suitable carrier. Alternatively, local application may be achieved by applying a solution or dispersion of the compound in a suitable carrier or diluent onto the surface of, or incorporating it into, solid or semisolid implants conventionally used in orthopedic surgery.
The present invention can also be administered using an injectable, flowable composition that provides sustained release at the local site of the injection by forming a biodegradable solid or gel depot, matrix or implant.
In addition to the ingredients particularly mentioned above, the formulations may include other agents conventional in the art having regard to the type of formulation in question, for example those suitable for oral administration may include flavouring agents.
The compounds of the invention may be used in combination with other therapeutic agents, for example COX-2 inhibitors, such as celecoxib, rofecoxib, valdecoxib or parecoxib; 5-lipoxygenase inhibitors; analgesics such as paracetamol; NSAI D's, such as diclofenac, indomethacin, nabumetone, naproxen or ibuprofen; leukotriene receptor antagonists; DMARD's such as methotrexate; sodium channel blockers, such as lamotrigine; N-type calcium channel antagonists; NMDA receptor modulators, such as glycine receptor antagonists; gabapentin, pregabalin and related compounds; tricyclic antidepressants such as amitriptyline; neurone stabilising antiepileptic drugs; mono-aminergic uptake inhibitors such as venlafaxine; opioid analgesics; local anaesthetics; 5HT1 agonists, such as triptans, for example sumatriptan, naratriptan, zolmitriptan, eletriptan, frovatriptan, almotriptan or rizatriptan; EP1 receptor ligands; EP2 receptor ligands; EP3 receptor ligands; EP1 antagonists; EP2 antagonists and EP3 antagonists; cannabanoid receptor agonists; VR1 antagonists. When the compounds are used in combination with other therapeutic agents, the compounds may be administered either sequentially or simultaneously by any convenient route.
The compounds of the invention may also be used in combination with known agents useful for treating or preventing the bone disorders described above. The present invention therefore includes combinations of the presently disclosed compounds with other agents including the following: Progestins (such as algestone acetophenide, altrenogest, amadinone acetate, anagestone acetate, chlormadinone acetate, cingestol, clogestone acetate, clomegestone acetate, delmadinone acetate, desogestrel, dimethisterone, dydrogesterone, ethynerone, ethynodiol diacetate, etonogestrel, flurogestone acetate, gestaclone, gestodene, gestonorone caproate, gestrinone, haloprogesterone, hydroxyprogesterone caproate, levonorgestrel, lynestrenol, medrogestone, medroxyprogesterone acetate, melengestrol acetate, methynodiol diacetate, norethindrone, norethindrone acetate, norethynodrel, norgestimate, norgestomet, norgestrel, oxogestone phenpropionate, progesterone, quingestanol acetate, quingestrone, and tigestol), polyphosphonates (such as geminal diphosphonates (also referred to as bis-phosphonates), tiludronate disodium, ibandronic acid, alendronate and zoledronic acid), bisphosphonate(s), estrogen agonists/antagonists (such as droloxifene, tamoxifen, 4-hydroxy tamoxifen, raloxifene, toremifene, centchroman, levormeloxifene and idoxifene), estrogen, an estrogen receptor modulator, estrogen/progestin combinations, an androgen receptor modulator, Premarin®, estrone, estriol or 17α- or 17β-ethynyl estradiol, other anti bone-resorptive agents, other bone anabolic agents, also referred to as bone mass augmenting agents, a prostaglandin, or prostaglandin agonist/antagonist, IGF-1 , sodium fluoride, parathyroid hormone (PTH), active fragments of parathyroid hormone, growth hormone or growth hormone secretagogues, a cathepsin K inhibitor, an inhibitor of osteoclast proton ATPase, an inhibitor of HMG-CoA reuctase, an integrin receptor antagonist, an osteoblast anabolic agent such as PTH, calcitonin, Vitamin D or a synthetic Vitamin D analogue, and the pharmaceutically acceptable salts and mixtures thereof.
The invention thus provides, in a further embodiment, a combination comprising a compound of the invention or a pharmaceutically acceptable derivative thereof together with a further therapeutic agent or agents. In a further embodiment of the invention there is provided a combination comprising an EP4 receptor agonist of the invention or a pharmaceutically acceptable derivative thereof and paracetamol.
The combinations referred to above may conveniently be presented for use in the form of a pharmaceutical formulation and thus pharmaceutical formulations comprising a combination as defined above together with a pharmaceutically acceptable carrier or diluent comprise a further aspect of the invention. The individual components of such combinations may be administered either sequentially or simultaneously in separate or combined pharmaceutical formulations. When a compound of the invention or a pharmaceutically acceptable derivative thereof is used in combination with a second therapeutic agent active against the same disease, the dose of each compound may differ from that when the compound is used alone. Appropriate doses will be readily appreciated by those skilled in the art.
In one embodiment of the invention there is provided a method of treating a human or animal subject suffering from a condition which is mediated by the action, or by loss of action, of PGE2 at EP4 receptors which comprises administering to said subject an effective amount of a compound of the invention or a pharmaceutically acceptable derivative thereof and paracetamol. In one embodiment of the invention there is provided a method of treating a human or animal subject suffering from a Bone Disorder which comprises administering to said subject an effective amount of a compound of the invention or a pharmaceutically acceptable derivative thereof and paracetamol.
A proposed daily dosage of compounds of the invention or their pharmaceutically acceptable salts for the treatment of man is from 0.001 to 30 mg/kg body weight per day and more particularly 0.1 to 3 mg/kg body weight per day, calculated as the free acid, which may be administered as a single or divided dose, for example one to four times per day. The dose range for adult human beings is generally from 0.1 to 1000 mg/day, such as from 10 to 800 mg/day, preferably 10 to 200 mg/day, calculated as the free acid.
A suitable daily dosage of paracetamol is up to 4000 mg per day. Suitable unit doses include 200, 400, 500 and 1000 mg, one, two, three or four times per day.
The precise amount of the compounds of the invention administered to a host, particularly a human patient, will be the responsibility of the attendant physician. However, the dose employed will depend on a number of factors including the age and sex of the patient, the precise condition being treated and its severity, the route of administration, and any possible combination therapy that may be being undertaken.
The ester intermediates of the compounds of the invention are novel and form an aspect of the invention. In one embodiment the ester intermediates are: Ethyl (3-chloro-4-{[(5-chloro-2-{[(3- chloropheny^methyljoxyjpheny^carbonyljaminojpheny^acetate, ethyl {4-[({5-chloro-2-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetate, ethyl {3-chloro-4-[({5-chloro-2-
[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetate, ethyl {4-[({2-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetate, ethyl (4-{[(5-chloro-2-{[(3-chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}-2- fluorophenyl)acetate, ethyl {3-chloro-4-[({2-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetate, ethyl (3-chloro-4-{[(2-{[(3- chlorophenyOmethy^oxyJphenyOcarbonyπaminoJphenyOacetate, ethyl {4-[({5-chloro-2-[(phenylmethyl)amino]phenyl}carbonyl)amino]phenyl}acetate, ethyl (3-ch loro-4-{[(5-ch loro-2-{[(2- chlorophenylJmethylJoxyJphenyOcarbonylJaminoJphenyOacetate,
Ethyl (4-{[(5-chloro-2-{[(3- chlorophenyl)methyl]amino}phenyl)carbonyl]amino}phenyl)acetate, ethyl (4-{[(5-chloro-2-{[(2- chlorophenylJmethyllaminojphenylJcarbonyllaminojphenyOacetate, ethyl {4-[({2-chloro-6-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetate, and ethyl (4-{[(2-chloro-6-{[(3- chlorophenyljmethylloxyjphenyljcarbonyllaminojphenyljacetate.
The present invention provides processes for the preparation of the compounds of the invention and pharmaceutically acceptable derivatives thereof. Thus, in one embodiment of the invention there is provided a process for preparing a compound of the invention comprising reacting an ester intermediate with a suitable base, such as sodium hydroxide, and optionally thereafter forming a pharmaceutically acceptable derivative of the compound so formed, and/or converting one compound of formula (I) to another.
In one embodiment the above-mentioned reaction comprising an ester intermediate is performed in a suitable solvent, such as ethanol, under reflux.
The following examples illustrate the preparation of the compounds the invention. The examples show the preparation of intermediates ("Intermediates") and compounds of the invention ("Examples"). The starting material for the preparation of intermediates may not necessarily have been prepared from the batch referred to unless expressly indicated. The intermediates for the preparation of the examples may not necessarily have been prepared from the batch referred to unless expressly indicated.
Abbreviations
CV Column volume
DCM Dichloromethane
DMF Dimethylformamide
DMSO Dimethylsulfoxide
EDAC 1 -Ethyl-3-[3-dimethylaminopropyl]carbodiimide
ES+/ES- Electrospray positive/negative
EtOAc Ethyl acetate
HCI Hydrochloric acid
HOBt 1 -Hydroxybenzotriazole
LCMS Liquid chromatography/Mass spectroscopy
MeOH Methanol
MS Mass spectroscopy
MDAP Mass Directed Auto Preparation
NaOH Sodium hydroxide
NMR
1H NMR spectra were recorded on a Bruker AVANCE 400 NMR spectrometer or a Bruker DPX250 NMR spectrometer. Chemical shifts are expressed in parts per million (ppm, δ units). Coupling constants (J) are in units of hertz (Hz). Splitting patterns describe apparent multiplicities and are designated as s (singlet), d (doublet), t (triplet), q (quartet), dd (double doublet), dt (double triplet), m (multiplet), br (broad).
Purification Techniques
Purification of the Examples may be carried out by conventional methods such as chromatography and/or recrystallisation using suitable solvents. Chromatographic methods include column chromatography, flash chromatography, HPLC (high performance liquid chromatography), SFC (supercritical fluid chromatography), SCX (strong cation exchange chromatography) and MDAP (mass directed autopreparation). The term "Biotage" when used herein refers to commercially available pre-packed silica gel cartridges.
Mass Directed Auto Preparation (MDAP) Column
Waters Atlantis: 19mm x 100mm (small scale); and 30mm x 100mm (large scale). Stationary phase particle size, 5μm.
Solvents
A: Aqueous solvent = Water + 0.1% Formic Acid B: Organic solvent = Acetonitrile + 0.1 % Formic Acid Make up solvent = Methanol : Water 80:20 Needle rinse solvent = Methanol
Methods
Five methods were used depending on the analytical retention time of the compound of interest:
(1 ) Large/Small Scale 1.0-1.5 = 5-30% B
(2) Large/Small Scale 1.5-2.2 = 15-55% B
(3) Large/Small Scale 2.2-2.9 = 30-85% B
(4) Large/Small Scale 2.9-3.6 = 50-99% B
Runtime, 13.5 minutes, comprising 10-minute gradient followed by a 3.5 minute column flush and re-equilibration step.
(5) Large/Small Scale 3.6-5.0 = 80-99% B
Runtime, 13.5 minutes, comprising 6-minute gradient followed by a 7.5 minute column flush and re-equilibration step.
Flow rate
20mls/min (Small Scale) or 40mls/min (Large Scale).
Starting materials are available from commercial sources. For example, methyl 5- chloro-2-hydroxybenzoate, ethyl 4-aminophenylacetate, 2- [(phenylmethyl)oxy]benzoic acid and methyl 2-hydroxybenzoate may be obtained from Alfa Aesar; 5-chlorosalicylic acid, methyl 2-amino-5-chlorobenzoate and 6- chloro-2H-3,1-benzoxazine-2,4(1 H)-dione may be obtained from Aldrich; 2-amino-6- (methyloxy)benzoic acid may be obtained from Fluorochem.
Intermediate 1 : Methyl 5-chloro-2-{[(3-chlorophenyl)methyl]oxy}benzoate
Figure imgf000021_0001
To a mixture of methyl 5-chloro-2-hydroxybenzoate (3.5 g, 18.7 mmol) in DMF (25 ml) were added potassium carbonate (5.16 g, 37.4 mmol, 2 eq) and 3-chlorobenzyl bromide (3.7 ml, 28.2 mmol, 1.5 eq). The mixture was heated at 6O0C for 2.5 hours. On cooling the mixture was diluted with ethyl acetate (300 ml) and washed with water (2x60 ml) then brine (60 ml). Organic layer dried and evaporated in vacuo. The residue was purified by column chromatography (Biotage SP4, 100 g silica column) eluting with 0-40% ethyl acetate in hexanes to afford the title compound as a white solid. 1H-NMR (400MHz, c/6-DMSO) δ 3.84 (3H, s), 5.25 (2H, s), 7.26-7.71 (7H, m).
Intermediate 2: 5-Chloro-2-{[(3-chlorophenyl)methyl]oxy}benzoic acid
Figure imgf000021_0002
A solution of methyl 5-chloro-2-{[(3-chlorophenyl)methyl]oxy}benzoate (4.5 g, 14.5 mmol) in dioxane (50 ml) and water (25 ml) was treated with lithium hydroxide (monohydrate) (914 mg, 21 .8 mmol, 1.5 eq). The resulting mixture was stirred at room temperature for 2 hours. The solvent was then evaporated in vacuo, the residue take up into water (50 ml) and washed with ether (100 ml). The aqueous layer was then acidified with 2M HCI the extracted with ether (2x200 ml). Organic layers combined, washed with brine, dried and evaporated in vacuo to afford the title product as a white solid. MS (ES-) m/z 295 [M-H]" (C14H10 35CI2O3). 1H-NMR (400MHz, Ci6-DMSO) δ 5.23 (2H,s), 7.21-7.66 (7H,m), 13.1 (1 H, s).
Intermediate 3: Ethyl (4-amino-3-chlorophenyl)acetate
Figure imgf000022_0001
N-chlorosuccinimide (1 eq, 7.45g, 55.8mmol) was added to a solution of ethyl A- aminophenylacetate (10g, 55.8mmol) in chloroform (20OmIs). The reaction mixture was stirred at room temperature, under argon, for 15 minutes.
The reaction mixture was washed with water (25OmIs) and the organic layer collected using a hydrophobic frit. This was evaporated to dryness to give a dark brown oil,
9.8g.
This was purified in 2 batches using the Biotage Horizon, reverse phase 100g C18 cartridge. The product was eluted using a 5-100% gradient of acetonitrile in water. Approx. 120OmIs solvent was used for each batch.
Clean fractions from the first batch were combined and evaporated to dryness to yield the title compound as a dark red/brown oil, 2.28g. MS (ES+) m/z 214 [M+H]+ (C1OH12 35CINO2). 1H-NMR (400MHz, CDCI3) δ 1.25 (3H, t, J 1 1.2), 3.47 (2H, s), 4.00 (2H, bs), 4.14 (2H, t, J 12), 6.71 (1 H, d, J 13.2), 6.98 (1 H, dd, J 13.3, J 3.2), 7.19 (1 H, d, J 3.2).
Intermediate 4: Ethyl (3-chloro-4-{[(5-chloro-2-{[(3- chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetate
Figure imgf000022_0002
A solution of 5-chloro-2-{[(3-chlorophenyl)methyl]oxy}benzoic acid (250 mg, 0.84 mmol) in dichloromethane (4 ml) was treated with Λ/-[2-(dimethylamino)ethyl]-Λ/'- ethylcarbodiimide hydrochloride (193 mg, 1.01 mmol, 1.2 eq) and stirred at room temperature for 30 minutes. A solution of ethyl (4-amino-3-chlorophenyl)acetate (216 mg, 1.01 mmol, 1 .2 eq) in dichloromethane (1 ml) was added and the resulting mixture heated at 4O0C overnight. As some starting material was still present, another 100 mg of Λ/-[2-(dimethylamino)ethyl]-/v1-ethylcarbodiimide hydrochloride were added and the mixture heated at 4O0C for another 2 hours. On cooling, the mixture was diluted with dichloromethane (50 ml) and water (30 ml), the layers separated and the aqueous layer extracted again into dichloromethane (2x100 ml). Organic layers combined, washed with brine, dried over magnesium sulphate and evaporated. The residue was purified by SCX cartridge eluting with methanol to afford the title compound as a light yellow oil. MS (ES+) m/z 492 [M+H]+ (C24H20 35CI3NO4). 1H-NMR (400MHz, d6-DMSO) δ 1.19 (3H, t, J 6.8), 3.68 (2H, s), 4.08 (2H, q, J 6.8), 5.42 (2H,s), 7.24-8.14 (10H,m), 10.2 (1 H, s).
Example 1 : (3-chloro-4-{[(5-chloro-2-{[(3- chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetic acid
Figure imgf000023_0001
A solution of Ethyl (3-chloro-4-{[(5-chloro-2-{[(3- chlorophenylJmethylJoxyJphenyOcarbonylJaminoJphenyOacetate (160mg, 0.33 mmol) in acetic acid (5 ml) and 2M HCI (5 ml) was heated at 9O0C for 2 hours. On cooling solvent was evaporated in vacuo and the residue purified by MDAP to afford the title compound as a white solid. MS (ES+) m/z 464 [M+H]+ (C22H16 35CI3NO4). 1H-NMR (400MHz, de-DMSO) δ 5.42 (2H,s), 7.23-8.15 (10H,m), 10.2 (1 H, s), 12.5 (1 H, s).
Intermediate 5: 5-Chloro-2-[(phenylmethyl)oxy]benzoic acid
Step 1 :
Figure imgf000024_0001
Benzyl bromide (2.79ml, 23.5mmol) and potassium carbonate (4.87g, 35.3mmol) were added to 5-chlorosalicylic acid (2.03g, 1 1.8mmol) in DMF (20ml) and stirred at room temperature for 16 hours. LCMS indicated a mixture of mono and dialkylated material. The mixture was then heated at 6O0C for 1 hour giving a ratio of 10:1 , dkmono alkylated product. The mixture was cooled, diluted with water (150ml) and extracted with EtOAc (x3). The organics were washed with water (x2), brine, dried (MgSO4) and concentrated in vacuo to yield a yellow oil that was used immediately in the next step.
Step 2:
Figure imgf000024_0002
2M NaOH (20ml) was added to phenylmethyl 5-chloro-2-
[(phenylmethyl)oxy]benzoate (~11.8mmol) (generated in step 1 ) in ethanol (40ml) and heated under reflux for 2 hours. The mixture was cooled, concentrated in vacuo, acidified with 2M HCI, extracted with EtOAc (x3). The organics were washed with brine, dried (MgSO4) and concentrated to give a yellow oil. Purified by reverse phase chromatography (C18 cartridge, elution with CH3CN/H2O), fractions containing product were combined and concentrated to give 5-chloro-2- [(phenylmethyl)oxy]benzoic acid as a white solid (1.9g, 62% over 2 steps).
LCMS [MNa+] = 285/287
Intermediate 6: Ethyl {4-[({5-chloro-2- [(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetate
Figure imgf000025_0001
A solution of 5-chloro-2-[(phenylmethyl)oxy]benzoic acid (200 mg, 0.76 mmol) in dichloromethane (5 ml) was treated with /V-[2-(dimethylamino)ethyl]-/V- ethylcarbodiimide hydrochloride (173 mg, 0.9 mmol, 1.2 eq) and stirred at room temperature for 30 minutes. Ethyl (4-aminophenyl)acetate (163 mg, 0.9 mmol, 1.2 eq) was added and the resulting mixture heated at 40°C overnight. The crude mixture was diluted with methanol and purified by SCX cartridge eluting with methanol. Fractions evaporated in vacuo, residue purified by chromatographic column on silica gel eluting with 0-40% ethyl acetate in hexane to afford the title compound as a white solid. MS (ES+) m/z 424 [M+H]+ (C24H22 35CINO4). 1H-NMR (400MHz, CZ6-DMSO) δ 1.18 (3H, t), 3.33 (2h, s), 3.61 (2H, s), 4.07 (2H, q), 5.24 (2H, s), 7.19 (2H, d), 7.30- 7.40 (4H, m), 7.50-7.58 (4H, m), 7.66 (1 H, d), 10.2 (1 H, s).
Example 2: {4-[({5-chloro-2- [(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid
Figure imgf000025_0002
A solution of ethyl {4-[({5-chloro-2-
[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetate (60mg, 0.14 mmol) in acetic acid (1 ml) and 2M HCI (1 ml) was heated at 9O0C for 2 hours. On cooling water was added and the mixture was filtered and washed with water to give a solid which was then further purified by MDAP to afford the title compound as a white solid. MS (ES+) m/z 396 [M+H]+ (C22H18 35CINO4). 1H-NMR (400MHz, cfe-DMSO) δ 5.25 (2H, s), 7.18 (2H, d), 7.31-7.40 (4H, m), 7.48-7.58 (4H, m), 7.67 (1 H, d), 10.2 (1 H, s), 12.3 (1 H, s).
Intermediate 7: Ethyl {3-chloro-4-[({5-chloro-2-
[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetate
Figure imgf000026_0001
A solution of 5-chloro-2-[(phenylmethyl)oxy]benzoic acid (300 mg, 1.14 mmol) in dichloromethane (3 ml) was treated with /V-[2-(dimethylamino)ethyl]-/V- ethylcarbodiimide hydrochloride (265 mg, 1.37 mmol, 1.2 eq) and stirred at room temperature for 30 minutes. A solution of ethyl (4-amino-3-chlorophenyl)acetate (292 mg, 1.37 mmol, 1 .2 eq) in DCM (1 ml) was added and the resulting mixture heated at 4O0C overnight. The crude mixture was diluted with dichloromethane and water and passed through a Phase Sep cartridge so the water was retained. Solvent evaporated in vacuo, residue further purified by SCX cartridge eluting with methanol. Fractions combined and evaporated in vacuo, residue purified by chromatographic column on silica gel eluting with 0-35% ethyl acetate in hexane to afford the title compound as a light yellow solid. MS (ES+) m/z 458 [M+H]+ (C24H2I35CI2NO4). 1H- NMR (400MHz, d6-DMSO) δ 1.19 (3H, t), 3.67 (2H, s), 4.08 (2H, q), 5.44 (2H, s), 7.25 (1 H, dd), 7.35-7.43 (5H, m), 7.53 (2H, dd), 7.63 (1 H, dd), 7.96 (1 H, d), 8.19 (1 H, d), 10.3 (1 H, s).
Example 3: {3-chloro-4-[({5-chloro-2- [(phenylmethyOoxylpheny^carbonylJaminolpheny^acetic acid
Figure imgf000026_0002
A solution of ethyl {3-chloro-4-[({5-chloro-2- [(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetate (80mg, 0.18 mmol) in acetic acid (1 ml) and 2M HCI (1 ml) was heated at 9O0C for 2 hours. On cooling water was added and the mixture was filtered. Solid collected and dried then further purified by MDAP to afford the title compound as a white solid. MS (ES+) m/z 430 [M+H]+ (C22H17 35CI2NO4). 1H-NMR (400MHz, d6-DMSO) δ 3.57 (2H, s), 5.44 (2H, s), 7.24 (1 H, dd), 7.36-7.43 (5H, m), 7.53 (2H, dd), 7.63 (1 H, dd), 7.96 (1 H, s), 8.18 (1 H, d), 10.3 (1 H, s), 12.5 (1 H, s).
Intermediate 8: Ethyl {4-[({2- [(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetate
Figure imgf000027_0001
A solution of 2-[(phenylmethyl)oxy]benzoic acid (250 mg, 1.1 mmol) in dichloromethane (3 ml) was treated with /V-[2-(dimethylamino)ethyl]-/V- ethylcarbodiimide hydrochloride (306 mg, 1.6 mmol, 1.2 eq) and stirred at room temperature for 30 minutes. A solution of ethyl (4-aminophenyl)acetate (295 mg, 1.6 mmol, 1.2 eq) in DCM (2 ml) was added and the resulting mixture heated at 4O0C overnight. The crude mixture was diluted with methanol and purified by SCX cartridge eluting with methanol. Fractions combined and evaporated in vacuo, residue further purified by chromatographic column on silica gel eluting with 0-50% ethyl acetate in hexane to afford the title compound as a white solid. MS (ES+) m/z 390 [M+H]+ (C24H23NO4). 1H-NMR (400MHz, d6-DMSO) δ 1.16-1.19 (3H, m), 3.60 (2H, s), 4.06-4.08 (2H, m), 5.25 (2H, s), 7.10-7.71 (13H, m), 10.2 (1 H, s).
Example 4: {4-[({2-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid
Figure imgf000027_0002
A solution of ethyl {4-[({2-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetate (180mg, 0.46 mmol) in acetic acid (3 ml) and 2M HCI (3 ml) was heated at 900C for 2 hours then left at room temperature over the weekend. On cooling water was added, the resulting solid was filtered and dried to afford the title compound. MS (ES+) m/z 362 [M+H]+ (C22H19NO4). 1H-NMR (400MHz, c/6-DMSO) δ 3.51 (2h, s), 5.26 (2H,s), 7.10 (1 H, t), 7.17 (1 H, d), 7.30 (1 H, d), 7.33-7.41 (3H, m), 7.46-7.57 (5H, m), 7.72 (1 H, dd), 10.2 (1 H, s), 12.3 (1 H, s). Intermediate 9: Ethyl phenyl methyl (2-fluoro-4-nitrophenyl)propanedioate
Figure imgf000028_0001
Benzyl ethyl malonate (2.9g, 12.6mmol) in dry DMF (20ml) was cooled in an ice bath and the temperature monitored whilst sodium hydride (504mg, 12.6mmol) was added portionwise. This was stirred at room temperature for 10 minutes until H2 evolution ceased. 3,4-Difluoronitrobenzene (2g, 12.6mmol) was added under an argon atmosphere and gave a dark red colour change. The reaction mixture was heated at 1000C for 20 hours under argon. Thin layer chromatography (20% ethyl acetate in hexane) showed completion of the reaction. The reaction mixture was cooled to room temperature and partitioned between 2N Hydrochloric acid (75ml) and ethyl acetate (75ml). The aqueous layer was extracted with ethyl acetate (2x 75ml) and the combined organic fractions were evaporated to a yellow oil. Purification by chromatography on silica gel eluting with 0-20% ethyl acetate in hexane gave the title compound as a yellow oil (3.86g, 10.6mmol). [MH]+ 362
Intermediate 10: Ethyl (4-amino-2-fluorophenyl)acetatepropanedioate
Figure imgf000028_0002
Ethyl phenylmethyl (2-fluoro-4-nitrophenyl)propanedioate (3.86g, 10.6mmol) dissolved in ethanol (50ml), was treated with ammonium formate (6.7g, 10.6mmol) under argon. Palladium on carbon 10% paste (380mg) was added and the reaction was stirred under reflux for 3 hours (600C). The reaction was cooled to room temperature and the catalyst removed by filtration through celite. Solvent was removed to give a brown oil. The crude material was purified by chromatography on silica gel eluting with 0-50% ethyl acetate in hexane (1 :1 ) over 45 minutes. Fractions were evaporated to give the title compound as a yellow oil (1.26g, 6.4mmol). [MH]+ 198
Intermediate 11 : Ethyl (4-{[(5-chloro-2-{[(3- chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}-2-fluorophenyl)acetate
Figure imgf000029_0001
A solution of 5-chloro-2-{[(3-chlorophenyl)methyl]oxy}benzoic acid (250 mg, 0.84 mmol) in dichloromethane (3 ml) was treated with Λ/-[2-(dimethylamino)ethyl]-Λ/'- ethylcarbodiimide hydrochloride (365 mg, 1.9 mmol, 1.5 eq) and stirred at room temperature for 30 minutes. A solution of ethyl (4-amino-2-fluorophenyl)acetate (295 mg, 1.6 mmol, 1.2 eq) in DCM (1 ml) was added and the resulting mixture heated at 8O0C in a microwave (high absorption) for 20min. The crude mixture was diluted with methanol and purified by SCX cartridge eluting with methanol. Fractions combined and evaporated in vacuo to afford the title compound as a white solid. MS (ES+) m/z 476 [M+H]+ (C24H2IF35CI2NO4). 1H-NMR (400MHz, c/6-DMSO) δ 1.18 (3H, t), 3.67 (2H, s), 4.09 (2H, q), 5.23 (2H, s), 7.26-7.35 (3H, m), 7.37-7.44 (3H, m), 7.57-7.64 (4H, m), 10.45 (1 H, s).
Example 5: (4-{[(5-chloro-2-{[(3- chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}-2-fluorophenyl)acetic acid
Figure imgf000029_0002
A solution of ethyl (4-{[(5-chloro-2-{[(3- chloropheny^methylJoxyJphenyOcarbonylJaminoJ^-fluorophenyOacetate (165mg,
0.35 mmol) in acetic acid (3 ml) and 2M HCI (3 ml) was heated at 900C for 4 hours.
As starting material was still present another 3ml 2M HCI were added and the mixture heated at 9O0C overnight. As starting material was still present 2ml of 5M HCI were added and the mixture heated at 9O0C for 4 hours. The mixture was then cooled to room temperature, water was added, and the mixture filtered. An attempt was made to purify the resulting solid by MDAP but some material was insoluble in DMSO:acetonitrile 1 :1 , therefore the mixture was filtered. The filtrate contained most of the product, so water was added and the resulting solid filtered and washed with methanol (x2) to afford the title compound as a white solid. MS (ES+) m/z 448 [M+H]+ (C22H16 35CI2FNO4). 1H-NMR (400MHz, c/6-DMSO) δ 3.57 (2h, s), 5.24 (2H,s), 7.25- 7.33 (3H, m), 7.38-7.44 (3H, m), 7.57-7.64 (4H, m), 10.42 (1 H, s), 12.5 (1 H, s).
Intermediate 12: Ethyl {3-chloro-4-[({2- [(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetate
Figure imgf000030_0001
A solution of 2-[(phenylmethyl)oxy]benzoic acid (250 mg, 1.1 mmol) in dichloromethane (3 ml) was treated with /V-[2-(dimethylamino)ethyl]-/V- ethylcarbodiimide hydrochloride (306 mg, 1.6 mmol, 1.2 eq) and stirred at room temperature for 30 minutes. A solution of ethyl (4-amino-3-chlorophenyl)acetate (280 mg, 1.32 mmol, 1 .2 eq) in DCM (2 ml) was added and the resulting mixture heated at 4O0C overnight, then for another 3.5hours. The crude mixture was diluted with acetonitrile and purified by SCX cartridge eluting with acetonitrile. Residue further purified by MDAP to afford the title compound as an orange solid. MS (ES+) m/z 424 [M+H]+ (C24H22 35CINO4). 1H-NMR (400MHz, ^6-DMSO) δ 1.19 (3H, t), 3.66 (2H, s), 4.08 (2H, q), 5.45 (2H, s), 7.15 (1 H, t), 7.25 (1 H, dd), 7.35-7.42 (5H, m), 7.53-7.60 (3H, m), 8.07 (1 H, dd), 8.28 (1 H, d), 10.32 (1 H, s).
Example 6: {3-chloro-4-[({2- [(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid
Figure imgf000030_0002
A solution of ethyl {3-chloro-4-[({2-
[(phenylmethyl)oxy]phenyl}carboπyl)amino]phenyl}acetate (110mg, 0.26 mmol) in acetic acid (3 ml) and 2M HCI (3 ml) was heated at 9O0C for 2 hours. On cooling water was added and the mixture was filtered. Solid collected and dried then further purified by MDAP to afford the title compound as a white solid. MS (ES+) m/z 396 [M+H]+ (C22H18 35CINO4). 1H-NMR (400MHz, c/6-DMSO) δ 3.56 (2H, s), 5.45 (2H, s), 7.15 (1 H, t), 7.23 (1 H, dd), 7.35-7.42 (5H, m), 7.53-7.60 (3H, m), 8.07 (1 H, d), 8.26 (1 H, t), 10.32 (1 H, s).
Intermediate 13: Methyl 2-{[(3-chlorophenyl)methyl]oxy}benzoate
Figure imgf000031_0001
To a mixture of methyl 2-hydroxybenzoate (5.0 g, 32.8 mmol) in DMF (30 ml) were added potassium carbonate (6.8 g, 49 mmol, 1.5 eq) and 3-chlorobenzyl bromide (5.2 ml, 39 mmol, 1.2 eq). The mixture was heated at 6O0C for 2.5 hours. On cooling the mixture was diluted with ethyl acetate (500 ml) and washed with water (2x150 ml) then brine (150 ml). Organic layer dried and evaporated in vacuo. The residue was purified by column chromatography (Biotage SP4, 100 g silica column) eluting with 0- 30% ethyl acetate in hexanes to afford the title compound as a clear oil which turned to white solid on standing. 1H-NMR (400MHz, Cf6-DMSO) δ 3.83 (3H, s), 5.24 (2H, s), 7.06 (1 H, t), 7.22 (1 H, d), 7.38-7.45 (3H, m), 7.53-7.60 (2H, m), 7.71 (1 H, dd).
Intermediate 14: 2-{[(3-Chlorophenyl)methyl]oxy}benzoic acid
Figure imgf000031_0002
A solution of methyl 2-{[(3-chlorophenyl)methyl]oxy}benzoate (5.0 g, 18.1 mmol) in dioxane (100 ml) and water (50 ml) was treated with lithium hydroxide (650 mg, 27 mmol, 1.5 eq). The resulting mixture was stirred at room temperature for 2 hours, then a further 2 hours and a further 1 h. The solvent was then evaporated in vacuo, the residue take up into water and washed with ether (100 ml). The aqueous layer was then acidified with 2M HCI the extracted with ether (2x300 ml). Floating solid was filtered off. Organic layers combined, washed with brine (100ml), dried with magnesium sulphate and evaporated in vacuo to afford the title product as a white solid. 1H-NMR (400MHz, ^6-DMSO) δ 5.22 (2H, s), 7.03 (1 H, t), 7.18 (1 H, dd), 7.36- 7.52 (4H, m), 7.62 (1 H, s), 7.68 (1 H, dd), 12.8 (1 H, s).
Intermediate 15: Ethyl (3-chloro-4-{[(2-{[(3- chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetate
Figure imgf000032_0001
A solution of 2-{[(3-chlorophenyl)methyl]oxy}benzoic acid (400 mg, 1.53 mmol) in dichloromethane (3 ml) was treated with Λ/-[2-(dimethylamino)ethyl]-/V- ethylcarbodiimide hydrochloride (440 mg, 2.3 mmol, 1.5 eq) and stirred at room temperature for 30 minutes. A solution of ethyl (4-amino-3-chlorophenyl)acetate (490 mg, 2.3 mmol, 1.5 eq) in DCM (3 ml) was added and the resulting mixture heated at 4O0C for 2 hours, then kept at room temperature over the weekend, then heated at 4O0C for another 2 hours. On cooling the mixture was diluted with acetonitrile and purified by SCX cartridge eluting with acetonitrile. Residue further purified by MDAP to afford the title compound as a light yellow solid. MS (ES+) m/z 458 [M+H]+
(C24H2I 35CI2NO4). 1H-NMR (400MHz, d6-DMSO) δ 1.19 (3H, t), 3.67 (2H, s), 4.09 (2H, q), 5.43 (2H,s), 7.16 (1 H, t), 7.25 (1 H, dd), 7.35 (1 H, d), 7.40-7.43 (3H, m), 7.49- 7.52 (1 H, m), 7.56-7.60 (1 H, m), 7.62 (1 H, s), 7.68 (1 H, dd), 8.03 (1 H, dd), 8.24 (1 H, d), 10.21 (1 H, s).
Example 7: (3-chloro-4-{[(2-{[(3- chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetic acid
Figure imgf000033_0001
A solution of ethyl (3-chloro-4-{[(2-{[(3- chlorophenyOmethylloxyJphenyOcarbonyllaminoJphenyOacetate (160mg, 0.35 mmol) in acetic acid (3 ml) and 2M HCI (3 ml) was heated at 9O0C for 2 hours. On cooling water was added and the mixture was filtered to afford the title compound as a white solid. MS (ES+) m/z 430 [M+H]+ (C22H17 35CI2NO4). 1H-NMR (400MHz, d6-DMSO) δ 3.58 (2H, s), 5.43 (2H, s), 7.13-7.26 (2H, m), 7.30-7.64 (8H, m), 8.03 (1 H, dd), 8.21 (1 H, d), 10.21 (1 H, s), 12.45 (1 H, s).
Intermediate 16: Methyl 5-chloro-2-[(phenylmethyl)amino]benzoate
Figure imgf000033_0002
To a solution of methyl 2-amino-5-chlorobenzoate (1.51 g, 8.13 mmol) in DCM (25 ml) was added benzaldehyde (1.24 ml, 12.2 mmol, 1.5 eq). The mixture was stirred at room temperature for 10 min, then treated with sodium triacetoxyborohydride and stirred at room temperature overnight. As starting material still remained, more sodium triacetoxyborohydride (1.3g) was added and the mixture was stirred at room temperature for 4 hours. The reaction was then worked up by addition of a few drops of methanol and 2M NaOH (50ml). Mixture stirred at room temperature for 10min then diluted with DCM (150ml). Layers separated, aqueous layer extracted again with DCM (150 ml). Organic layers combined, washed with brine (50 ml), dried over magnesium sulphate and evaporated to afford the title compound as a yellow oil. 1H- NMR (400MHz, Cy6-DMSO) δ 3.83 (3H, s), 4.49 (2H, d), 6.73 (1 H, d), 7.25-7.38 (6H, m), 7.75 (1 H, s), 8.13 (1 H1 1).
Intermediate 17: 5-Chloro-2-[(phenylmethyl)amino]benzoic acid
Figure imgf000034_0001
A solution of methyl 5-chloro-2-[(phenylmethyl)amino]benzoate (1.5 g, 5.45 mmol) in dioxane (40 ml) and water (20 ml) was treated with lithium hydroxide (monohydrate) (460 mg, 10.9 mmol, 2 eq). The resulting mixture was stirred at room temperature overnight. The solvent was then evaporated in vacuo, the residue take up into water (50 ml) and washed with ether (2x50 ml). The aqueous layer was then acidified with 2M HCI then extracted with ether (2x100 ml). Organic layers combined, washed with brine, dried and evaporated in vacuo to afford the title product as a light yellow/orange solid (batch 1 ). Another batch of the product was obtained by evaporating in vacuo the first ether extraction to afford the title product as a yellow solid (batch 2). 1H-NMR (400MHz, c/6-DMSO) δ 4.32 (2H, d), 6.42 (1 H, d), 7.00 (1 H, dd), 7.23 (1 H, m), 7.29-7.34 (4H, m), 7.75 (1 H, d), 9.85 (1 H, t).
Intermediate 18a: Ethyl {4-[({5-chloro-2-
[(phenylmethyl)amino]phenyl}carbonyl)amino]phenyl}acetate
Figure imgf000034_0002
A solution of 5-chloro-2-[(phenylmethyl)amino]benzoic acid (batch 2 of Intermediate 17) (250 mg, 0.96 mmol), Λ/-[2-(dimethylamino)ethyl]-Λ/'-ethylcarbodiimide hydrochloride (258 mg, 1.44 mmol, 1.5 eq) and ethyl (4-aminophenyl)acetate (258 mg, 1.44 mmol, 1 .5 eq) in dichloromethane (4 ml) was heated at 80°C in a microwave (high absorption) for 20min. The crude mixture was diluted with methanol and purified by SCX cartridge eluting first with methanol then with 2M NH4OH in methanol. Both methanol fractions and ammonia fractions contained the desired product therefore they were combined and evaporated in vacuo. The resulting oil was purifed by column chromatography (Biotage SP4) eluting with 0-20% ethyl acetate in hexanes to afford the title compound as a yellow oil. MS (ES+) m/z 423 [M+H]+ (C24H23 35CIN2O3). 1H-NMR (400MHz, c/6-DMSO) δ 1.18 (3H, t), 3.62 (2H1 s), 4.08 (2H, q), 4.41 (2H, s), 6.67 (1 H, d), 7.22-7.35 (9H, m), 7.65 (2H, d), 7.74 (1 H, s), 10.2 (1 H1 S).
Intermediate 18b: Ethyl {4-[({5-chloro-2-
[(phenylmethyl)amino]phenyl}carbonyl)amino]phenyl}acetate
Figure imgf000035_0001
A solution of 5-chloro-2-[(phenylmethyl)amino]benzoic acid (batch 1 of intermediate 17) (250 mg, 0.96 mmol) in dichloromethane (5 ml) was treated with N-[2- (dimethylamino)ethyl]-/v1-ethylcarbodiimide hydrochloride (220 mg, 1.15 mmol, 1.2 eq) and stirred at room temperature for 5 minutes. Ethyl (4-aminophenyl)acetate (206 mg, 1.15 mmol, 1 .2 eq) was added and the resulting mixture heated at 400C overnight. As starting material was still present, more /V-[2-(dimethylamino)ethyl]-/V- ethylcarbodiimide hydrochloride (220 mg, 1.15 mmol, 1.2 eq) was added and the mixture heated at 4O0C for another 2 hours. On cooling, the mixture was diluted with dichloromethane (50 ml) and water (30 ml), the layers separated and the aqueous layer extracted again into dichloromethane (50 ml). Organic layers combined, washed with brine (30ml), dried over magnesium sulphate and evaporated. The residue was purified by chromatographic column (Biotage SP4) on silica gel eluting with 0-30% ethyl acetate in hexane to afford the title compound as a yellow oil. MS (ES+) m/z 423 [M+H]+ (C24H23 35CIN2O3). 1H-NMR (400MHz, d6-DMSO) δ 1.18 (3H, t), 3.63 (2H, s), 4.08 (2H, q), 4.42 (2H, s), 6.67 (1 H, d), 7.22-7.35 (8H, m), 7.64 (2H, d), 7.74 (1 H, d), 10.2 (1 H, s).
Example 8: {4-[({5-chloro-2- [(phenylmethyljaminojpheny^carbonyljaminolpheny^acetic acid
Figure imgf000035_0002
A solution of ethyl {4-[({5-chloro-2-
[(phenylmethyl)amino]phenyl}carbonyl)amino]phenyl}acetate (Intermediate 18a and Intermediate 18b) (112mg, 0.26 mmol) in acetic acid (3 ml) and 2M HCI (3 ml) was heated at 9O0C for 2 hours. On cooling, the mixture was diluted with water, some solid precipitated but it was not possible to filter it, so the solid and filtrate were recombined and evaporated in vacuo. The residue was purified by MDAP to afford the title compound as a white solid. MS (ES+) m/z 395 [M+H]+ (C22Hi9 35CIN2O3). 1H- NMR (400MHz, c/6-DMSO) δ 3.53 (2H, s), 4.41 (2H, d), 6.67 (1 H, d), 7.21-7.35 (8H, m), 7.63 (1 H, m), 7.74 (1 H, d), 7.92 (1 H, t), 10.21 (1 H, s), 12.4 (1 H, s).
Intermediate 19: Methyl 5-chloro-2-{[(2 chlorophenyl)methyl]oxy}benzoate
Figure imgf000036_0001
To a mixture of methyl 5-chloro-2-hydroxybenzoate (3.5 g, 18.7 mmol) in DMF (25 ml) was added potassium carbonate (5.16 g, 37.4 mmol, 2 eq) and i-(bromomethyl)- 2-chlorobenzene (5.78g, 28.15 mmol, 1.5 eq). The mixture was heated at 600C for 2.5 hours. On cooling, the mixture was diluted with water. The resulting white solid was collected by filtration and washed with water and dried in the vacuum oven (6.06g). [MH]+ 31 1.
This was triturated with hexane to remove traces of 1-(bromomethyl)-2- chlorobenzene. The white solid was collected by filtration and washed with hexane to give the title compound (5.47g, 17.65mmol).
Intermediate 20: 5-Chloro-2-{[(2-chlorophenyl)methyl]oxy}benzoic acid
Figure imgf000037_0001
A solution of methyl 5-chloro-2-{[(2-chlorophenyl)methyl]oxy}benzoate (5.47 g, 17.65 mmol) in methanol (50 ml) and 2N sodium hydroxide solution (50ml) was heated to reflux for 1 hour. The solvent was then evaporated in vacuo, and then acidified with 2N hydrochloric acid. The resulting white solid was collected by filtration to give the title compound (5.245g, 17.72mmol). [MH]+ 297.
Intermediate 21 : Ethyl (3-chloro-4-{[(5-chloro-2-{[(2- chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetate
Figure imgf000037_0002
A solution of 5-chloro-2-{[(2-chlorophenyl)methyl]oxy}benzoic acid (250 rmg, 0.84 mmol) in dichloromethane (10 ml) was treated with ethyl (4-amino-3- chlorophenyl)acetate (216mg, LOmmol) followed by EDAC (324 mg, 1.69 mmol), HOBT (228mg, 1.69mmol) and triethylamine (0.35ml, 2.53mmol). The reaction mixture was stirred at room temperature overnight, and then heated to reflux for 1.5 hours. The mixture was partitioned between DCM (x2) and water in hydrophobic frit. The combined organics were evaporated to a clear oil. This was purified by chromatography, eluting with 7-60% ethyl acetate in hexane over 12CV. Fractions containing the desired product were evapoated to an orange oil (300mg, 0.61 mmol) - contains -50% impurity. [MH]+ 492.
Example 9: (3-chloro-4-{[(5-chloro-2-{[(2- chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetic acid
Figure imgf000038_0001
To ethyl (3-chloro-4-{[(5-chloro-2-{[(2- chlorophenyljmethyljoxyjphenyljcarbonyljaminojphenyljacetate (300mg, 0.61 mmol) was added ethanol (5 ml_) and 2N sodium hydroxide (5 ml_). This was heated to reflux for 30 minutes. Reaction evaporated, then 2N hydrochloric acid was added and the resulting solid collected by filtration and dried in a vacuum oven. Further purification by trituration with diethyl ether gave the title compound as a cream solid (74mg, 0.16mmol). [MH]+ 464.
1H-NMR (400MHz, c/6-DMSO) δ 5.45 (2H, s), 7.15 (1 H, d), 7.25 (1 H, s), 7.35-7.5 (4H, m), 7.55 (1 H, d), 7.65 - 7.7 (2H, m), 8.00 (1 H, d), 8.10 (1 H,d), 10.00 (1 H, s).
Intermediate 22: Ethyl (4-{[(2-amino-5- chlorophenyl)carbonyl]amino}phenyl)acetate.
Figure imgf000038_0002
A mixture of 6-chloro-2H-3,1-benzoxazine-2,4(1 H)-dione (998mg, 5.05mmol), ethyl (4-aminophenyl)acetate (996mg, 5.56mmol) and 4-dimethylaminopyridine (31 mg, 0.252mmol) in dimethylformamide (20ml) was heated at 1 100C for 18 hrs. After cooling the solvent was evaporated and the residue partitioned between saturated aqueous sodium bicarbonate and ethyl acetate. The organic layer was separated, dried (Na2SO4) and the solvent evaporated to afford a brown oil. This was purified by flash chromatography (Biotage SP4, 40+M, 0 — > 50% ethyl acetate / hexane) to afford the title compound as a yellow solid (670mg, 40%). MS (ES+) m/z 333 [M+H+] (Ci7H17 35CIN2O3).
1H-NMR (250MHz, CDCI3) δ 1.26 (3H, t, J 7.25), 3.60 (2H, s), 4.15 (2H, q, J 7.25), 5.30 (2H, broad s), 6.65 (1 H, d, J 8.75), 7.19 (1 H, dd, J 8.75, 2.5), 2.28 (2H, m), 7.42 (1 H, d, J 2.25), 7.51 (2H, m), 7.67 (1 H, broad s). Intermediate 23: Ethyl (4-{[(5-chloro-2-{[(3- chlorophenyl)methyl]amino}phenyl)carbonyl]amino}phenyl)acetate.
Figure imgf000039_0001
3-Chlorobenzyl bromide (237 μl, 1.81 mmol) was added to a suspension of ethyl (4- {[(2-amino-5-chlorophenyl)carbonyl]amino}phenyl)acetate (200mg, 0.602mmol) and potassium carbonate ( 125mg, 0.904mmol) in dimethylformamide (10ml) and the reaction was stirred at room temperature for 3 days. The solvent was evaporated and the residue partitioned between saturated aqueous sodium bicarbonate and ethyl acetate. The organic layer was separated, dried (Na2SO4) and the solvent evaporated to afford an oil. This was purified by flash chromatography (biotage SP4, 25+M, 0 → 40% ethyl acetate / hexane) to afford the title compound as a pale yellow solid (21 Omg, 60%).
MS (ES+) m/z 457 [M+H+] (C24H22 35CI2N2O3).
1H-NMR (250MHz, CDCI3) δ 1.26 (3H, t, J 7.25), 3.61 (2H, s), 4.17 (2H, q, J 7.25), 4.38 (1 H, broad s), 6.53 (1 H, d, J 9), 7.19-7.32 (7H, m), 7.46-7.54 (3H, m), 7.67 (1 H, broad s), 7.92 (1 H, broad s).
Example 10: (4-{[(5-chloro-2-{[(3- chlorophenyl)methyl]amino}phenyl)carbonyl]amino}phenyl)acetic acid.
Figure imgf000039_0002
Lithium hydroxide monohydrate (29mg, 0.691 mmol) was added to a solution of Ethyl (4-{[(5-chloro-2-{[(3- chlorophenyl)methyl]amino}phenyl)carbonyl]amino}phenyl)acetate (the compound of intermediate 17) in dioxane (4ml) and water (2ml) and the reaction was stirred at room temperature for 18hrs. The solvent was evaporated and the residue dissolved in water. Acidification (2M HCI, pH~1 ) afforded a colourless solid which was collected by filtration and dried invacuo to give the title compound (150mg, 76%). MS (ES+) m/z 429 [M+H+] (C22H18 35CI2N2O3).
1H-NMR (250MHz, d6-DMSO) δ 3.15 (2H, s), 4.44 (2H, d, J 5.75), 6.59 (1 H, d, J 9), 7.15 (2H, d, J 8.5), 7.25-7.39 (5H, m), 7.51 (2H, d, J 8.5), 7.73 (1 H, d, J 2.5). 7.97 (1 H, broad t, J 6), 10.14 (1 H, s).
Intermediate 24: Ethyl (4-{[(5-chloro-2-{[(2- chlorophenyl)methyl]amino}phenyl)carbonyl]amino}phenyl)acetate
Figure imgf000040_0001
A mixture of ethyl (4-{[(2-amino-5-chlorophenyl)carbonyl]amino}phenyl)acetate (150 mg, 0.45 mmol), potassium carbonate (93mg, 0.68mmol, 1.5eq) and 2-chlorobenzoyl chloride (76 ul, 0.59 mmol, 1 .3 eq) in DMF (5 ml) was stirred at room temperature for 2hours, then overnight (as there was still starting material present). After another 8hours at room temperature the reaction was worked up: the mixture was diluted with ethyl acetate (300ml), washed with water (2x100ml), dried over magnesium sulphate and evaporated. The residue was further purified by MDAP to afford the title compound as an off-white solid. MS (ES+) m/z 457 [M+H]+ (C22H16 35CI2N2O3). 1H- NMR (400MHz, cfe-DMSO) δ 1.18 (1 H, t), 3.63 (2H, s), 4.08 (2H, q), 4.49 (1 H, d), 6.60 (1 H, d), 7.24 (2H, d), 7.29-7.32 (3H, m), 7.37 (1 H, m), 7.47 (1 H, m), 7.65 (2H1 d), 7.76 (1 H, d), 7.92 (1 H, t).
Example 11 : (4-{[(5-Chloro-2-{[(2- chlorophenyl)methyl]amino}phenyl)carbonyl]amino}phenyl)acetic acid
Figure imgf000041_0001
A solution of ethyl (4-{[(5-chloro-2-{[(2- chlorophenyl)methyl]amino}phenyl)carbonyl]amino}phenyl)acetate (87mg, 0.19 mmol) in acetic acid (3 ml) and 2M HCI (3 ml) was heated at 9O0C for 2 hours. On cooling, the mixture was diluted with water and the resulting precipitate was filtered. The residue was further purified by MDAP to afford the title compound as an off-white solid. MS (ES+) m/z 429 [M+H]+ (C22H18 35CI2N2O3). 1H-NMR (400MHz, d6-DMSO) δ 3.53 (2H, s), 4.47 (2H, d), 6.59 (1 H, d), 7.23 (2H, d), 7.29-7.38 (4H, m), 7.46-7.49 (1 H, m), 7.64 (2H, d), 7.75 (1 H, d), 7.94 (1 H, t), 10.24 (1 H, s).
Intermediate 25: 2-Chloro-6-(methyloxy)benzoic acid.
Figure imgf000041_0002
To a stirred solution of tert- Butyl n itrite (1 .62ml, 13.65mmol) and copper (II) chloride (1.47g, 10.9mmol) in acetonitrile (35ml) under argon was added 2-amino-6- (methyloxy)benzoic acid (1.52g, 9.1 mmol) in acetonitrile (5ml) dropwise over 5 mins. Stirring was continued for 18 hrs. The solvent was evaporated and the residue suspended in water. This was basified (5M NaOH, pH~14) and the solid filtered off. The aqueous layer was washed with ethyl acetate, acidified (cone. HCI, pH~1 ) and extracted with ethyl acetate. The organic layer was dried (Na2SO4), the solvent evaporated and the residue purified by mass directed auto-prep (MDAP) to afford the title compound as a colourless solid (462mg, 27%). MS (ES+) m/z 169 [M-OH"] (C8H7 35CIO3).
1H-NMR (250MHz, CDCI3) δ 3.90 (3H, s), 6.86 (1 H, dd, J 8.5, 0.5), 7.02 (1 H, dd, J 8.25, 0.75), 7.32 (1 H, t, J 8.5).
Intermediate 26: Ethyl [4-({[2-chloro-6- (methyloxy)phenyl]carbonyl}amino)phenyl]acetate.
Figure imgf000042_0001
2-chloro-6-(methyloxy)benzoic acid (460mg, 2.47mmol) in thionyl chloride (5ml) was stirred at 600C for 3hrs. The excess thionyl chloride was evaporated to afford a yellow oil. This was dissolved in chloroform (5ml) and ethyl (4-aminophenyl)acetate (443mg, 2.47mmol) added and the reaction was heated at 600C for 1 hour. After cooling the solution was poured into saturated sodium bicarbonate and the phases separated. The organic layer was dried (Na2SO4), solvent evaporated and the residue purified by flash chromatography (SP4, 25+M, 0 → 50% ethyl acetate / hexane) to afford the title as a light brown solid (682mg, 76%). MS (ES+) m/z 348 [M+H+] (Ci8H18 35CINO4).
1H-NMR (250MHz, CDCI3) 51.26 (3H, t, J 7), 3.60 (2H, s), 3.85 (3H, s), 4.14 (2H1 q, J 7.25), 6.85 (2H, d, J 8.5) 7.02 (2H, d, J 7.75), 7.30 (3H, m), 7.41 (1 H, broad s), 7.60 (2H, d, J 8.5).
Intermediate 27: Ethyl (4-{[(2-chloro-6- hydroxyphenyl)carbonyl]amino}phenyl)acetate.
Figure imgf000042_0002
Boron tribromide (557μl, 5.9mmol) was added dropwise to a solution of ethyl [4-({[2- chloro-6-(methyloxy)phenyl]carbonyl}amino)phenyl]acetate 682mg, 1 .97mmol) in dichloromethane (30ml) at -78°C under argon and the reaction was stirred for 1 hour prior to warming to 00C and stirring was continued for a further 90mins. The reaction was quenched by the careful addition of water, phases separated, the organic layer dried (Na2SO4) and solvent evaporated to afford the title compound as a colourless solid (609mg, 93%). MS (ES+) m/z 334 [M+H+] (C17H16 35CINO4). 1H-NMR (250MHz, CDCI3) δ 1.26 (3H, t, J 7.25), 3.62 (2H, s), 4.14 (2H, q, J 7.25), 6.98 (2H, m), 7.32 (3H, m), 7.57 (2H1 m), 9.13 (1 H1 broad s), 12.21 (1 H1 s).
Intermediate 28: Ethyl {4-[({2-chloro-6- [(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetate.
Figure imgf000043_0001
Benzyl bromide (64 μl, 0.54mmol) was added to a suspension of ethyl (4-{[(2-chloro- 6-hydroxyphenyl)carbonyl]amino}phenyl)acetate (150mg, 0.45mmol) and potassium carbonate (81 mg, 0.59mmol) in dimethylformamide (5ml) and the reaction was stirred at room temperature for 18 hrs. The solvent was evaporated and the residue partitioned between saturated aqueous sodium bicarbonate and ethyl acetate. The organic layer was separated, dried (Na2SO4) and the solvent evaporated to afford the title compound as a colourless solid (169mg, 89%). MS (ES+) m/z 424 [M+H+] (C24H22 35CINO4).
1H-NMR (250MHz, CDCI3) δ 1.26 (3H, t, J 7), 3.60 (2H, s), 4.14 (2H, q, J 7.25), 5.16 (2H, s), 6.90 (1 H, d, J 8), 7.06 (1 H, m), 7.23-7.40 (9H, m), 7.52 (2H, d, 8.5).
Example 12: {4-[({2-chloro-6-
[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid.
Figure imgf000043_0002
Lithium hydroxide monohydate (25mg, 0.599mmol) was added to a solution of ethyl {4-[({2-chloro-6-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetate (169mg, 0.399mmol) in dioxane (4ml) and water (2ml) and the reaction was stirred at room temperature for 2 hrs. The solvent was evaporated and the residue dissolved in water. Acidification (cone. HCI, pH~1 ) afforded a colourless solid which was collected by filtration and dried invacuo to give the title compound (154mg, 98%). MS (ES+) m/z 396 [M+H+] (C22H18 35CINO4).
1H-NMR (250MHz, d6-DMSO) 3.53 (2H, s), 5.21 (2H, s), 7.1 1-7.44 (1 OH, m), 7.61 (2H, d, J 8.5), 10.50 (1 H, s), 12.30 (1 H , broad s).
Intermediate 29: Ethyl (4-{[(2-chloro-6-{[(3- chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetate.
Figure imgf000044_0001
3-Chloro benzyl bromide (62μl, 0.47mmol) was added to a suspension of ethyl (4- {[(2-chloro-6-hydroxyphenyl)carbonyl]amino}phenyl)acetate (150mg, 0.45mmol) and potassium carbonate (81 mg, 0.59mmol) in dimethylformamide (3ml) and the reaction was stirred at room temperature for 18 hrs. The solvent was evaporated and the residue partitioned between saturated aqueous sodium bicarbonate and ethyl acetate. The organic layer was separated, dried (Na2SO4) and the solvent evaporated to afford the title compound as a colourless solid (194mg, 94%). MS (ES+) m/z 458 [M+H+] (C24H2I35CI2NO4).
1H-NMR (250MHz, CDCI3) δ 1.26 (3H, t, J 7), 3.60 (2H, s), 4.14 (2H, q, J 7), 5.16 (2H, s), 6.85 (1 H, m), 7.08 (1 H, m), 7.23-7.45 (8H, m), 7.52 (2H, m).
Example 13: (4-{[(2-chloro-6-{[(3- chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetic acid.
Figure imgf000045_0001
Lithium hydroxide monohydate (27mg, 0.64mmol) was added to a solution of ethyl (4-{[(2-chloro-6-{[(3-chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetate (194mg, 0.424mmol) in dioxane (4ml) and water (2ml) and the reaction was stirred at room temperature for 18 hrs. The solvent was evaporated and the residue dissolved in water. Acidification (cone. HCI, pH~1 ) afforded a colourless solid which was collected by filtration and dried invacuo to give the title compound (180mg, 99%). MS (ES+) m/z 430 [M+l-T] (C22H17 35CI2NO4). 1H-NMR (250MHz, d6-DMSO) 3.51 (2H, s), 5.21 (2H, s), 7.08-7.50 (9H, m), 7.61 (2H, m), 10.56 (1 H, s), 12.30 (1 H , broad s).
Biological data
Studies were performed using HEK-293(T) cells expressing the recombinant human prostanoid EP4 receptor (HEK-EP4 cells). Cells were grown as a monolayer culture in DMEM-F12/F12 containing glutamax II™ (a source of L-Glutamine) (Gibco) and supplemented with 10% foetal bovine serum (Gibco) and 0.4mg.ml-1 G418. HEK- EP4 cells were pre-treated 24hr and 30mins prior to the experiment with 10μM indomethacin and harvested using Versene™ (EDTA) containing 10μM indomethacin. The cells were resuspended in assay buffer (DMEM:F12, 10μM indomethacin and 200μM IBMX) at 1 χ106 cells per ml and incubated for 20min at 370C. Thereafter, 50μl of cells were added to 50μl test compound (compound of the invention) and incubated at 37°C for 4 minutes before stopping reactions with 10Oμl of 1 % Triton® X-100 (non-ionic surfactant). cAMP levels in the cell lysates were determined using a competition binding assay. In this assay the ability of cell lysates to inhibit 3H-cAMP (Amersham) binding to the binding subunit of protein kinase A was measured and cAMP levels were calculated from a standard curve. The data for each compound were expressed as a % of the response to a 1OnM maximal concentration of the standard agonist PGE2. For each compound the maximal response and concentration of compound causing 50% of its maximal response were calculated (pEC50). Intrinsic activity is expressed relative to the maximal response to PGE2 [(maximum response to test compound) * 100 / (maximum response to PGE2)]. Unless stated, reagents were purchased commercially from Sigma.
The Examples of the present invention were tested in the above-mentioned assay and exhibited average pEC50 values of 6.0 or higher, and average intrinsic activities of 20% or higher.

Claims

Claims:
1. A compound selected from the group consisting of: (3-chloro-4-{[(5-chloro-2-{[(2- chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetic acid;
{4-[({5-chloro-2-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid;
{3-chloro-4-[({5-chloro-2-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid;
(3-chloro-4-{[(5-chloro-2-{[(3- chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetic acid;
{4-[({2-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid;
(4-{[(5-chloro-2-{[(3-chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}-2- fluorophenyl)acetic acid;
{3-chloro-4-[({2-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid; (3-chloro-4-{[(2-{[(3-chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetic acid;
{4-[({2-chloro-6-[(phenylmethyl)oxy]phenyl}carbonyl)amino]phenyl}acetic acid;
(4-{[(2-chloro-6-{[(3-chlorophenyl)methyl]oxy}phenyl)carbonyl]amino}phenyl)acetic acid; {4-[({5-chloro-2-[(phenylmethyl)amino]phenyl}carbonyl)amino]phenyl}acetic acid;
(4-{[(5-chloro-2-{[(3-chlorophenyl)methyl]amino}phenyl)carbonyl]amino}phenyl)acetic acid; and
(4-{[(5-chloro-2-{[(2-chlorophenyl)methyl]amino}phenyl)carbonyl]amino}phenyl)acetic acid, or pharmaceutically acceptable salts thereof.
2. A compound according to claim 1 for use in human or animal medicine.
3. A compound according to claim 1 for use in the treatment of a condition which is mediated by the action, or loss of action of PGE2 at EP4 receptors.
4. A compound according to claim 1 for use in the treatment of a Bone Disorder.
5. A method of treating a human or animal subject suffering from a condition which is mediated by the action, or by loss of action, of PGE2 at EP4 receptors which comprises administering to said subject an effective amount of a compound according to claim 1.
6. A method of treating a human or animal subject suffering from a Bone Disorder which comprises administering to said subject an effective amount of a compound according to claim 1 .
7. Use of a compound of claim 1 for the manufacture of a medicament for the treatment of a condition which is mediated by the action, or by loss of action, of PGE2 at EP4 receptors.
8. Use of a compound of claim 1 for the manufacture of a medicament for the treatment of a Bone Disorder.
9. A pharmaceutical composition comprising a compound of claim 1 and a pharmaceutically acceptable carrier or diluent thereof.
10. A pharmaceutical composition according to claim 9 comprising one or more additional therapeutic agents.
11. Compound according to claim 3 or method according to claim 5 or use according to claim 7 wherein the condition is pain.
12. Compound or method or use according to claim 1 1 wherein the pain condition is selected from the group consisting of chronic articular pain; musculoskeletal pain; lower back and neck pain; sprains and strains; neuropathic pain; sympathetically maintained pain; myositis; pain associated with cancer and fibromyalgia; pain associated with migraine; pain associated with influenza or other viral infections; rheumatic fever; pain associated with functional bowel disorders; pain associated with myocardial ischemia; post operative pain; headache; toothache and dysmenorrhea.
13. Compound according to claim 4 or method according to claim 6 or use according to claim 8 wherein the Bone Disorder is selected from the group consisting of fracture healing, bone grafting, a periodontal indication and malignant bone tumour e.g. osteosarcoma.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005021508A1 (en) * 2003-09-03 2005-03-10 Pfizer Inc. Phenyl or pyridyl amide compounds as prostaglandin e2 antagonists
WO2005080367A1 (en) * 2004-02-12 2005-09-01 Pharmagene Laboratories Limited Ep2 receptor agonists
WO2005116010A1 (en) * 2004-05-26 2005-12-08 Merck Frosst Canada Ltd. Ep4 receptor agonist, compositions and methods thereof
WO2008071736A1 (en) * 2006-12-15 2008-06-19 Glaxo Group Limited Benzamide derivatives as ep4 receptor agonists

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005021508A1 (en) * 2003-09-03 2005-03-10 Pfizer Inc. Phenyl or pyridyl amide compounds as prostaglandin e2 antagonists
WO2005080367A1 (en) * 2004-02-12 2005-09-01 Pharmagene Laboratories Limited Ep2 receptor agonists
WO2005116010A1 (en) * 2004-05-26 2005-12-08 Merck Frosst Canada Ltd. Ep4 receptor agonist, compositions and methods thereof
WO2008071736A1 (en) * 2006-12-15 2008-06-19 Glaxo Group Limited Benzamide derivatives as ep4 receptor agonists

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