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WO2017032699A1 - Procédé de production d'esters d'acide (méth)acrylique à bas point d'ébullition - Google Patents

Procédé de production d'esters d'acide (méth)acrylique à bas point d'ébullition Download PDF

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Publication number
WO2017032699A1
WO2017032699A1 PCT/EP2016/069674 EP2016069674W WO2017032699A1 WO 2017032699 A1 WO2017032699 A1 WO 2017032699A1 EP 2016069674 W EP2016069674 W EP 2016069674W WO 2017032699 A1 WO2017032699 A1 WO 2017032699A1
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alcohol
reaction
methyl
alkyl group
compounds
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PCT/EP2016/069674
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German (de)
English (en)
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Martin KALLER
Harald Roessler
Mathieu BLANCHOT
Thorsten Friese
Bolette Urtel
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Basf Se
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C213/00—Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton
    • C07C213/06—Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton from hydroxy amines by reactions involving the etherification or esterification of hydroxy groups
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C213/00—Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton
    • C07C213/10—Separation; Purification; Stabilisation; Use of additives
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C67/00—Preparation of carboxylic acid esters
    • C07C67/03—Preparation of carboxylic acid esters by reacting an ester group with a hydroxy group
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C67/00—Preparation of carboxylic acid esters
    • C07C67/48—Separation; Purification; Stabilisation; Use of additives
    • C07C67/52—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation
    • C07C67/54—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation by distillation

Definitions

  • the present invention relates to a process for the preparation of low-boiling (meth) acrylic acid esters in the presence of at least one metal, metal oxide, organo-metal oxide or metal alkoxide catalyst.
  • (Meth) acrylic esters are important synthesis building blocks which are required, inter alia, for the preparation of polymers.
  • (meth) acrylic esters with short-chain ester groups so-called low-boiling (meth) acrylic esters, are of great commercial interest because of the high demand. There is therefore a need for effective and economical processes for the preparation of low-boiling (meth) acrylic esters.
  • (meth) acrylic esters can be obtained industrially by transesterification of lower (meth) acrylic esters. Since the transesterification is an equilibrium reaction, in order to achieve high reaction conversions, it is necessary to use one of the starting materials in a large excess and / or to continuously remove one of the reaction products (generally the liberated lower alcohol) from the reaction mixture ,
  • JP 01258642 describes inter alia the preparation of allyl methacrylate by transesterification of methyl methacrylate with allyl alcohol in the presence of a polymerization inhibitor and tetraisobutyl titanate as a transesterification catalyst.
  • JP1 12224661 describes a process for preparing (meth) acrylic esters by transesterification of methyl or ethyl (meth) acrylate with C3-C24 alcohols in the presence of tetramethyl titanate and a polymerization inhibitor with removal by distillation of an azeotropic mixture of the liberated lower alcohol and used in excess methyl or ethyl (meth) acrylate.
  • EP 2807141 B1 describes a process for the preparation of 2-octyl acrylate by transesterification of ethyl acrylate with 2-octanol in the presence of ethyl titanate or 2-octyl titanate, in which an azeotropic mixture of ethyl acrylate and ethanol is continuously discharged with the aid of a distillation column during the transesterification and the remaining bottoms product is then purified via two distillation columns.
  • EP 1399408 B1 describes a process for the continuous preparation of higher (meth) acrylic esters by transesterification of a lower (meth) acrylic ester with a higher alcohol in the presence of a metal alkoxide catalyst.
  • the lower alcohol liberated in the reaction is separated off continuously by distillation together with part of the lower (meth) acrylic acid ester, the reflux ratio being 5-15: 1 and, as a rule, part of the condensate is applied as reflux to the column top ,
  • a solution of a polymerization inhibitor in the lower (meth) acrylic ester is applied to the column.
  • the metal alkoxide catalyst used is prepared in advance of the reaction of a lower metal alkoxide and the higher alcohol used for transesterification. Specifically, dimethylaminoethanol is used as the higher alcohol in this process.
  • the present invention is based on the object, an improved process for the preparation of (meth) acrylic acid esters, in particular low-boiling
  • the present invention thus relates to a process for the preparation of
  • R 1 is hydrogen or methyl
  • R 2 is a straight or branched C 3 -C 10 -alkyl group, a C 5 -C 7
  • Cycloalkyl group wherein the cycloalkyl group is unsubstituted or may be substituted by at least one Ci-Cio-alkyl radical, an unbranched or branched C2-Cio-alkenyl group containing 1, 2 or 3 double bonds, or a C 2 -Cio-alkyl group, the is substituted with a -N (R 3 a R 3b ) 2 group or a - (OR 4 ) n -OR 5 - group, where n can assume the values 0, 1, 2, 3 or 4, and
  • R 3a and R 3b are independently hydrogen, a d-Cs-alkyl group, a C5-C7-cycloalkyl or phenyl, where the substituents R 3a and R 3b in -N (R 3 a R 3 b), together with the N Atom to which they are attached can also form a 5- to 7-membered ring,
  • R 4 is a Ci-C4-alkylene group
  • R 5 is a Ci-Cs-alkyl group in which at least one compound of general formula II
  • R 1 has the abovementioned meaning
  • R 6 is methyl, ethyl, n-propyl, isopropyl or n-butyl, b) the at least one compound II provided in step a) in the presence of at least one alcohol R 2 -OH and in the presence of at least one catalyst which is selected from Mineral acids, metals, metal salts, organometallic compounds or metal alkoxides, to obtain a reaction mixture containing at least one (meth) acrylic acid ester of the general formula I, wherein the alcohol formed during the reaction R 6 -OH together with a part of at least one compound II, a column is at least discharged continuously by distillation and a depleted R 6 -OH the reaction mixture is obtained, c) subjecting the product obtained in step b) depleted R 6 -OH the reaction mixture a DES tilla tive separation, thereby obtaining a to the at least one compound II enriched fraction which optionally contains alcohol R 2 -OH, and one to the verbin
  • the radical R 6 is selected from Mineral acids,
  • Step b) used alcohol R 2 -OH and wherein during the distillative removal in step b) a liquid stream containing methanol, ethanol, n-propanol, isopropanol or butanol or a mixture of these alcohols, in the region of the head of the at least one column is initiated continuously.
  • the amount of methanol, ethanol, n-propanol, isopropanol or butanol or a mixture of these alcohols, which is contained in the continuously introduced during the distillative removal in step b) liquid stream in this case is preferably at least 80 wt .-%, based on the total weight of the liquid stream.
  • the fraction obtained after removal of the desired (meth) acrylic acid ester enriched in the at least one compound II, optionally containing the alcohol R 2 -OH used, can be used for further reactions or, in the case of continuous process control, back into the reaction in step b). to be led back. As a result, an almost complete recovery of the valuable material used R 2 -OH can be achieved.
  • the inventive method is characterized by its efficiency and cost-effectiveness and is thus advantageously suitable for the industrial production of low-boiling (meth) acrylic acid esters.
  • the catalyst used in the process of the invention can be reused after separation of the compounds of general formula I for further reactions or stored for a long time.
  • (meth) acrylic acid, (meth) acrylate or (meth) acrylate refer to acrylic acid or the corresponding acrylic esters or acrylates as well as to methacrylic acid or the corresponding methacrylic acid esters or methacrylates.
  • C 1 -C 10 -alkyl refers to unbranched alkyl groups having 1 to 10 carbon atoms or branched alkyl groups having 3 to 10 carbon atoms.
  • Ci-Ci 0- alkyl stands for unbranched alkyl groups having 1 to 8 carbon atoms or for branched alkyl groups having 3 to 8 carbon atoms. These include, for example, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 2-pentyl, 2-methylbutyl, 3-methylbutyl,
  • C 1 -C 0 -alkyl is unbranched C 1 -C 6 -alkyl groups or branched C 3 -C 6 -alkyl groups.
  • Ci-Ci 0 alkyl the terms “C3-C1 0-alkyl” includes “d-Cs-alkyl” and "CC 4 alkyl” includes within its definition.
  • C 2 -C 10 -alkenyl refers to unbranched alkenyl groups having 2 to 10 carbon atoms or branched alkenyl groups having 3 to 10 carbon atoms containing 1, 2 or 3 double bonds.
  • C2-Cio-alkenyl preferably represents unbranched alkenyl groups having 2 to 8 carbon atoms or branched alkenyl groups having 3 to 8 carbon atoms containing 1, 2 or 3 double bonds. These include, for example, vinyl, 1-propenyl,
  • C2-Cio-alkenyl to unbranched or branched alkenyl groups having 3 to 6 carbon atoms, containing 1 or 2 double bonds, in particular unbranched or branched alkenyl groups having 3 to 6 carbon atoms, containing a double bond.
  • C5-C7-cycloalkyl for the purposes of the present invention comprises cyclic hydrocarbons having 5 to 7, in particular having 5 or 6 carbon atoms. These include cyclopentyl, cyclohexyl or cycloheptyl.
  • Substituted Cs-Cz-cycloalkyl groups may, depending on their ring size, have one or more (eg 1, 2, 3 or 4) C 1 -C 10 -alkyl substituents.
  • Examples of substituted Cs-Cz-cycloalkyl groups are 2- and 3-methylcyclopentyl, 2- and 3-ethylcyclopentyl, 2-, 3- and 4-methylcyclohexyl, 2-, 3- and 4-ethylcyclohexyl, 2-, 3- and 4 Propylcyclohexyl, 2-, 3- and 4-isopropylcyclohexyl, 2-, 3- and 4-butylcyclohexyl, 2-,
  • C 1 -C 4 -alkylene refers to unbranched bivalent hydrocarbon radicals having 1 to 4 carbon atoms or to branched bivalent hydrocarbon radicals having 1 to 4 carbon atoms. These include, for example, methylene, 1,2-ethylene, 1,2-propylene, 1,3-propylene,
  • C 1 -C 4 -alkylene is 1,2-ethylene, 1,2-propylene or 1,3-propylene, in particular 1,2-ethylene or 1,3-propylene.
  • Ci-Ci 0 alkyl In the case of singly or multiply branched Ci-Ci 0 alkyl, Ci-Ci 0 alkenyl groups, -C 4 alkylene or substituted C 5 -C 7 cycloalkyl groups, the carbon atom at the branching point or the carbon atoms at the respective can Branching points, independently of each other have an R- or an S-configuration or both configurations in equal or different proportions.
  • R 2 is a straight-chain or branched C 4 -C 8 -alkyl group, a C 5 -C 6 -cycloalkyl group, where the cycloalkyl group is unsubstituted or may be substituted by one or two C 1 -C 4 -alkyl radicals, an unbranched or branched C 2 -C 6 -alkenyl group containing 1 or 2 double bonds, or a C 2 -C 6 -alkyl group substituted by a -N (R 3a R 3b ) group or a - (OR 4 ) n -OR 5 group, where n is 0, 1, 2 or 3, and
  • R 3a and R 3b are each independently hydrogen or a Ci-C4-alkyl group, wherein the substituents R 3a and R 3b in -N (R 3a R 3b ), together with the N-atom to which they are attached, also a 5 - can form up to 6-membered ring, R 4 for a C2-C3-alkylene group and
  • R 5 is a d-Cs-alkyl group.
  • R 2 is an unbranched or branched C 4 -C 6 -alkyl group, a C 5 -C 6 -cycloalkyl group, where the cycloalkyl group is unsubstituted or may be substituted by a C 1 -C 4 -alkyl radical, containing a straight or branched C 3 -C 6 -alkenyl group 1 or 2 double bonds, or an unbranched C 2 -C 4 -alkyl group which is substituted by a -N (R 3a R 3b ) group or an -OR 5 group,
  • R3a is hydrogen, an unbranched C 1 -C 4 -alkyl group or a branched one
  • R 3b represents an unbranched C 1 -C 4 -alkyl group or a branched C 3 -C 4 -alkyl group and
  • R 5 is an unbranched C 1 -C 4 -alkyl group.
  • R 2 is an unbranched or branched C 4 -C 6 -alkyl group, a C 1 -C 6 -cycloalkyl group, a straight or branched C 3 -C 6 -alkenyl group, containing
  • R3a is hydrogen, an unbranched C 1 -C 4 -alkyl group or a branched one
  • R 3b represents an unbranched C 1 -C 4 -alkyl group or a branched C 3 -C 4 -alkyl group and
  • R 5 is an unbranched C 1 -C 3 -alkyl group.
  • R 2 is -OH and in the compounds of general formula I.
  • R 2 is an unbranched or branched C 4 -C 6 -alkyl group, a straight-chain or branched C 3 -C 6 -alkenyl group containing one double bond, or an unbranched C 2 -C 3 -alkyl group which is substituted by an -N (R 3a R 3b ) Group is substituted,
  • R3a is hydrogen or an unbranched Ci-C4-alkyl group
  • R 3b represents an unbranched C 1 -C 4 -alkyl group or a branched C 3 -C 4 -alkyl group.
  • R 2 -OH and in the compounds of general formula IR 2 is an unbranched or branched C 4 -C 6 -alkyl group or a straight or branched C 3 -C 6 -alkenyl group containing a double bond.
  • R 1 is hydrogen or methyl
  • R 2 is an unbranched or branched C 4 -C 6 -alkyl group, a C 5 -C 6 -cycloalkyl group, where the cycloalkyl group is unsubstituted or may be substituted by a C 1 -C 4 -alkyl radical, containing a straight or branched C 3 -C 6 -alkenyl group 1 or 2 double bonds, or an unbranched one
  • R3a is hydrogen, an unbranched C 1 -C 4 -alkyl group or a branched one
  • R 3b represents an unbranched C 1 -C 4 -alkyl group or a branched C 3 -C 4 -alkyl group and
  • R 5 is an unbranched C 1 -C 3 -alkyl group.
  • R 1 is hydrogen or methyl
  • R 2 is a straight or branched C 4 -C 6 -alkyl group, a straight or branched C 3 -C 6 -alkenyl group containing one double bond, or a straight-chain C 2 -C 3 -alkyl group which is substituted by a -N (R 3a R 3b ) group is
  • R3a is hydrogen or an unbranched Ci-C4-alkyl group
  • R 3b represents an unbranched C 1 -C 4 -alkyl group or a branched C 3 -C 4 -alkyl group.
  • the at least one compound of the general formula II provided in step a) of the process according to the invention can be present either pure or as a mixture of different esters.
  • the compounds of general formula II are methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, n-butyl acrylate, methyl methacrylate, methacrylic acid ethyl ester, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate or mixtures thereof.
  • the compounds of the general formula II are preferably methyl acrylate, ethyl acrylate, propyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, or mixtures thereof.
  • the compounds of general formula II are methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate or mixtures thereof.
  • the compounds of general formula II are methyl acrylate or methyl methacrylate.
  • the compounds II can either be obtained commercially or synthesized by known methods familiar to the person skilled in the art.
  • step b) The transesterification in step b) can be represented by the following reaction equation:
  • the starting materials ie the compound of the general formula II and the alcohol R 2 -OH
  • the starting materials are chosen so that the boiling point at 1013 mbar of the corresponding released alcohol R 6 -OH, ie methanol, ethanol, n-propanol, Isopro - Panol or n-butanol, at least 15 ° C below the boiling point of the alcohol used R 2 -OH.
  • the boiling point at 1013 mbar of the liberated alcohol R 6 -OH is preferably at least 20 ° C., in particular at least 25 ° C., below the boiling point of the alcohol R 2 -OH used.
  • the at least one alcohol R 2 -OH used in step b) of the process according to the invention can either be obtained commercially or synthesized by known methods known to the person skilled in the art.
  • the alcohol R 2 -OH is, for example, to
  • R 2 is -OH
  • 3-methylpentanol 4-methylpentanol, 1, 1-dimethylbutanol, 2,2-dimethylbutanol, 3,3-dimethylbutanol, 1, 2-dimethylbutanol,
  • R 2 -OH is particularly preferably 1-butanol, 2-butanol, 2-methyl-
  • R 2 -OH is 1-butanol, 2-butanol, 2-methyl-1-propanol, 1-pentanol, 2-pentanol, 2-methylbutanol, 3-methylbutanol, 1-hexanol, 2-hexanol, 2-methylpentanol, 3-methylpentanol, 4-methylpentanol, 1-propenol,
  • R 2 -OH is 1-butanol, 2-methyl-1-propanol, 1-pentanol,
  • step b) of the process of the invention the at least one alcohol R 2 -OH in the deficit, based on the amount of the at least one compound of the general formula II used.
  • the molar ratio of the least a compound of general formula II for at least one alcohol R 2 -OH in the reaction mixture is usually in the range of 1, 1: 1 to 10: 1, preferably in the range of 1, 2: 1 to 5: 1 and in particular in the range of 1, 3: 1 to 3: 1.
  • the total amount of the at least one alcohol R 2 -OH in the reaction mixture of the reaction in step b) of the process according to the invention is usually in the range from 0.1 to 0.99 mol, preferably in the range from 0.2 to 0.9 mol, in particular in the range from 0.3 to 0.8 mol, based on 1 mol of compound II used.
  • the reaction mixture of the reaction in step b) of the process according to the invention comprises at least one polymerization inhibitor, which is also referred to below as a stabilizer.
  • Suitable polymerization inhibitors are all stabilizers known to those skilled in the art. These are, for example, For example, in the earlier German patent application with the file number 10249507.6 and in DE-A 10258329, DE-A 198 56 565 and in EP-A 765856. Polymerization inhibitors are phenolic compounds,
  • N-oxyl compounds aromatic amines, phenylenediamines, sulfonamides, oximes, hydroxylamines, phosphorus-containing compounds, sulfur-containing compounds and metal salts, and optionally mixtures thereof in question.
  • phenolic compounds suitable as stabilizers are, for example,
  • Alkylphenols e.g. o-, m- or p-cresol (methylphenol), 2-tert-butyl-4-methylphenol, 6-tert-butyl-2,4-dimethylphenol, 2,6-di-tert-butyl-4- methylphenol, 2-tert-butylphenol, 4-tert-butylphenol, 2-tert-butyl-6-methylphenol, 2,4,6-tris-tert-butylphenol, 2,6-di-tert-butylphenol , 2,4-di-tert-butylphenol, 4-tert-butyl-2,6-dimethylphenol, 2-methyl-4-tert-butylphenol, 2,2'-methylene-bis (6-tert. butyl-4-methylphenol), octylphenol, nonylphenol, 2,6-dimethylphenol or 2,6-di-tert-butyl-p-cresol;
  • Aminophenols such as.
  • p-aminophenol p-aminophenol
  • Nitrophenols such as p-nitrophenol
  • Tocopherols such as. B. ⁇ , ⁇ , or ⁇ -tocopherol
  • Hydroxycumarans e.g. 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran (2,2-dimethyl-7-hydroxycoumaran);
  • 2-alkoxyphenols such as 2-methoxyphenol (guaiacol)
  • 3-alkoxyphenols such as. 3-methoxyphenol or 3-ethoxyphenol
  • Hydroquinones such as. Hydroquinone, 2-methylhydroquinone, 2-tert-butylhydroquinone or 2,5-di-tert-butylhydroquinone, and
  • Hydroquinone monoalkyl ethers e.g. 4-methoxyphenol (hydroquinone monomethyl ether) or 2-tert-butyl-4-methoxyphenol or 2,5-di-tert-butyl-4-methoxyphenol.
  • Stabilizer effective N-oxyl compounds i. stable nitroxyl or N-oxyl radicals are z. 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-0x0-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-methoxy-2,2, 6,6-tetramethyl-piperidine-N-oxyl,
  • aromatic amines are, for. N, N-diphenylamine,
  • N-nitrosodiphenylamine or nitrosodiethylaniline N-nitrosodiphenylamine or nitrosodiethylaniline.
  • N N'-dialkyl-p-phenylenediamine, wherein the alkyl radicals may be the same or different and each independently of one another consist of 1 to 4 carbon atoms and may be straight or branched, for example N, N'-di-sec-butyl -p-phenylenediamine (Kerobit® BPD from BASF SE).
  • Suitable sulfonamides as stabilizer are, for example, N-methyl-4-toluenesulfonamide, N-tert-butyl-4-toluenesulfonamide, N-tert-butyl-N-oxyl-4-toluenesulfonamide, N, N'-bis (4 -sulfanilamide) piperidine or 3 - ⁇ [5- (4-aminobenzoyl) -2,4-dimethylbenzenesulfonyl] ethylamino ⁇ -4-methylbenzenesulfonic acid.
  • Suitable oximes as stabilizers are aldoximes, ketoximes or amidoximes, for example diethylketoxime, acetone oxime, methylethylketoxime, cyclohexanone oxime, dimethylglyoxime, 2-pyridinaldoxime, salicylaldoxime or other aliphatic or aromatic oximes or their reaction products with alkyl transfer reagents.
  • hydroxylamines are, for. N, N-diethylhydroxylamine.
  • a stabilizer effective phosphorus compounds are, for. B. triphenylphosphine, triphenyl phosphite, hypophosphorous acid, trinonyl phosphite or triethyl phosphite.
  • As a stabilizer effective sulfur compounds are z.
  • diphenyl sulfide phenothiazine and sulfur-containing natural products such as cysteine.
  • As a stabilizer effective metal salts are, for. For example, copper, manganese, cerium, nickel, chromium, carbonate, chloride, dithiocarbamate, dialkyldithiocarbamate, in particular dibutyldithiocarbamate, stearate, sulfate, salicylate, acetate or ethylhexanoate.
  • TAA tetraazazene
  • dibenzotetraaza [14] annulenes and porphyrins as described in Chem. Soc. Rev. 1998, 27, 105-1 15, imines, z. B.
  • Methylethyli- min (2-hydroxyphenyl) benzoquinone imine, (2-hydroxyphenyl) benzophenone imine, ⁇ , ⁇ -dimethylindoaniline, thionine (7-amino-3-imino-3H-phenothiazine), methylene violet (7-dimethylamino-3-phenothiazinon ) and urea derivatives such as urea or thiourea in question.
  • the polymerization inhibitors used in step b) of the process according to the invention are preferably selected from phenolic compounds, N-oxyl compounds, sulfonamides and sulfur-containing compounds, and mixtures thereof.
  • Particularly preferred polymerization inhibitors are phenothiazine, hydroquinone monomethyl ether, N, N'-di-sec-butyl-p-phenylenediamine and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl.
  • one or more, for example two or three, of the abovementioned polymerization inhibitors are used in the reaction in step b) of the process according to the invention.
  • Two or more, in particular two, of the abovementioned polymerization inhibitors are preferably used in the reaction in step b) of the process according to the invention.
  • the total amount of the at least one stabilizer in the reaction mixture of the reaction in step b) of the process according to the invention is usually in the range of 0.005 to 5 wt .-%, preferably in the range of 0.01 to 2 wt .-%, in particular in the range from 0.02 to 1% by weight, based on the amount of compound II used.
  • Catalyst The reaction according to the invention in step b) is generally carried out in the presence of a catalyst.
  • Suitable catalysts are the customary catalysts usually used for transesterification reactions, which are usually also used in esterification reactions.
  • the at least one catalyst used in step b) of the process according to the invention is mineral acids, metals, metal salts, organometallic compounds or metal alkoxides.
  • Suitable as a catalyst mineral acids are, for.
  • sulfuric acid and phosphoric acid and organic sulfonic acids such as methanesulfonic acid and p-toluenesulfonic acid.
  • Suitable catalysts for the reaction in step b) of the process according to the invention are also metals such as Sn, Ti or Zr.
  • the metals are preferably used for this purpose finely divided in the form of powders.
  • Metal salts which are suitable as catalyst are, for example, metal oxides, acetates, acetyl acetonates, chlorides, hydroxides, phosphates or carbonates of Li, Na, K, Rb, Cs, Mg, Ca, Mn, Ti, Co, Ni, Zn, Zr, Ge, Hf, Al, Cr, Fe, Sb or Sn.
  • metal salts are, for example, metal oxides, acetates, acetylacetonates, of Li, Ti, Zr, Ni, Zn, Sb or Sn, such as antimony (III) oxide, tin (II) oxide, tin (IV) oxide, nickel ( II) acetylacetonate and zinc (II) acetylacetonate.
  • Suitable organometallic compounds as catalyst are, for example, organotin compounds, such as
  • Dialkyltin laurates e.g. B. dimethyltin dilaurate or dibutyltin dilaurate;
  • Dialkyltin halides e.g. Dimethyldichloride, dipropyltin dichloride or dibutyltin dichloride;
  • dialkyltin dialkoxides e.g. B. Dimethylzinndimethanolat, Dimethylzinndiethanolat,
  • Dialkyltin diacetates e.g. Dimethyl tin diacetate or dibutyltin diacetate;
  • Dialkyltin oxides e.g. Dibutyltin oxide or dioctyltin oxide;
  • Monoalkylzinndioxide z.
  • Metal alkoxides suitable as catalyst are, for example, titanium alkoxides, such as titanium (IV) ethanolate, titanium (IV) isopropoxide or titanium (IV) butanolate; Triethanolamine titanates such as triethanolamine isopropyl titanate or diethanolamine di (isopropyl) titanate; Zirconium alkoxides, such as zirconium (IV) propoxide, zirconium (IV) butanolate or zirconium (IV) pentanoate; Triethanolaminzirkonat; Alkali or Erdalkalialkoxide and mixtures of said metal alkoxides.
  • organotin compounds or metal alkoxides are preferably used as catalysts.
  • metal alkoxides as defined above and below, are used as catalysts.
  • the amount of catalyst used is preferably from 0.001 to 15% by weight, more preferably from 0.005 to 10% by weight, based on the components used in step b).
  • step b) can be carried out in the absence or in the presence of an added organic solvent. If the reaction in step b) is carried out in the presence of an added organic solvent, these are at least one of methanol, ethanol, n-propanol, isopropanol, n-butanol, the alcohol R 2 -OH and the compounds (II) various organic solvent LM. In a first preferred embodiment of the process according to the invention, step b) is carried out in the presence of another solvent LM other than methanol, ethanol, n-propanol, isopropanol, n-butanol, the alcohol R 2 -OH and the compounds (II).
  • the at least one solvent LM is preferably an organic solvent which is inert under the reaction conditions.
  • organic solvent include, for example, aliphatic and alicyclic hydrocarbons, halogenated aliphatic and alicyclic hydrocarbons, aromatic and substituted aromatic hydrocarbons or ethers.
  • the solvent is preferably selected from pentane, hexane, heptane, ligroin, petroleum ether, cyclopentane, cyclohexane, dichloromethane, trichloromethane, carbon tetrachloride, 1, 2-dichloroethane, benzene, toluene, xylene, chlorobenzene, dichlorobenzenes, diethyl ether, methyl tert. Butyl ether, dibutyl ether, THF, dioxane, acetonitrile and mixtures thereof.
  • the at least one further solvent LM is selected from aliphatic and alicyclic hydrocarbons containing 5 to 8 carbon atoms, in particular hexane, heptane and cyclohexane, and mixtures thereof.
  • step b) is carried out in the absence of a solvent LM other than methanol, ethanol, n-propanol, isopropanol, n-butanol, the alcohol R 2 -OH and the compounds (II).
  • a solvent LM other than methanol, ethanol, n-propanol, isopropanol, n-butanol, the alcohol R 2 -OH and the compounds (II).
  • the reaction in step b) and the distillative removal of the alcohol R 6 -OH formed during the reaction are generally carried out at a temperature in the range from 30 to 175 ° C., preferably at a temperature in the range from 40 to 150 ° C and in particular carried out at a temperature in the range of 80 to 120 ° C.
  • the reaction in step b) and the distillative removal of the alcohol R 6 -OH formed during the reaction can generally be carried out at ambient pressure or reduced pressure.
  • the reaction takes place in step b) and the distillative discharge of the alcohol R 6 -OH, at least at the beginning of the reaction, at ambient pressure.
  • the pressure can also be reduced stepwise or continuously during the reaction in step b) once or several times in order to accelerate the removal of the alcohol R 6 -OH formed during the reaction.
  • the pressure in the course of the reaction in step b) is reduced stepwise or continuously.
  • step b) and the removal of the alcohol R 6 -OH by distillation at the beginning of the reaction at ambient pressure are particularly preferably carried out, the pressure being reduced stepwise or continuously in the course of the reaction in step b).
  • the reaction in step b) can be carried out in the absence or in the presence of an inert gas.
  • An inert gas is generally understood to mean a gas which, under the given reaction conditions, does not react with the starting materials, reagents, solvents or the products formed.
  • the transesterification is carried out without the addition of an inert gas under the reaction conditions.
  • the oxygen-containing gas mixture is introduced continuously into the reaction zone for this purpose.
  • the oxygen-containing gas mixture is usually gas mixtures containing oxygen.
  • the oxygen-containing gas mixture is preferably gas mixtures having an oxygen content in the range from 1 to 30% by volume, preferably from 2 to 15% by volume and particularly preferably from 3 to 10% by volume.
  • the oxygen-containing gas mixture is lean air.
  • the low-boiling alcohol R 6 -OH released in the reaction in step b) is continuously removed in order to shift the equilibrium of the transesterification reaction. Due to the formation of an azeotropic mixture, part of the at least one compound II is generally entrained in the distillative discharge of the liberated, low-boiling alcohol R 6 -OH. In the gel in the distillative removal of the lower alcohol R 6 -OH in the process according to the invention entrainment of the alcohol used in the reaction in step b) R 2 -OH is not observed. By distillative removal of a depleted in R 6 -OH reaction mixture is obtained.
  • lower boiling alcohol R 6 -OH together with a portion of the at least one compound II are generally all devices for the distillative separation of reaction mixtures containing liquid components.
  • Suitable devices include distillation columns, such as tray columns, which may be equipped with bubble cap trays, sieve plates, trays, packing or packing, or rotary belt column evaporators, such as thin film evaporators, falling film evaporators, forced circulation evaporators, Sambay evaporators, etc., and combinations thereof.
  • the lower-boiling alcohol R 6 -OH liberated in the reaction in step b) is particularly preferably used together with a part of the at least one compound II distillation columns and / or rotary column columns, in particular distillation columns.
  • the distillation column required for distillative discharge is usually in direct contact with the transesterification reactor, preferably it is installed directly on this. In the case of using several transesterification reactors connected in series, each of these reactors may be equipped with a distillation column or, preferably from the last boilers of the transesterification reactor cascade, the evaporated alcohol mixture may be fed via one or more manifolds to a distillation column.
  • a vapor is first withdrawn from the reaction mixture obtained in step b) which is then at least partially condensed.
  • suitable capacitors can be used. These can be cooled with any cooling media. Capacitors with air cooling and / or water cooling are preferred, with air cooling being particularly preferred.
  • the condenser is usually at the top, ie at the top of the distillation column, or is integrated in the top of the column.
  • the term "head of the column” or “column head” is understood to mean the region of a distillation column which is located at the upper end, ie. H. usually in the upper fifth, preferably in the upper tenth, of the distillation column is located.
  • the reflux ratio in the column in the distillative discharge in step b) is in the range from 10: 1 to 1: 100, preferably in the range of 8: 1 to 1:50, more preferably in the range of 7: 1 to 1: 30 and especially in the range of 6: 1 to 1:25.
  • the reflux ratio in the column in the distillative removal in step b) is in the range from 5: 1 to 1:20, in particular in the range from 4: 1 to 1:15.
  • step b) the discharge of the liberated in the reaction in step b), lower boiling alcohol R 6 -OH is started as soon as the temperature at the top of the column after the start of the reaction in step b) does not change significantly. This is the case, for example, after a few minutes to a few hours, for example after 15 or 20 minutes.
  • the reflux ratio is preferably adjusted so that the temperature at the top of the column remains as constant as possible.
  • the term "as constant as possible” in this context means that the temperature at the top of the column varies by less than 10 ° C, for example by less than 5 ° C or 3 ° C.
  • a liquid stream containing methanol, ethanol, n-propanol, isopropanol or butanol or a mixture of these alcohols is introduced continuously in the region of the head of the at least one column.
  • a mixture of methanol, ethanol, n-propanol, isopropanol or butanol is used in the liquid stream, this is a mixture of at least two, preferably two or three, in particular two of these alcohols.
  • the alcohol present in the liquid stream which is selected from methanol, ethanol, n-propanol, isopropanol, n-butanol or a mixture of these alcohols, preferably corresponds to the at least one alcohol R 6 -OH released in the reaction in step b).
  • the liquid stream continuously introduced during the distillative removal in step b) preferably contains at least 80% by weight, more preferably at least 90% by weight, in particular at least 95% by weight, based on the total weight of the liquid stream, of methanol, ethanol , n-propanol, isopropanol or butanol or a mixture of these alcohols.
  • the liquid stream introduced at the top of the column during the distillative removal in step b) additionally comprises at least one stabilizer (polymerization agent). hibitor).
  • stabilizer polymerization agent
  • hibitor a stabilizer
  • the total amount of at least one stabilizer contained in the liquid stream is usually in the range of 0.001 to 15 wt .-%, preferably in the range of 0.002 to 12 wt .-%, in particular in the range of 0.002 to 10 wt .-%, based on the Total weight of the injected liquid stream.
  • the liquid stream continuously introduced at the top of the column during the distillative removal in step b) consists of methanol, ethanol, n-propanol, isopropanol or butanol or a mixture of these alcohols containing at least one stabilizer, as before Are defined.
  • a liquid stream of methanol or ethanol containing the at least one stabilizer, as defined above, is introduced continuously during the distillative removal in step b) at the top of the column.
  • a liquid stream of methanol containing the at least one stabilizer, as defined above, is introduced continuously during the distillative removal in step b) at the top of the column.
  • the introduction of the liquid stream at the top of the column begins shortly after the beginning of the reaction in step b), more precisely 1 to 30 minutes, for example 2, 5 or 10 minutes, after the beginning of the reaction in step b).
  • the introduction of the liquid stream at the top of the column preferably begins before the discharge of the lower-boiling alcohol R 6 -OH released in the reaction in step b).
  • the introduction of the liquid stream at the top of the column is usually carried out continuously over the entire course of the reaction in step b), in particular at least until the discharge of the liberated, low-boiling alcohol R 6 - OH is completed.
  • the amount of liquid stream introduced hourly at the top of the column during the distillative discharge in step b) of the process according to the invention is usually from 0.1 to 25% by weight.
  • step b) in the absence of a further solvent LM or other, different from methanol, ethanol, n-propanol, isopropanol, n-butanol, the alcohol R 2 -OH and the compounds II or, according to the first described above preferred karten embodiment, is carried out in the presence of such a solvent LM and the proportion of the distilled off together with the alcohol R 6 -OH solvent LM in the case of recovery, as described below, directly in the reaction in step b) is recycled, which is during the distillative discharge in step b) of the process according to the invention hourly at the top of the column introduced amount of liquid stream preferably 0.5 to 20 wt .-%, particularly preferably 1 to 15 wt .-% and in particular 2 to 10 wt .-%, based to the total amount of the alcohol used in the reaction in step b) R 2 -OH.
  • a further solvent LM or other different from methanol, ethanol, n-propanol, is
  • At least one compound II is additionally supplied for the reaction in step b), in order to compensate for the losses occurring at the at least one compound II during the reaction.
  • the feeding of the at least one compound II for the reaction in step b) can be carried out stepwise or continuously, preferably continuously, over the entire course of the reaction.
  • the feed is intended to compensate for the loss of compound II in the reaction mixture caused by the distillative removal of the low-boiling alcohol R 6 -OH.
  • the feeding of the at least one compound II preferably takes place in such a way that the amount of compound II in the reaction mixture remains as constant as possible during the distillative removal of the alcohol R 6 -OH.
  • step b) If the reaction in step b), according to the first preferred embodiment described above, carried out in the presence of another solvent LM other than methanol, ethanol, n-propanol, isopropanol, n-butanol, the alcohol R 2 -OH and the compounds II is distilled off in the discharge of the low-boiling alcohol R 6 -OH, at least a portion of the solvent LM together with the alcohol R 6 -OH and a portion of the at least one compound II continuously.
  • the solvent LM here has the function of an entraining agent, which should facilitate the discharge of the low-boiling alcohol R 6 -OH.
  • the discharged at least one solvent LM together with the at least one compound II can be separated from the alcohol R 6 -OH and recycled to the reaction in step b).
  • the customary methods known to those skilled in the art for the separation of liquid-liquid mixtures are suitable.
  • the separation of the solvent LM and the at least one takes place Compound II of the alcohol R 6 -OH on the way of liquid-liquid extraction. The separation is preferably carried out continuously.
  • this is the discharged mixture containing the alcohol R 6 -OH, the organic solvent LM and at least one compound II, mixed with water and passed into a phase separator (decanter), where this by mechanical settling in two phases (an aqueous Phase, which contains the alcohol R 6 -OH, and an organic phase which contains predominantly the solvent LM and the at least one compound II), which can be removed separately.
  • the organic phase containing the solvent LM and the at least one compound II is then returned to the reaction in step b).
  • the aqueous phase containing the alcohol R 6 -OH can be subjected to a purification, preferably a distillative purification, wherein the alcohol R 6 -OH is obtained as valuable material.
  • the thus recovered alcohol R 6 -OH can be sold or used for the synthesis of compounds II.
  • the distillative removal of the low-boiling alcohol R 6 -OH preferably comprises the following steps: b1) continuous distillative removal of at least part of the Solvent LM together with the alcohol R 6 -OH and a part of the at least one compound II via at least one column;
  • step b2) at least partially extractive separation of the solvent LM discharged in step b1) and the at least one compound II of the alcohol R 6 -OH and
  • step b3) at least partial recycling of the solvent LM separated off in step b2) and of the at least one compound II in the reaction in step b).
  • the recycling of the separated solvent LM and the at least one compound II into the reaction in step b) can be carried out in several ways.
  • the separated solvent LM and the at least one compound II can either be pumped directly back into the reaction zone of the reaction in step b) or at least partially introduced via the top of at least one column used for distillative discharge of the lower alcohol R 6 -OH.
  • the separated solvent LM and the at least one compound II can be introduced separately from or combined with the liquid stream containing the lower alcohol and the at least one stabilizer.
  • the separated solvent LM and the at least one compound are preferred.
  • tion II separated from the liquid stream containing the lower alcohol and the at least one stabilizer initiated.
  • the separated solvent LM is at least partially passed over the top of at least one used for distillative removal of the lower alcohol R 6 -OH, at least one column in the reaction zone of the reaction in step b), which is during the distillative discharge in step b) of the process according to the invention hourly at the top of the column introduced amount of liquid stream preferably 0.1 to 10 wt .-%, particularly preferably 0.2 to 5 wt .-% and in particular 0.3 to 3 wt .-%, based to the total amount of the alcohol used in the reaction in step b) R 2 -OH.
  • step b) If the reaction in step b), according to the second preferred embodiment described above, carried out in the absence of another solvent LM other than methanol, ethanol, n-propanol, isopropanol, n-butanol, the alcohol R 2 -OH and the compounds II , the at least one compound II also entrained in the removal by distillation of the low-boiling alcohol R 6 -OH can also be at least partially separated off from the alcohol R 6 -OH, analogously to the above-described procedure for the separation of liquid-liquid mixtures become.
  • another solvent LM other than methanol, ethanol, n-propanol, isopropanol, n-butanol, the alcohol R 2 -OH and the compounds II .
  • step b In order to reduce losses of the at least one compound II by the discharge of the low-boiling alcohol R 6 -OH in step b), it is preferred that in the distillative discharge of the low-boiling alcohol R 6 -OH entrained, at least one compound II also , analogous to the procedure described above, from the alcohol R 6 -OH at least partially separate. The separation is preferably carried out continuously.
  • the separation of the at least one compound II from the alcohol R 6 -OH is preferably carried out by liquid-liquid extraction.
  • the aqueous phase obtained in the liquid-liquid extraction can contain significant amounts of compound II in addition to the alcohol R 6 -OH.
  • the aqueous phase can be subjected to a separation, preferably a distillative separation, for the recovery of the alcohol R 6 -OH and the compound II.
  • the separated from the low-boiling alcohol R 6 -OH, at least one compound II may still contain residual amounts of water (residual water), especially if their separation was carried out by the extractive route. Depending on the purpose, z. B. a return to the reaction in step b), then the separated compound II must be separated from the residual water.
  • the separation of the residual water is preferably carried out by distillation.
  • the at least one compound II separated from the low-boiling alcohol R 6 -OH can, if appropriate after removal of the residual water, be recycled back into the reaction in step b) as defined above or be retained for later reactions.
  • the separated, at least one compound II optionally after removal of the residual water, directly back into the reaction in step b), as defined above, recycled.
  • the recovered alcohol R 6 -OH can be sold or used for the synthesis of compounds II.
  • the at least one catalyst used in step b) is selected from metal alkoxides obtained by reacting at least one metal or by reacting at least one metal compound selected from metal oxides, alkylmetal oxides, metal salts such as metal hydroxides or metal alkoxides of the general formula M [0 (C 1 -C 8 -alkyl)] m , where m has the values 1, 2, 3 or 4, with at least one alcohol R 2 - OH.
  • metal alkoxides used as catalysts in step b) of the process according to the invention are also referred to below as metal alkoxide catalysts.
  • the metal of the metal compound used to prepare the at least one metal alkoxide catalyst is selected from K, Na, Ca, Mg, Ti, Zr, Mn, Fe, Co, Zn, Cd, Al, Ge, Sn and Sb.
  • Metal oxides, metal hydroxides or metal alkoxides of the general formula M [O (C 1 -C 5 -alkyl)] m are particularly preferably used for the preparation of the at least one metal alkoxide catalyst, the metal being selected in each case from K, Na, Ca, Mg, Ti, Zr and Zn.
  • Particularly preferred metallic starting materials for preparing the at least one metal alkoxide catalyst are, for example, potassium hydroxide (KOH), sodium methoxide (NaOMe), calcium oxide (CaO), magnesium oxide (MgO), zinc oxide (ZnO), titanium tetrachloride, titanium (IV).
  • titanium (IV) ethanolate titanium (IV) isopropoxide, titanium (IV) butoxide, titanium (IV) acetylacetonate, zirconium tetrachloride, Zirconium (IV) propoxide, zirconium (IV) butoxide, zirconium (IV) pentoxide, zirconium (IV) acetylacetonate, or mixtures thereof.
  • At least one metal alkoxide catalyst titanium alkoxides (Ti [0 (C 1 -C 8 -alkyl)] 4) and zirconium alkoxides
  • Suitable and preferred alcohols R 2 -OH used to prepare the at least one metal alkoxide catalyst are those as defined above.
  • the alcohol used for the preparation of at least one metal alkoxide catalyst corresponds to the alcohol R 2 -OH R 2 -OH used in the reaction in step b).
  • the alcohol R 2 -OH used for the preparation of the at least one metal alkoxide catalyst is in a 1, 1 to 50-fold molar excess, preferably in a 1, 5 to 30-fold molar excess, in particular in a 2 to 15-fold molar excess, based on the amount of metal oxide, metal hydroxide or metal alkoxide M [0 (C 1 -C 5 -alkyl)] m used.
  • the preparation of the at least one metal alkoxide catalyst is generally carried out at a temperature of 10 to 200 ° C, preferably at a temperature of 20 to 150 ° C and in particular at a temperature of 30 to 130 ° C.
  • the preparation of the at least one metal alkoxide catalyst can be carried out in the absence or in the presence of an inert gas as defined above.
  • the preparation of the at least one metal alkoxide catalyst can generally be carried out at ambient pressure or reduced or elevated pressure. Preferably, the preparation of the at least one metal alkoxide catalyst is carried out at ambient or reduced pressure.
  • the low-boiling components formed in the preparation of the at least one metal alkoxide catalyst are usually removed by distillation during and / or at the end of the preparation.
  • the low-boiling components are usually water, a C 1 -C 8 alcohol, or other organic solvents.
  • the distillative removal of the low-boiling components formed during the preparation of the at least one metal alkoxide catalyst is preferably carried out under reduced pressure.
  • the alcohol used in excess R 2 -OH is also removed by distillation after completion of the reaction.
  • the preparation of the at least one metal alkoxide catalyst is preferably carried out in situ.
  • the term "in situ" means that the preparation of the catalyst occurs immediately prior to the reaction in step b) and the metal alkoxide catalyst obtained directly, i. H. without further work-up or purification, in the reaction in step b) is used.
  • the amount of the metal alkoxide catalyst used in step b) is 0.01 to 10 mol%, preferably 0.02 to 7 mol% and in particular 0.05 to 5 mol%, based on the total amount of the compound (II) in the reaction mixture.
  • the R 6 -OH depleted reaction mixture obtained in step b) is then subjected to distillative separation to obtain a fraction enriched in the at least one compound II, which optionally contains alcohol R 2 -OH, and one of the compounds I and at least a catalyst-enriched bottoms product.
  • fractional distillation of the product fraction is preferably carried out using distillation columns, in particular packing columns.
  • step c) the fraction obtained in step c) which has been enriched in the at least one compound II and optionally contains alcohol R 2 -OH is returned to the reaction in step b).
  • Recycling into the reaction in step b) means that the fraction enriched in the at least one compound II, which optionally contains alcohol R 2 -OH, is passed back into the reaction zone of the reaction in step b).
  • the bottom product obtained in step c) and enriched in the compounds I and the at least one catalyst, which optionally contains at least one stabilizer is subsequently subjected to a further purification.
  • the bottom product obtained in step c) and enriched in the compounds I and the at least one catalyst, which optionally contains at least one stabilizer is subjected to further distillative separation, in particular fractional distillation (fine distillation), to obtain a compound which is attached to the compound. fertilizing the general formula I enriched product fraction and a sump fraction enriched in the at least one catalyst and the at least one stabilizer.
  • distillation apparatuses For distillative separation of the enriched in the compounds I and the at least one catalyst bottom product, which optionally contains at least one stabilizer, are also the aforementioned distillation apparatuses.
  • the distillative separation of the bottoms product enriched in the compounds I and the at least one catalyst, which optionally contains at least one stabilizer, is preferably carried out in fractionated form.
  • fractions with a high content of compounds I e.g. with a content of at least
  • the product fractions enriched in the compounds of the general formula I are combined with a lower content of compounds I, for example a content of compounds I of less than 95% by weight, for example 85, 90 or 94% by weight, and as described above, purified by distillation. This procedure can also be repeated several times until the compounds I are present in the desired purity.
  • the content of compounds I in the product fraction thus obtained is usually above 95% by weight, frequently above 98% by weight or higher, for example above 99% by weight.
  • the product fraction enriched in the compounds of general formula I contains no alcohol R 2 -OH and no catalyst used in the reaction in step b).
  • the sump fraction enriched in the at least one catalyst and the at least one stabilizer can then be stored for a longer time or used further directly for a further reaction in step b).
  • the reaction zone may consist of a reactor or of an arrangement of several reactors. Several reactors are preferably connected in series.
  • the process according to the invention can be carried out batchwise or continuously.
  • At least one of steps b), c) or the subsequent purification (fine distillation) is carried out continuously.
  • the reactors used in the process according to the invention may be any reactors which are suitable for carrying out chemical reactions in the liquid phase.
  • Suitable reactors are non-backmixed reactors, such as tubular reactors or built-in residence time vessels, but preferably backmixed reactors, such as stirred tanks, loop reactors, jet loop reactors or jet nozzle reactors. However, combinations of successive backmixed reactors and non-backmixed reactors may also be used.
  • several reactors can be combined in a multi-stage apparatus. Such reactors are, for example, loop reactors with built-in sieve trays, cascaded vessels, tube reactors with intermediate feed or stirred columns.
  • stirred tank reactors are used.
  • the stirred tank reactors are usually made of metallic materials, with stainless steel being preferred.
  • the reaction mixture is preferably mixed intensively with the aid of a stirrer or a circulation pump.
  • step b) of the process according to the invention is carried out in a single stirred tank.
  • step b) of the process according to the invention is carried out in at least two stirred tanks, which are connected to one another in the form of a cascade.
  • the individual reactors are passed through the reaction mixture in succession, wherein the outlet of the first reactor to the second reactor, the outlet of the second reactor to the third reactor, etc. is supplied.
  • the cascade can z. B. 2 to 10 reactors, with 2, 3, 4 or 5 reactors are preferred.
  • all reactors of the cascade can be operated at the same temperature. In general, however, it is preferable to steadily increase the temperature from the first to the last reactor of a cascade, wherein a reactor is operated at the same or higher temperature than the upstream reactor in the flow direction of the reaction mixture. Conveniently, all reactors can be operated at substantially the same pressure.
  • streams of the educts and optionally of the organic solvent (LM) into the reactor or, if a reactor cascade is used are preferably introduced into the first reactor of the cascade which contains the catalyst and optionally the at least one stabilizer (polymerization inhibitor). contains.
  • the residence time in the reactor or the individual reactors is determined by the volume of the reactors and the flow rate of the reactants.
  • a stream of the lower alcohol R 6 -OH and the at least one compound II is continuously discharged.
  • a vapor is withdrawn from the reactor or the individual reactors containing the lower alcohol R 6 -OH and a part of at least one compound II.
  • the vapors drawn off for discharging the lower alcohol R 6 -OH from the respective reactors of a cascade can be combined and condensed together.
  • the depleted R 6 -OH reaction mixture is transferred to a distillation apparatus in which the excess of the at least one compound II and the optionally still present alcohol R 2 -OH is removed by distillation ( Step c)).
  • the distillation in step c) of the process according to the invention is preferably carried out at reduced pressure.
  • a vapor is withdrawn which contains the at least one compound II and optionally the remaining alcohol R 2 -OH.
  • the at least one compound II and optionally the alcohol R 2 -OH in the reactor or the reactor cascade of the reaction in step b) is returned.
  • step b it is preferable not to pass the at least one compound II and the optionally attributable alcohol R 2 -OH back into the last reactor of the cascade of the reaction in step b).
  • the at least one compound II to be recycled and the optional alcohol R 2 -OH to be recycled are passed exclusively or predominantly into the first reactor of the cascade.
  • step c) the bottom product enriched in the compounds I, the at least one catalyst and optionally the at least one stabilizer is transferred again into a distillation apparatus for further purification (purification step).
  • the purification is preferably carried out by means of fractional distillation at reduced pressure, with fractions having different contents of compounds I being obtained.
  • Fractions having a low content of compounds I are recycled back to the reactor or reactor cascade of the reaction in step b) and / or to the distillation apparatus in step c).
  • Fractions having the desired content of compounds I for example having a content of compounds I of at least 95% by weight, as defined above, are discharged from the process.
  • the catalyst remaining in the bottom after the purification step and optionally remaining at least one stabilizer is then recycled back into the reactor in step b) or into the first reactor of the cascade of step b) or into a new batch process in a batchwise process Implementation to be used.
  • MMA stands for methyl methacrylate
  • EA stands for ethyl acrylate
  • AMA stands for allyl methacrylate
  • DMAE dimethylaminoethanol
  • DMAEMA stands for dimethylaminoethyl methacrylate
  • TBAEMA is 2- (N-tert-butylamino) ethyl methacrylate
  • MeHQ stands for methylhydroquinone
  • PTZ stands for phenothiazine
  • MeOH is methanol
  • GC gas chromatography
  • GC area% is the percentage of the area of a substance peak in relation to the total area of the peaks in a gas chromatogram (GC area percent);
  • Ti (OiPr) 4 is titanium (IV) isopropanolate
  • Ti (OnBu) 4 is titanium (IV) n-butoxide
  • Tyzor (Tyzor TPT 20 B) stands for a mixture of tetraisopropyl titanate and
  • Tetra (n-butyl) titanate 80:20, 1 mol% based on the amount of allyl alcohol used).
  • the stabilizer solution is a solution of a suitable polymerization inhibitor in an organic compound, which may or may not be identical to one of the components in the stirred tank.
  • a liquid distributor for adjusting the reflux ratio was attached on the separation column.
  • Example 11.1 Preparation of allyl methacrylate with addition of MMA to the reaction solution and a solution of PTZ in MeOH overhead
  • the reactor was charged with 2635 mL (2477 g, 24.74 mol) MMA, 752 mL (639 g, 11 mol) allyl alcohol, 1.75 g MeHQ, and 0.7 g PTZ.
  • the catalyst represented in the preceding step was added tetraallyloxy titanium (IV) (62.8 g, 221 mmol, 2 mol% based on allyl alcohol) at a temperature of 96 ° C and atmospheric pressure in the reactor.
  • the reaction mixture was heated to boiling while the temperature in the kettle was between 93 and 103 ° C.
  • the distillation column was operated at the beginning of the reaction for 15 min with full reflux.
  • MMA and allyl alcohol (2.6% of the amount used) were removed in vacuo; wherein the recovered amount of allyl alcohol can be reused in the next experiment.
  • AMA was subsequently purified by distillation. There were obtained 605 g (4.76 mol, 44% yield) AMA with a purity of 99.3% (GC). [Another 588 g, 4.66 mol, 42% yield with a purity of 95.9%. Another 168 g, 1, 33 mol, 12% yield with lower purity. Total 98% yield]. Colorless product.
  • Example II.3 Distillation of an AMA reaction mixture
  • Comparative Example 11.1 Preparation of allyl methacrylate with addition of an MMA PTZ solution overhead The reaction was carried out in the manner described in Example 11.1. However, a solution of PTZ in MMA was added at the top of the column. Within the first three hours of the reaction time, 3% of the amount of allyl alcohol used was lost via the distillates removed.
  • Comparative Example II.2 Preparation of Allyl Methacrylate Using Tyzor (Tyzor TPT 20 B) as Catalyst The reaction was carried out as in Example 11.1 except that a mixture of tetraisopropyl titanate and tetra (n-butyl) titanate (80:20, 1 mol% based on the amount of allyl alcohol used). 1276 g of AMA were obtained (10.1 mol, 92% of theory). Of these, only 206 g (1.63 mol, 15% of theory) had a purity of> 99%. Colorless product.
  • Example II.4 Preparation of dimethylaminoethyl methacrylate (DMAEMA) with addition of MMA to the reaction solution and a solution of PTZ in MeOH overhead
  • Example II.5 Preparation of isoamyl methacrylate with addition of MMA to the reaction solution and a solution of PTZ in MeOH overhead
  • Tetraisoamyl titanate was prepared as described in Example 11.5 and to a mixture of ethyl acrylate (2253 g, 22.5 mol), isoamyl alcohol (882 g, 10 mol), and methylhydroquinone (3.20 g) and phenothiazine (1.30 g ).
  • ethyl acrylate 2253 g, 22.5 mol
  • isoamyl alcohol 882 g, 10 mol
  • methylhydroquinone 3.20 g
  • phenothiazine (1.30 g ).
  • azeotropic mixture of ethanol and ethyl acrylate was withdrawn.
  • the losses by distillation were compensated by adding fresh ethyl acrylate (650 g, 6.49 mol in 6 h).
  • Example II.7 Preparation of isobutyl methacrylate with the addition of MMA to the reaction solution and a solution of PTZ in MeOH overhead
  • Example 8 Preparation of dimethylaminoethyl methacrylate (DMAEMA) using a solvent and dibutyltin oxide as catalyst
  • the reactor was treated with dimethylaminoethanol (802 g, 9 mol), MMA (1694 g, 16.9 mol), heptane (253 g), dibutyltin oxide (17.9 g), MEHQ (2.5 g) and PTZ (1, 25 g) and the mixture is heated to boiling at atmospheric pressure.
  • the reflux ratio was changed so that the temperature at the top of the column did not exceed 64 ° C.
  • the azeotropic mixture of methanol and heptane separated off at the top of the column was mixed continuously with stirring in a mixing vessel with the same amount of water (50 to 250 ml / h) and then transferred to a decanter. The methanol-containing water phase was discarded while the organic phase was pumped back into the reactor.
  • Example 9 Preparation of allyl methacrylate using a solvent and dibutyltin oxide as a catalyst
  • the reactor was treated with allyl alcohol (799 g, 12.1 mol), MMA (1630 g, 16.3 mol), heptane (265 g), dibutyltin oxide (34.9 g), MEHQ (5 g) and PTZ (18 g ) and the mixture is heated to boiling at atmospheric pressure.
  • the reflux ratio (R: D) was changed in such a way (6: 4 - 1:10) that the temperature at the top of the column did not exceed 58 ° C.
  • the azeotropic mixture of methanol and heptane separated off at the top of the column was mixed continuously with stirring in a mixing vessel with the same amount of water (50 to 250 ml / h) and then transferred to a decanter.
  • MMA was metered in continuously during the reaction (20 mL / h).
  • a 9% by weight solution of MEHQ in methanol was metered into the top of the column (30 ml / h).
  • 80% conversion based on the amount of allyl alcohol used was achieved. Allyl alcohol was not carried to the distillates.
  • the crude product mixture thus obtained was vacuum-distilled to give allyl alcohol methacrylate (AMA) in a purity of 98% and a yield of 61 to 80%.
  • AMA allyl alcohol methacrylate
  • Example 10 Preparation of 2- (N-tert-butylamino) ethyl methacrylate (TBAEMA) without addition of MMA during the reaction, addition of a stabilizer solution to the top of the column, addition of the extracted solvent to the top of the column, partial conversion and recycling with reuse of catalyst and stabilizer.
  • TAAEMA 2- (N-tert-butylamino) ethyl methacrylate
  • the resulting azeotropic mixture of methanol and heptane and traces of MMA were mixed with the same amount of water, transferred to a phase separation vessel, the aqueous, methanol-containing, phase removed from the system and the organic phase returned to the top of the distillation column.
  • An 8% by weight solution of hydroquinone monomethyl ether in methanol (about 100 ml in 18 h) was metered onto the top of the distillation column. The temperature of the reaction mixture increased during the reaction from 100 ° C to 1 10 ° C.
  • Fraction 1 Fraction 1 was stored for use in later reactions and the entire unit was cleaned by boiling out with methanol, removing the distillation residue from the system and discarding it.
  • the fractions 2) obtained in the three reactions described above were combined and subjected to distillative purification (fine distillation) to give the following fractions: A) traces of heptane, MMA, alcohol, traces of TBAEMA (recycling in subsequent reactions), B) traces of MMA , Alcohol and TBAEMA (storage for recycling in further fine distillations) and C) pure TBAEMA with a purity> 99%.
  • the yield of pure TBAEMA is by this method usually -75% (4772 g, 25.76 mol) of a colorless product ( ⁇ 20 Hazen, APHA).
  • Example 1 Preparation of 2- (N-tert-butylamino) ethyl methacrylate (TBAEMA) without addition of MMA during the reaction, metered addition of a stabilizer solution to the top of the column, metered addition of the solvent to the top of the column, full conversion and recycling under Discard catalyst and stabilizer, with residue work-up.
  • TAAEMA 2- (N-tert-butylamino) ethyl methacrylate
  • the distillation residue remains in the reaction vessel and the distillation residues obtained from the two previous reactions are added and the mixture is purified by distillation again to give a further fraction of pure TBAEMA (> 99 GC area%, ⁇ 20 Hazen, APHA) , The remaining residue may optionally be used in whole or in part in further reactions.

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  • Organic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

La présente invention concerne un procédé de production d'esters d'acide (méth)acrylique à bas point d'ébullition en présence d'au moins un catalyseur métallique, à oxyde métallique, à oxyde organométallique ou à alcoxyde métallique.
PCT/EP2016/069674 2015-08-21 2016-08-19 Procédé de production d'esters d'acide (méth)acrylique à bas point d'ébullition WO2017032699A1 (fr)

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CN108569972A (zh) * 2018-06-05 2018-09-25 李守莉 一种甲基丙烯酸叔丁基氨基乙酯的制备方法

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JPH01258642A (ja) 1988-04-06 1989-10-16 Mitsubishi Gas Chem Co Inc （メタ）アクリル酸エステルの製造法
EP0765856A1 (fr) 1994-06-27 1997-04-02 Lutz Riemenschneider Compositions d'acide acrylique stabilisées
JPH11222461A (ja) 1998-02-02 1999-08-17 Mitsubishi Rayon Co Ltd （メタ）アクリル酸エステルの製造方法
DE19856565A1 (de) 1998-12-08 2000-06-15 Basf Ag Verfahren zur Stabilisierung von wenigstens eine ethylenisch ungesättigte Bindung aufweisenden chemischen Verbindungen gegen unerwünschte radikalische Polymerisation
WO2003055837A1 (fr) * 2002-01-04 2003-07-10 Röhm GmbH & Co. KG Procede de fabrication continue d'alkyl(meth)acrylates
DE10258329A1 (de) 2002-01-30 2003-07-31 Basf Ag Sulfonamide als Stabilisatoren polymerisationsfähiger Verbindungen
DE10249507A1 (de) 2002-10-23 2004-05-06 Basf Ag Verfahren zur Bestimmung der Menge an aus (Meth)acrylsäure und/oder (Meth)acrylsäureestern abgeschiedenem Polymer
EP1399408B1 (fr) 2001-06-08 2006-03-22 Basf Aktiengesellschaft Procede de production d'esters d'acide (meth)acrylique
WO2009003744A1 (fr) * 2007-07-05 2009-01-08 Evonik Röhm Gmbh Procédé de production de (méth)acrylates
EP2807141B1 (fr) 2012-01-23 2015-10-21 Arkema France Procede de production d'acrylate de 2-octyle par transesterification

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01258642A (ja) 1988-04-06 1989-10-16 Mitsubishi Gas Chem Co Inc （メタ）アクリル酸エステルの製造法
EP0765856A1 (fr) 1994-06-27 1997-04-02 Lutz Riemenschneider Compositions d'acide acrylique stabilisées
JPH11222461A (ja) 1998-02-02 1999-08-17 Mitsubishi Rayon Co Ltd （メタ）アクリル酸エステルの製造方法
DE19856565A1 (de) 1998-12-08 2000-06-15 Basf Ag Verfahren zur Stabilisierung von wenigstens eine ethylenisch ungesättigte Bindung aufweisenden chemischen Verbindungen gegen unerwünschte radikalische Polymerisation
EP1399408B1 (fr) 2001-06-08 2006-03-22 Basf Aktiengesellschaft Procede de production d'esters d'acide (meth)acrylique
WO2003055837A1 (fr) * 2002-01-04 2003-07-10 Röhm GmbH & Co. KG Procede de fabrication continue d'alkyl(meth)acrylates
DE10258329A1 (de) 2002-01-30 2003-07-31 Basf Ag Sulfonamide als Stabilisatoren polymerisationsfähiger Verbindungen
DE10249507A1 (de) 2002-10-23 2004-05-06 Basf Ag Verfahren zur Bestimmung der Menge an aus (Meth)acrylsäure und/oder (Meth)acrylsäureestern abgeschiedenem Polymer
WO2009003744A1 (fr) * 2007-07-05 2009-01-08 Evonik Röhm Gmbh Procédé de production de (méth)acrylates
EP2807141B1 (fr) 2012-01-23 2015-10-21 Arkema France Procede de production d'acrylate de 2-octyle par transesterification

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108569972A (zh) * 2018-06-05 2018-09-25 李守莉 一种甲基丙烯酸叔丁基氨基乙酯的制备方法

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