Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D207/00—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom
  • C07D207/02—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom
  • C07D207/04—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members
  • C07D207/10—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
  • C07D207/12—Oxygen or sulfur atoms

Definitions

• the present invention relates to a process for the catalytic preparation of (meth) acrylic acid esters of N-hydroxyalkylated lactams and their use.
• (meth) acrylic acid is understood to mean acrylic acid and / or methacrylic acid, acrylic acid esters and / or methacrylates being esters of (meth) acrylates.
• (meth) acrylic esters are also referred to as (meth) acrylates.
• the preparation of (meth) acrylic esters is usually carried out by catalytic esterification of (meth) acrylic acid or transesterification of other (meth) acrylic esters with alcohols.
• strong acids or bases are often used, so that acid- or base-sensitive (meth) acrylic acid esters can not be selectively produced by an esterification or transesterification in this way as a rule.
• WO 03/006568 A1 describes the acidic esterification of acrylic acid with hydroxyethylpyrrolidone with p-toluenesulfonic acid as catalyst. However, the yield is only 71%.
• German patent application DE 10 2005 052 931.3 discloses a catalytic process for the preparation of (meth) acrylic acid esters of N-hydroxyalkylated lactams, in which the esterification or transesterification is carried out in the presence of a heterogeneous inorganic salt.
• DE 1 595 233 discloses the transesterification of N-hydroxyalkyl-lactams with (meth) acrylic esters in the presence of titanium tetraalcoholates and alkali metal alcohols.
• a disadvantage of this method is that the catalyst must be removed from the reaction mixture by an additional purification step, usually a washing step.
• GB 930 668 also describes the esterification of N-hydroxyalkylated lactams with (meth) acrylic acid and the transesterification with (meth) acrylic esters. Accordingly, both acids such as benzenesulfonic acid and titanium tetraalcoholates such as titanium tetraisopropylate or titanium tetraisobutylate can be used as catalysts for the esterification.
• acids such as benzenesulfonic acid and titanium tetraalcoholates such as titanium tetraisopropylate or titanium tetraisobutylate
• alkaline catalysts such as alkali metal or ammonium alcoholates.
• Lactam (meth) acrylic acid esters by reaction of N-hydroxyalkyl lactams with (meth) acrylic acid chloride described.
• (meth) acryloyl chloride leads to salt formation and because of its high reactivity to unselective reactions, such as Michael additions.
• a disadvantage of the process described in the prior art is that the alkali metal alcoholates used as catalysts are used as alcoholic solutions. Furthermore, the catalyst addition is staggered in GB 930 668 (Example 1) and in DE 1 595 233 (Example A), i. The catalyst solution is added continuously in the course of the reaction. This is particularly disadvantageous for large-scale processes.
• the object of the present invention was to provide an alternative process with which (meth) acrylic acid esters of N-hydroxyalkylated lactams can be prepared in high conversions and high purities from simple starting materials.
• the synthesis should proceed under mild conditions, resulting in products with a low color number and high purity.
• the implementation of the method should be industrially feasible.
• R 1 is C 1 -C 6 -alkylene or by one or more oxygen and / or sulfur atoms and / or one or more substituted or unsubstituted imino groups and / or by one or more cycloalkyl-, - (CO) -, -O (CO) O-, - (NH) (CO) O-, -O (CO) (NH) -, -O (CO) - or - (CO) O- groups interrupted C2-C2o-alkylene, wherein said radicals each by Aryl, alkyl, aryloxy, alkyloxy, heteroatoms and / or heterocycles may be substituted
• R 1 may not have any atom other than a carbon atom directly adjacent to the lactam carbonyl group
• R 2 is C 1 -C 20 -alkylene, C 5 -C 12 -cycloalkyl, C 6 -C 12 -arylene or by one or more oxygen and / or sulfur atoms and / or one or more substituted or unsubstituted imino groups and / or by one or more Cycloalkyl-, - (CO) -, -O (CO) O-, - (NH) (CO) O-, -O (CO) (NH) -, -O (CO) - or - (CO) O- groups interrupted C2-C2o-alkylene, wherein each of said radicals may be substituted by aryl, alkyl, aryloxy, alkyloxy, heteroatoms and / or heterocycles, or
• the process according to the invention uses the metal salt of C 1 -C 10 -alkanolates (A) used as catalyst in the absence of solvents, ie as pure substance.
• the metal salt of C 1 -C 10 -alkanolates (A) is preferably added as a solid.
• no further component is added to the reaction system, which has to be removed with difficulty.
• This is particularly advantageous in comparison to the prior art, since the methanolates used in the prior art are used in methanolic solutions. However, since methanol is liberated during the esterification, the reaction equilibrium is shifted to the side of the starting materials by additionally introduced methanol.
• the metal salt of a C1-C10alkanolate used as a catalyst is added completely at the beginning of the reaction, i. not continuously during the course of the reaction. This is particularly advantageous for industrially applicable processes, since a staggered or continuous addition of the catalyst is often not possible due to technical problems.
• C 1 -C 20 -alkylene optionally substituted by aryl, alkyl, aryloxy, alkyloxy, heteroatoms and / or heterocycles, for example methylene, 1, 2-ethylene, 1, 2-propylene, 1, 3-propylene, 1, 4-butylene, 1, 6-hexylene, 2-methyl-1, 3-propylene, 2-ethyl-1,3-propylene, 2,2-dimethyl-1,3-propylene, 2,2-dimethyl-1,4-butylene,
• C 5 -C 12 -cycloalkylene optionally substituted by aryl, alkyl, aryloxy, alkyloxy, heteroatoms and / or heterocycles, for example, cyclopropylene, cyclopentylene, cyclohexylene, cyclooctylene, cyclododecylene,
• R 1 are 1, 2-ethylene, 1, 2-propylene, 1, 1-dimethyl-1, 2-ethylene, 1-hydroxymethyl-1, 2-ethylene, 2-hydroxy-1, 3-propylene, 1 , 3-propylene, 1, 4-butylene, 1, 5-pentylene, 2-methyl-1,3-propylene, 2-ethyl-1,3-propylene, 2, 2-dimethyl-1,3-propylene and 2 , 2-Dimethyl-1, 4-butylene, preferred are 1, 4-butylene, 1, 5-pentylene and 1, 3-propylene, more preferably 1, 3-propylene.
• R 2 examples are 1, 2-ethylene, 1, 2-propylene, 1, 1-dimethyl-1, 2-ethylene, 1-hydroxy-methyl-1, 2-ethylene, 2-hydroxy-1, 3-propylene , 1, 3-propylene, 1, 4-butylene, 1, 6-hexylene, 2-methyl-1, 3-propylene, 2-ethyl-1, 3-propylene, 2, 2-dimethyl-1, 3-propylene and 2,2-dimethyl-1,4-butylene, 1,2-cyclopentylene, 1,3-cyclopentylene, 1,2-cyclohexylene, 1,3-cyclohexylene, ortho-phenylene, 3-oxa-1,5-pentylene , 3,6-dioxa-1, 8-octylene and 3,6,8-trioxa-1, 8,11-undecylene, preferred are 1,2-ethylene, 1,2-propylene, 1,3-propylene, especially 1, 2-ethylene and 1, 2-propylene are preferred, and very particular preference is 1, 2-ethylene.
• Preferred individuals (L) are N- (2-hydroxyethyl) pyrrolidone, N- (2-hydroxypropyl) pyrrolidone, N- (2 '- (2-hydroxyethoxy) ethyl) pyrrolidone, N- (2-hydroxyethyl) -caprolactam, N- (2-hydroxypropyl) -caprolactam and N- (2 '- (2-hydroxyethoxy) -ethyl) -caprolactam, preferred are N- (2-hydroxyethyl) -pyrrolidone and N- (2-hydroxypropyl) - pyrrolidone, particularly preferred is N- (2-hydroxyethyl) pyrrolidone.
• N-hydroxyalkylated lactams (L) are optically active, they are preferably used racemically or as a mixture of diastereomers, but it is also possible to use them as pure enantiomers or diastereomers or as enantiomer mixtures.
• (meth) acrylic acid (S) or for transesterification (meth) acrylic ester (D) of a saturated alcohol can be used, preferably saturated C 1 -C 10 -alkyl esters or C 3 -C 12 -cycloalkyl esters of (meth) acrylic acid, particularly preferably saturated C 1 -C 4 -alkyl esters.
• C4-alkyl esters of (meth) acrylic acid preferably saturated C 1 -C 10 -alkyl esters or C 3 -C 12 -cycloalkyl esters of (meth) acrylic acid, particularly preferably saturated C 1 -C 4 -alkyl esters.
• Examples of compounds (D) are (meth) acrylic acid, methyl, ethyl, n-butyl, isobutyl, tert-butyl, n-octyl and 2-ethylhexyl esters, 1,2-ethylene glycol di and mono (meth) acrylic esters, 1,4-butanediol and mono (meth) acrylic esters, 1, 6 Hexanediol and mono (meth) acrylic acid esters, trimethylolpropane tri (meth) acrylic acid esters and pentaerythritol tetra (meth) acrylic esters.
• (meth) acrylic acid methyl, ethyl, n-butyl and 2-ethylhexyl esters very particular preference to methyl, ethyl and n-butyl (meth) acrylates, in particular (meth) acrylic acid methyl and ethyl ester and especially methyl (meth) acrylate.
• Metal salts of C 1 -C 10 -alkanolates (A) which can be used according to the invention are basic compounds of metal cations and the anion of a C 1 -C 10 -cohol.
• basic compounds are understood as meaning those alkanolates which have a pKa of not more than 7.0, preferably not more than 6.0, and more preferably not more than 4.0.
• the metal cation of the metal salts of Ci-Cio-alkanolates is usually selected from the group consisting of alkali and alkaline earth metals and aluminum.
• Preferred alkali metal cations are lithium, sodium and potassium.
• Preferred alkaline earth metal cations are magnesium and calcium.
• Ci-Cio-alkanolate anions preferably Ci-C ⁇ -alkanolate anions are used. These are, for example, anions of methanol, ethanol,
• Ci-C ⁇ -alkanolate anions are methanolate, ethanolate, n- and iso-propanolate and n-, iso- and tert-butoxide, very particularly preferred
• Particularly preferred metal salts of C 1 -C 10 -alkanolates (A) are sodium methoxide
• the esterification or transesterification catalyzed by a metal salt of C 1 -C 10 -alkanolates (A) is generally carried out at from 30 to 140 ° C., preferably from 30 to 100 ° C., more preferably from 40 to 90 ° C., and very preferably from 50 up to 80 ° C.
• the reaction is carried out under a slight vacuum of, for example, 200 hPa to atmospheric pressure, preferably 200 to 600 hPa and particularly preferably 300 to 500 hPa, if the water released during the esterification or the ent in the transesterification ent - standing low-boiling alcohol, optionally as an azeotrope, to be distilled off.
• a slight vacuum of, for example, 200 hPa to atmospheric pressure, preferably 200 to 600 hPa and particularly preferably 300 to 500 hPa, if the water released during the esterification or the ent in the transesterification ent - standing low-boiling alcohol, optionally as an azeotrope, to be distilled off.
• the molar ratio between (meth) acrylic acid (S) or (meth) acrylic acid ester (D) and N-hydroxyalkylated lactam (L) is generally in the case of the esterification or transesterification catalyzed by a metal salt of C 1 -C 10 -alkanolates (A) 1-6: 1 mol / mol, preferably 1-5: 1 mol / mol and particularly preferably 1-4 mol / mol.
• the reaction time in the case of the esterification or transesterification catalyzed by a metal salt of C 1 -C 10 -alkanolates (A) is generally 45 minutes to 18 hours, preferably 2 hours to 12 hours and particularly preferably 3 to 10 hours.
• the content of metal salts of C 1 -C 10 -alkanolates (A) in the reaction medium is generally in the range of about 0.01 to 5 mol%, preferably 0.1 to 1.8, and particularly preferably 0.3 to 1.5 mol % based on the sum of the N-hydroxyalkylated lactams (L) used.
• the products having a color number below 500 APHA, preferably below 200 and particularly preferably below 150 are generally obtained.
• the reaction can take place in organic solvents or mixtures thereof or without the addition of solvents.
• the batches are largely water-free, i. H.
• the water content is preferably less than 10, more preferably less than 5, more preferably less than 1 and most preferably less than 0.5 wt.%.
• the water content is between 100 and 5000 ppm, preferably between 500 and 1000 ppm.
• the approaches are largely free of primary and secondary alcohols, i. below 10, preferably below 5, more preferably below 1 and most preferably below 0.5 wt .-% alcohol content.
• Suitable organic solvents are known for this purpose, for example tertiary monools, such as Cs-C ⁇ alcohols, preferably tert-butanol, tert-amyl alcohol, pyridine, poly-Ci-C4-alkylenglykoldi-Ci-C4-alkyl ether, preferably polyethylene glycol C 1 -C 4 -alkyl ethers, for example 1, 2-dimethoxyethane, diethylene glycol dimethyl ether, polyethylene glycol dimethyl ether 500, C 1 -C 4 -alkylene carbonates, in particular propylene carbonate, C 6 -C 6 -alkyl acetic acid esters, in particular tert-butyl acetic acid esters, THF, toluene, 1,3-dioxolane, acetone, isobutyl methyl ketone, ethyl methyl ketone, 1,4-dioxane, tert-but
• the reaction is carried out in the (meth) acrylic acid ester (D) used as starting material.
• the product (F) is obtained after completion of the reaction as about 10 to 80% strength by weight solution in the (meth) acrylic acid ester (D) used as starting material, in particular as 20 to 50 wt .-% solution.
• the educts are either dissolved, suspended as solids or in emulsion in the reaction medium before.
• the metal salt of C 1 -C 10 -alkanolates (A) is used in the absence of solvents and preferably as a solid.
• the reaction can be carried out continuously, for example in a tubular reactor or in a stirred reactor cascade, or discontinuously. According to the invention, however, the metal salt of Ci-Cio-alkanolates (A) is added completely at the beginning of the reaction, i. not continuously during the course of the reaction.
• the reaction can be carried out in all reactors suitable for such a reaction. Such reactors are known to the person skilled in the art.
• the reaction preferably takes place in a stirred tank reactor or a fixed bed reactor.
• any method can be used. Special stirring devices are not required.
• the mixing can be carried out, for example, by feeding in a gas, preferably an oxygen-containing gas (see below).
• the reaction medium can be monophase or polyphase and the reactants are dissolved, suspended or emulsified therein.
• the temperature is adjusted to the desired value during the reaction and, if desired, can be increased or decreased during the course of the reaction.
• the removal of water in the case of esterification or alcohols which are released in a transesterification of the (meth) acrylic acid esters (D) is carried out continuously or stepwise in a conventional manner, e.g. by vacuum, azeotropic removal, stripping, absorption, pervaporation and diffusion via membranes or extraction.
• the stripping can be carried out, for example, by passing an oxygen-containing gas, preferably an air or air-nitrogen mixture, through the reaction mixture, optionally in addition to a distillation.
• an oxygen-containing gas preferably an air or air-nitrogen mixture
• molecular sieves or zeolites pore size, for example, in the range of about 3-10 angstroms
• separation by distillation or by means of suitable semipermeable membranes are preferred.
• reaction mixture obtained from the esterification or transesterification can be used without further purification or, if necessary, purified in a further step.
• a separation from the catalyst is usually carried out by filtration, electro filtration, absorption, centrifugation or decantation or by distillation or rectification.
• the separated catalyst can then be used for further reactions.
• the separation from the organic solvent is usually carried out by distillation, rectification or solid reaction products by filtration.
• the optionally purified reaction mixture is preferably subjected to a distillation in which the (meth) acrylic acid ester (F) of the N-hydroxyalkylated lactams is separated by distillation from unreacted (meth) acrylic acid (S) or unreacted (meth) acrylic ester (D) and optionally formed by-products ,
• the distillation units are usually rectification columns of conventional design with circulation evaporator and condenser.
• the feed is preferably in the bottom region, the bottom temperature is here for example 130- 160 0 C, preferably 150- 160 0 C, the head temperature preferably 140-145 0 C and the top pressure 3-20, preferably 3 to 5 mbar.
• the skilled person can also determine other temperature and pressure ranges in which the respective (meth) acrylic acid esters (F) of the N-hydroxyalkylated lactams are purified by distillation can. What is essential here is a separation of the desired product of reactants and by-products under conditions in which the desired product is exposed to as possible no degradation reaction.
• the distillation unit usually has from 5 to 50 theoretical plates.
• the distillation units are of a known type and have the usual installations. In principle, all standard installations are suitable as column internals, for example trays, packings and / or fillings. Of the bottoms, bubble-cap trays, sieve trays, valve trays, Thormann trays and / or dual-flow trays are preferred; of the trays are those with rings, coils, calipers, Raschig, Intos or Pall rings, Barrel or Intalox saddles, Top-Pak etc. or braids preferred.
• the desired product is distilled batchwise, initially low-boiling components are removed from the reaction mixture, usually solvent or unreacted (meth) acrylic acid (S) or (meth) acrylic acid ester (D). After separation of these low boilers, the distillation temperature is increased and / or reduced the vacuum and the desired product distilled off.
• initially low-boiling components are removed from the reaction mixture, usually solvent or unreacted (meth) acrylic acid (S) or (meth) acrylic acid ester (D).
• the distillation temperature is increased and / or reduced the vacuum and the desired product distilled off.
• the remaining distillation residue is usually discarded.
• the reaction conditions in the esterification or transesterification according to the invention are mild. Due to the low temperatures and other mild conditions, the formation of by-products in the reaction is avoided, which may otherwise be due to, for example, strongly acidic or basic catalysts or unwanted radical polymerization of the (meth) acrylic compound (B) used, which would otherwise can be prevented by adding stabilizers.
• additional stabilizer can be added to the reaction mixture beyond the storage stabilizer which is present in the (meth) acrylic compound (B), for example hydroquinone monomethyl ether, phenothiazine, phenols, such as 2-tert-butyl-4-methylphenol, 6-tert Butyl-2,4-dimethyl-phenol or N-oxyls, such as 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-oxo-2,2,6,6-tetramethyl piperidine-N-oxyl or Uvinul ® 4040P from BASF Aktiengesellschaft or amines such as BPD Kerobit ® from BASF Aktiengesellschaft (N, N'-di-sec-butyl-p-phenylenediamine), for example in quantities of 50 to 2000 ppm.
• hydroquinone monomethyl ether for example hydroquinone monomethyl ether, phenothiazine, phenols, such as 2-tert-butyl-4-methylphenol, 6-tert Buty
• the esterification or transesterification is advantageously carried out in the presence of an oxygen-containing gas, preferably air or air-nitrogen mixtures.
• an oxygen-containing gas preferably air or air-nitrogen mixtures.
• the metal salts of C 1 -C 10 -alkanolates used according to the invention show only a slight tendency to side reactions.
• the metal salts are mostly sufficiently basic to catalyze esterification or transesterification but not too basic to catalyze side reactions such as Michael reactions to a greater extent.
• reaction under the reaction conditions according to the invention is very selective, it is generally less than 10%, preferably less than 5% by-products (based on the conversion).
• the (meth) acrylic esters (F) of N-hydroxyalkylated lactams prepared according to the invention are used, for example, as monomers or comonomers in the preparation of dispersions, for example acrylic dispersions, as reactive diluents, for example in radiation-curable coating compositions or in paints, preferably in exterior paints, and in dispersions for Paper application.
• the transesterification took place in a 750 ml miniplane reactor with Oldershaw column and liquid distributor.
• the reflux ratio was 25: 1 (reflux: drain), the stirring speed (armature stirrer) 400 rpm and the air inlet 1, 5 L / h.
• reaction product was then analyzed by GC, containing 63.2% of product (N- (2- (methacryloyl) -ethyl) -pyrrolidone), 0.4% N- (2-hydroxyethyl) -pyrrolidone and 34.5% methyl methacrylate.
• product N- (2- (methacryloyl) -ethyl) -pyrrolidone
• N- (2-hydroxyethyl) -pyrrolidone 0.4%
• N- (2-hydroxyethyl) -pyrrolidone 34.5% methyl methacrylate.
• the sum of the other by-products was 1, 9%.
• Example 1 of GB 930 668 was followed, but a mixture of phenothiazine and hydroquinone monomethyl ether was used instead of the commercially no longer available p-hydroxydiphenylamine as a stabilizer.
• the catalyst solution was prepared by diluting 18 g of a 25% strength by weight methanolic solution of sodium methoxide with methanol to a volume of 50 ml.
• a transesterification apparatus (1 L three-necked flask with mechanical stirrer and distillation bridge) was charged with 285 g (2 mol) of N- (2-hydroxyethyl) pyrrolidone, 400 g (4 mol) of methyl methacrylate, 2 g of phenothiazine and 2 g of hydroquinone monomethyl ether and heated to 90.degree 0 C heated. Subsequently, first 6 g of the catalyst solution were added and then every 5 minutes, in each case 2 g. A short time after the first catalyst addition, the mixture began to boil. The mixture was heated until the steam temperature rose to> 70 0 C, this was the case after 70 minutes. Distillate was continuously removed during the reaction.
• reaction mixture was cooled.
• reaction product was then analyzed by GC, containing 18.2% product (N- (2- (methacryloyl) ethyl) pyrrolidone), 19.7% N- (2-hydroxyethyl) pyrrolidone and 41.2% methyl methacrylate. The sum of the other by-products was 20.9%.

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• Other In-Based Heterocyclic Compounds (AREA)
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• 2008
  • 2008-02-11 KR KR1020097019201A patent/KR101440653B1/ko active IP Right Grant
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  • 2008-02-11 WO PCT/EP2008/051584 patent/WO2008098885A1/de active Application Filing
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