JPS59106436A - Esterification for ester - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to transesterification of carboxylic acid esters and carbonic acid esters.
) regarding the method.

For example methyl acetate, methyl propionate and i'i'
Esters such as ethyl esters are useful eutectics in industry and also have wide use as industrial solvents.

The method of producing another ester by reacting an ester with an alcohol is called transesterification and is well known. Transesterification catalysts described in the prior art include alkali metal alkoxides, titanates, and metal carboxylates. Transesterification methods involve reacting cyclic carbonates with alcohols to form dialkyl carbonates. , is described in the prior art in British Patent No. 1,489,736, which uses organic Lewis bases as insect media.
sbase) is used. As examples of organic Lewis bases, tertiary aliphatic amines such as tributylamine and polymers containing tertiary aliphatic amine groups are mentioned. However, nothing is described regarding the use of cyclic amicines or guanisines, which form the subject of the present invention.

Furthermore, the use of guanidine as a catalyst is disclosed in British Patent Specification No. 955 for the transesterification of terephthalate esters with glycols to form macromolecular polymethylene terephthalates. ．． Previously described in No. 232.

(1) The presence of an epoxide promotes amicine-catalyzed transesterification, and not only amidines but also all Lewis bases containing Group V elements can promote it as well, and (11) guanidine It has now been found that cyclic amicines, including cyclic amicines, are even more effective catalysts than the acyclic guanidines described in the aforementioned British Patent No. 262.

The present invention relates to a method of converting a carboxylic acid ester or a carbonic acid ester and an alcohol under transesterification conditions in the presence of either (1) a Lewis base containing a Group V element and an epoxide or (!'dA-like amicin) as a catalyst. This is a method for transesterification of carboxylic acid esters or charcoal esters, which is characterized by a reaction.

The carboxylic ester starting material may be an alkyl, aryl, aralkyl or alkaryl ester of a saturated or unsaturated aliphatic or aromatic carboxylic acid. The carbonate ester starting material may be an alkyl, aralkyl (or corresponding divalent group such as, for example, an alkylene group) ester of carbonic acid.

In the case of C to C, alkyl ester or carbonic acid, Ha02
~C12 alkylene esters are advantageous.

The alcohol is conveniently a 01-C 2-alkanol. Alcohol is a primary alcohol.

Glycols and polyols such as ethylene glycol can be used.

Unless specifically required otherwise, the terms alkyl and aryl herein are meant to include aralkyl (eg, benzyl) and alkaryl groups, respectively.

Group V refers to the group of elements consisting of nitrogen, phosphorus, arsenic, antimony and bismuth.

Lewis bases are trivalent phosphorus or trivalent nitrogen, for example of the formula R3X, where X is hydrogen or phosphorus and B is hydrogen or a monovalent organic group having up to 12 carbon atoms. Conveniently, organic compounds containing . The R groups may be the same or different.

In the case of nitrogen, the Lewis base may be, for example, a primary, secondary or tertiary aliphatic or aromatic amine.

(7) # Is i g may be amidine. When the Lewis base is a cyclic amicin, the epoxide will enhance the action of the amicin, but the use of the epoxide is not essential.

The word amidine means a group of.

The free valence on the nitrogen atom
Conveniently the free valence on the carbon atom is bonded to another carbon or nitrogen atom. An example of the structure described in the author would constitute a guanidine group.

The terms amicin and guanidine are therefore not mutually exclusive, but have a co-terminus or species relationship.

Provided that an epoxide is present, the compound containing an amidine group may be cyclic or acyclic. What is cyclic amidine?
At least one of the nitrogen atoms in the above structure is meant to be in a ring, which may be the same or different rings. Conveniently, all three atoms of the above structure are present in one or more rings. The amicin group can form part of a fused ring system. For example, the amicin is 1
．． 5-cyazubicyclo(4,3,0)non-5-ene,
or 1,8cyazubicyclo(5,4,0)undes-7-ene or 1,5,7-triazbicycloC4,
'4.0) Des-5-ene.

In the case of acyclic guanidine, the nitrogen atom preferably has two or more substituents having n or more carbon atoms.

Suitable trivalent phosphorus-containing compounds are trialkyl or triarylphosphines, optionally containing one or more phosphorus atoms.

Epoxides include 1:2 alkylene oxide such as ethylene oxide, 1:2 propylene oxide, 1
: 2-butylene oxide, etc.

A convenient molar ratio of Lewis base to epoxide is 1:1.
The ratio is 0 to 20:1, preferably 1:10 to 1:1.

The molar ratio of alcohol to ester starting material is from 1:10 to
The ratio is 10:1.

As mentioned above, in the absence of epoxide, the amicin is essentially cyclic.

In this case, the amidine may be any of the cyclic compounds mentioned above.

This reaction is conveniently carried out within the range of 15 DEG to 150 DEG C. and a pressure of, for example, 1 to 150 par.

The process can be carried out at room temperature and atmospheric pressure, e.g.

The invention is illustrated by the following examples. In all of this examples, the reactants and products were in liquid phase.
The catalyst was then used as a solution.

Examples 1-10 illustrate the use of cyclic amidines, and Examples 11-25 illustrate the use of epoxides to promote various Lewis bases.

2gl of methanol and 0.0'L3 of 1.5.7
-Doriazubicyclo(4,4,0)des-5-ene(T
Ethyl acetate (2 g) was added to the solution containing BD ) and the resulting mixture was maintained at 24 °C for 1 h.

Analysis of the liquid product by gas chromatography showed that the conversion of ethyl acetate to methyl acetate was 76%.

Example 2 - Conversion of Ethyl Formate to Gibamethyl The procedure of Example 1 was repeated except that 29 ethyl formate was used in place of ethyl acetate. Analysis of the liquid product showed 77% conversion of ethyl formate to methyl formate.

The procedure of Example 1 was repeated except that ethyl propionate of 29 was used instead of ethyl if. After 2 hours, analysis of the liquid product showed 79% conversion of ethyl propionate to methyl propionate. Methyl acetate (29) was added to a solution containing □2 liters of ethanol and 0.0139 TBD, and the resulting mixture was maintained at 24°C for 1 hour. Analysis of the liquid product showed 54% conversion of methyl acetate to ethyl acetate.

The procedure of Example 4 was repeated except that two methyl methacrylates were used in place of methyl acetate.

Analysis of the liquid product showed 64% conversion of methyl methacrylate to ethyl methacrylate.

EXAMPLE 6 - The procedure of Example 4 was repeated except that methyl acrylate of 27 was used in place of methyl acrylate acetate and the reaction time was increased by two cycles. Analysis of the liquid product showed 24% conversion of methyl acrylate to ethyl acrylate.

Benzyl acetate (2 parts) was added to a solution containing 2 parts methanol and 0.0392 parts TBD. The resulting solution was maintained at 24°C for 2 hours.

Analysis of the product showed 92% conversion of benzyl acetate to methyl acetate.

0.075 of 1,5-zoadebicyclo(4,3,0)-non-5-ene (DBN) as a catalyst instead of TBD.
) and the method of Example 1 was repeated except that the reaction time was increased to 2 hours. Analysis of the liquid product showed 67% conversion of ethyl acetate to methyl acetate.

As a catalyst, 0.079 of 1.8-cyazbicyclo(5,4,0)undes-7-ene was used instead of DBN. The method of Example 8 was repeated, except that: Analysis of the liquid product showed 52% conversion of ethyl acetate to methyl acetate.
showed that.

0.079 N, N, instead of TBD as catalyst
The procedure of Example 1 was repeated except that N',N'-tetramethylguanisine was used. Analysis of the liquid product showed 65% conversion of ethyl acetate to methyl acetate.

Ethyl benzoate (2) was added to a solution containing 2 g of methanol and 0.0489 TBD and the resulting solution was maintained at 24° C. for 2 hours. Analysis of the liquid product showed 86% conversion of ethyl benzoate to methyl benzoate.

The method of Example 1 was repeated in the absence of TBD.

Analysis of the liquid product showed that no reaction had occurred.

The method of Example 1 was repeated except that 0.089 triethylamine was used instead of TBD as the catalyst. Analysis of the liquid product showed that no reaction had occurred.

Ethyl acetate was added to a solution containing 2 g of methanol, 0.073 parts of 1,5-cyazbicyclo(4,3,0)non-5-ene (DBN), and 0.11 parts of 1=2 propylene oxide. was added and the resulting solution was heated to 24°C for 2
Time was maintained. Analysis of the liquid product by gas chromatography revealed that the conversion of ethyl acetate to methyl acetate was 7.
It showed 6%.

Example 12 Example 1 in the absence of 1:2 propylene oxide
Repeat method 1. Analysis of the liquid product showed 67% conversion of ethyl acetate to methyl acetate.

Demonstrating Example 16 2 parts methanol, 0.00759 DBN and 0.
The solution containing 1:2 propylene oxide of 00359 was allowed to stand at room temperature for 90 hours, after which time 2L;l of ethyl acetate was added and the resulting mixture was maintained at 24°C for 2 hours. Analysis of the liquid product showed 47% conversion of ethyl acetate to methyl acetate.

Example 14 Product analysis shows conversion of ethyl acetate to methyl acetate: 5
It showed 8%.

Example 15 The procedure of Example 1 was repeated in the presence of 0.0175 parts of 1=2 propylene oxide 4. Analysis of the liquid product showed 65% conversion of ethyl acetate to methyl acetate.
showed that.

Example 16 The method of Example 16 was repeated in the presence of 0.035 parts of 1:2 propylene oxide r. Analysis of the liquid product showed 71% conversion of ethyl acetate to methyl acetate.

Example 17 Example 1 in the absence of 1:2 propylene oxy-P
Step 6 was repeated. The liquid product after 6.5 hours had only 14% conversion of ethyl acetate to methyl acetate.

Example 18 The method of Example 15 was repeated except that the mixture of methanol, DBN and 1:2 propylene oxide was left for 140 hours and 27 ethyl formate was used instead of ethyl acetate. Analysis of the liquid product after 1.5 hours showed 78% conversion of ethyl formate to methyl formate.

Example 10 of methanol, 1.759 of 1:2 propylene oxide and 6.0! A solution containing M tributylphosphine was heated to 100°C in a sealed Fischer-Porter tube initially under 50 psi nitrogen pressure.

After cooling, the solution was diluted 50 times with methanol,
Two parts of the resulting solution was added to 29 parts of ethyl acetate.

Analysis of the liquid product after 2 hours showed 79% conversion of ethyl acetate to methyl acetate.

Comparative Example D Example 1 in the absence of 1:2 propylene oxide
Step 9 was repeated. Analysis of the liquid product showed that no reaction had occurred.

Example 20 The procedure of Example 19 was repeated except that 2 g of benzyl acetate was used instead of ethyl acetate.

Analysis of the monomer product showed 91% conversion of benzyl acetate to methyl acetate.

Example 21 The procedure of Example 19 was repeated except that 3,059 triethylamine was used in place of tributylphosphine.

Analysis of the liquid product showed 66% conversion of ethyl acetate to methyl acetate.

Example 22 The procedure of Example 21 was repeated except that 27 benzyl acetate was used in place of ethyl acetate.

Analysis of the liquid product showed 86% conversion of benzyl acetate to methyl acetate.

EXAMPLE The procedure of Example 19 was repeated except that 2.359 pyricine was used in place of tributylphosphine. Analysis of the liquid product showed that the conversion of ethyl acetate to methyl acetate was 5.
It showed 0%.

19 methanol, 0.05 DBN and 0.09
Propylene carbonate (19) was added to a solution of 1=2 propylene oxide in 59, and the resulting mixture was
Maintained at 4°G for 10 minutes. The analysis of the liquid product is
The conversion rate of propylene carbonate to dimethyl carbonate was 40%.

Example 25 The method of Example 24 was repeated in the absence of 1:27° propylene oxide. Analysis of the product shows that the conversion of propylene carbonate to dimethyl carbonate is 11
%showed that.

The abbreviations g, h, and psi in the examples above refer to grams, hours, and pounds per square inch, respectively.

Agent Asamura Hao

Claims (10)

[Claims] (1) A process for transesterification of a carboxylic acid ester or carbonic acid ester comprising reacting a carboxylic acid ester or carbonic acid ester with an alcohol under transesterification conditions in the presence of a catalyst, the catalyst comprising (1) The above method, characterized in that it is a Lewis base containing a Group V element and an epoxide or a cyclic amicin. (2) The method according to claim 1, wherein the Lewis base is an organic compound containing trivalent phosphorus or nitrogen. (3) The method according to claim 2, wherein the Lewis base is an amine. (4) The method according to claim 6, wherein the amine is amidine. (5) The method according to claim 4, wherein the amidine is a cyclic amidine. (6) The method according to claim 115, paragraph 5, wherein the cyclic amicine has its bivalent atoms in the ring. (7) the cyclic amicine is a 6- and 5-membered ring, or a 6- and 5-membered ring;
and forming part of a fused ring system containing a 7-membered ring or two 6-membered rings. (8) The method according to any one of claims 1 to 6, wherein the temperature is 15 to 150°C. (9) The molar ratio of Lewis base to epoxide is 1:
9. A method according to any one of claims 1 to 8, characterized in that the ratio is between 10 and 20:1. (10) The method according to any one of claims 1 to 9, wherein the method for producing dialkyl carbonate comprises reacting an alkylene carbonate with an alkanol.