# US 5,710,316 A · Transesterification process for making allyl esters of aromatic carboxylic acids

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,710,316 A
- Document ID: US5710316A
- Status: Granted
- Kind: A
- Application number: 08/757,522
- Filed: 1996-11-27
- Granted: 1998-01-20
- Earliest claimed: 1996-11-27
- Assignees: Arco Chemical Technology, L.P.
- Inventors: Jude T. Ruszkay; Katherine A. McCarron
- Web page: https://patentgrep.com/patent/US5710316A

## CPC

- C07C 67/03: by reacting an ester group with a hydroxy group
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

A transesterification process for making allyl esters of aromatic carboxylic acids from the corresponding alkyl esters and allylic alcohols is disclosed. The alkyl ester/allylic alcohol mixture is dried by distillation to less than about 200 ppm water before heating it in the presence of the transesterification catalyst. The resulting allyl ester is obtained rapidly in high yield with a minimal level of catalyst. In addition, product isolation is simple, and color is exceptionally low. The process is particularly valuable for making diallyl phthalate from dialkyl esters of phthalic acid.

## Claims

### Claim 1

A transesterification process for making an allyl ester of an aromatic carboxylic acid, said process comprising:
(a) preparing a mixture of an alkyl ester of an aromatic carboxylic acid and an allylic alcohol;
(b) distilling the mixture to produce a dry mixture that contains less than about 200 ppm of water;
(c) heating the dry mixture in the presence of an amount of a transesterification catalyst effective to produce an allyl ester of the carboxylic acid and an alcohol by-product;
(d) distilling alcohol by-product from the mixture to produce a purified allyl ester of the carboxylic acid.

### Claim 2 (depends on 1)

The process of claim 1 wherein the allylic alcohol is allyl alcohol, the alkyl ester is dimethyl phthalate or diethyl phthalate, and the allyl ester is diallyl phthalate.

### Claim 3 (depends on 1)

The process of claim 1 wherein the transesterification catalyst is an alkali metal alkoxide selected from the group consisting of sodium methoxide and potassium methoxide.

### Claim 4 (depends on 1)

The process of claim 1 wherein the transesterification catalyst is added incrementally to the heated reaction mixture.

### Claim 5 (depends on 1)

The process of claim 1 wherein the total amount of transesterification catalyst used is less than about 500 ppm based on the amount of alkyl ester.

### Claim 6 (depends on 1)

The process of claim 1 wherein the transesterification catalyst is sodium methoxide, and the total amount of sodium methoxide used is within the range of about 10 to about 200 ppm based on the amount of alkyl ester.

### Claim 7 (depends on 2)

The process of claim 2 wherein the resulting diallyl phthalate has an APHA color less than or equal to about 100.

### Claim 8

A transesterification process for making diallyl phthalate, said process comprising:
(a) preparing a mixture of an ester selected from the group consisting of dimethyl phthalate and diethyl phthalate, and allyl alcohol;
(b) distilling the mixture to produce a dry mixture that contains less than about 150 ppm of water;
(c) heating the dry mixture in the presence of an amount of an alkali metal alkoxide catalyst effective to produce diallyl phthalate and methanol or ethanol;
(d) distilling methanol or ethanol from the mixture to produce purified diallyl phthalate.

### Claim 9 (depends on 8)

The process of claim 8 wherein the alkali metal alkoxide catalyst is selected from the group consisting of sodium methoxide and potassium methoxide.

### Claim 10 (depends on 8)

The process of claim 8 wherein the alkali metal alkoxide catalyst is added incrementally to the heated reaction mixture.

### Claim 11 (depends on 8)

The process of claim 8 wherein the total amount of alkali metal alkoxide catalyst used is less than about 500 ppm based on the amount of dimethyl or diethyl phthalate.

### Claim 12 (depends on 8)

The process of claim 8 wherein the alkali metal alkoxide catalyst is sodium methoxide, and the total amount of sodium methoxide used is within the range of about 10 to about 200 ppm based on the amount of dimethyl or diethyl phthalate.

### Claim 13 (depends on 8)

The process of claim 8 wherein the diallyl phthalate has an APHA color less than or equal to about 100.