Method for producing alpha-acyloxycarboxylic acid ester

Patent metadata

Field	Value
Publication number	US-12378181-B2
Application number	US-202017627626-A
Country	US
Kind code	B2
Filing date	Jul 9, 2020
Priority date	Jul 19, 2019
Publication date	Aug 5, 2025
Grant date	Aug 5, 2025

Abstract

A method for producing an α-acyloxycarboxylic acid ester of Formula (1) is described. The method involves reacting an α-hydroxycarboxylic acid ester compound with an acylating agent in the presence of a catalyst comprising an iron halide compound. R 1 represents a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, or a tert-butyl group, R 2 and R 3 each independently represent a methyl group or an ethyl group, and R 4 represents a linear, branched, or cyclic alkyl group having from 1 to 6 carbon atoms.

First claim

The invention claimed is:

1. A method for producing an α-acyloxycarboxylic acid ester compound of Formula (1), the method comprising:
reacting an α-hydroxycarboxylic acid ester compound of Formula (2) with an acylating agent of Formula (3) in the presence of a catalyst comprising an iron halide compound,

where R 1 is a hydrogen atom, a methyl group, an ethyl group, a n-propyl group, an isopropyl group, or a tert-butyl group,
R 2 and R 3 are each independently a methyl group or an ethyl group,
R 4 is a linear, branched, or cyclic alkyl group having from 1 to 6 carbon atoms,

Z is chlorine, bromine, or an acyloxy group represented by R 1 C(═O)O—,
wherein a molar ratio of iron atoms in the iron halide compound to the α-hydroxycarboxylic acid ester compound is from 50×10 −6 to 0.7×10 −2 .

2. The method according to claim 1 , wherein the catalyst comprises at least one selected from the group consisting of
(i) an iron halide compound is at least one selected from the group consisting of FeCl 3 , FeBr 3 , FeCl 2 , and FeBr 2 ,
(ii) a hydrate of the iron halide compound,
(iii) a complex of the iron halide compound with a ligand coordinated thereto, and
(iv) a mixture of any one of (i)-(iii).

3. The method according to claim 1 , wherein the catalyst comprises at least one selected from the group consisting of FeCl 3 , a hydrate thereof, a complex with a ligand coordinated thereto, and a mixture thereof.

4. The method according to claim 1 , wherein the acylating agent is a carboxylic anhydride of Formula (7):

5. The method according to claim 1 , wherein, in the ester compound of Formula (1), R 4 is a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 2,2-dimethylpropyl group, a n-hexyl group, a 2-methylpentyl group, a 4-methylpentan-2-yl group, a cyclopentyl group, or a cyclohexyl group.

6. The method according to claim 1 , wherein R 2 and R 3 are both methyl groups in the ester compound of Formula (1).

7. The method according to claim 1 , wherein the reacting is performed in absence of a solvent.

8. The method according to claim 2 , wherein the acylating agent is a carboxylic anhydride of Formula (7):

9. The method according to claim 3 , wherein the acylating agent is a carboxylic anhydride of Formula (7):

10. The method according to claim 2 , wherein, in the ester compound of Formula (1), R 4 is a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 2,2-dimethylpropyl group, a n-hexyl group, a 2-methylpentyl group, a 4-methylpentan-2-yl group, a cyclopentyl group, or a cyclohexyl group.

11. The method according to claim 3 , wherein, in the ester compound of Formula (1), R 4 is a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 2,2-dimethylpropyl group, a n-hexyl group, a 2-methylpentyl group, a 4-methylpentan-2-yl group, a cyclopentyl group, or a cyclohexyl group.

12. The method according to claim 4 , wherein, in the ester compound of Formula (1), R 4 is a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 2,2-dimethylpropyl group, a n-hexyl group, a 2-methylpentyl group, a 4-methylpentan-2-yl group, a cyclopentyl group, or a cyclohexyl group.

13. The method according to claim 2 , wherein R 2 and R 3 are both methyl groups in the ester compound of Formula (1).

14. The method according to claim 3 , wherein R 2 and R 3 are both methyl groups in the ester compound of Formula (1).

15. The method according to claim 4 , wherein R 2 and R 3 are both methyl groups in the ester compound of Formula (1).

16. The method according to claim 5 , wherein R 2 and R 3 are both methyl groups in the ester compound of Formula (1).

17. The method according to claim 2 , wherein the reacting is performed in absence of a solvent.

18. The method according to claim 3 , wherein the reacting is performed in absence of a solvent.

19. The method according to claim 4 , wherein the reacting is performed in absence of a solvent.

20. The method according to claim 5 , wherein the reacting is performed in absence of a solvent.

Assignees

• Mitsubishi Gas Chemical Co

Inventors

• Okamoto Atsushi
• Hiraoka Kyoko

Classifications

• C07B61/00

  Other general methods · CPC title

• C07B41/08

  of carboxyl groups or salts, halides or anhydrides thereof · CPC title

• C07C67/08 Primary

  by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds · CPC title

• C07C69/67

  of saturated acids · CPC title