Processes for the recovery of optically active diacyltartatic acids

• US 20060058546A1
• Filed: 12/22/2003
• Published: 03/16/2006
• Est. Priority Date: 01/16/2003
• Status: Active Grant

• Current Assignee: Toray Fine Chemicals Co., Ltd. (Toray Industries Incorporated)
• Original Assignee: Toray Fine Chemicals Co., Ltd. (Toray Industries Incorporated)
• Inventors: Fujino, Toshihiro, Morii, Seiji, Sato, Haruyo
• Granted Patent: US 7,358,384 B2
• Time in Patent Office: Days
• US Class Current: 560/66
• CPC Class Codes: C07B 2200/07 Optical isomers
• CPC Class Codes: C07C 67/52 by change in the physical state, e.g. crystallisation
• CPC Class Codes: C07C 69/76 Esters of carboxylic acids having a carboxyl group bound to a carbon atom of a six-membered aromatic ring
• CPC Class Codes: Y02P 20/582 Recycling of unreacted starting or intermediate materials

Abstract

When a salt of an amine and an optically active diacyltartaric acid, or a diastereomer salt of an optically active amine and an optically active diacyltartaric acid, obtained by optically resolving a racemic amine using the optically active diacyltartaric acid, is salt-exchanged with an acid aqueous solution, the optically active diacyltartaric acid is added in the acid aqueous solution beforehand. Furthermore, a raw material containing a racemic amine and an optically active diacyltartaric acid is optically resolved, and the diastereomer salt of the optically active amine and the optically active diacyltartaric acid respectively of one isomer type, is separated. The obtained diastereomer salt is dissociated using an acid aqueous solution containing the optically active diacyltartaric acid, for recovering the optically active diacyltartaric acid, and the obtained optically active diacyltartaric acid is recycled into an optical resolution step as a raw material of the optical resolution step.

Claims

1. A process for recovering an optically active diacyltartaric acid from a salt of an amine and the optically active diacyltartaric acid in an acid aqueous solution, characterized in that the optically active diacyltartaric acid is added beforehand in the acid aqueous solution.

2. A process for recovering an optically active diacyltartaric acid, according to claim 1, wherein the salt of an amine and the optically active diacyltartaric acid is a diastereomer salt obtained by optically resolving a racemic amine using the optically active diacyltartaric acid.

3. A process for recovering an optically active diacyltartaric acid, according to claim 1, wherein the temperature of the acid aqueous solution is from 0 to 50°

C.

4. A process for recovering an optically active diacyltartaric acid, according to claim 1, wherein the optically active diacyltartaric acid is an optically active dibenzoyltartaric acid, optically active ditoluoyltartaric acid, or optically active dimethoxybenzoyltartaric acid.

5. A process for recovering an optically active diacyltartaric acid, according to claim 1, wherein the added amount of the optically active diacyltartaric acid is from 0.05 to 3 wt % based on the weight of the acid aqueous solution.

6. A process for recovering an optically active diacyltartaric acid, according to claim 1, wherein the acid aqueous solution is an aqueous solution of an inorganic acid.

7. A process for recovering an optically active diacyltartaric acid, comprising an optical resolution step for optically resolving a raw material containing a racemic amine and the optically active diacyltartaric acid and separating the diastereomer salt of one isomer type of the optically active amine and the optically active diacyltartaric acid, a salt dissociation step for dissociating the obtained diastereomer salt into the optically active amine and the optically active diacyltartaric acid using an acid aqueous solution, and a recycling step for recovering the optically active diacyltartaric acid obtained in the salt dissociation step and recycling the recovered optically active diacyltartaric acid into the optical resolution step as a raw material of the optical resolution step, wherein the optically active diacyltartaric acid is added beforehand in the acid aqueous solution used in the salt dissociation step.