Process for producing optically active carboxylic acid substituted in 2-position
US7094926B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 2001 |
| Grant date | Aug 22, 2006 |
| Priority date | — |
| Expiry date | Feb 7, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C59/48
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A nitrous acid salt is added at a temperature of 10 to 80° C. to an aqueous solution which contains an optically active 2-aminocarboxylic acid (4) and a protonic acid, the amount of the latter acid being 1 to 3 equivalents to the former, and which has a proton concentration of 0.5 to 2 mol/kg to conduct a reaction to thereby produce an optically active 2-hydroxycarboxylic acid (1). Thionyl chloride and a basic compound are caused to act on the compound (1) to chlorinate it and simultaneously invert the configuration in the 2-position. Thus, an optically active 2-chlorocarboxylic acid chloride (5) is induced. The compound (5) is hydrolyzed to induce an optically active 2-chlorocarboxylic acid (2). The compound (2) is reacted with a thioacetic acid salt to incorporate an acetylthio group thereinto and simultaneously invert the configuration in the 2-position to thereby produce an optically active 2-acetylthiocarboxylic acid (3).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.