Synthesis of substituted thiazoline carboxylic acids
US7285670B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 3, 2005 |
| Grant date | Oct 23, 2007 |
| Priority date | — |
| Expiry date | Oct 3, 2025 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07B2200/07
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A useful and efficient method of preparing an alkylated thiazoline carboxylic acid, or a derivative thereof, comprises coupling a substituted aryl nitrile such as, for example, 2,4-dimethoxybenzonitrile or 4-methoxybenzonitrile, with a cysteine ester to form a substituted thiazoline carboxylic acid ester; optionally hydrolyzing the substituted thiazoline carboxylic acid ester to form a substituted thiazoline carboxylic acid; optionally, protecting the carboxyl group; alkylating the thiazoline ring at the 4-carbon position, as indicated in Structural Formula (I), with a compound of the formula R1-L, wherein R1 is as defined above and L is a leaving group, in the presence of a phase transfer catalyst; and, optionally, deprotecting the carboxyl group.In one embodiment of the present invention, a cinchona-alkaloid derived phase transfer catalyst is used to alkylate a protected substituted thiazoline carboxylic acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.