2-[2-(4-CHLOROPHENYL)-1,3-THIAZOL-4-YL]ACETIC ACID

Fenclozic Acid,ZYF Pharm Chemical

Fenclozic Acid is a a potent antiinflammatory agent with analgesic and antipyretic properties and is a human hepatotoxic drug.

3.7 parts of 2-(4-chlorophenyl)-4-cyanomethylthiazole and 35 parts of 6 N hydrochloric acid are heated under reflux for 2 hours. The solution is cooled by the addition of ice and made alkaline to pH 8 by the addition of 30% aqueous ammonia. The mixture is filtered to remove trace impurities, and an excess of 40% sodium hydroxide solution is then added to the filtrate to cause precipitation of a sodium salt, which is collected by filtration and crystallised from water. There is thus obtained sodium 2-(4-chlorophenyl)thiazol-4- ylacetate, M.P. 13°C (decomposition).
This sodium salt is dissolved in hot water, and the solution is brought to pH 4 by the addition of acetic acid, which causes the precipitation of 2-(4- chlorophenyl)thiazol-4-ylacetic acid. This is collected by filtration, washed with water, and dried in vacuo over phosphorus pentoxide. It has an M.P. 155- 156°C (from ethyl acetate).

Antiinflammatory, Analgesic, Antipyretic