Synthesis of some new thiazole derivatives of pharmaceutical interest

Reaction of 4-amino-3-phenyl-5-ethoxycarbonyl-thiazole-2-thione with phenylisothiocyanate gave (2) which when boiled with acetic acid gave (3). Treatment of (2) with monochloroacetic acid resulted in the formation of thiazolidinone derivative (4). Reaction of (2) with malonic acid gave (5). Condensation of (1) with aromatic aldehydes afforded Schiffe base derivatives (6a,b). Treatment of (1) with malononitrile, ethyl cyanoacetate and acetonitrile resulted the formation of pyridine derivatives (7a,b,c). The reaction of (1) with urea and thiourea gave compound (8). Condensation of (1) with o-phenylenediamine and o-aminophenol gave compound (9). Reaction of (1) with nitrous acid followed by coupling with ethylacetoacetate afforded (10). Bromination of (10) gave bromo derivative (11). The structures of the hitherto unknown compounds have been confirmed by analytical and spectral methods. The newly synthesized compounds were screened for antibacterial activity.