Novel Synthesis and Antimicrobial Activity of 7-Substituted Derivatives of 7-(methylthio)-5-oxo-2-phenyl-5H-[1,3,4]thiadiazolo[3,2-b]- pyrimidine-6-carbonitrile

2-Amino-5-phenyl-1,3,4-thiadiazole on reaction with ethyl-2-cyano-3,3-bis(methylthio)acrylate in the presence of N,N′-dimethyl formamide and catalytic amount of anhydrous potassium carbonate afforded 7-(methylthio)-5-oxo-2-phenyl-5H-[1,3,4]thiadiazolo[3,2-b]pyrimidine- 6-carbonitrile under similar experimental condition, compounds 7-(methylthio)-5-oxo-2-phenyl-5H-[1,3,4]thiadiazolo[3,2-b]pyrimidine-6-carbonitrile on treatment independently with aryl amines/ heteryl amines/phenols containing active methylene group yielded correspon-ding 7-substituted derivatives. All these newly synthesized compounds were screened for antimicrobial activity.