Synthesis of novel Schiff bases and evaluation of their antimicrobial activities

摘要

An easy route for the synthesis of Schiff bases containing dihydropyrimidinone moiety has been reported for the first time. The dihydropyrimidinones on treatment with thiosemicarbazide result in the formation of the corresponding hydrazinecarbothioamide. Dehydrated annulation of hydrazinecarbothioamide with concentrated sulphuric acid, followed by ammonia yield the corresponding 1,3,4-thiadiazol-2-amine, which on condensation with various selected aromatic aldehydes furnish the Schiff bases 4a-f. The antimicrobial studies of the novel Schiff bases have been carried out on different microbes.