Uses of 1-cyanoacetyl-4-phenyl-3-thiosemicarbazide in heterocyclic synthesis: Synthesis of thiazole, coumarin, and pyridine derivatives with antimicrobial and antifungal activities

The reaction of cyanoacetyl hydrazine with phenylisothiocyanate gave the thiosemicarbazide 3. The latter underwent a series of heterocyclization reactions when it reacts with either aromatic aldehydes or alpha-haloketones, follwed by further reaction of the products with cyanomethylene reagents or hydrazines to give either thiazole, coumarin, or pyridine derivatives. The newly synthesized product showed antimicrobial and antifungal activities.