SYNTHESIS OF AZOLES, AZINES AND AZOLOAZINES: A VERSATILE APPROACH

Abstract

A novel procedure for the synthesis of heterocycles 5, 7 have been developed from the acid catalysed condensation-cyclization of benzylidene and benzylmalononitriles with thiosemicarbazide. Base catalysed cyclization of 2 with dicyandiamide led to the formation of pyrimidine 3. Reaction of 5 and 7 with phenacyl bromide separately afforded 6 and 8 while interaction of 7 with ethyl acetoacetate gave a mixture of 9 and 10.

Key Words:

• Benzylmalononitrile
• 1,3,4-thiadiazolylacrylonitriles
• 1,3,4-thiadiazolylacrylates, bis(1,3,4-thiadiazolyl)ethanes
• bis[1,3,4-thiadiazolo[3,2-a]pyrimidinyl]ethanes
• cyanoaminopyrimidines