4-Hydroxycoumarin in heterocyclic synthesis: Part III. Synthesis of some new pyrano[2,3- d]pyrimidine, 2-substituted[1,2,4]triazolo[1,5- c]pyrimidine and pyrimido[1,6- b][1,2,4]triazine derivatives

Abstract

The synthesis of new [1]benzopyrano[3′,4′:5,6]pyrano[2,3- d]pyrimidines and related heterocycles has been reported. The key intermediate 2-amino-3-cyano-4-methyl-4 H,5 H-pyrano[3,2- c][1]benzopyran-5-one ( 3) was obtained in one pot synthesis from the reaction of 4-hydroxycoumarin and acetaldehyde–malononitrile ( 2). The antimicrobial screening was performed for some of the synthesized compounds.