Heteroaromatization with 4-hydroxycoumarin Part hSynthesis of some new pyranocoumarins and coumarinopyranopyrimidinesf

Abstract

Considerable interest has been shown in coumarin derivatives, on account of their excellent pharmacological activity1-3. In continuation of our work4-6, it was of interest to synthesize new coumarin derivatives, which might be biologically active. Thus condensation of 4-hydroxycoumarin 1 with various substituted a-cyanocinnamonitrile 2a-n in ethanolic piperidine afforded pyrano[3, 2-c]coumarin derivatives 3a-n (Scheme 1).