Heteroaromatization with 4-Hydroxycoumarin Part I: Synthesis of some new Pyranocoumarins and Coumarinopyranopyrimidines

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