Synthesis of New Fused Furo- and Thienopyridines

Abstract

A method was developed for the synthesis of new fused derivatives of pyrano[4,3-b]thieno(furo)-pyridine, namely 8,8-dimethyl-11-(2-furyl)-7,10-dihydro-8H-pyrano[3″,4″:5′,6′]pyrido[3′,2′:4,5]thieno(furo)[3,2-d]- pyrimidine-4(3H)-ones, from 2,2-dimethyltetrahydropyran-4-one. Optimal conditions for carrying out the cyclization reaction of ethyl {7,7-dimethyl-4-(2-furyl-3-cyano-7,8-dihydro-5H-pyrano[4,3-b]pyridin-2-yl]oxy}acetate into the corresponding amino ester were determined.