Reactions of beta-carbonyl-substituted 4H-chromenes and 1H-benzo[f]chromenes with 5-aminopyrazoles

Abstract

A method for the preparation of pyrazolo[1,5-a]pyrimidines containing a 2-hydroxybenzyl or (2-hydroxynaphthalen-1-yl)methyl group in position 6 based on the reaction of beta-carbonyl-substituted 4H-chromenes and their benzo analogs with 5-aminopyrazoles is proposed. A new type of ring-chain tautomerism with the participation of 7-(trifluoromethyl)pyrazolo[1,5-a]pyrimidines was discovered.