A Simple Efficient Procedure for the Synthesis of Benzopyrano[2,3‐c]pyrazoles

Abstract

A one‐step procedure is proposed for synthesizing 2‐acyl benzopyrano[2,3‐c]pyrazoles and 2‐aryl benzopyrano[2,3‐c]pyrazoles. The method is based on the condensation of 2‐iminocoumarin‐3‐carbonitriles with hydrazides and hydrazines in acid as catalysts. A mechanism of reaction is proposed. All prepared compounds are identified by FTIR, 1H NMR, 13C NMR, mass spectroscopy, and elemental analysis.