New one step synthesis of 3,5‐disubstituted pyrazoles under microwave irradiation and classical heating

Abstract

Abstract magnified image A convenient one pot procedure for the synthesis of 3,5‐disubstituted pyrazoles by condensation of chalcones, hydrazine hydrate and sulfur in ethanol under microwave irradiation and conventional heating method is reported. The hydrogen sulfide is produced during the reaction. The pyrazoles are obtained in good yields and excellent state of purity. The structures of new compounds were confirmed by IR, 1 H, and 13 C NMR, MS and elemental analysis.