One-pot synthesis of ۴H-pyrano[۲,۳-c]pyrazoles in the presence of Keggin supported on C۳N۴ as catalyst

A facile and versatile procedure has been explored for the synthesis ۱,۴-dihydropyrano[۲,۳-c]pyrazol-۵-yl cyanides. This protocol employes the one-pot three-component condensation of aromatic aldehydes and malononitrile with ۳-methyl-۱-phenyl-۲-pyrazolin-۵-ones in ethanol under the catalytic effect of Keggin heteropolyacid supported on carbon nitride and visible light irradiation. Simple manipulation, high reaction rates, improved yields, use of inexpensive and non-toxic catalyst, and also use of ethanol as a relatively environmentally benign solvent are the main advantages of this protocol.

Keywords:

pyrazole , g-C۳N۴ , visible light