Aluminium oxide-catalyzed mild and facile synthesis of dihydropyrano[2,3-c]pyrazole derivatives

An effective approach to the synthesis of dihydropyrano[2,3-c]pyrazole derivatives via a one-pot four-component reaction of ethyl acetoacetate, hydrazine hydrate, aryl aldehyde derivatives and malononitrile in the presence of aluminium oxide as an efficient catalyst has been reported. The present procedure offers advantages such as simple workup, short reaction time and offers rapid access to a variety of dihydropyrano[2,3-c]pyrazole derivatives.

Keywords:

Dihydropyrano[2 , 3-c]pyrazole derivatives , Al2O3 (Aluminium oxide) , Multi-component reaction , One-pot procedure.