Greener and facile aqueous synthesis of pyrazoles using Amberlyst-70 as a recyclable catalyst

An environmentally benign, room temperature aqueous synthesis of pyrazoles by the condensation of hydrazines/hydrazides with 1,3-diketones using Amberlyst-70 as a recyclable catalyst is described. The use of resinous, nontoxic, thermally stable and inexpensive Amberlyst-70 as a heterogeneous catalyst and simple reaction workup are the additional eco-friendly attributes of this synthetic protocol.