Five membered nitrogen heterocycles are historically known to exhibit diverse therapeutic properties. In particular, the pyrazole analogues have shown a wide range of pharmacological profiles and a number of drugs containing this scaffold approved for the treatment of various ailments and disorders. Hence, a lot of efforts have been made to develop efficient synthetic strategies for the preparation of a variety of pyrazoles in the past several decades. However, this review describes the environmentally benign protocols for the synthesis of substituted and fused pyrazole molecules.
Keywords: Aromaticity, biological activity, eco-friendly methods, ionic liquids, pyrazoles, pyrano[2, 3-c]pyrazoles.