Recent developments in synthetic chemistry and biological activities of pyrazole derivatives

Pyrazole, a five-membered heterocycle containing two nitrogen atoms, is extensively found as a core framework in a huge library of heterocyclic compounds that envelops promising agro-chemical, fluorescent and biological potencies. Attributed to its several potential applications, there is a rise in the significance of designing novel pyrazoles, disclosing innovative routes for synthesizing pyrazoles, examining different potencies of pyrazoles, and seeking for potential applications of pyrazoles. This review consists of two parts. The first part provides an overview on the recent developments in synthetic approaches to pyrazoles, which is related to the new or advanced catalysts and other ‘environment-friendly’ procedures, including heterogeneous catalytic systems, ligand-free systems, ultrasound and microwave-assisted reactions. The second part focuses on the recently reported novel biological affinities of pyrazoles. This systematic review covers the published studies from 1990 to date. It is expected that this review will be helpful in future research and for new thoughts in the quest for rational designs for developing more promising pyrazoles. Graphic Abstract The review consists of two parts: (i) an overview on the recent advances in synthetic approaches for the preparation of pyrazoles, including eco-friendly methodologies, heterogeneous catalytic systems, ligand-free systems, ultrasound and microwave-assisted reactions, and (ii) a summary of recently reported novel biological affinities of pyrazoles.