Abstract
Pyrazolone and its derivatives are an crucial class of heterocyclic compounds that may be traced in in a number of well-established drugs, such as celecoxib, Lonazolac and Mepirizole (anti-inflammatory), Rimonabant (anti-obesity), CDPPB (anti-psychotic), Difenamizole (analegesic), Betazole (H
2
-receptor agonist) and Fezolamine (anti-depressant). This review is an attempt to organize the reactivity of 3-amino-1-substituted-1H-pyrazol-5(4H)-ones reported in last 60 year to till date.