Synthesis of 1,3-substituted 1H-indazole derivatives and evaluation of anti-inflammatory activity in Sprague Dawley rats

Indazole is a very significant group of heterocyclics. Aim of the research was thus planned to synthesize novel derivatives of indazole and evaluate their anti-inflammatory activity. Novel compounds of indazole were first synthesized from reaction of 2-chlorobenzonitrile with phenylhydrazine in presence of catalyst potassium t-butoxide (t-BuOK) and the solvent diglyme. Synthesized derivatives of indazole were analyzed by ¹H-NMR and MS spectroscopic techniques. All the synthesized derivatives of indazole were evaluated for their anti-inflammatory activity in Sprague Dawley rats by carrageenan-induced rat paw edema method. All the synthesized derivatives of indazole had shown very good activity in both docking and anti-inflammatory activity in rats in comparison to the standard etoricoxib. Compound 1a in a dose of 30 ​mg/kg body weight had shown most significant inhibition of edema as compared to toxic group and the inhibition was comparable to that of the standard drug, etoricoxib in a dose of 10 ​mg/kg body weight. A convenient means for the synthesis of derivatives of indazole was developed which may find applications in heterocyclic synthesis of derivatives of indazole. Compound 1a i.e., 3-(4-carboxyphenyl)amino-1-phenyl-1H-indazole had shown best anti-inflammatory activity amongst all the synthesized compounds.