Novel 4-[5-{4-[(2-Benzylidenehydrazine)Carbonyl]phenyl}-3-(Trifluoromethyl)-1<i>H</i>-Pyrazol-1-yl]Benzenesulfonamides: Synthesis, Crystal Structure, Anti-Inflammatory and Ulcerogenecity Studies

A series of novel 4-{5-[(2-benzylidenehydrazine)carbonyl]phenyl}-3-(trifluoromethyl)-1 H-pyrazol-1-yl]benzenesulfonamides was synthesised from 4-[1-(4-aminosulfonylphenyl)-3-(trifluoromethyl)-1 H-pyrazol-5-yl]benzoic acid (celecoxib). Initially, celecoxib was selectively oxidised. The product was then esterified and this was followed by hydrazinolysis to get the carbohydrazide. The carbohydrazide was subsequently reacted with a number of benzaldehyde derivatives to give the title compounds. These compounds were characterised by spectral and elemental analyses along with the single crystal X-ray crystallography of a representative compound. All the synthesised compounds were found active for their anti-inflammatory activity in the carrageenan-induced rat paw oedema model. A few of them possessed even greater in vivo anti-inflammatory activities when compared to the reference drug celecoxib and showed minimal or no ulcerogenic effect.