Synthesis of new pyrazoles and pyrozolo [3,4-b] pyridines as anti-inflammatory agents by inhibition of COX-2 enzyme.

New pyrazoles and pyrazolo[3,4-b] pyridines were synthesized and their structure was confirmed by elemental analyses as well as IR, 1H NMR, 13C NMR, and mass spectral data. All the newly synthesized derivatives were evaluated in vitro for inhibitory activity against COX-1 and COX-2 enzymes and their IC50 values were calculated, most of the derivatives showed good inhibitory activity with derivatives IVb, IVh and IVJ showing inhibitory activity better than celecoxib. Moreover, the eight most potent derivatives IVa, IVb, IVc, IVd, IVe, IVh, IVJ, and IVL were selected for in vivo assay to measure their effect on paw edema in rates and their ulcerogenic effect. Compounds IVa, IVb and IVc were found to be the most active and selective as COX-2 inhibitors and most effective in protection from edema, they were also found to have lowest ulcerogenic effect among all derivatives.