Synthesis of 1,5-Diarylpyrazoles as Potential COX-2 Inhibitors with Nitric Oxide Releasing Ability

A few celecosib like 1,5-diarylpyrazoles conjugated with nitric oxide (NO) donating nitrate ester group were synthesized and evaluated for their selective COX-2 inhibitory activity along with NO releasing ability of corresponding nitrate esters. Most of the synthesized compounds exhibited improved COX-2 inhibition when compared with the reference drug celecoxib. The nitrate ester derivatives (coxib prodrugs) 7 (nitrate ester of 1,5-diarylpyrazole with 2 carbon linker), and 9 (nitrate ester of 1,5-diarylpyrazole with 3 carbon linker), upon incubation in human whole blood were partly transformed into the corresponding alcohols 6, and 8 respectively. Molecular docking studies were performed on alcohol derivatives and revealed additional H-bond interactions compared to celecoxib.