Molecular modeling, synthesis, characterization and pharmacological evaluation of benzo[d]oxazole derivatives as non-steroidal anti-inflammatory agents

A series of N-(2-(4-chlorobenzyl)benzo[d]oxazol-5-yl)-3-substituted-propanamide (3a-3n) were synthesized and evaluated for their acute and chronic anti-inflammatory potential. The structure of the compounds was elucidated by elemental and spectral (IR, 1H NMR and MS) analysis. The synthesized compounds (at a dose of 20 mg/kg b.wt. p.o.) have shown their ability to provide 45.1-81.7% protection against carrageenan-induced paw edema, in comparison with diclofenac sodium (69.5%) and ibuprofen (64.7%). The most active compounds 3a, 3l and 3n were screened for chronic anti-inflammatory activity (cotton-pellet-induced granuloma) and to study their ulcerogenic activity. Compounds 3a, 3l and 3n showed 48.4%, 39.3% and 44.0% protection against cotton pellets-induced granuloma compared to diclofenac sodium (60.2%). The tested compounds were less ulcerogenic than the ibuprofen. Molecular modeling studies suggest that these compounds have strong interaction with the COX-2 enzyme, which is responsible for the activity.