Synthesis and analgesic activities of some new 5-chloro-2(3H)-benzoxazolone derivatives

Affordable and practical synthesis methods in drug development have always been very attractive. Herein, microwave assisted synthesis was utilized to prepare piperazine substituted 5-chloro-2(3H)-benzoxazolone derivatives in 5 minutes. Structural characterization of these 5-chloro-2(3H)-benzoxazolone derivatives was achieved by IR, NMR, ESI-MS and elemental analysis. Since these types of compounds have been shown to have anti-inflammatory and analgesic activities there biological activities were also examined. Indomethacin (INDO) and acetylsalicylic acid (ASA) were used as reference. Carrageenan-induced hind paw edema in mice test was used to study anti-inflammatory activity. Compound 1 (100 mg / kg dose) showed the longest anti-inflammatory activity among the title compounds synthesized. For the analgesic activities, both hot-plate and tail-flick tests were employed. Compound 3 was found to have the highest activity in the hot-plate test whereas in the tail-flick test, compounds 1 and 2 showed higher anti-nociceptive activity.