Synthesis and antinociceptive activity of (5-chloro-2(3H)-benzothiazolon-3-yl)propanamide derivatives

Ten new (5-chloro-2(3H)-benzothiazolon-3-yl)propanamide derivatives have been synthesized. The compounds were tested for antinociceptive activity by tail clip, tail flick, hot plate and writhing test by using aspirin and dipyrone as standards. Among these compounds, 1-[3-(5-chloro-2(3H)-benzothiazolon-3-yl)-propanoyl]-4-(4-chlorophenyl)piperazine (11e) has been found to be significantly more active than the other compounds synthesized as well as the standards in all tests.