Synthesis and analgesic-antiinflammatory activities of novel acylarylhydrazones with a 5-phenyl-4-R-3-pyrrolyl-acyl moiety

A new series of arylidene 5-phenyl-4-R-pyrrole-3-carbohydrazides 1a-j were prepared and evaluated for their analgesic-antiinflammatory activities. All synthesized compounds showed a significant analgesic action in mice after intraperitoneal administration at a dose of 100 μM/kg. Two of these, 1b, (4′-methylbenzylidene)-5-phenyl-1 H-pyrrole-3-carbohydrazide, and 1d, (4′-chlorobenzylidene)-5-phenyl-1H-pyrrole-3-carbohydrazide, were found to be more potent as antinociceptive agents respect to dipyrone and indometacin, used as reference drugs. Among compounds 1, only 1b showed a moderate antiinflammatory effect in rats while 1d proved to be a potent non antiinflammatory analgesic.