Synthesis and analgesic profile of novel N-containing heterocycle derivatives: arylidene 3-phenyl-1,2,4-oxadiazole-5-carbohydrazide

This paper describes recent results of a research program aimed at the synt hesis and pharmacological evaluation of new heterocyclic N-acylhydrazone (N AH) compounds, belonging to the arylidene (3-phenyl)-1,2,4-oxadiazolyl-5-ca rboxyhydrazide (8a-p) series. These compounds were structurally planned by applying the molecular hybridization strategy on previously described aryli dene 1-phenylpyrazole-4-carbohydrazide (5) derivatives, considered as lead- compounds, which present potent analgesic properties. The analgesic profile of the title compounds 8a-p, evaluated in the model of abdominal constrict ions induced by acetic acid, showed that the 4-methoxybenzylidene derivativ es 8c and 8k were the most active ones, exhibiting a relative analgesic act ivity comparable with that of dipyrone 1 used as standard. (C) 1999 Elsevie r Science S.A. All rights reserved.