1,8-Naphthyridines VII. New substituted 5-amino[1,2,4]triazolo[4,3-a][1,8]naphthyridine-6-carboxamides and their isosteric analogues, exhibiting notable anti-inflammatory and/or analgesic activities, but no acute gastrolesivity.

The [1,2,4]triazolo[4,3-a][1,8]naphthyridine-6-carboxamide derivatives 5-amino (2) or 5-alkoxy (3) substituted and the 5-amino[1,2,4]triazolo[ 4,3-a]quinoline-4-carboxamide derivatives (4), designed to obtain new effective analgesic and/or anti-inflammatory agents were synthesized. Ten compounds 2 and 4 showed an interesting analgesic activity: the most potent ones are 2j (36% inhibition, P < 0.05) and 4b (77% inhibition, P < 0.01) at 6.25 and 25 mg kg-1 doses, respectively. Compounds 2iel and 4c showed notable anti-inflammatory properties: the most potent ones are 2i (68% inhibition, P < 0.01) and 2l (42% inhibition, P < 0.05) at 12.5 and 6.25 mg kg-1 doses, respectively. The replacement in compounds 2 of the N-substituted 5-amino substituents with similar alkoxy groups usually afforded less active compounds 3.