Synthesis and anti-inflammatory activity evaluation of novel 7-alkoxy-1-amino-4,5-dihydro[1,2,4]triazole[4,3-a]quinolines

In this study, a novel series of 7-alkoxy-1-amino-4,5-dihydro[1,2,4]triazole[4,3-a]quinolines were synthesized by using 6-hydroxy-3,4-dihydro-2(1H)-quinolone as the starting material. These compounds were evaluated for anti-inflammatory activity through monitoring their ability to inhibit xylene-induced ear edema in mice. Some of the tested compounds exhibited significant activity, and the compounds 5f (7-(benzyloxy)-4,5-dihydro[1,2,4]triazolo[4,3-a]quinolin-1-amine) and 5i (7-(p-chlorobenzyloxy)-4,5-dihydro[1,2,4]triazolo[4,3-a]quinolin-1-amine) showed the highest anti-inflammatory activity (52% and 58% inhibition, respectively, at 2 h pre-administration) which were comparable to or even slightly more potent than the reference drug ibuprofen (55%). Furthermore, the structure-activity relationship of these 1,2,4-triazole quinolines was demonstrated.