Synthesis and positive inotropic evaluation of 2-(4-(4-substituted benzyloxy)-3-methoxybenzyl)-1,4-diazepan-1-yl)-N-(4,5-dihydro-1-methyl[1,2,4]triazolo[4,3-a]quinolin-7-yl)-acetamides.

In an attempt to search for more potent positive inotropic agents, a series of 2-(4-(4-substituted benzyloxy)-3-methoxybenzyl)-1,4-diazepan-1-yl)-N-(4,5-dihydro-1-methyl[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamides was synthesized and their positive inotropic activities were evaluated by measuring left atrium stroke volume on isolated rabbit-heart preparations. Several compounds showed favorable activity compared with the standard drug Milrinone among which 2-(4-(4-(2-chlorobenzyloxy)-3-methoxybenzyl)-1,4-diazepan-1-yl)-N-(4,5-dihydro-1-methyl-[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamide 6e was found to have the most desirable potency with the 6.79 +/- 0.18% increased stroke volume (Milrinone: 1.67 +/- 0.64%) at a concentration of 1 x 10(-5) M in our in-vitro study. The chronotropic effects of those compounds having inotropic effects were also evaluated in this work.