Synthesis and antihypertensive activity of novel 3-benzyl-2-substituted-3H-[1,2,4]triazolo[5,1-b]quinazolin-9-ones.

A series of 3-benzyl-2-substituted-3H-[1,2,4]triazolo[5,1-b]quinazolin-9-ones have been synthesized by the cyclocondensation of 3-amino-2-benzylamino-3H-quinazolin-4-one with a variety of one-carbon donors. The starting material 3-amino-2-benzylamino-3H-quinazolin-4-one was synthesized from methyl anthranilate by a novel innovative route. The title compounds were evaluated for their in vivo antihypertensive activity using spontaneously hypertensive rats (SHR). While all the test compounds exhibited significant antihypertensive activity, 3-benzyl-2-methyl-3H-[1,2,4]triazolo[5,1-b] quinazolin-9-one exhibited antihypertensive activity more than the reference standard prazocin.