A series of 1, 3-disubstituted 2, 4(1H, 3H)-quinazolinediones was prepared from the 3-substituted 2, 4(1H, 3H)-quinazolinediones by treatment with sodium hydride and the desired alkyl halide in xylene. These compounds showed varying degrees of vasodilation and antihypertensive activity without significant blockade of α-adrenergic receptors. 1-[3-(N, N-Dimethylamimo)propyl]-3-[3-(4-phenyl-1-piperazinyl)propyl]-2, 4(1H, 3H)-quinazolinedione, which was selected for further studies, was more potent than papaverine in inducing vasodilation and induced a prolonged decrease in systolic blood pressure of hypertensive rats upon oral administration. © 1979, American Chemical Society. All rights reserved.
