The dihydroquinone derivatives of piperidine and piperazine are 7-piperazinyl and 7-piperadinyl-3,4-dihydroquinazolin-2(1H)-ones that exhibit D2 and 5-HT1A receptor binding affinities, making them suitable for use as the active ingredient of pharmaceuticals for the treatment of schizophrenia. The derivatives have the general formula: where X is carbon or nitrogen and R is a group selected from a through f having the formula: or a pharmaceutically acceptable salt thereof. The piperazine compounds are prepared by condensing 4-bromo-2-nitro-benzonitrile with 1-Boc-piperazine (1-tert-butoxycarbonyl-piperazine) to form an intermediate that is converted to a piperazinyl-3,4-dihydroquinazolin-2(1H)-one. Subsequent reductive amination with the biarylaldehydes a through f completes the synthesis of the 7-piperadinyl-3,4-dihydroquinazolin-2(1H)-ones. The piperadinyl compounds are prepared from tert-butyl-4-(2-oxo-1,2,3,4-tetradihydroquinazolin-7-yl)piperidine-1-carboxylate, which is converted to 7-(piperidin-4-yl)-3,4-dihyroquinazolin-2(1H)-one. Subsequent reductive amination with the biarylaldehydes a through f completes the synthesis of the 7-piperidinyl-3,4-dihydroquinazolin-2(1H)-ones.