Pyrimidinone, oxazolidinone, and (alkyl)aryl derivatives, their synthesis, and their use as alpha 1a adrenergic receptor antagonists are disclosed. One application of these compounds is in the treatment of benign prostatic hyperplasia. These compounds are selective in their ability to relax smooth muscle tissue enriched in the alpha 1a receptor subtype without at the same time inducing hypotension. One such tissue is found surrounding the urethral lining. Therefore, one utility of the instant compounds is to provide acute relief to males suffering from benign prostatic hyperplasia, by permitting less hindered urine flow. Another utility of the instant compounds is provided by combination with a human 5-alpha reductase inhibitory compound, such that both acute and chronic relief from the effects of benign prostatic hyperplasia are achieved. Among the disclosed derivatives are piperidinyl aminoalkylpiperidinyl pyrimidinones, including those of formula: R1 is selected from unsubstituted, mono- or poly-substituted phenyl wherein the substituents on the phenyl are independently selected from halogen, CF3, cyano, nitro, N(R7)2, NR7COR19, NR7CON(R19)2, NR7SO2R19, NR7SO2N(R19)2, OR6, (CH2)0-4CO2R7, (CH2)0-4CON(R7)2, or C1-4 alkyl; or unsubstituted, mono- or poly-substituted pyridyl, pyrazinyl, thienyl, thiazolyl, furanyl, quinazolinyl or naphthyl wherein the substituents on the pyridyl, pyrazinyl, thienyl, thiazolyl, furanyl, quinazolinyl or naphthyl are independently selected from CF3, cyano, nitro, amino, (CH2)0-4CO2R7, (CH2)0-4CON(R7)2, (CH2)0-4SO2N(R7)2, (CH2)0-4SO2R6, phenyl, OR6, halogen, C1-4 alkyl or C3-8 cycloalkyl; m and p are each integers from zero to two, wherein the sum m+p=2; n and o are each integers from zero to two, wherein the sum n+o=2; q is an integer of from zero to three, provided that when q is zero, R26 is hydrogen; s is an integer of from zero to four; and E, G, J, L, M, W, X, R2, R3, R4, R5, R6, R7, R8, R11, R12, R13, R14, R15, R16, R19 and R26 are defined herein.