Two series of N-substituted spiperone analogues were prepared and evaluated in vitro to measure their affinities for dopamine D2 and serotonin 5-HTz receptors. Substitution of the amide nitrogen with an alkyl group of five carbon units or less resulted in analogues displaying a low selectivity for D2 compared to 5-HT2 receptors. However, a moderate improvement in selectivity for D2 receptors was observed with N-benzylspiperone. ...
