L-161664

A series of N,N'-diacylpiperazine-2-carboxamides are shown to be antagonists of the NK-1 (Substance P) receptor.Elaboration of the C2 side chain with aminoalkyl groups leads to two series of potent antagonists, one containing simple dialkylamino groups and the second featuring 2-methoxybenzylamino derivatives with divergent SARs with respect to substitution at the C2 amide bond.