SYNTHETIC APPLICATIONS OF 2-ARYL-4-PIPERIDONES .10. SYNTHESIS OF 3-AMINOPIPENDINES, POTENTIAL SUBSTANCE-P ANTAGONISTS

A general method is described for the synthesis of 3-aminopiperidines from 4-piperidones based on a KOEt treatment of the tostylate of the c orresponding oximes (Neber rearrangement). The procedure is applied to the synthesis of N-benzyl-3-amino-4,4-diethoxypiperidine (13), (R)-N- (2-hydroxy-1-phenyl)ethyl analogues 18, and 2-phenyl derivatives 27-28 . The methoxybenzylation of the primary amino group of these aminopipe ridines leads to a series of potential substance P antagonists.