Forward- and reverse-synthesis of piperazinopiperidine amide analogs: a general access to structurally diverse 4-piperazinopiperidine-based CCR5 antagonists†
Abstract
Piperazinopiperidine amide analogs are among the most promising CCR5 antagonists. As an effective extension of a previously-reported methodology to synthesize such compounds, forward- and reverse-syntheses were successfully developed in which the convergent synthesis of the piperazinopiperidine nucleus, with a building block of 4-substituent-4-aminopiperidine, served as a common key step. The two-way approach affords a comprehensive access to the piperazinopiperidine templated library with variation on the pharmacophore sites. Thus, a SAR study of our synthesized piperazinopiperidine-based CCR5 antagonists was conducted with respect to the structure and configuration of the substituent on the