Reductive Amination of 2,6-Diarylpiperidin-4-ones

Abstract

The 4-aminopiperidines are of considerable interest as analgesics, neuroleptics, and antihistamines. In the present investigation, reductive amination of 2,6-diaryl-3-methylpiperidin-4-ones was achieved in almost quantitative yield using sodium cyanoborohydride at room temperature. The product 4-amino-2,6-diaryl-3-methylpiperidines exist in chair conformation with an amino group in axial orientation. The products are characterized by various spectral and analytical techniques.

Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for full spectral details.

GRAPHICAL ABSTRACT

Keywords:

• Amination
• aminopiperidine
• conformation
• cyanoborohydride
• orientation
• piperidone

ACKNOWLEDGMENTS

The authors are thankful to the NMR Research Center, Bangalore, for spectral measurements. One of the authors, S.S., is thankful to the Cavinkare Research Center for a research fellowship.