The preparation of N-aryl-4-t-butylcyclohexylamines via anils

Abstract

Condensation of 4-t-butylcyclohexanone with aniline, p-anisidine and, less readily, p-nitroaniline, followed by reduction of the anils with sodium borohydride, gives mixtures of N-aryl-cis- and trans-4-t-butylcyclohexylamines in which the latter predominate. With 2β,6β-dibenzyl-4β-t-butylcyclohexanone (readily prepared by condensing 4-t-butylcyclohexanone with benzaldehyde and hydrogenating the dibenzylidene ketone) and the (±)-2β-benzyl ketone, anil formation is more difficult.

Structural assignments in this series are based on the n.m.r. of the 1-protons and the i.r. N–H stretching bands.