Syntheses of beta,beta-difluorotryptamines

Abstract

Tryptamines disubstituted at the beta-position with fluorine have been synthesized as part of our research program to study the effects of fluorine substitution on the biological activities of neuroactive amines. Treatment of N-Boc-3-azidoacetyl indoles, prepared from readily available 2-chloracetylindoles, with dimethoxyethylamino sulfurtrifluoride produced the corresponding 3-(2-azido-1,1-difluoroethyl)indoles. Reduction of the azide to amine with hydrogen over Pd-C and careful removal of the N-Boc protecting group produced beta,beta-difluorotryptamines.