Gassman indole synthesis

The Gassman Indole synthesis is a variant of the Gassman reaction, which leads to substituted indoles. It was published first in 1973 by Paul G. Gassman.

Aniline, or mono-N- alkylated anilines are reacted in a first step with tert -butyl hypochlorite to give the corresponding N-chloro aniline, which in turn is reacted with a β - carbonyl, which may be the radical R2 is a alkyl or aryl group. The resulting product can then by adding a base, usually triethylamine, is converted to the desired product. The whole synthesis can be carried out as one-pot reaction without isolation of the intermediates. The thioether can by hydrogenolysis, for example, Raney nickel, simply be removed.