N-substituted 1-aminoindoles from electrogenerated N-substituted 2-(ortho-nitrosophenyl)ethylamines

An electrochemical methodology offering efficient access to N-alkyl- and N- aryl-substituted 1-aminoindoles has been developed. N-Substituted 2-(ortho- nitrosophenyl) ethylamines, electrogenerated in a "redox" flow cell, underg o intramolecular cyclization to hydrocinnoline-type intermediates. Under sl ightly basic conditions, these undergo spontaneous ring-contraction to prod uce the N-substituted heterocycles in good yields. The reactions have been studied in slightly acidic and slightly basic aqueous alcoholic media.