One-Pot Synthesis of Quinoline-2(lH)-thiones from 2-Isocyanostyrenes via Electrocyclic Reaction of the Corresponding 2-Isothiocyanatestyrenes

摘要

The reaction of a-substituted 2-isocyanostyrenes, which could be readily prepared from commercially available 2-ami-nophenyl ketones or 2-aminobenzonitriles, with sulfur in the presence of a catalytic amount of selenium proceeded smoothly to give the corresponding 2-isothiocyanatestyrenes. The latter spontaneously underwent the electrocyclic reaction to afford 4-substituted quinolinc-2(lH)-thiones in one-pot with isolated yields ranging from 37 to 91%.