Synthesis of 5-substituted indole derivatives.Part 3: A facile synthesis of 5-chloromethyl-1H-indole-2-carboxylates: replacement of sulfonic acid functionality by chlorine

摘要

Valuable new synthetic intermediates,5-chloromethyl-1H-indole-2-carboxylates,were prepared by the elimination of SO_2 from 2-ethoxycarbonyl-1H-indole-5-methanesulfonic acids,which are easily accessible by Fischer-type indolization.