Facile Preparation of 5-(3-Indolylmethylene) hydantoins

Abstract

A facile preparation of 5-(3-indolylmethylene) hydantoins, which are useful intermediates for syntheses of tryptophan and its derivatives, was achieved by condensation of hydantoin with 3-(aminomethylene)-3H-indoles formed in situ by the reaction of indoles with Vilsmeier-Haack reagent followed by neutralization with anhydrous bases.