Abstract

Direct, preparative methods utilizing high-temperature aqueous media were developed for indole and indole-2-carboxylic acid from ethyl indole-2-carboxylate. Yields were excellent for these reactions, which were carried out in 1 h or less, at temperatures up to 270°C, in a microwave batch reactor of the authors" design. Avoidance of undesirable copper salts, high-boiling organic bases and heat-transfer oils made the methods environmentally benign.