A simple one-pot synthesis of quinoline-4-carboxylic acids by the Pfitzinger reaction of isatin with enaminones in water

A simple one-pot method for synthesizing quinoline-4-carboxylic acids (3) by the reaction of enaminones (I) and isatin (2) using the Pfitzinger reaction conditions is described. Additionally, a plausible mechanism for this transformation is presented. (C) 2015 Elsevier Ltd. All rights reserved.