A One-Step Synthesis of 2,4-Unsubstituted Quinoline-3-carboxylic Acid Esters from <i>o</i>-Nitrobenzaldehydes

Abstract

A straightforward and efficient one-step procedure for the synthesis of 2,4-unsubstituted quinoline-3-carboxylic acid ethyl esters is described. The simple reductive cyclization is carried out by treating various substituted o-nitrobenzaldehydes with inexpensive, commercially available 3,3-diethoxypropionic acid ethyl ester and SnCl(2).2H(2)O in refluxing ethanol.