Convenient synthesis of fluorazone derivatives by one-pot pyrrolation/cyclization of anthranilic acids

A series of fused heterocyclic compounds based on a fluorazone structure has been prepared from anthranilic or ortho-aminoheteroaryl carboxylic acids by one-pot sequential pyrrolation/cyclization catalyzed by 4-chloropyridine hydrochloride, in generally good yield. (C) 2011 Elsevier Ltd. All rights reserved.