Download PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... 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.