O-Acylbenzonitriles: Synthesis and Heterocyclization under Acid Hydrolysis of the Cyano Group

Abstract

2-Cyanobenzophenones were synthesized by reaction of 2-bromobenzophenones with copper(I) cyanide in DMF, and their transformations involving acid hydrolysis of the cyano group were studied. Reactions of o-benzoylbenzonitriles with trifluoroacetic acid in the presence or in the absence of sulfuric acid afforded 3-hydroxyphthalimidines in high yields. Under analogous conditions, benzonitriles having no acyl group in the ortho position were converted to the corresponding benzamides. 2-Cyanobenzophenones reacted with sulfuric acid in the absence of trifluoroacetic acid to give only substituted anthraquinones.