INTRAMOLECULAR AMIDATION OF ARYLALKYLHYDROXAMIC ACIDS

Article abstract of DOI:10.1007/BF00514464

It is shown that mixtures of two isomeric benzolactams, viz., compounds of the benzamide and anilide type, are formed in the intramolecular amidation of arylalkylhydroxamic acids under the influence of polyphosphoric acid (PPA).A general reaction scheme that includes three pathways, viz., direct amidation, Losen rearrangement of the hydroxamic acids with subsequent cyclization of the isocyanates, and Beckmann rearrangement of the oximes of the cyclic ketones formed in the thermal cleavage of the starting hydroxamic acids in PPA, is proposed on the basis of a study of racemic and optically active arylalkylhydroxamic acids.