Aromatization of Benzamide 1,2-Oxide and N,N-Dimethylbenzamide 1,2-Oxide

Article abstract of DOI:10.1021/jo00210a005

The mechanisms for aromatization of the title compounds have been investigated through product studies and studies with the deuterium-labeled arene oxides.Results from the primary amide 6 show that the relative amounts C1-O and C2-O cleavage under acidic and neutral conditions are similar to those observed previously for the corresponding methyl ester and carboxylic acid derivatives.Aromatization of the cation derived from initial C2-O cleavage occurred by both substituent loss and substituent migration; substituent loss was the major pathway under acid-catalyzed conditions and the minor pathway under neutral conditions.Substantially more C1-O cleavage was observed with arene oxide 7.For the reaction proceeding via C2-O cleavage of 7, substituent loss predominated over substituent migration at pH 0.1, but only substituent migration was observed at higher pH (4.0, 7.0).