Preparation, Characterization and Stereochemistry of Mixed Anhydrides of O-Alkylbenzohydroximic Acid

A number of stable isoimides have been prepared by acylation and sulfonylation of O-benzylbenzohydroxamic acid and O-butylbenzohydroxamic acid by anisoyl chloride, benzoyl chloride, phenoxyacetyl chloride, p-toluenesulfonyl chloride, benzenesulfonyl chloride and p-nitrobenzenesulfonyl chloride in the presence of pyridine. Spectral investigations indicate that the products have the mixed anhydride structure with (Z)-configuration. Corresponding (E)-isomers and isomeric N-acetylated products if formed, could not be isolated. An attempt has been made to study 1,3-rearrangement of the mixed anhydrides by thermal method.