Abstract
Anodic oxidation of several imidate esters (I) was investigated at a glassy carbon electrode in acetonitrile. On cyclic voltammetry, I showed one, two, or three anodic peaks depending upon the structure. Controlled potential electrolysis of methyl N-p-methoxyphenylbenzimidate (Ic) at the potential of the first anodic peak gave p-benzoquinone and methylbenzoate, together with the protonated starting material. Electrolysis of Ic and methyl N-phenylbenzimidate (Ia) in the presence of excess pyridine gave pyridinated imidate esters in which the pyridinium group is attached to the aniline ring. An intramolecular cyclization reaction to form spirodienones was observed on electrolysis, in the presence of perchloric acid, of aryl N-p-methoxyphenylbenzimidates with aryl groups of low oxidation potential (Ie-g). Possible mechanisms for the reactions are discussed.
