ELECTROLYTIC OXIDATION OF KETONES IN AMMONIACAL METHANOL IN THE PRESENCE OF CATALYTIC AMOUNTS OF KI

The indirect electrooxidation of ketones in ammoniacal methanol using iodide ion as a mediator afforded 2,2-dialkyl-2,5-dihydro-1H-imidazoles 3 via an oxidative cyclocoupling of ketimine intermediates formed from ketones and ammonia. The treatment of 3 with dilute HCl gave alpha-amino ketone hydrochlorides 4 and the parent ketones in good yields. A similar electrooxidation of 3 resulted in the formation of the corresponding W-imidazoles 6, which were hydrolyzed to alpha-diketones and the parent ketones. The same products 6 could also conveniently be obtained by chemical oxidation of 3 with aqueous NaOCl.