Aminoketone Rearrangements . 11 . The Rearrangement of Phenyl a - Aminoketonesl

Phenyl a-aminoketones have been shown to undergo carbon skeleton rearrangement to unconjugated aminoketones when heated a t 200-240". The probable intermediate is an unconjugated hydroxyimine formed by base removal of an amine hydrogen and migration of an alkyl group. The hydroxyimine can subsequently rearrange by base removal of a hydroxyl proton and migration of the phenyl grouping. An amine hydrogen has been shown to be necessary by the inactivity of tertiary aminoketones. Unconjugated hydroxyketones have been synthesized and converted to the corresponding unconjugated aminoketones by heating with methylamine at 200'. This lends evidence to the proposed hydroxyimine intermediate.