NEW OXIDATIVE REACTIONS OF 1,2,3,6-TETRAHYDROPYRIDINES - IMINATION, LACTAMINATION AND DECYCLISATION IN THE PRESENCE OF POTASSIUM-PERMANGANATE

A novel oxidative imination reaction of 1-methyl-4-phenyl-1,2,3,6-tetr ahydropyridine 1a by 4-nitroaniline/potassium permanganate has been fo und to occur yielding 2-(4-nitrophenyl)imino -1,2,5,6-tetrahydropyridi ne 4; in the absence of nitroaniline the shorter reaction time allows the reaction to be stopped at the unsaturated lactam 5 formation stage ; the oxidation of la hydrochloride leads to l-(N-formyl-N-methyl)amin o-3-phenylpropan 6 via decyclisation-elimination steps, providing a ne w method for N-formyl-substituted aminoketone synthesis.