Metazocine

The benzomorphan, metazocine (6), can be obtained from a variation of the morphinan synthesis. : Reaction of the Grignard reagent from p-methoxybenzyl chloride (1) with the lutidine methiodide (2) affords the benzylated dihydropyridine (3). Reduction of the enamine π-bond leads to the tetrahydropyridine (4). Cyclization by means of acid leads directly to the benzomorphan ring system (5). Demethylation of the aromatic ring system gives the phenol. Although this last compound is in fact a relatively potent analgesic, it is not available commercially as a drug. Also see: ==See also==