| abstract |
Process for the preparation of 3,14 beta -dihydroxy-17-normorphinan <IMAGE> (I) A suitable economic process for the preparation of 3,14 beta -dihydroxy-17-normorphinan of a general formula (I) is being solved, which is a key intermediate of a semisynthetic synthesis of an effective analgesic of Butorphanol from thebaine. Synthesis includes a two step N-demethylation, and concerted dephenoxylation of 4-phenoxy-14 beta -hydroxy-3-methoxymorphinan in the first step by means of a chloroformate, then, in the second step, by means of sodium action in a liquid ammonia, and by means of the following O-demethylation under action of a complex of aluminium chloride - dialkylsulfide. |