| 摘要 |
A process for preparing a compound of formula (3), comprising: providing an aqueous acidic solution comprising a compound of formula (1) and an impurity of formula (2); and hydrogenating the aqueous acidic solution in the presence of a hydrogenation catalyst such that the compound of formula (2) dehydrates to form a compound of formula (1) and the compound of formula (1) is reduced to form an aqueous acidic solution of the compound of formula (3); wherein the hydrogenation is carried out at one or more temperatures greater than ambient, preferably 75-100 °C; and wherein for the compounds of formulae (1), (2) and (3): i) R1 is —OH, R2 is —OH and R3 —H; or ii) R1 is —OCH3, R2 is —H and R3 —CH3; or iii) R1 is —OH, R2 is —H and R3 —CH3, or iv) R1 is —OCH3, R2 is —H and R3 —H; or v) R1 is —OH, R2 is —H and R3 —H; or vi) RI is —OCH3, R2 is —OH and R3 —H. Preferably the reaction comprises a two step hydrogenation of nor-14-hydroxymorphinone to noroxymorphone in the presence of phosphoric acid and a palladium on carbon (Pd/C) catalyst where the first hydrogenation takes place at ambient temperature and the second at 75-100 °C. |
