| 摘要 |
The invention concerns a new process for the preparation of apovincaminic acid ester derivatives of the general formula (I) <IMAGE> (I) wherein R1 and R2 independently represent an alkyl group having 1 to 6 carbon atoms, and pharmaceutically acceptable salts thereof. According to the invention the apovincaminic acid ester derivatives of the general formula (I) are prepared by reacting the corresponding 9- and/or 10- and/or 11-halo-14-oxo-15-hydroxyimino-E-homo-eburnane derivatives with an alkanol of the general formula R1-OH, wherein R1 is as defined above, and with a dehydrating concentrated acid, and subsequently reducing the 9- and/or 10- and/or 11-halo-apovincaminic acid esters obtained, selectively on the aromatic ring. Alternatively, the 9- and/or 10- and/or 11-halo-apovincaminic acid esters can also be used as starting materials. The invention includes the preparation of racemic and optically active apovincaminic acid ester derivatives and of their pharmaceutically acceptable salts, as well. |
