摘要 |
A new Process of preparing cisapride, and the pharmaceutically acceptable acid addition salts thereof, by reductively aminating 1-[3-(4-fluorophenoxy)-propyl]-3-methoxy-4-piperidinone in the presence of benzylamine under hydrogen in a reaction-inert solvent, yielding 1-[3-(4-fluorophenoxy)-propyl]-3-methoxy-4-piperidinamine having a cis/trans ratio of about 93/7, which is enriched in the amount of cis-stereoisomer by converting it into its acid addition salt, by treatment with a suitable inorganic acid, in an appropriate solvent, subsequent crystallisation and conversion to its free base form by treatment with an appropriate base, yielding 1-[3-(4-fluorophenoxy)-propyl]-3-methoxy-4-piperidinamine having a cis/trans ratio of equal to or higher than 98/2. |