摘要 |
The present invention relates to a method for the preparation of mirtazapine and tetracyclic analogous compounds having substantial enantiomeric excess of the R or S form. The invention further relates to a novel intermediate and its use for the preparation of mirtazapine having a substantial enantiomeric excess of the R or S form. The method comprising the steps of a: providing a carboxylic acid compound according to Formula I having a substantial enantiomeric excess of the R or S form, b: converting the carboxylic acid group of compound I into a ketone group, producing a ketone compound of Formula II, c: optionally reducing ketone compound II with a mild reduction agent to form the intermediate hydroxy compound of Formula III and d: forming the mirtazapine of Formula IV by reduction of the ketone compound II or of the hydroxy compound III using a strong reduction agent.
|