Process for the preparation of 9-amino camtothecin

摘要

9-Amino-20(S)-camptothecin (I) is prepared by reducing 12-nitro-20(S)-camptothecin (II); converting the resulting 12-amino-20(S)-camptothecin (III) into a compound of formula (IV)whereinX is a group which can be reductively removed; reacting the compound of formula (IV) with a nitrating agent, to obtain thereby the corresponding 9-nitro-20(S)-camptothecin compound of formula (V) substituted at the 12-position by the group X; reducing in a single step the compound of formula (V), so obtaining the 9-amino-20(S)-camptothecin of formula (I); or reducing the compound of formula (V), so obtaining the corresponding 9-amino-20(S)-camptothecin compound of formula (VI) substituted at the 12-position by the group X and reductively removing the X group from the compound of formula (VI), so obtaining 9-amino-20(S)-camptothecin.