Crystalline form II of 7-(dimethoxy-methyl) camptothecin, its use as intermediate and products obtained therefrom

摘要

This invention relates to a process for preparing a crystalline form of (4S)-11(dimethoxymethyl)-4-ethyl-4-hydroxy-1H-pyrano[3′4′:6,7]indolizino[1,2-b]quinoline-3,14(4H,12H)-dione, also named 7-(dimethoxy-methyl)camptothecin). With the provision of a particular crystallization step, in appropriate way, a new crystalline form of the above compound is obtained. The process for the preparation of the polymorph Form II comprises transforming camptothecin to the corresponding 7-(dimethoxy-methyl)-camptothecin, and crystallizing from methanol.