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]qui-no line-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 it from methanol.
这项发明涉及一种制备(4S)-11-(二甲氧甲基)-4-乙基-
4-羟基-1H-
吡喃并[3',4':6,7]
吲哚并[1,2-b]喹诺啉-3,14(4H,12H)-二酮(又名7-(二甲氧甲基)
喜树碱)的晶型的方法。通过提供特定的结晶步骤,以适当的方式,得到了上述化合物的新晶型。制备多形式II的方法包括将
喜树碱转化为相应的7-(二甲氧甲基)-
喜树碱,并从
甲醇中结晶化。