| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for crystallizing a vitamin D derivative represented by formula (I), the method being carried out more economically and in a shorter time than the conventional technique. <P>SOLUTION: A crude vitamin D derivative represented by formula (I) is dissolved, at room temperature, in a carboxylic acid (acetic acid or propionic acid) at a proportion of 1 g of the former to 10-50 ml of the latter, and then an adequate poor solvent (hydrocarbon or water) is added to deposit the crystal of the vitamin D derivative. Then, the deposited crystal is filtrated and dried to gain the crystal of the vitamin D derivative which is high in purity. The method gains the objective crystal at a shorter time and at a higher yield than the conventional method. <P>COPYRIGHT: (C)2012,JPO&INPIT |
