| 摘要 |
A method of stably obtaining optically active phenylalanine anhydrous crystals is developed, and the anhydrous crystals having excellent handleability are produced. An inorganic salt or the like is added to an aqueous solution containing optically active phenylalanine to adjust an osmotic pressure pi to 10,500 - 450 T + 4.4 T<2> (T is a crystallization/precipitation temperature), after which the optically active phenylalanine is crystallized and precipitated to obtain phenylalanine anhydrous crystals. According to the present invention, optically active phenylalanine anhydrous crystals having excellent separability can be stably obtained. Since the optically active phenylalanine anhydrous crystals could be obtained so far in the low-temperature region, the improvement in the yield or the like is expected. Thus, it is quite advantageous in view of the industrial production. |
