The invention relates to purification of (2S,3S)-3-[[(1S)-1-isobutoxymethyl-3-methylbutyl]carbamoyl]oxirane-2-carboxylic acid [hereinafter, referred to as the carboxylic acid] using the salt of the carboxylic acid with an organic amine selected from the group consisting of piperazine, adamantane amines and others. The invention also relates to providing crystalline sodium salt of the carboxylic acid. The sodium salt is usable as a material for preparing medicaments and improved in storage stability, and has the following characteristics:
DSC: exothermic peak observed at a temperature in the range of 170 to 175° C. with weight decrease; and
characteristic absorption bands of infrared absorption spectrum (KBr tablet) 3255, 2950, 2860, 1670, 1630, 1550, 1460, 1435, 1395, 1365, 1310, 1260, 1110, 890 cm−1.
本发明涉及使用来自于
吡啶、
金刚烷胺和其他有机胺的盐对(2S,3S)-3-[[(1S)-1-异丁氧甲基-3-甲基丁基]
氨基甲酰基]环氧
丙烷-2-
羧酸[以下简称
羧酸]进行纯化的方法。本发明还涉及提供
羧酸的晶体钠盐。该钠盐可用作制备药物的材料,并具有改善的储存稳定性,具有以下特征:
DSC:在170至175°C范围内观察到放热峰并伴随重量下降;以及红外吸收光谱(KBr片)的特征吸收带3255、2950、2860、1670、1630、1550、1460、1435、1395、1365、1310、1260、1110、890 cm-1。