The present invention provides with a process of preparing an optically active succinimide derivative, which is a key intermediate for production of ranirestat. A compound (3) is easily prepared by treating the derivative of succinic acid diester of the formula (2):
wherein R
1
is an amino group protected with a group removed by hydrogenolysis or a tert-butoxycarbonylamino group and R
2
is an ethyl group optionally substituted with one or two methyl group(s) at α-position, provided that R
2
is not a tert-butyl group when R
1
is a tert-butoxycarbonylamino group; with alkali metal alkoxide and the compound (3) can be an important intermediate for production of ranirestat.
本发明提供了一种制备光学活性琥珀
酰亚胺衍
生物的方法,该衍
生物是生产拉尼瑞斯塔的关键中间体。通过处理公式(2)的
琥珀酸二酯衍
生物,可以轻松制备化合物(3):其中R1是通过氢解去除的保护
氨基或叔丁氧羰基
氨基,R2是在α位上可选地取代一个或两个甲基的乙基基团,但当R1是叔丁氧羰基
氨基时,R2不能是叔丁基基团。使用碱
金属醇盐处理化合物(3),可以得到生产拉尼瑞斯塔的重要中间体。