申请人:Sumitomo Chemical Company, Limited
公开号:EP1057810A1
公开(公告)日:2000-12-06
There is disclosed a method for producing an essentially enantiomerically pure N-protected-azetidine-2-carboxylic acid of formula (I):
which method is characterized by:
subjecting a crude enantiomerically excess N-protected-azetidine-2-carboxylic acid comprising said enantiomer represented by formula (1) in excess to the other enantiomer thereof to crystallization in an organic solvent selected from aromatic hydrocarbon, aliphatic ether, aliphatic alcohol, aliphatic ketone, aliphatic nitrile, aliphatic amide, aliphatic sulfoxide, aliphatic ester and a mixed solvent thereof,
wherein R is:
an optionally substituted alkyl, alicyclic or alicyclicalkyl group,
an optionally substituted alkenyl group,
an optionally substituted aryl group,
an optionally substituted heteroaryl group, or
a dialkylamino group and
absolute configuration of the asterisked asymmetric carbon atom is S or R.
本发明公开了一种生产基本对映体纯的式(I)N-保护氮杂环丁烷-2-羧酸的方法:
该方法的特征在于
将粗对映体过量的 N-保护-氮杂环丁烷-2-羧酸在选自芳香烃、脂肪醚、脂肪醇、脂肪酮、脂肪腈、脂肪酰胺、脂肪亚砜、脂肪酯及其混合溶剂的有机溶剂中结晶、
其中 R 是
任选取代的烷基、脂环基或脂环烷基、
任选取代的烯基
任选取代的芳基
任选取代的杂芳基,或
二烷基氨基,以及
星号不对称碳原子的绝对构型为 S 或 R。