申请人:American Cyanamid Company
公开号:US05245053A1
公开(公告)日:1993-09-14
A process is disclosed for obtaining the R,R isomer of: ##STR1## wherein R.sub.1 and R.sub.2 may be one or more groups which may be the same or different and are selected from the group consisting of hydrogen, C.sub.1 to C.sub.4 alkyl, C.sub.1 to C.sub.4 alkoxy, hydroxy, halogen, trifluoromethyl, carboxy, hydroxyalkyl, alkoxycarbonyl, C.sub.1 to C.sub.4 thioalkyl, sulfonyl and sulfinyl; X is a divalent radical consisting of ##STR2## wherein R' is hydrogen; R.sub.2 and R.sub.3 may be the same or different and are selected from the group consisting of hydrogen and C.sub.1 to C.sub.4 alkyl; R.sub.5 and R.sub.6 are selected from the group consisting of hydrogen, carboxy, alkoxycarbonyl, hydroxymethyl, --CH.sub.2 OCH.sub.2 COOR.sub.7 and --CH.sub.2 OCH.sub.2 CH.sub.2 OR.sub.7 where R.sub.7 is hydrogen or C.sub.1 to .sub.4 alkyl; except that R.sub.5 and R.sub.6 may not both be hydrogen; and the asterisks denote asymmetric carbon atoms; said process comprising the steps of: (a) reacting Mosher's acid with a compound of formula I to attach a group of the formula ##STR3## at the N-9 position of a mixture of (+) and (-) enantiomers of said compound to form a new pair of diastereoisomers; and (b) separating said new pair of diastereoisomers by HPLC and recovering the R,R isomer. The process is based on reacting Mosher's acid with the compound of formula I and thereafter using HPLC to separate the R,R isomer.
本发明公开了一种获得R,R异构体的方法:##STR1## 其中,R1和R2可以是一个或多个基团,可以相同也可以不同,选择自氢、C.sub.1到C.sub.4烷基、C.sub.1到C.sub.4烷氧基、羟基、卤素、三氟甲基、羧基、羟基烷基、烷氧羰基、C.sub.1到C.sub.4硫代烷基、磺酰基和亚磺酰基的群;X是一个二价基团,由##STR2##组成,其中R'是氢;R2和R3可以相同也可以不同,选择自氢和C.sub.1到C.sub.4烷基;R5和R6选择自氢、羧基、烷氧羰基、羟甲基、--CH.sub.2 OCH.sub.2 COOR.sub.7和--CH.sub.2 OCH.sub.2 CH.sub.2 OR.sub.7,其中R.sub.7是氢或C.sub.1到C.sub.4烷基;但R.sub.5和R.sub.6不能同时为氢;星号表示不对称碳原子;该方法包括以下步骤:(a)将Mosher酸与式I化合物反应,将##STR3##式的基团附加到该化合物的(+)-和(-)-对映体混合物的N-9位置,形成一对新的对映异构体;(b)通过HPLC分离所述新的对映异构体并回收R,R异构体。该方法基于将Mosher酸与式I化合物反应,然后使用HPLC分离R,R异构体。