申请人:Kim Moon-Sung
公开号:US20090281301A1
公开(公告)日:2009-11-12
The present invention relates to more improved process for preparing 2′-deoxy-2′,2′-difluoronucleoside and its intermediate. The present invention provide a process for preparing an erythro enantiomer in greater than 98% purity, comprising forming a lactone ring by hydrolyzing ethyl (3RS)-2,2-difluoro-3-hydroxy-3-(2,2-dimethyloxolan-4-yl)propionate is hydrolyzed in the presence of hydrolysis reagents selected from acetic acid or chloroacetic acid, water and a mixture of organic solvents selected from the group comprising acetonilrile, dioxane, tetrahydrofuran or toluene, introducing a substituted benzoyl protecting group at the 3-position and 5-position, and recrys- tallizing said erythro enantiomer. Further, the present invention provides a process for selectively preparing, in greater than 99% purity, a beta-anomer 2′-deoxy-2′,2′-difluoronucleoside at the 3′-position and 5′-position that are protected by a substituted benzoyl in a 2:3 alpha/beta anomeric ratio.
本发明涉及一种更改进的制备2'-去氧-2',2'-二氟核苷和其中间体的方法。本发明提供了一种制备大于98%纯度的鼠李糖对映体的方法,包括在乙酸或氯乙酸、水和丙腈、二噁英、四氢呋喃或甲苯等有机溶剂组成的混合物存在下,通过水解乙基(3RS)-2,2-二氟-3-羟基-3-(2,2-二甲氧杂环戊烷-4-基)丙酸酯形成内酯环,引入取代苯甲酰保护基于3-位和5-位,并重新结晶所述鼠李糖对映体。此外,本发明提供了一种选择性制备大于99%纯度的β-异构体2'-去氧-2',2'-二氟核苷的方法,其中3'-位和5'-位被取代苯甲酰保护,并在2:3α/β异构比率下。