Manufacturing Process of 2' ,2' - Difluoronucleoside and Intermediate
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.