A process for the preparation of cladribine of API grade is provided by direct coupling of O-protected 2-deoxy-ribofuranose with silylated 2-chloroadenine followed by deprotection of the resultant protected nucleoside in a separate step and then a purification step. Following the coupling, the desired N-9-glycosylated β-anomer of the nucleoside is directly isolated as a solid from the coupling reaction mixture by filtration in relatively high purity and yield, and it does not require purification.
提供一种制备A
PI级别的克拉德利宾的方法,通过保护O-2-去氧
核糖与
硅烷化的2-
氯腺嘌呤直接偶联,然后在单独的步骤中去保护所得的保护核苷,然后进行纯化步骤。在偶联后,所需的核苷的N-9-糖基化β异构体可以通过过滤在相对高的纯度和收率下直接从偶联反应混合物中固态分离,而且不需要纯化。