7472-61-9Relevant academic research and scientific papers
Stereoselective N-glycosylation with N4-acyl cytosines and efficient synthesis of gemcitabine
Liu, Tongchao,Tang, Jiadeng,Liang, Jianpeng,Chen, Yabin,Wang, Xiaowen,Shen, Jingkang,Zhao, Dongmei,Xiong, Bing,Cen, Jun-Da,Chen, Yue-Lei
, p. 1203 - 1213 (2019/01/29)
Through systematical comparison of various N4-protected cytosine derivatives in the glycosylation step of gemcitabine synthesis, highly beta-stereoselective and high yielding TBAI catalyzed N-glycosylation was achieved with N4-Bz cytosine and anomeric mixture of 2,2‘-difluororibose mesylate donor. The subsequent global deprotection gave gemcitabine efficiently. Meanwhile, the anomeric chloride intermediate and fluoride-displaced side products of this N-glycosylation were identified, too. This new glycosylation method reveals the importance of N4-protection in the stereoselective preparation of pyrimidine nucleoside, also provides a potential alternative to current industrial process to gemcitabine.
Preparation method of cytidine
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Paragraph 0057-0060, (2019/12/10)
The invention provides a preparation method of cytidine 1, which comprises the following steps: (1) carrying out a condensation reaction on a compound 6 and a compound 7 in the presence of stannic chloride to generate a compound 8; (2) removing an alpha-isomer and other reaction impurities in the compound 8 to obtain the beta-isomer compound 8; and (3) carrying out a deprotection reaction on the beta-isomer compound 8 in the presence of an alcohol solvent, and then carrying out a salt forming reaction with hydrochloric acid to obtain a compound 1. The nucleoside compound 8 can be obtained withhigh beta-stereoselectivity starting from a cheap raw material 7 with a mixed anomeric carbon configuration, especially the raw material 7a, and a slightly excessive basic group 6, especially the basic group 6a; the trace alpha-compound 8 isomer impurities can be removed from the nucleoside compound 8 through a simple pulping method; and subsequently, deprotection and salifying reactions for beta-compound 8 have high yield, so that the method can reduce the production cost of the compound 1.
