The Improvement Study On Process Of Synthesizing 1-Cl-2-Deoxy-3,5-bis(-O-p-chlorobenzoyl)-D-Ribofuranose

In the medical field,Zidovudine and Stavudine are a good curative effect of antiviral drugs.Research shows that ?-thymidine is a kind of indispensable intermediate in the process of preparation of the drug.Meanwhile,1-chloro-2-deoxy-3,5-bis(-O-p-chlorobenzoyl)-D-ribofuranose is a necessary raw material for the preparation of ?-thymidine.Therefore,it is very important to optimize the synthesis method.1-chloro-2-deoxy-3,5-bis(-O-p-chlorobenzoyl)-D-ribofuranose was prepared with 2-deoxy-N-phenyl pentosamine as raw material via hydrolyzation,methylation,esterification,chlorination.In the actual production process,some critical steps are characterized with poor yields,time-consuming process and rigorous reaction conditions.What's more,the use of a great number of highly toxic materials and large quantity of waste make it difficult to meet the environmental and economic requirements.From these angles,This paper explore from different aspects and get a better synthetic method.Include,during the preparation of methyl thymus indican,one-step reaction was used instead of previous two-step one,and get a better condition from the study of the reaction temperature,the water content of the reaction system and the amount of catalyst.Not only simplified the process line,reduced the kinds of raw material,reaction time and the energy consumption,but also increased the yield by 2.85%.In the preparation of 1-O-methy-2-deoxy-3,5-bis(-O-pchlorobenzoyl)-D-ribofuranose,HCl was removed by vacuum system instead of triethylamine.At the same time,get a better condition from the analyze of the reaction temperature,the pH valve of the reaction system.And ensured that the process has a good environmental protection.In addition,using the reaction of acetyl chloride and concentrated hydrochloric acid in the system to get dry HCl,in the preparation of 1-chloro-2-deoxy-3,5-bis(-O-p-chlorobenzoyl)-D-ribofuranose,which can not only accurately control the reaction process,improve the safety coefficient,but also reach a yield of 96% which is 6% higher than the previous process.In this paper,the synthesis process is optimized by the above aspects.To a certain extent,the environmental protection and economic benefits are improved,and have an important significance for the large-scale production in the future.