Synthesis method of 5-substituted-4-sulfur-2',3',5'-O-tri-tert-butyldimethylsilyl nucleoside compound

The invention belongs to the technical field of chemical synthesis, and relates to a synthetic method of a 5-substituted-4-sulfur-2',3',5'-O-tri-tert-butyldimethylsilyl nucleoside compound. The preparation method comprises the following steps: under the protection of nitrogen, a 5-substituted nucleoside compound reacts with tert-butyldimethylsilyl chloride (TBSCl), post-treatment is performed after the reaction, and a compound a is obtained; and the compound a reacts with P2S5 and NaHCO3 which are dissolved in a diethanol dimethyl ether solvent, and a yellow solid b is obtained. The synthesismethod has the advantages of short reaction time, specific product, high reaction yield, few byproducts, simple post-treatment and the like, a pyridine solvent with high toxicity and foul smell is prevented from being usedin the synthesis process, a 1, 4-dioxane solvent with high boiling point is prevented from being used, a Lawesson's reagent which is easy to deteriorate and has many reaction byproducts is prevented from