Method for synthesizing ridecevir

The invention relates to a method for synthesizing ridecevir. The method comprises the following steps of: adding (2R, 3R, 4S, 5R)-2-(4-aminopyrrole [2, 1-f] [1, 2, 4] triazine-7-yl)-3, 4-dihydroxy-5-(hydroxymethyl) tetrahydrofuran-2-carbonitrile, 2, 2-dimethoxypropane and a first acid catalyst into a first solvent, stirring, protecting ortho-dihydroxyl by using 2, 2-dimethoxypropane to synthesize an intermediate 4, and adjusting alkali and cooling after the reaction is finished; adding anhydrous magnesium chloride and the intermediate 7 into the reaction, introducing nitrogen flow for protection, uniformly stirring, dropwise adding an alkali catalyst, heating and stirring to synthesize an intermediate 5, and performing extraction and liquid separation after the reaction is finished; and dropwise adding a second acid catalyst in the reaction, stirring, and carrying out post-treatment to obtain a crude ridecevir product. The three-step reaction takes the first solvent as a medium for reaction, and after the th