PREPARATION PROCESS OF ISOSORBIDE DINITRATE

The invention belongs to the technical field of medicine synthesis, and particularly relates to a preparation process of isosorbide dinitrate. The preparation process comprises the following steps: evaporating a sorbitol solution at normal pressure to remove water, dehydrating and cyclizing under the action of sulfuric acid to obtain dehydrated sorbitol, and reacting the dehydrated sorbitol with nitric acid to obtain isosorbide dinitrate. According to the preparation process of isosorbide dinitrate, when the sorbitol is dehydrated, the dehydration temperature is controlled, so that the dehydration reaction of the sorbitol is complete; when the distillate is collected, the vacuum degree is controlled, and the temperature range for collecting the distillate is reduced, so that the quality of sorbitan can be improved; and in the synthesis and preparation of a crude product, the dropping speed of the ice hydrolysis and the stirring speed of an ice hydrolysis kettle are controlled, so that the ice hydrolysis crystallization is uniform, and impurities are not easy to separate out, thereby improving the quality and yield of the crude product.