The invention relates to a preparation technique of
isosorbide, belonging to the technical field of
pharmacy. In the preparation technique,
solid sorbitol is used as the
raw material, a mixture of perfluoro-
sulfonic acid resin and
palladium on carbon is used as the catalyst, and
hydrogen is used as an anti-
carbonation agent to prepare the non-carbonized light-
colored isosorbide reaction liquid; and low-temperature concentration and
solvent crystallization are utilized to substitute the original high-temperature
distillation. The preparation technique comprises the following steps:
dehydration reaction,
neutralization decolorization,
electrodialysis desalination, water removal by concentration, extraction
crystallization, freeze-
drying, and quality inspection and packaging (after the product is qualified in inspection, packaging, and warehousing as the finished product). The invention can prevent
carbonization and prevent the reaction liquid from becoming dark, thereby enhancing the utilization ratio of the
raw material; most
calcium salts are precipitated due to low
solubility, and the electric
conductivity of the reaction liquid is low, thereby being beneficial to subsequent extraction; and the invention overcomes the defect of
high energy consumption in the high-temperature
distillation technique, and the quality of the prepared
isosorbide is more excellent.