Preparation method of dabigatran etexilate

The invention belongs to the technical field of medicine preparation and particularly relates to a preparation method of dabigatran etexilate. A compound 2 adopted in the preparation method has the characteristics of stable property, no pungent smell, low price and the like. According to the preparation method, the defect that anhydride or acyl chloride compounds are adopted in an existing synthetic route of dabigatran etexilate is overcome, and the compounds have the disadvantages of pungent smell, hygroscopicity and high anhydrous requirement on a reaction system. The reaction process is relatively easily operated and controlled, the synthetic route is short, the byproducts are few, and the cost is low. 本发明属于医药制备技术领域，特别涉及种达比加群酯的制备方法。本发明所采用的化合物2具有性质稳定、无刺激性气味，价格便宜等特点。克服了现有达比加群酯合成路线采用酸酐或者酰氯类化合物的缺陷，这类化合物的缺点是有刺激性气味、有吸湿性，对反应体系的无水要求高。本发明的反应过程更易操作和控制，合成路线短、副产物少、成本低廉。