Preparation method of acotiamide intermediate

The invention belongs to the field of medicines, and concretely relates to a preparation method of an acotiamide intermediate. The method comprises the following steps: preparing acyl chloride from 2,4,5-trimethoxybenzoic acid, condensing acyl chloride and thiourea, and carrying out ring closure on the obtained material and haloalkyl pyruvate to prepare the acotiamide intermediate compound I. The structural formula of the acotiamide intermediate is shown in the description. A simple and easily available initial raw material is used in the invention, so the production cost is reduced. The method has the advantages of advanced process route, mild reaction conditions, high reaction yield, few three wastes, no expensive or toxic reagents, easy separation and reuse of a reaction solvent, indiscriminate application of the reaction solvent after distillation, easy industrial production, large enforcement values, and large social, economic and environmentally-friendly benefits.