Preparation method of cefotiam hydrochloride crude product

The invention belongs to the field of medicament antibiotics, and particularly relates to a preparation method of a high-purity cefotiam hydrochloride crude product. The preparation method comprises the following steps of: taking ATA-HCl and a vilsmeier reagent as raw materials to prepare ATC-HCl; and (2) reacting 7-dimethyltryptamine (DMT) with ATC-HCl in an alkaline aqueous organic solvent, precisely filtering, adding acetone in the filtrate, and growing crystal to obtain the cefotiam hydrochloride crude product. According to the method, a precise filter technology is adopted, thus improving the purity of the crude product and reducing the content of impurities; and the method is simple and low in cost.