Preparation method of N-sulpho-N-carbobenzoxy-O-methane sulfonyl-L-threonine chlorseptol

The invention belongs to the technical field of medicine synthesis, and in particular relates to a preparation method of N-sulpho-N-carbobenzoxy-O-methane sulfonyl-L-threonine chlorseptol. The preparation method comprises the steps of adding an N-sulpho-N-carbobenzoxy-O-methane sulfonyl-L-threonine amide solid into a reaction still, adding an organic solvent, stirring and cooling, then adding methylsufonyl chloride and an acid-binding agent to obtain mixed reaction liquid, and adding chlorosulfonic acid for a temperature rise reaction, thus obtaining the N-sulpho-N-carbobenzoxy-O-methane sulfonyl-L-threonine chlorseptol after the solvent is dried by distillation. The preparation method is simple in technological operation, avoids the generation of waste water and waste gas, realizes green technology production, and is higher in product yield.