In the production of ceftriaxone sodium, the third generation cephalosporins semisynthetic broad spectrum antibiotic, 2-mercapto benzothiazole retained in mother liquid organic solvent, then it was discharged to kettle residue after mother liquor distillation. 2-mercapto benzothiazole in kettle residue was distilled through using two different kinds of solvents, adjusting water bath temperature in dissolution and the proportion of solvent kevaporation in crystallization and having optimization and combination, finally the purified 2-mercaptobenzothiazole content is over 98%, recovery rate reached 76%, completely conforms to the commercial use, thereby improving the economic benefit and environmental benefit of ceftriaxone sodium.
