Abstract: A method for synthesizing florfenicol comprises the steps of cyclization, selective reduction, fluorination, ring opening, deprotection, acylation, esterification with sulfonic acids, epimerization and hydrolysis. Florfenicol is prepared by successively purifying, selectively reducing, and epimerizing chiral (R)-amino ketones. This improves atom economy, reduces waste water pollution and accordingly reduces costs for treating waste water and pollution to the environment, thus lowering costs and simplifying the process. Furthermore, triethylamine hydrofluoride is used as a fluorinating reagent, resulting in improved safety, because of the use of liquid reaction conditions as compared to gaseous reaction conditions, and reduced corrosion to the reaction equipment.

Abstract: The present invention discloses a new florfenicol synthesizing method. The method synthesizes florfenicol products meeting requirements of the Drug Administration by a series of combinations of cyclization, selective reduction, fluorinated open ring, deprotection and acylation, hydroxyl sulfoacid esterified configuration converting reaction, hydrolysis reaction and the like. The synthesizing method of the present invention utilizing chiral amine closed-ring aziridine three-membered ring uses a physical separation method to repeatedly purify chiral aminoketone of high yield obtaining single R configuration, and uses selective reduction and converts the configuration to obtain florfenicol, greatly improving atom economy, while avoiding waste water pollution caused by the existing process, and greatly reducing costs for treating waste water and reducing pollution to the environment, thus lowering costs and simplifying the process.