Process for preparing L-ofloxacin and ofloxacin

Abstract

The invention relates to a process for preparing L-ofloxacin and ofloxacin which consists of, charging solution into 2-(2,3,4,5-tetrafluorobenzoyl-3-ethoxy-ethyl acrylate crude product, freezing, dropping L-amino propanol or DL-amino propanol, thermal insulating till the completion of conversion, alkalizing, reacting at the temperature of 50-90 deg. C, charging N-methyl piperazine into mother liquor, stirring for reaction 1-3 hours at 55-95 deg. C, decompressing and reclaiming N-methyl piperazidine, thermal insulating, plunging reaction liquor into water, agitating, cooling down and filtering, charging water and acid into filtrate, stirring, inversing flow till the completion of hydrolysis, adjusting the pH=7.0 with alkali liquor, extracting by adding in solvent extraction reagent, and concentrating the extract layer.

Description

technical field

[0001] The invention belongs to the field of chemistry, in particular to a preparation method of levofloxacin and ofloxacin. Background technique

[0002] Fluoroquinolones have achieved great success in clinical anti-infection treatment due to their high-efficiency, broad-spectrum, and low-toxic antibacterial properties. Ofloxacin and levofloxacin developed by Japan's Daiichi Pharmaceutical Company are excellent varieties among them . Levofloxacin, English name: Leovfloxacin, molecular formula: C 18 h 20 FN 3 o 4 1 / 2H 2 O, the structural formula is as follows:

[0003]

[0004] Ofloxacin, English name: Floxacin, molecular formula: C 18 h 20 FN 3 o 4 , the structural formula is as follows:

[0005]

[0006] The synthesis of levofloxacin mainly contains the following three methods:

[0007] 1. Resolution method: including high-pressure liquid phase resolution EP206283 (1986) and enzyme resolution (K, Sakano, Agina Biol.chem.: 1987, 51, 1265). ...

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