Novel method for synthesizing prulifloxacin

Abstract

The invention relates to a method for synthesizing prulifloxacin of formula (I) with a chemical name of 6-fluoro-1-methyl-7-[4-(5-Methyl-2-oxo-1,3-dioxol-4-yl)methyl-1-piperazinyl]-4-oxo-4H-[1,3]thiazeto[3,2-a]quinoline-3-carboxylicacid. The method for synthesizing prulifloxacin is suitable for industrial production and has the advantages of simple process, high purity and high yield.

Description

technical field [0001] The present invention generally relates to a novel synthetic method of quinolone antibacterial drugs, more specifically, the present invention relates to a method for synthesizing the following formula (I) prulifloxacin (prulifloxacin) [chemical name: 6-fluoro-1-methyl- 7-[4-(5-methyl-2-oxo-1,3-dioxol-4-yl)methyl-1-piperazinyl]-4-oxo-4H-[1, 3] A new method for thiazetidin[3,2-a]quinoline-3-carboxylic acid]. [0002] Background technique [0003] Since the advent of quinolone antibacterial drugs in the 1960s, they have become a large class of commonly used anti-infection drugs widely used in clinical practice. Due to the advantages of broad antibacterial spectrum, strong antibacterial power, simple structure, convenient administration, no cross-resistance with other commonly used antibacterial drugs, and high curative effect and price ratio, this kind of drugs has attracted more and more attention and has become the field of research and development...

AI Technical Summary

Problems solved by technology

[0008] Disadvantages: The first route has long reaction steps, and special reagent EtOMgCH(CO 2 Et) 2 ; At the same time, the route is also more polluting to the environment

[0011] Disadvantages: The reaction process of the second route requires a -78°C ultra-low temperature reaction, which is extremely unfavorable for scientific research and industrial production, and should not be used

[0015] Disadvantages: Although the third route has relatively short reaction steps, it must use the special reagent N-carboxylate triethylamine salt, which is difficult to meet large-scale production

[0018] Disadvantages: The fourth route has no special reaction during the synthesis process, but because the toxic reagent chloromethyl methyl ether is used in the reaction, and 1,1-dibromoethane is expensive; at the same time, the reaction yield of this route is low, If this route is chosen, the cost is too high

[0023] (1) bromide is unstable, and it is difficult to purify in large-scale production;

[0024] (2) Impurities such as I and II are inevitably produced due to excessive alkylation (as shown in the diagram below), and the process of removing these impurities is difficult, and at the same time, the product yield is greatly reduced;

[0026] In addition, the yields of the above synthetic methods are not high. Although the fifth synthetic route has great application value, it has very obvious defects, and the difficulty of industrialized large-scale production is very large. The present invention is based on this, and after screening and research , found better process conditions and solved the existing problems in the synthesis of prulifloxacin

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