Preparation method of moxifloxacin intermediate

Abstract

The invention discloses a preparation method of a moxifloxacin intermediate 6-benzyl-octahydro-pyrrolo[3,4-b]pyridine (as shown in formula I). The preparation method is to adopt an NaBH4 / H2SO4 reducing system to reduce 6-benzyl-hexahydro-pyrrolo[3,4-b]pyridine-5,7-dione (as shown in formula II), so as to obtain the target product. The method can be processed at normal temperature and normal pressure to take reaction with high total recovery; the raw material is cheap, easy to get, and easy to store; the operation is simple; the safety is high.

Description

technical field [0001] The invention relates to a method for preparing a moxifloxacin intermediate 6-benzyl-octahydro-pyrrolo[3,4-b]pyridine. Background technique [0002] The structure type of Moxifloxacin belongs to quinolones. Its chemical name is: 1-cyclopropyl-7-﹛(S,S)-2,8-diazo-bicyclo[4.3.0]non-8-yl﹜-6-fluoro-8-methoxy -1,4-Dihydro-4-oxo-3-quinolinecarboxylic acid. [0003] [0004] Moxifloxacin is the fourth-generation quinolone antibacterial drug. The biggest difference from other quinolone drugs is that a methoxy group is introduced into its 8-position carbon atom. It is based on this structural feature that it not only It has the activity of quinolones against Gram-negative bacteria, and also enhances the antibacterial effect against Gram-positive bacteria and atypical pathogenic bacteria, and has no obvious phototoxicity. Due to its high solubility, it reduces the risk of crystalluria formation . 6-Benzyl-hexahydro-pyrrolo[3,4-b]pyridine-5,7-dione (II) and...

AI Technical Summary

Problems solved by technology

6-Benzyl-hexahydro-pyrrolo[3,4-b]pyridine-5,7-dione (II) and 6-benzyl-octahydro-pyrrolo[3,4-b]pyridine (I) They are all key intermediates for synthesizing moxifloxacin. There are many reports on their synthetic methods, but they lack high safety and are suitable for industrial production.

[0006] CN101591336A reported the metal borohydride / BF3 reduction system for 6-benzyl-hexahydro-pyrrolo[3,4 -b] Reduction of pyridine-5,7-dione and its chiral isomers, the yield is 72%-91%, but the reduction system of BF3 is exposed to water or placed in humid air Decompose immediately to produce highly toxic hydrogen fluoride fumes. The reaction solvent and equipment need to be dried before the reaction. The operation is cumbersome and not suitable for industrial production.

[0007]CN102295645A carried out 6-benzyl-hexahydro-pyrrolo[3, The reduction of 4-b]pyridine-5,7-dione (Formula I) has short reaction time and high yield (up to 94%), but pressurized equipment is required, which requires high equipment

[0010] In summary, the synthesis of moxifloxacin intermediates is cumbersome and has a low safety factor, so it is not suitable for industrial production

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