Preparation method of 3,5-dihalogenated-4-pyridone-1-acetic acid

A technology of pyridone and dihalogenation, which is applied in the field of preparation of 3,5-dihalogeno-4-pyridone-1-acetic acid, and can solve the problem of high price of 4-aminopyridine, poor stability of diazonium salt, and operational requirements Advanced problems, to achieve the effect of high target reaction selectivity, good stability and high reaction selectivity
CN110483384AActive Publication Date: 2019-11-22XINFA PHARMA
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
XINFA PHARMA
Publication Date
2019-11-22

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Abstract

The invention provides a preparation method of 3, 5-dihalogenated-4-pyridone-1-acetic acid, and particularly relates to a preparation method of 3,5-dichloro-4-pyridone-1-acetic acid. The method comprises the following steps: performing a substitution reaction on piperidine-4-ketone hydrochloride (II) with chloroacetic acid in the presence of a proper solvent and an acid-binding agent to obtain 4-piperidone-1-acetic acid (III), carrying out a halogenation reaction on the 4-piperidone-1-acetic acid (III) and a halogenation reagent to obtain 3,3,5,5-tetrahalogenated-4-piperidone-1-acetic acid (IV), carrying out an elimination reaction in the presence of an alkali to remove hydrogen halide, and performing acidification with hydrochloric acid to obtain the 3,5-dihalo-4-pyridinone-1-acetic acid.The method has the advantages of cheap and easily available raw materials, low cost, simple operation, easy realization, less wastewater generation amount, environmental protection, high reaction selectivity, high product yield and purity, and suitableness for industrial production.
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Description

technical field

[0001] The invention relates to a preparation method of 3,5-dihalogenated-4-pyridone-1-acetic acid, belonging to the technical field of medicine and chemical industry. Background technique

[0002] 3,5-Dihalo-4-pyridone-1-acetic acid (I) including 3,5-dichloro-4-pyridone-1-acetic acid (I1), 3,5-dibromo-4-pyridone -1-acetic acid (I2) and 3,5-diiodo-4-pyridone-1-acetic acid (I3), wherein 3,5-dichloro-4-pyridone-1-acetic acid (3,5-Dichloro- 4-pyridone-N-acetic acid) is an important intermediate for the preparation of cefoxidone, and its structural formula is as follows:

[0003]

[0004] In the current prior art, there have been reports on the synthesis method of the intermediate 3,5-dichloro-4-pyridone-1-acetic acid.

[0005] For example, Chinese patent document CN104230958A takes 4-pyridone as starting material, and obtains 3,5-dichloro-4-pyridone through hypochlorite chlorination reaction, and then uses water as solvent, 70-78°C and pH= Under the reacti...

Claims

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