Method for preparing Roflumilast

A technology of roflumilast and difluoromethoxy, which is applied in the field of roflumilast and can solve the problems of low reaction yield and the like

Inactive Publication Date: 2013-09-25
HEILONGJIANG FUHE HUAXING PHARMA GROUP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The methods reported in the above two patents are all 4-amino-3,5-dichloropyridine excess (2-2.3 equivalents), otherwise the reaction is not complete, even so, the reaction yield is also low, and in the post-treatment process, a large amount of Discharge of by-products and incompletely reacted raw materials will inevitably pollute the environment

Method used

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  • Method for preparing Roflumilast

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Embodiment 1

[0014] 2.6g (10mmol) of 3-(cyclopropylmethoxy)-4-(difluoromethoxy)benzoic acid, 1.6g (10mmol) of 4-amino-3,5-dichloropyridine, 4.6g (38mmol) of DMAP ) was dissolved in NMP15mL, then HOBt2.7g (20mmol) was added, and the reaction was stirred at room temperature for 3 hours. The reaction solution was extracted with dichloromethane, and the organic phases were combined, dried and concentrated to obtain the crude product of roflumilast. The product was recrystallized from a mixed solution of 15 mL of isopropanol and 5 mL of cyclohexane to obtain 3 g of a white solid with a yield of 75%.

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Abstract

The invention relates to a method for preparing Roflumilast. The method uses 3-(cyclopropylmethoxy)-4-(difluoromethoxy)benzoic acid as raw material to react with 4-amino-3,5-dichloropyridine to obtain Roflumilast.

Description

technical field [0001] The present invention relates to methods of roflumilast. Background technique [0002] Roflumilast is a selective phosphodiesterase (PDE4) inhibitor. By inhibiting the activity of PED4 enzyme, it blocks the pulmonary inflammatory process that leads to COPD, thereby reducing the symptoms of patients, preventing disease progression, and improving lung function. . As a new treatment drug for COPD, Roflumilast has broad market prospects and huge market potential. [0003] Patent WO9501338 reports a method for the preparation of Roflumilast by adding 3-(cyclopropylmethoxy)-4-(difluoromethoxy)benzoyl chloride to 4-amino-3,5-dichloropyridine With sodium hydrogen in THF suspension, react at room temperature to obtain roflumilast. The preparation method of roflumilast reported in patent WO080967 uses the potassium salt of 4-amino-3,5-dichloropyridine, and 3-(cyclopropylmethoxy)-4-(difluoromethoxy)benzyl Acid chloride reaction gives roflumilast. The methods...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D213/75
Inventor 吴光彦
Owner HEILONGJIANG FUHE HUAXING PHARMA GROUP
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