Method for preparing isradipine impurity III

A technology for isradipine and impurities, which is applied in the field of preparation of isradipine impurity III, can solve problems such as separation difficulties and affecting the quality of the final product isradipine, and achieve the effects of easy-to-obtain raw materials, short routes, and simple preparation processes

Inactive Publication Date: 2017-08-04
CHONGQING CONQUER PHARML
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] Isradipine impurity III is produced during the preparation of compound 2, and may remain in the final product isradipine, affecting the quality of the final product isradipine, and the separation is difficult

Method used

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  • Method for preparing isradipine impurity III
  • Method for preparing isradipine impurity III
  • Method for preparing isradipine impurity III

Examples

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preparation example Construction

[0024] The invention provides a preparation method of isradipine impurity III, which is characterized in that: benzoxadiazole-4-carbaldehyde and 2-acetyl-3-benzofurazan-4-yl-methyl acrylate are used as The raw material undergoes a condensation reaction under weakly alkaline and organic conditions, and is separated to obtain isradipine impurity III. The reaction formula is as follows:

[0025]

[0026] Further, the preparation method of the isradipine impurity III specifically includes the following steps:

[0027] S1. Add 5-10g of 2-acetyl-3-benzofurazan-4-yl-methyl acrylate to 100-180ml of organic solvent and stir. After fully dissolving, add benzoxadiazole-4-formaldehyde 5- 7g, 0.3-1.1g of glacial acetic acid and 0.1-0.5g of catalyst, carry out heating and reflux reaction;

[0028] S2, filtering the reaction solution obtained in step S1 to obtain a filtrate;

[0029] S3. Add 10-30ml of organic solvent to the filtrate obtained in step S2, heat to reflux for 1-2h, cool do...

Embodiment 1

[0037] Add 130mL of isopropyl ether and 8.31g of compound 2 to the reaction flask in turn, stir and dissolve, then add 5g of compound 1, 0.6g of glacial acetic acid and 0.2g of piperidine, heat up and reflux for 4h; filter the reaction solution to obtain the filtrate, and pour the filtrate 15 mL of ethyl acetate was added to the mixture, stirred and heated to reflux for 1 h, cooled and filtered, and dried at 60°C to obtain isradipine impurity III with a purity of 99.5% and a weight of 6.75 g.

[0038] The mass spectrometry data and NMR data detection of the product obtained in this embodiment are as follows: ESI-MS: 377.30 [M+H] + ;1H-NMR: (δ-DMSO), δ3.814(3H, s), δ7.515~7.542(1H,d), δ7.578~7.627(2H,m), δ7.831~7.858(1H, d), δ7.905~7.916(1H,d), δ7.986~7.995(1H,d), δ8.041~8.079(1H,m), δ8.079~8.091(1H,d), δ8.229 (1H,s).

Embodiment 2

[0040] Add 100mL tetrahydrofuran and 5g compound 2 to the reaction flask in sequence, stir and dissolve, then add 5g compound 1, 0.4g glacial acetic acid and 0.1g piperidine, heat and reflux for 2h; filter the reaction solution to obtain the filtrate, add 10mL to the filtrate Acetone, stirred and heated to reflux for 2 hours, cooled and filtered, and dried at 60°C to obtain isradipine impurity III with a purity of 98.9% and a weight of 5.81g.

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Abstract

The invention discloses a method for preparing an isradipine impurity III. The method is characterized by comprising the following steps: taking benzodioxazole-4-formaldehyde and 2-acetyl-3-benzofuroxan-4-yl-methyl acrylate as raw materials, carrying out a condensation reaction under weakly alkaline and organic conditions, and separating, thereby obtaining the isradipine impurity III, wherein the equation is as shown in the specification. The isradipine impurity III is simple in preparation process, short in route and readily available in raw materials and does not need to be subjected to column purification, and the obtained product is high in purity (HPLC (High Performance Liquid Chromatography) is more than or equal to 98%) and can be directly used for quality study of isradipine I key intermediate 2-acetyl-3-benzofuroxan-4-yl-methyl acrylate.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and relates to a preparation method of isradipine impurity III. Background technique [0002] Isradipine is a new type of dihydropyridine calcium channel blocker, developed by Sandoz in Switzerland, and first approved for marketing by Ciba-Geigy in February 1989. Isradipine achieves the purpose of lowering blood pressure by dilating blood vessels, reducing peripheral vascular resistance, increasing coronary blood flow, and improving myocardial oxygen supply. Isradipine has a strong vasodilator effect, but no heart inhibitory effect, and almost does not cause reflex tachycardia. Clinical and animal experiments have proved that the drug has obvious antihypertensive and anti-atherosclerotic effects. By maintaining or restoring the blood flow under the left ventricular endothelium, it can prevent local ischemic damage and improve the health of patients with angina pectoris and congestive h...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D271/12
CPCC07D271/12
Inventor 陈用芳李斌徐刚
Owner CHONGQING CONQUER PHARML
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