Method for preparing triclabendazole

A technology of triclabendazole and dichloroaniline, which is applied in the field of preparation of triclabendazole, can solve the problems of high price, unsafety, and high risk, and achieve industrial production, avoid high-pressure reaction, and be environmentally friendly Effect

Active Publication Date: 2009-10-14
YANGZHOU TIANHE PHARM CO LTD
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Problems solved by technology

[0003] In terms of preparation: the intermediate improvement method published in the 4th issue of Volume 29 of "Guangzhou Chemistry" used expensive and dangerous metal sodium; Synthetic process research, with 1.2.4-trichlorobenzene as the starting route, after nitration and then high-pressure ammoniation, and the reaction temperature is 190°C, 4MPa high pressure is used in the reaction,

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  • Method for preparing triclabendazole

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Embodiment Construction

[0016] Steps:

[0017] 1. Preparation of acylate {3,4-dichloroacetanilide (3)}:

[0018] Put 10g of 3,4-dichloroaniline into the reaction flask at a temperature of 80-145°C, add 100g of acetic acid and stir to dissolve, heat up to reflux, add 15g of acetyl chloride dropwise, finish adding, reflux for 5 hours, exhaust the hydrogen chloride gas, Then, 200 ml of water was added, followed by suction filtration to obtain 11 g of acylate.

[0019] 2. Preparation of nitrate {4,5-dichloro-2-nitroacetanilide (4)}:

[0020] Put 20-150g of sulfuric acid and 10g of acylate into the reaction bottle, and add 18g of nitrating agent dropwise at the temperature of -10-40°C. Recrystallized to obtain 9g of refined product. Above nitrating agent can be nitric acid, also can be the mixture of nitric acid and acetic acid, can also be the mixture of nitric acid and sulfuric acid, or potassium nitrate.

[0021] 3. Preparation of hydrolyzate {4,5-dichloro-2-nitroaniline (5)}:

[0022] Under the t...

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Abstract

The invention discloses a method for preparing triclabendazole related to chemical synthesis methods. The invention comprises the following steps: using the 3,4-dichloroaniline as a raw material, preparing 4-chloro-5-(2,3-dichlorophenoxy)-2-mercapto-1H-benzimidazole through acylating, nitrating, hydrolyzing, etherifying, reduction and cyclization in succession and synthesizing triclabendazole using dimethyl sulfate as methylating agent. The invention avoids the use of the hazardous material sodium and a high pressure reaction, uses easily available dimethyl sulfate as methylating agent, and the yield thereof is equivalent to the report of literature. The invention is characterized by simplified work, moderate reaction condition, cheap production cost and the method is also environmentally-benign and easy to commercial process.

Description

technical field [0001] The invention relates to a chemical synthesis method, in particular to a preparation method of triclabendazole. technical background [0002] Triclobendazole, also known as Ganzhijing, chemical name 5-chloro-6-(2,3-dichlorophenoxy)-2-methylthio-1H-benzimidazole, white to off-white powder crystal , melting point 174 ~ 178 ° C. Triclobendazole is a high-efficiency anti-liver fluke drug, which is highly effective against adults and larvae of bovine and sheep liver flukes, and is superior to nitrophenol. It is safe to take orally, has few side effects, and is well tolerated. It is the drug of choice for the treatment of liver fluke, and it can be taken together with thiabendazole, benthiamidazole, and levamisole. [0003] In terms of preparation: the intermediate improvement method published in the 4th issue of Volume 29 of "Guangzhou Chemistry" used expensive and dangerous metal sodium; Synthetic process research, with 1.2.4-trichlorobenzene as the sta...

Claims

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Application Information

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IPC IPC(8): C07D235/28
Inventor 李西宁周启伍
Owner YANGZHOU TIANHE PHARM CO LTD
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