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Preparation method of thiabendazole intermediate

A technology for thiabendazole and intermediates, which is applied in the field of preparation of thiabendazole intermediates, can solve the problems of expensive pyruvic acid, difficult operation, and low process yield, and achieve novel synthesis methods, low cost, and high yield. high effect

Active Publication Date: 2020-12-11
PAPANNA BEIJING TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

At present, domestic and foreign patents, reports such as CN102816120A, CN101712677A, CN106349235A, CN103204849A, etc., the route of synthesizing thiabendazole intermediate is mainly based on the condensation reaction of o-phenylenediamine and lactic acid under acidic conditions, and then under acidic conditions with a large amount of high Potassium manganate oxidation or direct condensation reaction with o-phenylenediamine and pyruvic acid under acidic conditions, and then halogenation reaction with halogenating reagents, the process yield is low, pyruvic acid is expensive, the process is unsafe, and the operation is difficult. The amount of three wastes is large, which has a great impact on the environment. Under the current environmental protection pressure, industrialization is difficult.

Method used

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  • Preparation method of thiabendazole intermediate

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Experimental program
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Effect test

Embodiment 1

[0031] At room temperature (10-35°C), add 110.3g of o-phenylenediamine (1mol, 98%, Bailingwei Technology Co., Ltd.) 133.7g (1.1mol, 98%, Bailingwei Technology Co., Ltd. company) mixed in dilute hydrochloric acid, heated at 50-70°C for condensation reaction, the reaction time is 5-6h, after cooling, use 30% sodium hydroxide aqueous solution to adjust the pH between 7-8, the temperature is controlled not higher than 35°C, continue Stir for 30 minutes to precipitate solid, cool below 15°C, filter, wash the filter residue with water, and dry 201.8g of crude product 1 at about 50°C, the effective content is 91%, and the yield is 90% based on o-phenylenediamine; the crude product 1-201.8 g into a 1000ml four-neck bottle, add 500g of dichloroethane, heat at about 40°C, pass in chlorine gas for chlorination reaction, the reaction time is 4-5h, the liquid phase detection crude product 1<1%, stop the reaction, and recover the solvent under normal pressure Finally, 2-245.7g of the crude ...

Embodiment 2

[0033] At room temperature (10-35°C), 110.3g of o-phenylenediamine (1mol, 98%, Bailingwei Technology Co., Ltd.) 211.2g of diethyl oxaloacetate (1.1mol, 98%, Bailingwei Technology Co., Ltd.) mixed in dilute hydrochloric acid, heated at 50-70°C for condensation reaction, the reaction time is 5-6h, after cooling, adjust the pH to 7-8 with 30% sodium hydroxide aqueous solution, and control the temperature not higher than 35 ℃, continue to stir for 30 minutes, precipitate solid, cool below 15 ℃, filter, wash the filter residue with water, and dry 201.8g of crude product 1 at about 50 ℃, the effective content is 91%, and the yield is 90% based on o-phenylenediamine; the crude product Add 1-201.8g into a 1000ml four-neck bottle, add 500g of dichloroethane, heat at about 40°C, pass in chlorine gas for chlorination reaction, the reaction time is 4-5h, the liquid phase detection crude product 1<1%, stop the reaction, usually After recovering the solvent under pressure, 2-245.7g of the c...

Embodiment 3

[0037]At room temperature (10-35°C), add 110.3g of o-phenylenediamine (1mol, 98%, Bailingwei Technology Co., Ltd.) 133.7g (1.1mol, 98%, Bailingwei Technology Co., Ltd. company) mixed in dilute hydrochloric acid, heated at 50-70°C for condensation reaction, the reaction time is 5-6h, after cooling, use 30% sodium hydroxide aqueous solution to adjust the pH between 7-8, the temperature is controlled not higher than 35°C, continue Stir for 30 minutes to precipitate solid, cool below 15°C, filter, wash the filter residue with water, and dry 201.8g of crude product 1 at about 50°C, the effective content is 91%, and the yield is 90% based on o-phenylenediamine; the crude product 1-201.8 g into a 1000ml four-neck bottle, add 500g of dichloroethane, heat at about 40°C, pass in chlorine gas for chlorination reaction, the reaction time is 4-5h, the liquid phase detection crude product 1<1%, stop the reaction, and recover the solvent under normal pressure Finally, the crude product 2-245...

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Abstract

The invention provides a preparation method of a thiabendazole intermediate. The method uses a raw material containing o-phenylenediamine to prepare the thiabendazole intermediate shown as a formula (1), and comprises the following steps: in an acidic environment, carrying out condensation reaction on the raw material containing o-phenylenediamine to obtain a crude product 1; carrying out halogenation reaction on the crude product 1 to obtain a crude product 2; and carrying out decarboxylation reaction on the crude product 2, and purifying to obtain the thiabendazole intermediate. According tothe invention, the method is low in raw material cost, simple in synthetic route, inapplicable to catalysts, recyclable in solvent, almost zero in emission of three wastes, mild in reaction condition, simple to operate and suitable for modern industrial production, and the influence on the environment is avoided, and the yield is as high as 80% or above. R is Cl or Br.

Description

technical field [0001] The invention relates to the field of organic synthesis, in particular to a preparation method of a thiabendazole intermediate. Background technique [0002] 2-(2-Chloroacetyl)benzimidazole, white solid, is an important intermediate of Thiabendazole. At present, domestic and foreign patents, reports such as CN102816120A, CN101712677A, CN106349235A, CN103204849A, etc., the route of synthesizing thiabendazole intermediate is mainly based on the condensation reaction of o-phenylenediamine and lactic acid under acidic conditions, and then under acidic conditions with a large amount of high Potassium manganate oxidation or direct condensation reaction with o-phenylenediamine and pyruvic acid under acidic conditions, and then halogenation reaction with halogenating reagents, the process yield is low, pyruvic acid is expensive, the process is unsafe, and the operation is difficult. The amount of three wastes is large, which has a great impact on the environm...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D235/12
CPCC07D235/12
Inventor 焦体李星强
Owner PAPANNA BEIJING TECH
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