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Preparation method of prothioconazole intermediate 3, 5-dichloro-2-pentanone

A technology for prothioconazole and intermediates, which is applied in the field of preparation of prothioconazole intermediate 3,5-dichloro-2-pentanone, which can solve complex process, short process flow, large amount of waste acid and water, etc. problem, to achieve the effect of simple process, avoiding separation process and reducing production cost

Pending Publication Date: 2022-07-01
CAC NANTONG CHEM
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The preparation method overcomes the problems of complicated process, large amount of waste acid water, and high cost of raw materials in the prior art for preparing 3,5-dichloro-2-pentanone. The preparation method of the present invention has a process flow Shorter, more economical and environmentally friendly, suitable for industrial production

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  • Preparation method of prothioconazole intermediate 3, 5-dichloro-2-pentanone
  • Preparation method of prothioconazole intermediate 3, 5-dichloro-2-pentanone
  • Preparation method of prothioconazole intermediate 3, 5-dichloro-2-pentanone

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Effect test

Embodiment 1

[0071] The present embodiment provides a preparation method of 3,5-dichloro-2-pentanone, which specifically includes the following steps:

[0072] (1) Synthesis of α-chloro-α-acetyl-γ-butyrolactone

[0073] Add 128.8g α-acetyl-γ-butyrolactone (1.0mol, 99.5%, 1.0eq) to a 500mL four-necked reaction flask equipped with a mechanical stirring, a thermometer and a tail gas trapping device, and cool to 0°C;

[0074] Begin to pass 74.5g chlorine gas (1.05mol, 99.9%, 1.05eq), control the temperature not to exceed 5 ℃, and use 3h to pass through; after the chlorine pass is completed, continue to keep the temperature for 1h to complete the reaction;

[0075] 178.4g of reaction solution (containing about 13.4g of HCl, 1.0mol of α-chloro-α-acetyl-γ-butyrolactone) was obtained by weighing, and the reaction was directly entered into the next step without transferring materials;

[0076] The tail gas trapping device collected 24.9g (0.68mol, 99.0%) of HCl gas, which can be directly used in t...

Embodiment 2

[0086] The present embodiment provides a preparation method of 3,5-dichloro-2-pentanone, which specifically includes the following steps:

[0087] (1) Synthesis of α-chloro-α-acetyl-γ-butyrolactone

[0088]Add 128.8g α-acetyl-γ-butyrolactone (1.0mol, 99.5%, 1.0eq) to a 500mL four-necked reaction flask equipped with a mechanical stirring, a thermometer and a tail gas trapping device, and cool to 0°C;

[0089] Begin to pass 78.1g chlorine gas (1.1mol, 99.9%, 1.05eq), control the temperature not to exceed 5 ℃, and use 4h to pass through; after the end of chlorine pass, continue to keep warm for 1h and the reaction ends;

[0090] 180.0g of reaction solution (containing about 13.4g of HCl, 1.0mol of α-chloro-α-acetyl-γ-butyrolactone) was obtained by weighing, and the reaction was directly entered into the next step without transferring materials;

[0091] The tail gas was collected to obtain 26.9 g (0.73 mol, 99.0%) of HCl gas, which could be directly used in the next reaction;

...

Embodiment 3

[0098] The present embodiment provides a preparation method of 3,5-dichloro-2-pentanone, which specifically includes the following steps:

[0099] (1) Synthesis of α-chloro-α-acetyl-γ-butyrolactone

[0100] Add 128.8g α-acetyl-γ-butyrolactone (1.0mol, 99.5%, 1.0eq) to a 500mL four-necked reaction flask equipped with a mechanical stirring, a thermometer and a tail gas trapping device, and cool to 0°C;

[0101] Begin to pass 74.5g chlorine gas (1.05mol, 99.9%, 1.05eq), control the temperature not to exceed 5 ℃, and use 4h to pass through; after the chlorine pass ends, continue to keep warm for 1h and the reaction ends;

[0102] 178.5g of reaction solution (containing about 13.4g of HCl, 1.0mol of α-chloro-α-acetyl-γ-butyrolactone) were obtained by weighing, and the reaction was directly entered into the next step without transferring materials;

[0103] The tail gas was collected to obtain HCl gas 24.9g (0.68mol, 99.0%);

[0104] (2) Synthesis of 3,5-dichloro-2-pentanone

[0...

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Abstract

The invention provides a preparation method of a prothioconazole intermediate, namely 3, 5-dichloro-2-pentanone. The preparation method comprises the following steps: performing chlorination reaction on alpha-acetyl-gamma-butyrolactone and chlorine under a solvent-free condition to obtain an alpha-chloro-alpha-acetyl-gamma-butyrolactone crude product, and then performing ring opening and chlorination reaction on the alpha-chloro-alpha-acetyl-gamma-butyrolactone crude product in the presence of water and hydrogen chloride to obtain the alpha-chloro-alpha-acetyl-gamma-butyrolactone. And then carrying out a decarboxylation reaction to obtain the 3, 5-dichloro-2-pentanone. According to the invention, a chlorination reaction is carried out under a solvent-free condition by adopting a one-pot method, a catalytic amount of water is directly added after the chlorination reaction is finished, the next step of operation can be directly carried out without separation, and a target product is obtained through ring opening, chlorination and decarboxylation reactions. The preparation method is simple in process, easy to operate, high in yield, low in cost, economical, environmentally friendly and suitable for industrial production.

Description

technical field [0001] The invention belongs to the field of fine chemicals and relates to a preparation method of prothioconazole intermediate 3,5-dichloro-2-pentanone. Background technique [0002] 3,5-Dichloro-2-pentanone is an important intermediate in the synthesis of medicines and pesticides, especially in the field of pesticides, it is a key intermediate in the development of the fungicide prothioconazole by Bayer. [0003] At present, the mainstream synthetic route reported in the literature takes α-acetyl-γ-butyrolactone as raw material, chlorinated with chlorine gas (or sulfonyl chloride), and then carried out with hydrochloric acid (or using glacial acetic acid as solvent) (or in Lewis acid , in the presence of a phase transfer catalyst) chlorination ring-opening, decarboxylation reaction to obtain a mixture of 3,5-dichloro-2-pentanone and hydrochloric acid, the tar amount is large, and it is necessary to further obtain pure product 3 by distillation or steam dist...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C45/41C07C49/16
CPCC07D307/33C07C51/09C07C45/41C07C59/21C07C49/16
Inventor 丁亚伟杨丙连赵宏伟王建博温泰伟
Owner CAC NANTONG CHEM
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