Method for preparing 2,5-difluorobenzaldehyde through continuous oxidation of 2,5-difluorotoluene

A technology of difluorobenzaldehyde and difluorotoluene, which is applied in the fields of oxidative preparation of carbonyl compounds, chemical instruments and methods, organic chemistry, etc., can solve problems such as increasing production costs and shortening reaction time, and achieves production cost saving and reaction time Short, flexible effects for production

Inactive Publication Date: 2017-05-10
CHANGZHOU UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] In the production process of this method, the depth of chlorination needs to be strictly controlled to prevent a large amount of by-products; and a large amount of initiators and catalysts are needed to shorten the reaction time; and in the second step of production, strict control is required. The reaction temperature and time also need to add a large amount of acid catalyst to catalyze the reaction, resulting in a large amount of industrial waste water and increasing production costs, so it is difficult to implement in industry

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  • Method for preparing 2,5-difluorobenzaldehyde through continuous oxidation of 2,5-difluorotoluene
  • Method for preparing 2,5-difluorobenzaldehyde through continuous oxidation of 2,5-difluorotoluene
  • Method for preparing 2,5-difluorobenzaldehyde through continuous oxidation of 2,5-difluorotoluene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] (1) Device: refer to figure 2 Determine the connection mode of the tubular reactor, the pipeline type is: (3a+3b) direct flow channel + round cake type pulse variable diameter rectangular flat pipeline, the inner diameter and volume of the pipeline are determined according to the flow rate and reaction residence time, and the heat exchange medium is heat conduction Oil.

[0031] (2) Dissolve 1.01g of cobalt acetate and 1.01g of sodium molybdate in 200ml of 2,5-difluorotoluene and 200ml of acetic acid to form a mixed solution. At this time, n(cobalt acetate):n(2,5-difluorotoluene)= 0.0025:1, dissolve 1.01g NaBr in 20% H 2 o 2 form H 2 o 2 -Acetic acid solution, at this time n(sodium bromide):n(2,5-difluorotoluene)=0.0025:1,2,5-difluorotoluene-acetic acid solution and H 2 o 2 -Acetic acid solution is injected in the tubular reactor of continuous heat exchange by the flow rate of 5.33ml / min and 10.67ml / min respectively, at this moment n(H 2 o 2 ): n(2,5-difluoroto...

Embodiment 2

[0033] (1) Device: refer to figure 2Determine the connection mode of the tubular reactor. The pipeline type is: (3a+3c) direct flow channel + oblique square cake pulse variable diameter rectangular flat pipeline. The inner diameter and volume of the pipeline are determined according to the flow rate and reaction residence time. The heat exchange medium is heat transfer oil.

[0034] (2) Dissolve 6.06g of cobalt acetate and 6.06g of sodium molybdate in 200ml of 2,5-difluorotoluene and 200ml of acetic acid respectively to form a mixed solution. At this time, n(cobalt acetate):n(2,5-difluorotoluene)= 0.015:1, 6.06g NaBr dissolved in 20% H 2 o 2 form H 2 o 2 -Acetic acid solution, at this time n(sodium bromide):n(2,5-difluorotoluene)=0.015:1,2,5-difluorotoluene-acetic acid solution and H 2 o 2 -Acetic acid solution is injected in the tubular reactor of continuous heat exchange by the flow velocity of 8.33ml / min and 16.67ml / min respectively, at this moment n(H 2 o 2 ): n(2...

Embodiment 3

[0036] (1) Device: refer to figure 2 Determine the connection mode of the tubular reactor. The pipeline type is: (3a+3d) direct flow channel + enhanced mixed round cake type rectangular flat pipeline. The inner diameter and volume of the pipeline are determined according to the flow rate and reaction residence time, and the heat transfer medium is heat transfer oil. .

[0037] (2) Dissolve 6.06g of cobalt acetate and 6.06g of sodium molybdate in 200ml of 2,5-difluorotoluene and 200ml of acetic acid respectively to form a mixed solution. At this time, n(cobalt acetate):n(2,5-difluorotoluene)= 0.015:1, 6.06g NaBr dissolved in 20% H 2 o 2 form H 2 o 2 -Acetic acid solution, at this time n(sodium bromide):n(2,5-difluorotoluene)=0.015:1,2,5-difluorotoluene-acetic acid solution and H 2 o 2 -Acetic acid solution is injected in the tubular reactor of continuous heat exchange by the flow velocity of 8.33ml / min and 16.67ml / min respectively, at this moment n(H 2 o 2 ): n(2,5-dif...

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Abstract

The invention provides a method for preparing 2,5-difluorobenzaldehyde through continuous oxidation of 2,5-difluorotoluene and belongs to the technical field of organic synthesis processes. According to the method, a 2,5-difluorobenzaldehyde compound is used as raw material, one or more of metal ion complexes of cobalt, molybdenum and bromine are used as catalysts, hydrogen peroxide serves as an oxidizing agent, acetic acid is used as a solvent, and 2,5-difluorotoluene oxidation is continuously performed in a tubular reactor to prepare the 2,5-difluorobenzaldehyde. The method is mild in condition, short in reaction time, high in raw material utilization rate, capable of achieving effective control to the reaction process and continuous operation, safe, stable and high in production efficiency.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis technology, and relates to a method for preparing 2,5-difluorobenzaldehyde by continuous oxidation of 2,5-difluorotoluene under liquid phase reaction conditions, more specifically, 2,5-difluorobenzaldehyde Fluorotoluene is used as substrate, hydrogen peroxide is used as oxidant, one or several metal ion complexes of cobalt, molybdenum, and bromine are used as catalyst, and monocarboxylic acid is used as solvent. Continuously prepare 2 in tubular reactors with different microstructures, 5-Difluorobenzaldehyde product. Background technique [0002] 2,5-Difluorobenzaldehyde is a very important fine chemical, and it is an intermediate in the synthesis of many important chemicals. Its molecular weight is 142.10. It is a light yellow transparent liquid with a boiling point of 67-69°C and a flash point above 58°C. It is mainly used as an intermediate of medicine, pesticide and liquid crystal ...

Claims

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Application Information

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IPC IPC(8): C07C45/28C07C47/55B01J19/24
CPCC07C45/28B01J19/0093B01J19/2415B01J2219/00166B01J2219/00984C07C47/55
Inventor 刘建武蒋鑫张跃严生虎沈介发马晓明陈代祥辜顺林倪风超李彦飞王秋红陈明珠
Owner CHANGZHOU UNIV
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