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Method for preparing 3,4-dichloro-cyanobenzene

A technology of dichlorobenzonitrile and dichlorotoluene is used in the preparation of hydrocarbon ammoxidation, chemical instruments and methods, catalyst activation/preparation, etc., and can solve the problems of low catalyst yield, low mechanical strength, poor selectivity, etc. High conversion rate of raw materials, simple preparation method, and the effect of inhibiting deep oxidation

Active Publication Date: 2013-02-13
CAC NANTONG CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] In order to solve the above problems, the present invention overcomes the problems of low catalyst yield, poor selectivity, low mechanical strength and short life, and provides a method for preparing 3,4-dichlorobenzonitrile

Method used

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  • Method for preparing 3,4-dichloro-cyanobenzene
  • Method for preparing 3,4-dichloro-cyanobenzene
  • Method for preparing 3,4-dichloro-cyanobenzene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0040] Catalyst preparation: first mix 20.1g of V 2 o 5 Add it into a solution at a temperature of 80-90°C consisting of 300ml of water and 42g of oxalic acid, stir well, and react to obtain a vanadium oxalate solution.

[0041] Will contain 40% (weight) SiO 2 125g of silica sol was slowly added to the above solution under stirring, and then added by 79.8gCr(NO 3 ) 3 9H 2 A solution of O and 90ml of water, 6.86gH3 BO 3 and 56ml of water, and 27.3g (NH 4 ) 6 Mo 7 o 24 4H 2 A solution composed of O and 20ml of water, 0.11mol of phosphoric acid solution, and finally add 1.1g of KNO 3 A solution composed of 3 ml of water was stirred and mixed, heated and evaporated to a solid content of 35% by weight to obtain a viscous slurry. The slurry was sprayed into shape, and the formed catalyst was dried at 120°C for 12 hours, and calcined at 550°C for 8 hours. Catalyst composition V 1.0 Cr 0.9 B 0.5 P 0.5 K 0.05 Mo 0.2 / SiO 2 , the main load ratio of the catalyst is 50 / ...

Embodiment 2-7

[0044] Catalyst preparation method is the same as embodiment 1, changes the composition or proportioning of catalyst, evaluates by the evaluation condition of embodiment 1, and evaluation result is shown in Table 1:

[0045] Table 1

[0046] Reality

Embodiment 8

[0052] Catalyst preparation conditions are the same as in Example 1, and the evaluation conditions for changing the catalyst are: reaction temperature 400°C, raw material molar ratio 3,4-dichlorotoluene: ammonia: oxygen=1: 2.5: 7, reaction pressure 0.01MPa, space velocity 900h -1 .

[0053] Evaluation results: the conversion rate of 3,4-dichlorotoluene is 99.7%, the selectivity of 3,4-dichlorobenzonitrile is 90.5%, and the yield of 3,4-dichlorobenzonitrile is 90.2%.

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Abstract

The invention discloses a method for preparing 3,4-dichloro-cyanobenzene. In the invention, a fluid catalyst which uses V-Cr-B-Co as a main active ingredient is prepared by using a coprecipitation method; the reaction temperature is 350-460 DEG C, the reaction pressure is from normal pressure to 0.05 Mpa, the space velocity is 500-1800 h<-1>, the material molar ratio of 3,4-dichloro-cyanobenzene to ammonia to oxygen is 1: (1.2-8): (1.5-10), and a melting vessel catch process is utilized for the product catch. The 3,4-dichloro-cyanobenzene has high selectivity and yield, low material cost and long catalyst life. The invention has better popularization and application value and can be used for industrial production.

Description

technical field [0001] The invention relates to a method for preparing 3,4-dichlorobenzonitrile. Background technique [0002] At present, new pesticides and medicines containing fluorine are constantly emerging, and the demand for fluorinated aromatic compounds has increased dramatically. 3,4-dichlorobenzonitrile (DCBN) is an important pesticide intermediate, and its fluorinated derivatives, such as 3,4-difluorobenzonitrile, 4-fluoro-3-chlorobenzonitrile, 3,4-difluorobenzoic acid, 4-fluoro-3-chlorobenzoic acid, etc., can be widely used in pesticides, medicines, pigments, dyes and other industries. [0003] 3, the synthetic method of 4-dichlorobenzonitrile mainly contains α, α, α, 3, 4-pentachlorotoluene and ammonium chloride etc. are reacted and synthesized by European patent EP441004 and Japanese patent flat 08-119925 etc.; 3,4-dichlorobenzamide is dehydrated into nitrile in sulfuric acid; it is prepared by dehydration of 3,4-dichlorobenzaldehyde oxime. However, these m...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C255/50C07C253/28B01J37/03B01J27/199B01J23/28
Inventor 李强王海波田晓宏
Owner CAC NANTONG CHEM