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Preparation method of 2-nitro-4-trifluoromethylbenzonitrile

A technology of trifluoromethylbenzonitrile and chlorobenzonitrile, applied in the field of preparation of 2-nitro-4-trifluoromethylbenzonitrile, can solve the problem of low cost, high yield, 2-nitro -4-trifluoromethylbenzonitrile reaction selectivity and conversion rate are not high, to achieve the effect of improving yield

Active Publication Date: 2015-09-23
江苏省农用激素工程技术研究中心有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] The object of the present invention is to solve the problem that the prior art adopts 4-chloro-3-nitrobenzonitrile to prepare 2-nitro-4-trifluoromethylbenzonitrile reaction selectivity and conversion rate is not high problem, provides a kind of Not only the yield is higher, but also the preparation method of 2-nitro-4-trifluoromethylbenzonitrile with lower cost

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1）

[0020] The preparation method of the 2-nitro-4-trifluoromethylbenzonitrile of the present embodiment is as follows:

[0021] Add 90g of 3-nitro-4-chlorobenzotrifluoride (0.4mol), 100g of NMP, 100g of toluene, 52.1g of lithium bromide (0.6mol) and 1.8g Tetraphenylphosphine bromide, heated and refluxed for dehydration until no water beads flowed out (about 1h), then added 40.5g of cuprous cyanide (0.45mol), distilled toluene at normal pressure to a liquid temperature of 160°C, and controlled the temperature at 160°C for reaction 3h.

[0022] After the reaction, cool down to room temperature (0-40°C) and add 100mL of concentrated hydrochloric acid and 100mL of water. After stirring, add 150mL of dichloromethane to extract once, separate layers, add 100mL of dichloromethane to the upper layer for extraction once, and combine the dichloromethane layers. After washing once with hydrochloric acid and water, the layers were separated. The organic layer first recovered dichloromethane...

Embodiment 2～ Embodiment 7）

[0024] The preparation method of each embodiment is basically the same as that of Example 1, and the differences are shown in Table 1.

[0025] Table 1

[0026] lithium bromide Tetraphenylphosphine bromide Cuprous cyanide purity yield Example 1 52.1g (0.6mol) 1.8g 40.5g (0.45mol) 96% 95% Example 2 34.7g (0.4mol) 1.8g 40.5g (0.45mol) 89% 85% Example 3 69.4g (0.8mol) 1.8g 40.5g (0.45mol) 94% 93% Example 4 52.1g (0.6mol) 1.8g 36.0g (0.40mol) 94% 90% Example 5 52.1g (0.6mol) 1.8g 54.0g (0.60mol) 90% 92% Example 6 52.1g (0.6mol) 0.9g 40.5g (0.45mol) 85% 87% Example 7 52.1g (0.6mol) 3.6g 40.5g (0.45mol) 93% 90%

Embodiment 8）

[0028] The preparation method of the 2-nitro-4-trifluoromethylbenzonitrile of the present embodiment is as follows:

[0029] Add 90g of 3-nitro-4-chlorobenzotrifluoride (0.4mol), 100g of NMP, 52.1g of lithium bromide (0.6mol) and 1.8g of tetraphenyl to a 500mL reaction flask equipped with a thermometer and dehydration device Phosphine bromide, then add 40.5g of cuprous cyanide (0.45mol), and raise the temperature to 160°C for 3h.

[0030] After the reaction, cool down to room temperature (0-40°C) and add 100mL of concentrated hydrochloric acid and 100mL of water. After stirring, add 150mL of dichloromethane to extract once, separate layers, add 100mL of dichloromethane to the upper layer for extraction once, and combine the dichloromethane layers. After washing once with hydrochloric acid and water, the layers were separated. The organic layer first recovered dichloromethane under normal pressure, and then evaporated 76 g of the product under reduced pressure. The purity was 9...

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Abstract

The invention discloses a preparation method of 2-nitro-4-trifluoromethylbenzonitrile which is prepared by enabling 3-nitro-4-chlorobenzotrifluoride to react with cyanide with existence of organic solvent, bromide and tetraphenylphosphonium bromide. The organic solvent is N,N-dimethyl formamide, N,N-dimethyl acetamide, N-methyl pyrrolidone, sulfolane and cyanophenyl, bromide is lithium bromide, potassium bromide and cuprous bromide, cyanide is cuprous cyanide, potassium cyanide and sodium cyanide, reaction temperature is 100-200 DEG C, and reaction time is 2-5h. A catalyst system composed of tetraphenylphosphonium bromide and bromide is adopted in the preparation method, so that reaction yield identical with that when nickel bromide is used can be acquired, and cost of the catalyst system is smaller than half that when nickel bromide is used.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a preparation method of 2-nitro-4-trifluoromethylbenzonitrile. Background technique [0002] Benzoylisoxazole herbicides (such as isoxaflutole, pyrazole sulfoxazole, etc.) are a new type of spectral herbicide with a mechanism of action, which are inhibitors of p-hydroxyphenylpyruvate dioxygenase , by inhibiting the synthesis of p-hydroxyphenylpyruvate dioxygenase, leading to the accumulation of tyrosine, hindering the biosynthesis of plastoquinone and tocopherol, and then affecting the biosynthesis of carotenoids. [0003] 2-nitro-4-trifluoromethylbenzonitrile is one of the key intermediates for the preparation of isoxaflutole and sulfoxazone. [0004] At present, the preparation of 2-nitro-4-trifluoromethylbenzonitrile is basically all prepared by the reaction of 4-halo-3-nitrobenzotrifluoride and cyanide in the presence of a catalyst (see Chinese patent l...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C255/50C07C253/14
Inventor 孙永辉张元元孔繁蕾
Owner 江苏省农用激素工程技术研究中心有限公司