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Method for preparing p-nitrochlorobenzene by nitrifying chlorobenzene by using nitrogen dioxide

A technology of p-nitrochlorobenzene and nitrogen dioxide, which is applied in the preparation of nitro compounds and organic chemistry, can solve the problems of large fluctuations in demand for nitrochlorobenzene and serious environmental pollution, and achieve good nitration product selectivity, Reduction of environmental pollution and high safety effect

Inactive Publication Date: 2013-05-08
ANHUI HUAIHUA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in the process of preparing the crude nitrochlorobenzene mixture, using the mixture of nitric acid and sulfuric acid, it is necessary to establish unit facilities harmful to the environment to handle the acid and reclaim nitric acid and sulfuric acid, and the environmental pollution is serious
And this method is non-selective, and the composition of generating mononitrochlorobenzene isomer is o-nitrochlorobenzene 33%, p-nitrochlorobenzene 66% and 1% m-nitrochlorobenzene, o-nitrochlorobenzene The mass ratio of isomers is 0.5
At the same time, the market demand for o-p-nitrochlorobenzene often fluctuates greatly. Therefore, the development of green nitration pathways and the improvement of the selectivity of mononitration products have received extensive attention at home and abroad.

Method used

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  • Method for preparing p-nitrochlorobenzene by nitrifying chlorobenzene by using nitrogen dioxide

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] After stirring 5.5g of chlorobenzene, 0.55g of HZSM-5 type catalyst, and 0.11g of 3? molecular sieve evenly, pass in 0.15mL of nitrogen dioxide, stir magnetically in an oxygen atmosphere, and react at 15°C for 48h. After the reaction was completed, the reaction was terminated with deionized water to obtain a crude reaction product. Filter the crude product with a glass funnel to remove the catalyst and molecular sieve, and let stand to separate the organic phase. The organic phase was washed successively with sodium bicarbonate solution and distilled water several times until it became neutral, and 6.13 g of nitrochlorobenzene was obtained by distillation under reduced pressure, with a yield of 79.6%. After drying, nitrobenzene was used as an internal standard for high-performance liquid chromatography analysis. The internal standard method was used to calculate the mass of p-nitrochlorobenzene to be 5.52 g, and the mass fraction was 90.0%.

[0024]

Embodiment 2

[0026] Stir 5.5g of chlorobenzene, 1g of CuHZSM-5 catalyst, and 0.25g of 3? molecular sieve evenly, then inject 0.3mL of nitrogen dioxide, stir magnetically in a nitrogen atmosphere, and react at 30°C for 36h. After the reaction was completed, the reaction was terminated with deionized water to obtain a crude reaction product. Filter the crude product with a glass funnel to remove the catalyst and molecular sieve, and let stand to separate the organic phase. The organic phase was washed with 5% sodium bicarbonate solution and distilled water several times until it was neutral, and 6.34 g of nitrochlorobenzene was obtained by distillation under reduced pressure, with a yield of 82.3%. After drying, HPLC analysis was carried out with nitrobenzene as the internal standard. The mass of p-nitrochlorobenzene was calculated to be 5.43 g and the mass fraction was 85.7 % by internal standard method.

[0027]

Embodiment 3

[0029] Stir 5.5g of chlorobenzene, 2g of FeHZSM-5 catalyst, and 0.45g of 3? molecular sieve evenly, then inject 0.5mL of nitrogen dioxide, stir magnetically in an argon atmosphere, and react at 60°C for 24h. After the reaction was completed, the reaction was terminated with deionized water to obtain a crude reaction product. Filter the crude product with a glass funnel to remove the catalyst and molecular sieve, and let stand to separate the organic phase. The organic phase was washed with sodium bicarbonate solution and distilled water several times until it became neutral, and 6.04 g of nitrochlorobenzene was obtained by distillation under reduced pressure, with a yield of 78.4%. After drying, nitrobenzene was used as an internal standard for high-performance liquid chromatography analysis. The mass of p-nitrochlorobenzene was calculated to be 5.10 g and the mass fraction was 84.5 % by internal standard method.

[0030]

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Abstract

The invention relates to a method for preparing p-nitrochlorobenzene by nitrifying chlorobenzene by using nitrogen dioxide. The p-nitrochlorobenzene is prepared by taking chlorobenzene as raw material and nitrogen dioxide as a nitration reagent. The nitrogen dioxide nitration reagent is used for replacing the traditional nitration reagent of nitric acid-sulphuric acid mixed acid, not only is utilization rate of reaction atoms improved, but also environmental economical efficiency of industrial preparation is improved, as well as the environment pollution is reduced. Simultaneously, the invention provides a nitration method of an acid sensitive compound, and the nitration method can be applied to the nitration of a plurality of aromatic compounds, and even applied to the nitration of aromatic compounds containing a plurality of deactivating groups.

Description

technical field [0001] The invention relates to a method for preparing p-nitrochlorobenzene by nitrating chlorobenzene with nitrogen dioxide. [0002] Background technique [0003] p-Nitrochlorobenzene is light yellow crystal, hardly soluble in water, slightly soluble in cold ethanol, soluble in hot ethanol, ether, acetone and benzene and other organic solvents, its molecular formula is C 6 h 4 ClNO 2 , the relative molecular mass is 157.56, and its structural formula is: [0004] [0005] p-Nitrochlorobenzene is an important organic intermediate, which is widely used in explosives, medicine, pesticides, dyes and other fields. At present, the industrial production of nitrochlorobenzene mainly adopts the traditional nitric acid-sulfuric acid mixed acid method for nitration. Using chlorobenzene as raw material, crude nitrochlorobenzene, m-nitro Mixtures of chlorobenzene and p-nitrochlorobenzene. However, in the process of preparing the crude nitrochlorobenzene mixture...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C205/12C07C201/08
Inventor 彭新华韩松周皓
Owner ANHUI HUAIHUA
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