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Synthesis method of 4-nitro m-xylene by selective nitration of bismuth nitrate

A nitro-m-xylene and selectivity technology, applied in the preparation of nitro compounds, organic chemistry, etc., can solve the problems of low yield of 4-nitro-m-xylene, poor nitration selectivity, high production cost, etc., and meet the reaction conditions Ease of control, increased productivity, and low production costs

Inactive Publication Date: 2015-12-23
HEFEI NORMAL UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the problems of low yield of 4-nitro-m-xylene prepared by nitration of m-xylene in the prior art, poor nitration selectivity, long time consumption and high production cost, the present invention will provide a kind of nitric acid with strong selectivity and ideal yield Bismuth selective nitration method for synthesizing 4-nitro-m-xylene

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] Add 3mL of petroleum ether into a 25mL round bottom flask, and add 2.0mmol of m-xylene, 2.0mmol of acetic anhydride, Bi(NO 3 ) 3 ·5H 2 O2.0mmol and zeolite molecular sieve catalyst Hβ(500) 0.4g, after heating to reflux for 2h, add 4mL water to stop the reaction, filter and separate to remove zeolite molecular sieve catalyst Hβ(500), the catalyst can be kept for reuse, and the obtained liquid phase is sequentially washed with 10mL of water , the mass percentage is 5% NaHCO 3 The solution and water were washed, and then a small amount of magnesium sulfate was added to remove water and dried. After the above steps were completed, the gas chromatographic analysis was carried out with p-nitrotoluene as the internal standard. The results showed that the yield was 85.5%, of which 4-nitro-m-xylene accounted for 89.1%, 2-nitro-m-xylene accounted for 10.9%, and the 4- / 2-ratio reached 8.17. The zeolite molecular sieve catalyst Hβ(500) in the above steps can be replaced by any o...

Embodiment 2

[0024] Add 7mL of petroleum ether into a 25mL round bottom flask, and add 4.0mmol of m-xylene, 10.0mmol of acetic anhydride, Bi(NO 3 ) 3 ·5H 2 O4.0mmo and zeolite molecular sieve catalyst Hβ(500) 1.2g, add 6mL water to stop the reaction after heating to reflux for 6h, filter and separate to remove zeolite molecular sieve catalyst Hβ(500), the catalyst can be kept for reuse, and the obtained liquid phase is sequentially washed with 10mL water , the mass percentage is 5% NaHCO 3 The solution and water were washed, and then a small amount of magnesium sulfate was added to remove water and dried. After the above steps were completed, the gas chromatographic analysis was carried out with p-nitrotoluene as the internal standard. The results showed that the yield was 86.4%, of which 4-nitro-m-xylene accounted for 88.7%, 2-nitro-m-xylene accounted for 11.3%, and the 4- / 2-ratio reached 7.85.

[0025] Experiment 3

[0026] Add 5mL of petroleum ether into a 25mL round-bottomed flask,...

Embodiment 4

[0028] Add 3 mL of chloroform into a 25 mL round bottom flask, and add 3.0 mmol of m-xylene, 5.0 mmol of acetic anhydride, Bi(NO 3 ) 3 ·5H 2 O2.4mmol and zeolite molecular sieve catalyst Hβ(500) 0.6g, after heating to reflux for 3h, add 5mL water to stop the reaction, filter and separate to remove the zeolite molecular sieve catalyst Hβ(500), the catalyst can be kept for reuse, and the obtained liquid phase is sequentially washed with 10mL of water , the mass percentage is 5% NaHCO 3 The solution and water were washed, and then a small amount of magnesium sulfate was added to remove water and dried. After the above steps were completed, the gas chromatographic analysis was carried out with p-nitrotoluene as the internal standard. The results showed that the yield was 89.9%, of which 4-nitro-m-xylene accounted for 88.9%, 2-nitro-m-xylene accounted for 11.1%, and the 4- / 2-ratio reached 8.01.

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Abstract

A synthesis method of 4-nitro m-xylene by selective nitration of bismuth nitrate comprises the following steps: adding 3-7ml of petroleum ether to a round bottom flask under magnetic stirring, successively adding 2.0-4.0mmol of m-xylene, 2.0-10.0mmol of acetic anhydride, 2.0-4.0mmol of Bi(NO3)3.5H2O and 0.4-1.2g of a zeolite molecular sieve catalyst Hbeta (500); heating with refluxing for 2-6 h and terminating the reaction; filtering for removing the catalyst; and conducting liquid washing, dewatering and drying. The method can greatly improve the yield of 4-nitro m-xylene in a nitration product, and the nitration selectivity of m-xylene is significantly enhanced; and under the optimum conditions, the yield and selectivity of 4-nitro m-xylene reach 89.9% and 8.26. The method has the advantages of easy control of reaction conditions, short time consumption, simple process, low production cost, less pollution, and convenience for industrial production.

Description

technical field [0001] The invention belongs to the field of synthesis of fine chemical intermediate nitro-m-xylene, and in particular relates to a method for synthesizing 4-nitro-m-xylene by selective nitration of bismuth nitrate. Background technique [0002] The mononitration of m-xylene mainly produces 4-nitro-m-xylene and 2-nitro-m-xylene, which are important organic intermediates and are widely used in dyes, medicines, plastics, rubber additives, rust removal, sterilization and plant growth Regulators, etc. Among them, 4-nitro-m-xylene is mainly used in the pesticide industry, such as the production of organic nitrogen pesticides such as amitraz, monoformamidine, and acetamidine. Aniline, etc., so the development of 4-nitro-m-xylene has important practical value. At present, in industrial production, 4-nitro-m-xylene is still prepared by using m-xylene as raw material through nitric acid mixed acid nitration method, but with the development of the times, the shortcom...

Claims

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Application Information

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IPC IPC(8): C07C205/06C07C201/08
Inventor 董雄辎田燕卫艳新彭新华司圣柱王丽平
Owner HEFEI NORMAL UNIV
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