Method for catalytic nitration of o-chlorotoluene by using modified beta zeolite

A technology of o-chlorotoluene and β zeolite, which is applied in the field of nitration of organic matter, can solve the problems of environmental pollution and poor selectivity of nitrification waste acid, achieve the effects of increasing conversion rate and yield, improving reaction selectivity, and reducing the amount of waste acid treatment

Inactive Publication Date: 2018-10-16
LIHAI CHEM IND CO LTD OF JIANGSU JINQIAO SALT & CHEM GRP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The present invention provides a method for catalyzing the nitration of o-chlorotoluene by modified β zeolite, so as to overcome the pr

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Add 5mL of dichloromethane, 3.0mmol of o-chlorotoluene, 3.0mmol of acetic anhydride, 3mmol of fuming nitric acid, and 0.10g of zeolite molecular sieve Agβ catalyst (calcined at 500°C for 2h before use) into a 25mL round-bottom flask under magnetic stirring. ) and 0.1 g of silica-loaded perfluorosulfonic acid resin, heated to reflux for 4 h, added 5 mL of water to the reaction mixture to stop the reaction, filtered to remove the catalyst, and the organic phase was successively washed with 10 mL of water and 10 mL of NaHCO with a mass fraction of 5%. 3 Wash with 10mL of water and let stand to separate the organic phase. Gas chromatographic analysis was performed using p-nitrotoluene as an internal standard. The results showed that the yield was 56.3%, and the selectivity of 2-chloro-4-nitrotoluene reached 79.5%.

Embodiment 2

[0027] Under the condition of magnetic stirring, 5 mL of 1,2-dichloroethane, 3.0 mmol of o-chlorotoluene, 3.0 mmol of acetic anhydride, 6 mmol of fuming nitric acid, 0.10 g of zeolite molecular sieve Znβ catalyst and silica-supported Perfluorosulfonic acid resin 0.1g, after heating to reflux for 2h, add 5mL water to the reaction mixture to stop the reaction, filter to remove the catalyst, the organic phase is successively filled with 10mL water and 10mL NaHCO with a mass fraction of 5%. 3 Wash with 10mL of water and let stand to separate the organic phase. Gas chromatographic analysis was performed using p-nitrotoluene as an internal standard. The results showed that the yield was 74.3%, and the selectivity of 2-chloro-4-nitrotoluene reached 80.3%.

Embodiment 3

[0029] Add 5 mL of 1,2-dichloroethane, 3.0 mmol of o-chlorotoluene, 6.0 mmol of acetic anhydride, 3 mmol of fuming nitric acid, 0.10 g of zeolite molecular sieve Hβ catalyst and silica-supported Perfluorosulfonic acid resin 0.1g, after heating to reflux for 3h, add 5mL water to the reaction mixture to stop the reaction, after filtering to remove the catalyst, the organic phase is successively filled with 10mL water and 10mL NaHCO with a mass fraction of 5%. 3 Wash with 10mL of water and let stand to separate the organic phase. Gas chromatographic analysis was performed using p-nitrotoluene as an internal standard. The results showed that the yield was 67.7%, and the selectivity of 2-chloro-4-nitrotoluene reached 76.4%.

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Abstract

The invention discloses a method for catalytic nitration of o-chlorotoluene by using modified beta zeolite. The method comprises the following steps: while stirring, adding a solvent into a container,then sequentially adding o-chlorotoluene, acetic anhydride, fuming nitric acid, a modified beta zeolite molecular sieve catalyst and silicon dioxide loaded perfluorinated sulfonic acid resin; performing heating reflux for 1-9h before terminating the reaction. According to the method disclosed by the invention, acetic anhydride is applied to a nitration process of o-chlorotoluene; compared with anitration process of o-chlorotoluene using nitric-sulfuric acid, the use of strong acid sulfuric acid is avoided, and the treatment amount of waste acid is reduced; meanwhile, the silicon dioxide loaded perfluorinated sulfonic acid resin is adopted, with the perfluorinated sulfonic acid resin dispersed in a SiO2 network or pore channel; since the effective surface area is greatly increased, the acid site of the perfluorinated sulfonic acid resin is fully exposed, the potential of the resin catalyst is totally played, and the conversion rate and yield are increased; moreover, the modified zeolite molecular sieve catalyst Bibeta provides an acid center and a pore channel structure as well as shape selecting catalysis, the reaction selectivity is improved, the yield reaches 85.4%, and the selectivity of 2-chloro-4-nitrotoluene is up to 84.6%; the method is easy to operate and control and is a green and environment-friendly o-chlorotoluene nitration method.

Description

technical field [0001] The invention belongs to the field of nitration of organic matter, and in particular relates to a method for catalytic nitration of o-chlorotoluene by modified beta zeolite. Background technique [0002] Nitro-o-chlorotoluene is an important pesticide, dye, and pharmaceutical intermediate, which is mainly produced by nitration of o-chlorotoluene. The traditional preparation method of nitro-o-chlorotoluene is the mixed acid technology of nitric acid and sulfuric acid widely used in industry. The method has the advantages of rapid reaction and high conversion rate. However, with the development of the economy, the disadvantages of this method are also becoming more and more prominent, mainly in: strong acid production conditions severely corrode the equipment; the acid waste water produced seriously pollutes the environment; the selectivity of the nitrification reaction is poor; side reactions such as multiple nitrification and oxidation are prone to oc...

Claims

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Application Information

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IPC IPC(8): C07C201/08C07C205/12
CPCC07C201/08C07C205/12
Inventor 董雄辎彭新华臧涵申卫卫姜红来吉凤成韩勇蒋校
Owner LIHAI CHEM IND CO LTD OF JIANGSU JINQIAO SALT & CHEM GRP
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