Preparation method of o-chlorotoluene

A technology of o-chlorotoluene and toluene, which is applied in the field of preparation of o-chlorotoluene, can solve the problems of inability to separate Lewis acid, be unfavorable for industrial production, and pollute the environment, and achieve the effects of easy control of the reaction, benefit for industrial production, and high selectivity

Inactive Publication Date: 2015-08-05
JIANGSU UNIV
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Problems solved by technology

[0004] At present, o-chlorotoluene is mainly prepared by using Lewis acid as a catalyst, chlorine gas as a chlorination agent, and catalyzing the selective chlorination of toluene; according to the reported literature, in the toluene chlorination process, the ratio of o-chlorotoluene to p-chlorotoluene Close to 1:1; in addition, the traditional Lewis acid cannot be separated from the chlorination product, resulting in a large amount of waste water, polluting the environment, and is not conducive to industrial production

Method used

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  • Preparation method of o-chlorotoluene

Examples

Experimental program
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Effect test

Embodiment 1

[0025] (1) Ionic liquid [BMIM]Cl-2ZnCl 2 Preparation: under nitrogen protection, 1.3 mol of 1 – Methylimidazole and 1.4 mol of n-chlorobutane were stirred and mixed in a 500 mL three-neck flask with a condenser tube, and the temperature was raised to 80 °C under reflux for 48 h; the product was separated from the remaining unreacted liquid with a separatory funnel , the product was washed with ethyl acetate and washed three times; the crude product was rotary evaporated under vacuum at 60 °C to remove residual ethyl acetate, and dried in vacuum at 70 °C for 24 h, and the obtained light yellow liquid was [BMIM]Cl ionic liquid intermediate , stored in dry N 2 Reserve under atmosphere.

[0026] N 2 Atmosphere, 34.92 g (0.2mol) intermediate and 54.60 g (0.4mol) ZnCl 2 Add it to a three-necked flask, stir to disperse evenly, and react at 120 °C for 2 h.

[0027] (2) Toluene chlorination reaction step Add 1.0mol toluene to a 250 mL four-neck flask, add 0.03 mol [BMIM]Cl-2ZnCl ...

Embodiment 2

[0035] Adopt the same method of embodiment 1 to prepare [BMIM]Cl-2ZnCl 2 Ionic liquid, the process of toluene chlorination adopts the same method of embodiment 1, but changes [BMIM]Cl-2ZnCl 2 The dosage of ionic liquid is 0.01 mol, 0.05 mol, [BMIM]Cl-2ZnCl can be obtained 2 The impact of the amount of ionic liquid on the toluene chlorination process, as shown in Table 2:

[0036] Table 2 [BMIM]Cl-2ZnCl 2Effect of the dosage of ionic liquid on the chlorination reaction of toluene

[0037]

[0038] Table 2 shows the effect of catalyst dosage on toluene chlorination. When [BMIM]Cl-2ZnCl 2 When the ionic liquid is used as the catalyst, as the amount of catalyst increases from 1% to 3%, 5%, the conversion rate of toluene increases from 80.14% to 98.77%, 99.75%; the selectivity of o-chlorotoluene increases from 67.86% to 73.04%, Then it decreased to 68.58%.

[0039] As can be seen from Table 2, increasing the consumption of catalyst is conducive to the raising of toluen...

Embodiment 3

[0041] Adopt the same method of embodiment 1 to prepare [BMIM]Cl-2ZnCl 2 The process of ionic liquid and toluene chlorination reaction adopts the same method as in Example 1, but the reaction temperature is changed to 30°C, 50°C, and 90°C to obtain the influence of different reaction temperatures on the toluene chlorination process, as shown in Table 3:

[0042] Table 3 Effect of different reaction temperatures on the chlorination of toluene

[0043]

[0044] Table 3 reflects the influence of reaction temperature on the chlorination of toluene; as can be seen from Table 3, as the reaction temperature increases from 30 °C to 90 °C, the conversion rate of toluene increases from 78.25% to 99.84%; The selectivity increased first and then decreased. At 70 °C, the selectivity of o-chlorotoluene reached a maximum value of 73.04%; the selectivity of dichlorotoluene increased from 1.89% to 7.17%. increase and the selectivity of o-chlorotoluene, but also promote the generation o...

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Abstract

The invention relates to a preparation method of o-chlorotoluene. Particularly, methylbenzene is used as a raw material, Cl2 is used as a chlorine source, and [BMIM]Cl-nZnCl2(n is equal to 1, 2, 2.5, and n is a molar ratio of ZnCl2 to [BMIM]Cl) acidic ionic liquid is used as a catalyst to catalyze the methylbenzene to prepare the o-chlorotoluene; the [BMIM]Cl-nZnCl2(n is equal to 1, 2 or 2.5) acidic ionic liquid is used as a chlorinated catalyst, and the Cl2 is used as the chlorine source to perform selective chlorination on the methylbenzene. According to the method, the selectivity of the o-chlorotoluene in the product can be improved, the [BMIM]Cl-nZnCl2 ionic liquid catalyst separated from the product can also be repeatedly used, so the production cost is reduced, and the method is an important method for contributing to industrial production of the o-chlorotoluene.

Description

technical field [0001] The present invention relates to a kind of preparation method of o-chlorotoluene, specifically refers to using toluene as raw material, Cl 2 is the chlorine source, [BMIM]Cl–nZnCl 2 (n=1, 2, 2.5, n is ZnCl 2 The molar ratio to [BMIM]Cl) acidic ionic liquid is used as a catalyst to catalyze the preparation of o-chlorotoluene from toluene; it belongs to the technical field of toluene chlorination and also belongs to the technical field of ionic liquid. Background technique [0002] O-chlorotoluene is an important chemical raw material intermediate, widely used in pesticides, medicines, dyes and paints. It is also a medium-boiling organic solvent with good performance; at present, o-chlorotoluene is increasingly widely used in organic synthesis. [0003] Using o-chlorotoluene as raw material and aluminum chloride as a catalyst, thiazole pesticides and fungicides can be directly synthesized; the condensation reaction product of o-chlorotoluene and dichl...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C25/02C07C17/12
CPCY02P20/584
Inventor 朱晓燕殷恒波付玉军王爱丽
Owner JIANGSU UNIV
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