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Synthetic process of para-nitrotribromotoluene

A technology of nitrotribromotoluene and p-nitrotoluene, which is applied in the field of bromide synthesis technology, can solve the problems of harsh operating conditions, large bromine atom volume, and low product yield, and achieve low production cost and high product yield. High, high yield effect

Inactive Publication Date: 2007-10-03
BLUESTAR LEHIGH ENG INST CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] In the prior art, the synthesis process of p-nitrobenzotribromotoluene (or p-tribromomethylnitrobenzene) mainly adopts the direct bromination mode of p-nitrotoluene to produce, and there are mainly the following problems: p-nitrotoluene is produced in Direct bromination at 190-200°C. When bromine directly attacks the methyl group, p-nitrodibromotoluene is easy to form due to the large volume and steric hindrance of the bromine atom. Even at high temperatures, the third hydrogen atom on the methyl group It is also difficult to be replaced by bromine, so there are many problems such as high bromination temperature, harsh operating conditions, low product yield (only about 30%), many "three wastes", high production costs, and poor economic benefits.

Method used

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Examples

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Effect test

Embodiment 1

[0023] Example 1. A kind of synthesis technique of p-nitrobenzotribromotoluene, its step is as follows,

[0024] (1) The first step reaction: add p-nitrotoluene to the reaction kettle, open the tail gas absorption device, absorb the hydrogen bromide and excess bromine produced by the reaction with water; control the reaction temperature at 130°C, add bromine dropwise, and the reaction time Control within 3 hours; the reaction generates p-nitrodibromotoluene, and the temperature is lowered to 60°C;

[0025] (2) The second step reaction: put carbon tetrachloride, catalyst BTEAB, sodium hydroxide, and water into the above-mentioned reaction kettle in sequence, control the temperature at 40°C, then add bromine dropwise, and the reaction time is 2 hours, and the crude product is obtained by filtration ;

[0026] (3) Put the above crude product and ethanol into the reaction kettle, stir, heat up and reflux for 20 minutes, cool to room temperature, filter and dry to obtain the fini...

Embodiment 2

[0027] Example 2. A kind of synthesis technique of p-nitrobenzotribromotoluene, its step is as follows,

[0028] (1) The first step reaction: add p-nitrotoluene into the reaction kettle, open the tail gas absorption device, absorb the hydrogen bromide and excess bromine produced by the reaction with water; control the reaction temperature at 180°C, add bromine dropwise, and the reaction time Control within 8 hours; the reaction generates p-nitrodibromotoluene, and the temperature is lowered to 80°C; wherein, the molar ratio of p-nitrotoluene to bromine is: 1.0:2.0;

[0029] (2) The second step reaction: Put carbon tetrachloride, catalyst BTEAB, sodium hydroxide, and water into the above-mentioned reaction kettle in turn, control the temperature at 80°C, then add bromine dropwise, and the reaction time is 6 hours, and filter to obtain the crude product The molar proportioning ratio of the system is: p-nitrodibromotoluene: bromine: sodium hydroxide=1: 1.00: 1.10; the catalyst B...

Embodiment 3

[0031] Example 3. A kind of synthesis technique of p-nitrobenzotribromotoluene, its step is as follows,

[0032] (1) The first step reaction: add p-nitrotoluene to the reaction kettle, open the tail gas absorption device, absorb the hydrogen bromide and excess bromine produced by the reaction with water; control the reaction temperature at 150°C, add bromine dropwise, and the reaction time Control within 5 hours; react to generate p-nitrodibromotoluene, drop 70°C; wherein, the molar ratio of p-nitrotoluene to bromine is: 1.0:2.2;

[0033] (2) The second step reaction: Put carbon tetrachloride, catalyst BTEAB, sodium hydroxide, and water into the above-mentioned reaction kettle in sequence, control the temperature between 55°C, then add bromine dropwise, the reaction time is 4 hours, and filter Obtain crude product; The molar proportioning ratio of system is: p-nitrodibromotoluene: bromine: sodium hydroxide=1: 1.50: 1.60; Catalyst BTEAB consumption is 3% of p-nitrodibromotolue...

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Abstract

This invention relates to a synthesize craft of paranitro tri- bromine toluene. first adding paranitrotoluene to reactor, unclose vent gas absorption plant, using water to absorb hydrogen bromide and superfluous bromine generated by reaction; the temperature control at 130 to 180 deg; distribution droplets bromine, response time control at 3 to 8 hours; while reaction generate paranitro oxazole- toluene, cooling to 60 to 80 deg. secondary reaction: in turns add carbon tetrachloride, catalyzer BTEAB , sodium hydroxide, water to above described reactor, control temperature at 40 to 80 deg, then distribution droplets bromine, response time for 2 to 6 hours, and through filtration to gain crude product; add crude product and ethanol into reactor, whipping, heating-up and recirculate for 20 to 60 minutes, cooling to room temperature, then through filtration and dryness to gain finished product. The whole production process possess trait of operating stabilization, easy to control and low cost.

Description

technical field [0001] The invention relates to a synthesis process of bromide, in particular to a synthesis process of p-nitrobenzotribromotoluene. Background technique [0002] In the prior art, the synthesis process of p-nitrobenzotribromotoluene (or p-tribromomethylnitrobenzene) mainly adopts the direct bromination of p-nitrotoluene to produce, and there are mainly the following problems: p-nitrotoluene is produced in Direct bromination at 190-200°C. When bromine directly attacks the methyl group, p-nitrodibromotoluene is easy to form due to the large volume and steric hindrance of the bromine atom. Even at high temperatures, the third hydrogen atom on the methyl group It is also difficult to be replaced by bromine, so there are many problems such as high bromination temperature, harsh operating conditions, low product yield (only about 30%), many "three wastes", high production costs, and poor economic benefits. Contents o...

Claims

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Application Information

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IPC IPC(8): C07C201/12C07C205/11
Inventor 李学字赵焰张素芳费文丽云干
Owner BLUESTAR LEHIGH ENG INST CO LTD
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