Method for preparing pesticide intermediate 2,6-diethyl-4-methylphenyl bromide and method for recovering waste hydrobromic acid

A technology of methyl bromide and waste hydrobromic acid, applied in the preparation of halogenated hydrocarbons, chemical instruments and methods, organic chemistry, etc., can solve the problems of waste hydrobromic acid pollution, reduce production costs, etc., and achieve pollution, reduce The effect of reducing production cost and raw material cost

Inactive Publication Date: 2019-03-26
ANHUI RES INST OF CHEM IND
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] In view of the above-mentioned shortcoming of prior art, the object of the present invention is to provide a kind of pesticide intermediate 2, the preparation method of 6-diethyl-4-methyl bromide benzene and the recovery method of waste hydrobromic acid, the present invention not only Improve the yi...

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  • Method for preparing pesticide intermediate 2,6-diethyl-4-methylphenyl bromide and method for recovering waste hydrobromic acid
  • Method for preparing pesticide intermediate 2,6-diethyl-4-methylphenyl bromide and method for recovering waste hydrobromic acid
  • Method for preparing pesticide intermediate 2,6-diethyl-4-methylphenyl bromide and method for recovering waste hydrobromic acid

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Embodiment 1

[0033] The invention discloses a preparation method of a pesticide intermediate 2,6-diethyl-4-methylbromobenzene, specifically discloses a preparation process of 2,6-diethyl-4-methylbromobenzene, comprising the following step:

[0034] S1, in the reactor that has stirrer, thermometer and constant pressure dropping funnel, add the 2 of 0.2mol successively, the 40% hydrobromic acid of 6-diethyl-4-methylaniline and 100ml, stir and be heated to 80~90℃, react for 15-20 minutes, and obtain a white suspension;

[0035] S2, cooling the above white suspension to -10°C;

[0036] S3. Prepare a mixed solution of sodium nitrite and water, and control the temperature of the mixed solution at -5 to 0°C, wherein, 0.24 mol of sodium nitrite and 50 mL of water are slowly added dropwise to the above white suspension solution, after the dropwise addition, a yellow suspension was obtained;

[0037] S4. Add 160 mg of sulfamic acid or 500 mg of urea to the yellow suspension, continue to stir for ...

Embodiment 2

[0049] The invention discloses a preparation method of a pesticide intermediate 2,6-diethyl-4-methylbromobenzene, specifically discloses a preparation process of 2,6-diethyl-4-methylbromobenzene, comprising the following step:

[0050] S1, in the reactor that has stirrer, thermometer and constant pressure dropping funnel, add the 2 of 0.2mol successively, the 41.79% hydrobromic acid of 6-diethyl-4-methylaniline and 100ml, stir and be heated to 80~90 DEG C, reaction 15-20 minute, obtain white suspension liquid, wherein, 41.79% hydrobromic acid comes from the waste hydrobromic acid recovered when preparing 2,6-diethyl-4-methylbromobenzene in Example 1 ;

[0051] S2. Cool the above white suspension to -15°C;

[0052] S3. Prepare a mixed solution of sodium nitrite and water, and control the temperature of the mixed solution at -5 to 0°C, wherein, 0.24 mol of sodium nitrite and 50 mL of water are slowly added dropwise to the above white suspension solution, after the dropwise addi...

Embodiment 3

[0065] The invention discloses a preparation method of a pesticide intermediate 2,6-diethyl-4-methylbromobenzene, specifically discloses a preparation process of 2,6-diethyl-4-methylbromobenzene, comprising the following step:

[0066] S1, in the reactor that has stirrer, thermometer and constant pressure dropping funnel, add the 2 of 0.2mol successively, the 41.03% hydrobromic acid of 6-diethyl-4-methylaniline and 100ml, stir and be heated to 80~90 ℃, reaction 15-20 minute, obtain white suspension liquid, wherein, 41.03% hydrobromic acid comes from the waste hydrobromic acid recovered when preparing 2,6-diethyl-4-methylbromobenzene in Example 2 ;

[0067] S2. Cool the above white suspension to -12°C;

[0068] S3. Prepare a mixed solution of sodium nitrite and water, and control the temperature of the mixed solution at -5 to 0°C, wherein, 0.24 mol of sodium nitrite and 50 mL of water are slowly added dropwise to the above white suspension solution, after the dropwise additi...

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Abstract

The invention discloses a method for preparing a pesticide intermediate 2,6-diethyl-4-methylphenyl bromide. The method comprises the following steps: preparing a first reactive raw material solution and a second reactive raw material solution; enabling the first reactive raw material solution and the second reactive raw material solution to carry out a diazo-reaction; adding the diazo-reaction solution into a denitrification reaction catalyst solution so as to carry out a denitrification reaction; distilling the denitrification reaction product to obtain distillate and waste liquor; extractingthe distillate to obtain the pesticide intermediate; and distilling and recycling the waste liquor. The first reactive raw material solution is a reactive mixed solution of 2,6-diethyl-4-methylaniline and hydrobromic acid, the second reactive raw material solution is a diazotization agent, and the concentration of the hydrobromic acid is 40-43%. According to the method disclosed by the invention,the yield and purity of the 2,6-diethyl-4-methylphenyl bromide are improved, and the production cost is reduced; and moreover, due to a distillation recovery manner, the waste hydrobromic acid is treated so as to be recycled, the raw material cost is reduced, and the environmental pollution caused by the waste hydrobromic acid is solved.

Description

technical field [0001] The invention relates to a preparation technology of pesticides, in particular to a preparation method of a pesticide intermediate 2,6-diethyl-4-methylbromobenzene and a recovery method of waste hydrobromic acid. Background technique [0002] 2,6-Diethyl-4-methylbromobenzene is a yellow oily liquid with a boiling point of 259°C, a relative density of 1.211, and a flash point of 109°C. At present, the preparation of 2,6-diethyl-4-methylbromobenzene is carried out through the Sandmeyer reaction of 2,6-diethyl-4-methylaniline, that is, through two steps of diazotization and denitrogenation preparation. Most diazotization reactions use sodium nitrite for diazotization, and some use alkyl nitrite for diazotization, but due to poor thermal stability and inconvenient storage of alkyl nitrite, it is difficult to use in industry . And for denitrification process, the catalyzer that it uses has three classes: the first kind is not to use any catalyzer, direct...

Claims

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Application Information

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IPC IPC(8): C07C17/093C07C25/02
CPCC07C17/093C07C245/20C07C25/02
Inventor 王福祥曹泳徐守明申雁
Owner ANHUI RES INST OF CHEM IND
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