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Preparation method of o-dibromobenzene

A technology of o-dibromobenzene and o-bromoaniline, applied in the field of preparation of o-dibromobenzene, can solve the problems of high cost, low purity, waste of raw materials, etc., achieve low cost, easy availability of materials, and increase product purity and yield Effect

Inactive Publication Date: 2017-06-30
YANCHENG LONGSHENG CHEM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The invention is convenient and simple to prepare, and the raw materials are easy to obtain, but the purity of the reaction is low, and the waste of raw materials is large, and the cost is high

Method used

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  • Preparation method of o-dibromobenzene

Examples

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Comparison scheme
Effect test

Embodiment 1

[0027] A preparation method of o-dibromobenzene, comprising the following preparation steps:

[0028] S1: Add water into the reaction kettle, then add sodium nitrite while stirring, obtain sodium nitrite solution after the dissolution is complete, and put it in a bucket for later use;

[0029] S2: Add 18 parts of hydrobromic acid with a mass fraction of 48% in the reaction kettle, add 6 parts of o-bromoaniline under stirring, and start freezing to cool down after the two are completely dissolved, and drop it below 10°C, and then add it from the manhole Cool down with ice cubes, add 8 parts of sodium nitrite solution prepared in step S1 dropwise at a temperature of 0-5°C, and stir and cool for 1 hour after the dropwise addition;

[0030] S3: Perform suction filtration within the temperature range of 0-5°C to remove impurities to obtain a diazonium salt solution;

[0031] S4: Add 7 parts of hydrobromic acid with a mass fraction of 48% in a reaction kettle equipped with a steam ...

Embodiment 2

[0036] A preparation method of o-dibromobenzene, comprising the following preparation steps:

[0037] S1: Add water into the reaction kettle, then add sodium nitrite while stirring, obtain sodium nitrite solution after the dissolution is complete, and put it in a bucket for later use;

[0038] S2: Add 20 parts of hydrobromic acid with a mass fraction of 48% in the reaction kettle, add 7 parts of o-bromoaniline under stirring, and start freezing to cool down after the two are completely dissolved, and drop it below 10°C, and then add it from the manhole Cool down with ice cubes, add 9 parts of sodium nitrite solution prepared in step S1 dropwise at a temperature of 0-5°C, and stir and cool for 1 hour after the dropwise addition;

[0039] S3: Perform suction filtration within the temperature range of 0-5°C to remove impurities to obtain a diazonium salt solution;

[0040] S4: Add 7 parts of hydrobromic acid with a mass fraction of 48% in a reaction kettle equipped with a steam ...

Embodiment 3

[0045] A preparation method of o-dibromobenzene, comprising the following preparation steps:

[0046] S1: Add water into the reaction kettle, then add sodium nitrite while stirring, obtain sodium nitrite solution after the dissolution is complete, and put it in a bucket for later use;

[0047] S2: Add 23 parts of hydrobromic acid with a mass fraction of 48% in the reaction kettle, add 8 parts of o-bromoaniline under stirring, and start freezing to cool down after the two are completely dissolved, and drop it below 10°C, and then add it from the manhole Cool down with ice cubes, add 10 parts of sodium nitrite solution prepared in step S1 dropwise at a temperature of 0-5°C, and stir and cool for 1 hour after the dropwise addition;

[0048] S3: Perform suction filtration within the temperature range of 0-5°C to remove impurities to obtain a diazonium salt solution;

[0049] S4: Add 8 parts of hydrobromic acid with a mass fraction of 48% in a reaction kettle equipped with a steam...

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Abstract

The invention provides a preparation method of o-dibromobenzene, and belongs to the technical field of chemical engineering. The preparation method comprises the following steps: dropwise adding a sodium nitrite solution into a mixed solution of hydrobromic acid and o-bromoaniline at the temperature of 0-5 DEG C, cooling, removing impurities through suction filtration to obtain a diazonium salt solution, then dropwise adding the diazonium salt solution into a mixed solution of hydrobromic acid and cuprous bromide, distilling through water steam, washing, neutralizing and dewatering to obtain the o-dibromobenzene, and adding water into residual liquid after distillation, stirring, cooling, centrifuging and drying to obtain the cuprous bromide which is recyclable. By the preparation method of the o-dibromobenzene, provided by the invention, the purity is high, the yield is high, raw materials are easy to obtain and recyclable, and the cost is relatively low.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and in particular relates to a preparation method of o-dibromobenzene. Background technique [0002] Dibromobenzene is the general term for compounds obtained by replacing two hydrogen atoms on the benzene ring with bromine. Due to the different substitution positions of bromine, there are 1,2-dibromobenzene (or o-dibromobenzene), 1,3-dibromobenzene Benzene (or m-dibromobenzene) and 1,4-dibromobenzene (or p-dibromobenzene) are three isomers. O-dibromobenzene is a colorless or light yellow liquid, soluble in ethanol, easily soluble in ether, acetone, benzene and carbon tetrachloride, insoluble in water, and can be used in organic synthesis or dye intermediates. The traditional production method of o-dibromobenzene is produced by two-step method of diazotization and decomposition reaction. The dropwise reaction temperature of 1-10°C cannot produce a high-purity diazonium salt solution, a...

Claims

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Application Information

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IPC IPC(8): C07C17/093C07C25/02C07C245/20C01G3/04
CPCC07C17/093C01G3/04C07C245/20C07C25/02
Inventor 高井定
Owner YANCHENG LONGSHENG CHEM CO LTD
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