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Process for preparing phloroglucinol

A technology of phloroglucinol and aniline, applied in the field of preparation of phloroglucinol, can solve the problems of inconvenient operation, harsh reaction conditions, poor color and luster, and achieves improved stability, reduced waste liquid volume, and good color luster. Effect

Inactive Publication Date: 2005-06-08
ZHEJIANG NHU CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] In the above-mentioned second step diazotization reaction, this step reaction requires anhydrous, and the conditions of the reaction are extremely harsh. Since the sodium nitrite used is added in batches and it is solid, the operation is inconvenient, and the product obtained after the reaction 1,3,5-Tribromobenzene is a reddish-brown solid with poor color

Method used

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  • Process for preparing phloroglucinol

Examples

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Effect test

Embodiment 1

[0015] Embodiment 1 (2,4, the preparation of 6-tribromoaniline)

[0016] Add 100 ml of 10% hydrobromic acid aqueous solution and 10 g (0.1075 mol) of aniline to a 1000 ml three-neck flask equipped with a thermometer, a dropping funnel and a stirring device, and cool to below 10° C. in an ice-water bath. Dissolve 54.2g (0.3387mol) of liquid bromine in 600ml of 10% hydrobromic acid to prepare dilute bromine water. Add the prepared bromine water into the aniline solution within 30 minutes through the dropping funnel, and keep the temperature below 10°C. After the addition, the reaction was stirred for 10 minutes to end the reaction. The reaction solution was filtered under reduced pressure, the filter cake was washed with water until neutral, and the resulting solid was dried at 75°C to obtain 2,4,6-tribromoaniline as a white solid weighing 34.7g with a content of more than 99% .

Embodiment 2

[0017] Embodiment 2 (1,3, the preparation of 5-tribromobenzene)

[0018] Add 95% industrial ethanol 250ml and 100.0g dry 2,4,6-tribromoaniline solid and 0.5g copper sulfate pentahydrate in the 500ml four-neck flask with thermometer, dropping funnel, reflux device and stirring device, heat up to 50°C, stirring and dissolving for 15 minutes. Add 59.4g of concentrated sulfuric acid into the ethanol solution through the dropping funnel within 30 minutes, and the temperature is controlled at about 50°C. After the addition, keep at about 50°C and continue to stir for 15 minutes. 25.0g solid NaNO 2 Dissolved in water, dubbed a saturated aqueous solution. Prepared NaNO 2 The aqueous solution was added dropwise to the ethanol solution at 50°C within 2.0 hours through the dropping funnel. After the addition, continue to maintain 50°C, stir and react for 1.0 hour, then raise the temperature to reflux state, keep the reflux reaction for 2.0 hours, and end the reaction. The reaction ...

Embodiment 3

[0019] Embodiment 3 (1,3, the preparation of 5-tribromobenzene)

[0020] According to the method of Example 2, the feeding amount of copper sulfate pentahydrate was 2.0 g, and 91.2 g of 1,3,5-tribromobenzene was obtained after the reaction, with a content of 99.3%.

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Abstract

The invention relates to a preparation method of phloroglucinol. The post-treatment of the hydrolysis reaction in the existing method forms a large amount of waste residue and waste liquid, which increases the workload of the post-treatment, and the final product has poor color and low purity. In addition, the reaction conditions are harsh and the operation is inconvenient. The feature of the present invention is that in the complexing and hydrolysis reaction, the complexing agent anhydrous aluminum trichloride and 1,3,5-trimethoxybenzene are used for the complexation reaction, and then the hydrolysis reaction is carried out in concentrated hydrochloric acid , The hydrolyzed solution is cooled and crystallized to obtain crude phloroglucinol; the crude product of phloroglucinol is first decolorized with activated carbon, and then recrystallized in water. Without affecting the total yield, the invention can make the phloroglucinol have good color and high purity, shorten the reaction time, reduce the amount of waste liquid produced by the hydrolysis reaction, simplify the operation conditions and improve the stability of the reaction.

Description

technical field [0001] The invention relates to a preparation method of phloroglucinol. Background technique [0002] Phloroglucinol is mainly used as an intermediate in drug synthesis, and can also be used as a raw material for dye couplers, synthetic rubber stabilizers, tire tackifiers, and azo composite inks. Presently known phloroglucinol synthesis method mainly contains two kinds, and a kind of is to be starting raw material with trinitrotoluene (TNT), through a series of reactions such as oxidation, decarboxylation, reduction and hydrolysis, synthesize phloroglucinol, The total yield of the product is 46% to 53%; the other is 1,3,5-triisopropylbenzene as the starting material, which is oxidized to form peroxide, and then decomposed and refined to obtain high-purity m-benzenetribenzene Phenol, the total yield of the product is 50% to 60%. The former is an early synthesis process, which has the advantages of mature technology, but has the disadvantages of difficult tre...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C37/01C07C39/10
Inventor 徐华新
Owner ZHEJIANG NHU CO LTD
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