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Method for synthesizing 3-amino-4-bromophenol

A synthesis method and aminophenol technology are applied in the preparation of amino hydroxy compounds, chemical instruments and methods, preparation of organic compounds, etc., which can solve the problems of complex post-processing steps, serious pollution and high cost, and achieve complex post-processing and product quality. The effect of high yield and mild conditions

Active Publication Date: 2011-05-18
DALIAN JOIN KING FINE CHEM CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] The synthesis of 3-amino-4-bromophenol has problems such as large amount of post-treatment waste, serious pollution, and high cost. At present, there are no relevant reports and patent applications on the synthesis method of 3-amino-4-bromophenol in China.
According to the literature Organic letters, 12, 10, 2258, diazotization and bromination are generally used to reduce with iron powder under acidic conditions. This method produces a large amount of iron sludge, the amount of three wastes is very large, and the post-treatment steps are very complicated, so Caused product loss, low yield and other problems

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  • Method for synthesizing 3-amino-4-bromophenol

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Embodiment 1

[0017] (1) Diazotization reaction: Take 12g of 3-amino-4-nitrophenol, dissolve in 64g of 40wt% hydrobromic acid aqueous solution, and cool down to 0-10°C. At this temperature, 36 g of a 20 wt % sodium nitrite aqueous solution was added dropwise. Insulation reaction 1h. The obtained yellow liquid is an aqueous solution of 3-nitrophenol-4-diazonium salt, which is directly used in the next reaction.

[0018] (2) Bromination reaction: Take 1.2 g of cuprous bromide and dissolve it in 27 g of 40 wt % hydrobromic acid aqueous solution. After the temperature was raised to 40-45° C., the reaction solution obtained in step (1) was started to be added dropwise. After the dropwise addition was completed, the reaction was incubated for 1 h. The temperature was lowered to 20-25°C, and a solid was precipitated. The product was filtered off and the solid was washed with a little water and dried. 13.1 g of 3-nitro-4-bromophenol are obtained. Content 95%.

[0019] (3) Reduction reaction:...

Embodiment 2

[0022] (1) Diazotization reaction: Take 12g of 3-amino-4-nitrophenol, dissolve in 64g of 40wt% hydrobromic acid aqueous solution, and cool down to 0-10°C. At this temperature, 36 g of a 20 wt % sodium nitrite aqueous solution was added dropwise. Insulation reaction 1h. The obtained yellow liquid is an aqueous solution of 3-nitrophenol-4-diazonium salt, which is directly used in the next reaction.

[0023] (2) Bromination reaction: Take 1.2 g of cuprous bromide and dissolve it in 27 g of 40 wt % hydrobromic acid aqueous solution. After the temperature was raised to 40-45° C., the reaction solution obtained in step (1) was started to be added dropwise. After the dropwise addition was completed, the reaction was incubated for 1 h. The temperature was lowered to 20-25°C, and a solid was precipitated. The product was filtered off and the solid was washed with a little water and dried. 13.1 g of 3-nitro-4-bromophenol are obtained. Content 95wt%.

[0024] (3) Reduction reactio...

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Abstract

The invention relates to a method for synthesizing 3-amino-4-bromophenol. The method comprises the following steps of: (1) diazotization reaction: dissolving 3-nitro-4-aminophenol used as a raw material into hydrobromic acid, and dropping a sodium nitrite aqueous solution at 0-10 DEG C for reacting for 1-3 hours to obtain a 3-nitrophenol-4-diazonium brine solution; (2) bromination reaction: dropping the solution obtained in the step (1) into a hydrobromic acid aqueous solution of cuprous bromide, stirring at 40-50 DEG C for reacting, and crystallizing and filtering to obtain a 3-nitro-4-bromophenol solid; and (3) reduction reaction: dissolving the solid obtained in the step (2) into alcohol, adding an iron oxide catalyst, heating up to 50-100 DEG C, and adding a hydrazine hydrate aqueous solution to the mixture for reacting for 2-5 hours to obtain the 3-amino-4-bromophenol. The synthesis method of the 3-amino-4-bromophenol has the advantages of reasonable design, moderate condition, easiness of operation and higher product yield and is suitable for industrial production.

Description

technical field [0001] The invention belongs to the technical field of synthesizing carbocycles containing substituents in organic chemistry, and specifically relates to the preparation technology of nitrogen-containing and halogen-containing compounds on aromatic rings. Background technique [0002] 3-amino-4-bromophenol is an important pharmaceutical intermediate, the specific structure is as follows: [0003] [0004] The synthesis of 3-amino-4-bromophenol has problems such as a large amount of three wastes after treatment, serious pollution, and high cost. At present, there are no relevant reports and patent applications on the synthesis method of 3-amino-4-bromophenol in China. According to the literature Organic letters, 12, 10, 2258, diazotization and bromination are generally used to reduce with iron powder under acidic conditions. This method produces a large amount of iron sludge, the amount of three wastes is very large, and the post-treatment steps are very co...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C215/76C07C213/02
Inventor 郑涛杨源源刘洪丹
Owner DALIAN JOIN KING FINE CHEM CO LTD
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