Catalyst in use for bromophenol

A catalyst and bromination technology, applied in catalyst activation/preparation, physical/chemical process catalyst, organic chemistry, etc., can solve problems such as environmental pollution, waste, environmental pollution of hydrogen bromide discharge, and achieve good para-selectivity, The effect of simple preparation device and short preparation period

Inactive Publication Date: 2009-01-14
ANHUI NORMAL UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] Brominated aromatic compounds are important intermediates for the synthesis of a variety of biologically active substances, among which p-bromophenol is preferred, so the synthesis of p-bromophenol is particularly important. The early method of phenol bromination is to use directly Liquid bromine is used as a raw material, and the catalysts used are inorganic acids and metal halides. During production, half of the bromine generates hydrogen bromide, which is wasted, and the discharge of hydrogen bromide causes environmental pollution. At the same time, the catalyst is not easy to separate, and the generated bromine is para- Low selectivity, low conversion of bromide
The oxidative bromination method developed later, that is, in the process of phenol bromination, hydrogen bromide is selected as the bromine source, and hydrogen peroxide is used as the oxidant to brominate phenol. This method has good para-selectivity, but the conversion of the bromide The rate is low and can only reach about 30%, and the unreacted hydrogen bromide also causes environmental pollution

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] Example 1: Put 20 g of multi-walled carbon nanotubes into 1 liter of nitric acid with a weight concentration of 50%, reflux at 50°C for 24 hours, cool, dilute the acidified carbon tubes with water, and adjust the pH value to 7.0 with 0.1M sodium hydroxide , then filtered, washed with water, and finally the acidified carbon tube was dried at 100° C. for 4 hours to make the water content less than 0.5%, and the catalyst acidified carbon tube could be prepared.

Embodiment 2

[0022] Embodiment 2: except changing the nitric acid that the weight concentration is 50% to the weight concentration is that the volume ratio of the nitric acid that is 63% and the sulfuric acid that the weight concentration is 98% is 1: 3, backflow 24 hours and change ultrasonic 5 hours, all the other and Process 1 is the same.

Embodiment 3

[0023] Embodiment 3: get the product 5 grams that embodiment 2 makes and 0.5 liters of Cr (NO 3 ) 3 After the saturated solution is mixed and stirred at room temperature for 8 hours, it is fully washed until neutral, filtered, and dried at 100°C for 4 hours to make the water content less than 0.5%, and then the acidified carbon tube containing chromium can be prepared.

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Abstract

A catalyst for the bromonating reaction of phenol to obtain bromophenol is an acidified carbon nanotube. Its advantages are high impact resistance, stability, selectivity and output rate of product.

Description

technical field [0001] The invention belongs to the technical field of catalysts for organic reactions, in particular to the technical field of catalysts for phenol bromination. Background technique [0002] Brominated aromatic compounds are important intermediates for the synthesis of a variety of biologically active substances, among which p-bromophenol is preferred, so the synthesis of p-bromophenol is particularly important. The early method of phenol bromination is to use directly Liquid bromine is used as a raw material, and the catalysts used are inorganic acids and metal halides. During production, half of the bromine generates hydrogen bromide, which is wasted, and the discharge of hydrogen bromide causes environmental pollution. At the same time, the catalyst is not easy to separate, and the generated bromine is para- The selectivity is low, and the conversion rate of the bromide is low. The oxidative bromination method developed later, that is, in the process of ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B01J27/20B01J37/06C07C37/62C07C39/04
CPCY02P20/52
Inventor 魏先文徐静夏传俊
Owner ANHUI NORMAL UNIV
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