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Method for preparing o-bromoacetophenone by biomimetic catalytic oxidation of o-bromoethylbenzene with oxygen

A technology of o-bromoethylbenzene and oxygen oxidation, which is applied in the preparation of carbon-based compounds, chemical instruments and methods, preparation of organic compounds, etc., can solve the problems of complex process, large energy consumption of catalysts, increased operating costs and production costs, etc., To achieve the effect of lowering the reaction temperature

Inactive Publication Date: 2010-06-23
BEIJING UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] (1) This method catalyst consumption is bigger (400ppm), and catalyst needs recycling, and the recycling of catalyst needs to consume a large amount of energy;
[0007] (2) Due to the low activity and selectivity of the catalyst used in this method, even if the amount of catalyst used is more (400ppm), the reaction pressure (0.8MPa) and reaction temperature (140°C) are higher, but after 8 hours of reaction, the o-bromine The conversion rate of ethylbenzene is only 35%, and the selectivity and chromatographic yield of o-bromoacetophenone are only 70.4% and 24.64% respectively;
[0009] (4) the preferred reaction pressure of this method is higher (atmospheric pressure~3MPa), and particularly o-bromoethylbenzene needs to react under 0.8MPa, uses the reaction condition of high pressure, causes equipment investment and operation cost to increase exponentially, and energy consumption is extremely High, especially making production potentially dangerous and greatly reducing safety
Not only because of its toxicity and harmfulness, it may cause serious environmental pollution, but also because of the increase of energy consumption due to the recovery of solvents, which greatly increases operating costs and production costs;
[0020] (3) Due to the use of high-pressure reaction conditions, equipment investment and operating costs are doubled, and energy consumption is extremely high, especially making production potentially dangerous and greatly reducing safety;
[0021] (4) The use of loaded or polymerized metalloporphyrins results in high energy consumption, high discharge of three wastes, complex processes, and increased costs due to the complex preparation process
In addition, due to the large amount of catalyst used (480ppm), it must be separated and recovered after use, and the cost of separating and recovering the catalyst is high, energy consumption is large, and three wastes are discharged.
In addition, because the reaction using supported or polymerized metalloporphyrins is a heterogeneous reaction, the high catalytic activity of metalloporphyrins cannot be well reflected.
[0022] (5) The induction time of the reaction is too long (up to 3h), thus prolonging the entire reaction time, resulting in serious waste of energy and increase in operating costs

Method used

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  • Method for preparing o-bromoacetophenone by biomimetic catalytic oxidation of o-bromoethylbenzene with oxygen
  • Method for preparing o-bromoacetophenone by biomimetic catalytic oxidation of o-bromoethylbenzene with oxygen
  • Method for preparing o-bromoacetophenone by biomimetic catalytic oxidation of o-bromoethylbenzene with oxygen

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] In a 100mL three-necked flask, add 18.562g o-bromoethylbenzene, 1ppm (0.07mg) tetraphenyliron porphyrin (that is, R in formula (I) 11 for H, R 12 for H, R 13 for H, M 1 Fe), 10ppm (0.86mg) four-(p-chlorophenyl) cobalt porphyrin (that is, R in the formula (I) 11 for H, R 12 for H, R 13 for Cl, M 1 For Co), oxygen was introduced at a flow rate of 40 mL / min, the reaction was initiated at 150 °C, and the reaction was carried out at 100 °C for 8 h. The reacted mixture was distilled under reduced pressure to obtain o-bromoacetophenone, the conversion rate of o-bromoethylbenzene was 80.2%, the yield of o-bromoacetophenone was 73.4%, and the purity was 99.3%.

Embodiment 2

[0046] In a 100mL three-necked flask, add 18.495g o-bromoethylbenzene, 5ppm (0.38mg) tetra-phenylmanganese porphyrin chloride (that is, R in formula (II) 21 for H, R 22 for H, R 23 for H, M 2 is Mn, X is Cl), 5ppm (0.44mg) tetrakis-(o-methoxyphenyl) cobalt porphyrin chloride (that is, R in the formula (II) 21 for OCH 3 , R 22 for H, R 23 for H, M 2 is Co, X is Cl), oxygen was introduced at a flow rate of 40 mL / min, the reaction was initiated at 150 °C, and the reaction was carried out at 100 °C for 10 h. The reacted mixture was distilled under reduced pressure to obtain o-bromoacetophenone, the conversion rate of o-bromoethylbenzene was 83.4%, the yield of o-bromoacetophenone was 76.8%, and the purity was 99.1%.

Embodiment 3

[0048] In a 100mL three-necked flask, add 18.512g o-bromoethylbenzene, 1ppm (0.15mg) μ-oxygen-binuclear tetra-phenyliron porphyrin (that is, R in formula (III) 31 for H, R 32 for H, R 33 for H, M 3 , M 4 Fe), 5ppm (0.88mg) μ-oxygen-binuclear four-(p-chlorophenyl) cobalt porphyrin (that is, R in formula (III) 31 for H, R 32 for H, R 33 for Cl, M 3 , M 4 For Co), oxygen was introduced at a flow rate of 50 mL / min, the reaction was initiated at 150 °C, and the reaction was carried out at 90 °C for 10 h. The reacted mixture was distilled under reduced pressure to obtain o-bromoacetophenone, the conversion rate of o-bromoethylbenzene was 70.3%, the yield of o-bromoacetophenone was 64.3%, and the purity was 99.5%.

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Abstract

The invention relates to a method for preparing o-bromoacetophenone by biomimetic catalytic oxidation of o-bromoethylbenzene with oxygen, comprising the following steps: taking o-bromoethylbenzene as the raw material, selecting any one of 1-30ppm of mononuclear metalloporphyrin and mu-oxo-dinuclear metalloporphyrin or the composition of the two substances as the catalyst under normal pressure andin the absence of solvents, introducing oxygen at the flow rate of 10-60mL / min, initiating reaction at 140-170 DEG C and then carrying out reaction at 80-120 DEG C for 6-16h, thus obtaining the o-bromoacetophenone. In the method, the way of high temperature quick initiation and low temperature reaction is adopted, thus minimizing the reaction initiation time, greatly shortening the reaction time,improving the reaction efficiency, reducing the energy consumption, lowering the operation cost and improving the reaction safety.

Description

technical field [0001] The invention relates to a method for preparing aromatic ketones, in particular to a method for preparing o-bromoacetophenone by biomimetic catalytic oxygen oxidation of o-bromoethylbenzene. Background technique [0002] O-bromoacetophenone is an important intermediate in organic synthesis, widely used in the synthesis of medicines, pesticides, dyes, flavors and fragrances, perfumes, etc. At present, the preparation methods of o-bromoacetophenone mainly include Friedel-Crafts acylation method, 1-(2-bromophenyl)ethanol oxidation method and o-bromoethylbenzene oxidation method, etc., wherein o-bromoethylbenzene oxidation method is divided into chemical oxidation Oxygen is used as an oxidant that is cheap and easy to obtain, clean and pollution-free, and has good atom economy, and the method for preparing o-bromoacetophenone by direct oxidation of o-bromoethylbenzene with oxygen has significant advantages over other methods. sex. [0003] US 20030144554...

Claims

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Application Information

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IPC IPC(8): C07C49/807C07C45/36B01J31/22
Inventor 佘远斌赵文伯王磐钟儒刚
Owner BEIJING UNIV OF TECH