Method for preparing p-diacetylbenzene by biomimetic catalytic oxidation of p-diethylbenzene with oxygen

A technology of diacetylbenzene and p-diethylbenzene, which is applied in the field of biomimetic catalytic oxygen oxidation of p-diethylbenzene to prepare p-diacetylbenzene, can solve the problems of wasting raw materials, high air flow rate, and increased operating costs, and speed up production Cycle, gas flow rate savings, and operating cost reduction effects

Inactive Publication Date: 2010-06-30
BEIJING UNIV OF TECH
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  • Abstract
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Problems solved by technology

The use of co-catalysts not only increases the production cost, but also causes very serious corrosion to the equipment. It is necessary to greatly increase the investment and operating costs of the equipment. In addition, a large amount of salty wastewater will be added after the reaction, which will cause greater harm to the environment. Pollution, consuming more energy and resources;
[0008] (3) Although the method has used multiple catalysts and added a co-catalyst, its activity and selectivity are still extremely low, as p-diethylbenzene can only reach a conversion rate of 87.4% after reacting for 40 hours, especially for p-diethylbenzene The selectivity and chromatographic yield of acetylbenzene are only 25.2% and 22% respectively, if do not have under the existence of pyridine and hydrobromic acid, the conversion rate of p-diethylbenzene is only 27.4%, and the conversion ratio of p-diacetylbenzene Selectivity and chromatographic yield were only 17.4% and 4.78%, respectively
Such a low selectivity not only wastes a lot of raw materials and increases production costs, but also the existence of a large number of by-products brings great difficulties to the post-treatment process, consumes a lot of energy and resources, and causes very serious environmental pollution at the same time. Therefore this method cannot be used for industrialized production at all;
[0009] (4) The air flow rate (150mL/min) used in this method is too large, and too high gas flow rate will not only cause waste of energy and resource

Method used

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  • Method for preparing p-diacetylbenzene by biomimetic catalytic oxidation of p-diethylbenzene with oxygen
  • Method for preparing p-diacetylbenzene by biomimetic catalytic oxidation of p-diethylbenzene with oxygen
  • Method for preparing p-diacetylbenzene by biomimetic catalytic oxidation of p-diethylbenzene with oxygen

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Experimental program
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Effect test

Embodiment 1

[0044] In a 100mL three-necked flask, add 13.474g p-diethylbenzene, 1ppm (0.07mg) tetraphenyliron porphyrin (i.e. 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 110°C for 18h. The reacted mixture was frozen, centrifugally filtered, and then recrystallized with ethanol to obtain p-diacetylbenzene. The conversion rate of p-diethylbenzene was 80.4%, the yield of p-diacetylbenzene was 59.8%, and the purity was 99.1%.

Embodiment 2

[0046] In a 100mL three-necked flask, add 13.432g p-diethylbenzene, 5ppm (0.38mg) tetrakis-phenylmanganese porphyrin chloride (i.e. 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 120°C for 16h. The reacted mixture was frozen, centrifugally filtered, and then recrystallized with ethanol to obtain p-diacetylbenzene. The conversion rate of p-diethylbenzene was 85.1%, the yield of p-diacetylbenzene was 62.2%, and the purity was 99.3%.

Embodiment 3

[0048] In a 100mL three-necked flask, add 13.487g p-diethylbenzene, 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 100 °C for 16 h. The reacted mixture was frozen, centrifugally filtered, and then recrystallized with ethanol to obtain p-diacetylbenzene. The conversion rate of p-diethylbenzene was 75.3%, the yield of p-diacetylbenzene was 50.6%, and the purity was 99.4%.

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Abstract

The invention relates to a method for preparing p-diacetylbenzene by biomimetic catalytic oxidation of p-diethylbenzene with oxygen, comprising the following steps: taking p-diethylbenzene 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 and in 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 80-130 DEG C for 10-20h, thus obtaining the p-diacetylbenzene. 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 p-diacetylbenzene by biomimetic catalyzing oxygen oxidation of p-diethylbenzene. Background technique [0002] P-diacetylbenzene 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 p-diacetylbenzene are mainly Friedel-Crafts acylation method and p-diethylbenzene oxidation method, etc., wherein the p-diethylbenzene oxidation method is divided into chemical oxidation method and molecular oxygen oxidation method. Oxygen is cheap and easy to get, The method of preparing p-diacetylbenzene by directly oxidizing p-diethylbenzene with oxygen, which is a clean and pollution-free oxidizing agent with good atom economy, has significant advantages over other methods. [0003] JP2001226307 (publication date: February 16, 200...

Claims

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Application Information

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IPC IPC(8): C07C49/76C07C45/36
Inventor 佘远斌赵文伯李林莎钟儒刚
Owner BEIJING UNIV OF TECH
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