Method for preparing p-bromophenylacetone by biomimetic catalytic oxidation of p-bromoethylbenzene

Abstract

The invention relates to a method for preparing p-bromophenylacetone by biomimetic catalytic oxidation of p-bromoethylbenzene, comprising the following steps of: taking p-bromoethylbenzene as raw material; selecting either of 1-30ppm mononuclear metal porphyrin and mu-oxo-dinuclear metal porphyrin or the both as a catalyst; introducing oxygen at the flow speed of 10 to 60mL / min under normal pressure without solvents; initiating reaction at 140 DEG C to 170 DEG C; and reacting for 6 to 16h at 80 DEG C to 120 DEG C to obtain the p-bromophenylacetone. The method uses the mode of high-temperaturequick initiation and low-temperature reaction, greatly shortens the initiation time of the reaction and the reaction time, improves the reaction efficiency, reduces the energy consumption and operation costs and improves 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-bromoacetophenone by biomimetic catalyzing oxygen oxidation of p-bromoethylbenzene. Background technique [0002] p-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 p-bromoacetophenone mainly include Friedel-Crafts acylation method, 1-(4-bromophenyl) ethanol oxidation method and p-bromoethylbenzene oxidation method, etc., wherein p-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 p-bromoacetophenone by direct oxidation of p-bromoethylbenzene with oxygen has significant advantages over other methods. sex. [0003] Li Xiaogang ...

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Problems solved by technology

Therefore, a large amount of toxic and harmful waste water and waste residues are produced during the production process, and the high-priced metal salts used must be separated and recovered, which consumes a lot of energy, and the high-priced high-priced metal salts also greatly increase the production cost.

[0007] (3) This method uses the reaction condition of high pressure (1.5MPa), causes equipment investment and operation cost to increase exponentially, and energy consumption is extremely high, especially makes production have potential danger, and safety is greatly reduced;

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;

[0016] (3) The use of loaded or polymerized metalloporphyrins results in high energy consumption, high emissions 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.

[0017] (4) The induction time of the reaction is too long (up to 3h), thus prolonging the time of the whole reaction, resulting in a serious waste of energy and an increase in operating costs

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