A kind of method for preparing p-diacetophenone by homogeneous oxidation of p-diethylbenzene

Abstract

The invention relates to a method for preparing 4'-acetylacetophenone through homogeneous-phase oxidation of p-diethylbenzene. The method is characterized by taking p-diethylbenzene as the raw material, taking a soluble metal salt as a catalyst, adding an oxidation agent, additives and a solvent, uniformly stirring and carrying out reaction to obtain a product which is 4'-acetylacetophenone. The method is mild in reaction conditions, simple to operate, high in conversation rate of p-diethylbenzene and higher in yield of 4'-acetylacetophenone, has multiple advantages such as small catalyst consumption, low energy consumption, high reaction safety and high economic benefit, and has a broad industrial application prospect.

Description

technical field [0001] The invention relates to a method for preparing p-diacetophenone by homogeneous selective catalytic oxidation of p-diethylbenzene, which belongs to the technical field of fine chemicals. Background technique [0002] P-diacetophenone is an important chemical intermediate, which is mainly used in the fields of hair perm, medicine, pesticide and other production fields. At present, there is no large-scale device to produce p-diacetophenone in China. The p-diacetophenone used in industry mainly depends on imports, while the domestic supply of p-diethylbenzene is in a situation of oversupply. Therefore, the direct oxidation of p-diethylbenzene is developed to prepare p-diacetophenone Synthetic technology has broad market prospects and huge economic value. [0003] At present, the main production method of p-diacetophenone is Friedel-Crafts acylation reaction, with AlCl 3 as a catalyst. Patent EP 1053990A2 discloses a catalyst composed of at least one me...

AI Technical Summary

Problems solved by technology

[0004] (1) Adding ammonia water and organic alkali to the process will easily cause serious corrosion to the equipment, increase equipment investment costs and operating costs, and leave potential safety hazards;

[0005] (2) Various catalysts and additives are added in the process, but the conversion rate of p-diethylbenzene and the yield of p-diacetophenone are still low, and the catalytic activity of the catalyst is low, which wastes raw materials, increases production costs, and is a product Difficulty in separating

[0006] (3) The presence of water in the process can easily cause the hydrolysis of soluble metal salts, and is not conducive to the contact of reaction raw materials and catalyst active components

During the generation process, the water generated by the reaction needs to be separated and eliminated at any time, resulting in complex processes, increased equipment investment and operating costs, and the generated wastewater increases the load and cost of three wastes treatment;

[0007] (4) The air flow rate in the process is too large, and more oxidants are required, resulting in a decrease in oxidation efficiency and a waste of energy and resources

[0013] (1) The synthesis process needs to add corrosive substances such as strong acid or strong alkali, and produces a large amount of waste water, pollutes the environment, and causes equipment corrosion. Therefore, higher requirements are placed on the corrosion resistance of the equipment, thereby increasing equipment investment costs;

[0014] (2) The temperature required for the synthesis reaction is high, and the energy consumption is large, which greatly increases equipment requirements and operating costs, and there are potential safety hazards;

[0015] (3) Catalyst activity is low, causes p-diethylbenzene conversion rate and p-diacetophenone yield to be low, the by-product that generates in the synthetic process increases, has increased the difficulty of follow-up product separation and purification;

[0016] (4) The reaction time is long and the reaction efficiency is low