Alpha-amino acetophenone photoinitiator preparation method

Abstract

The present invention relates to an alpha-amino acetophenone photoinitiator preparation method, particularly to a preparation method of 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone and 2-(4-methylbenzyl)-2-dimethylamino-1-(4-morpholinophenyl)butanone. According to the present invention, 1-p-fluorophenyl-1-butanone is adopted as the raw material, and only the safe and cheap solvent is used in the whole method to conveniently prepare 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone and 2-(4-methylbenzyl)-2-dimethylamino-1-(4-morpholinophenyl)butanone; and the method has characteristics of cheap and readily available raw materials, high yield, no requirement of intermediate purification, and continuous reaction without solvent replacement, and is the preparation method with characteristics of low cost, environmental protection and easy operation and suitable for industrialization.

Description

technical field [0001] The present invention relates to a kind of preparation method of α-aminoacetophenone photoinitiator, be specifically related to 2-benzyl-2-dimethylamino-1-(4-morpholine phenyl) butanone and 2-(4 The preparation method of -methylbenzyl)-2-dimethylamino-1-(4-morpholine phenyl) butanone is to use 1-p-fluorophenyl-1-butanone as the raw material, and the whole method only uses safe and cheap solvent, convenient preparation of 2-benzyl-2-dimethylamino-1-(4-morpholine phenyl) butanone and 2-(4-methylbenzyl)-2-dimethylamino-1- (4-morpholinephenyl) butanone. The raw materials of the method are cheap and easy to obtain, the yield is high, and the intermediates can be continuously reacted without purification and replacement of solvents, and are cheap, environmentally friendly, easy to operate and suitable for industrialization. Background technique [0002] α-amino ketone derivatives are a class of important photoinitiators, in which 2-benzyl-2-dimethylamino-1...

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Problems solved by technology

[0009] From the perspective of these two preparation processes, there are many steps, the operation is complicated and cumbersome, and each step of the reaction needs to replace different types of solvents.

The disadvantages of the second preparation process are:

[0010] 1) After replacing fluorobenzene with chlorobenzene, the morpholinyl group is introduced through a high-pressure reaction. Although the cost is reduced, the equipment requirements are relatively high;

[0011] 2) At the same time, the use of high temperature and high pressure to feed or introduce catalyst cuprous chloride must go through complex operations such as activated carbon decolorization and thermal liquid separation, especially now that the restrictions on heavy metals are becoming more and more strict. The introduction of copper ions is not only not environmentally friendly but also It also affects the appearance of the product;

[0012] 3) Using glacial acetic acid as a solvent during bromination consumes a large amount of bromine. After the reaction is completed, a large amount of sodium hydroxide is used to neutralize glacial acetic acid, resulting in a large amount of high-salt wastewater. This method is uneconomical and environmentally friendly;

[0013] 4) In the experimental step of replacing bromine with dimethylamine, solid potassium carbonate is used as an acid-binding agent, butanone is used as a solvent, and dimethylamine gas is used for substitution reaction. The raw material bromide is dissolved in butanone as a liquid, and potassium carbonate as a solid. Dimethylamine is a gas, and the reaction is a three-phase reaction. The reaction contact is insufficient, and the reaction cannot be effective, resulting in the waste of dimethylamine gas and increasing the environmental pressure;

[0014] 5) In the rearrangement reaction, solid sodium hydroxide is added in batches under heating conditions, and the reaction temperature will rise rapidly when sodium hydroxide is added, and the reaction temperature should not be controlled

[0016] 1) The reaction uses ether as a solvent, which is not safe;

[0017] 2) Dimethylamine ether solution is used as reactant and acid-binding agent at the same time, the gaseous dimethylamine must be dissolved in ether first, which is inconvenient to operate;

[0018] 3) The rearrangement reaction first uses the polar solvent acetonitrile to generate a quaternary ammonium salt, then desolventizes, uses water as a solvent, and adds sodium hydroxide for rearrangement. The operation is cumbersome and many unit operations are added.

[0019] 4) The last step is to react morpholine, use DMSO as solvent, potassium carbonate as alkali, react at high temperature, and pour the reaction liquid into water for post-processing. Since DMSO is miscible with water, it is not easy to recycle and apply mechanically, which not only results in high raw material costs, but also produces A large amount of high-COD and high-salt wastewater puts pressure on the environment

But there is no outstanding progress, and the industrial operability is poor

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