Preparation method of 2-hydroxyl-1-{4-(2-hydroxyethyl) phenyl}-2-methyl-1-acetone

Abstract

The invention relates to a preparation method of 2-hydroxyl-1-{4-(2-hydroxyethyl) phenyl}-2-methyl-1-acetone, which comprises the following steps that: ethylene glycol phenyl ether acetate serves as the raw material and carries out friedel-crafts reaction with isobutyl chloride with the molar ratio of 1 to 1.2 times of equivalent under the catalysis of lewis acid, the reaction temperature is -5 to 5DEG C, and the reaction time is 3 to 6h; bromination is carried out under the catalysis of N, N-dimethylformamide or iodine; at room temperature, phase transfer catalyst is used for carrying out catalysis and hydrolysis to a brominated product; and finally the product is prepared through purification and crystallization. The preparation method of 2-hydroxyl-1-{4-(2-hydroxyethyl) phenyl}-2-methyl-1-acetone adopts dichloromethane or dichloroethane as the solvent during the bromination process, does not use acetic acid any more, carries out reaction under the catalysis of DMF or I2, so that the reaction time is greatly shortened. The phase transfer catalyst is introduced during the hydrolysis process, so that the intermediate brominated product directly has reaction with alkali in water, thereby preventing using a large amount of ethanol as the solvent, simplifying the process, reducing the production cost and improving the yield.

Description

technical field The invention relates to the technical field of organic chemistry, and relates to a method for synthesizing a photoinitiator 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone. Background technique 2-Hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone is a UV curing initiator, which is the only photoinitiator allowed by the FDA certification system, available In adhesives that are not in direct contact with food, low odor, low volatility, low yellowing, with active hydroxyethoxyl terminal hydroxyl groups, can participate in the reaction. It can be used in water-based light-curing systems with high melting point, and can also be used in UV-curable powder coatings. At present, the common method of synthesizing 2-hydroxyl-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone is: ethylene glycol phenyl ether acetate and isobutyryl chloride in Lewis acid The Friedel-Crafts reaction occurs under catalysis, and the product is brominated in the solven...

AI Technical Summary

Problems solved by technology

The main disadvantage of this process is that the bromination reaction uses glacial acetic acid as a solvent, which is highly corrosive to the equipment, and the reaction is relatively slow, requiring more than 10 hours

The hydrolysis process uses a large amount of ethanol as a solvent, and the post-treatment is cumbersome and costly

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