Halogenation method of aromatic compound

Abstract

The invention belongs to the field of organic synthesis, and particularly relates to synthesis of aromatic halides, in particular to a synthesis method for preparing corresponding ortho-halogenated products from aromatic compounds such as arylamine, carbazole and phenol. The preparation method comprises the following steps of: adding a metal sulfonate salt catalyst, aromatic compound reaction substrates containing hydrogen-heteroatom bonds such as arylamine, carbazole and phenol, a halogenating reagent and a reaction solvent according to a required stoichiometric ratio, cooling to room temperature after a specific reaction time at a specific reaction temperature, and opening a reaction container; extracting the reaction liquid by an organic solvent, drying the reaction liquid by a drying agent, determining the yield of a reaction product through column chromatography separation, and determining the structure through nuclear magnetic characterization; or determining the yield of the reaction product by gas chromatography (mass chromatography). By adopting the method, various ortho-substituted brominated and chlorinated products can be obtained at medium to excellent yield under the condition of a cheap metal salt catalyst.

Description

technical field [0001] The invention belongs to the field of organic synthesis, and in particular relates to the synthesis of aromatic halogenated products, in particular to a synthesis method for preparing corresponding halogenated products from aromatic compounds such as aromatic amines, carbazoles and phenols. Background technique [0002] Aromatic amines exist widely in nature, and converting them into halogenated arylamines with higher added value is the sublimation of their value. The halogenated arylamine is an important fine chemical intermediate, which is widely used in the fields of medicine, pesticide, dyestuff and so on. The ortho-halogenated aromatic amines can also be used as ligands for preparing complexes, as well as antioxidants and flame retardants. In recent years, with the development of polyurethane industry at home and abroad, o-chloroaniline is necessary for the production of polyurethane elastomer curing agent MOCA (3,3'-dichloro-4,4'-diaminodiphenyl...

AI Technical Summary

Problems solved by technology

And 1-bromo / chlorocarbazole is also a commonly used synthetic intermediate of luminescent materials, but there are relatively few reports about its synthetic method.

WO2011105161 reports a method for synthesizing 1-bromocarbazole using o-bromophenylhydrazine hydrochloride, phthalic anhydride, etc. as starting materials. This method has many reaction steps, and the process in actual use is cumbersome, unsuitable for operation, and high in cost. not conducive to industrial production

CN106397304A has reported to take 3,6-di-tert-butyl carbazole as raw material to synthesize 1-bromo-3,6-di-tert-butyl carbazole through bromination reaction, remove tert-butyl carbazole under aluminum chloride and isopropanol conditions Butyl is treated with alkali and purified to synthesize 1-bromocarbazole. This method not only has poor atom economy, but also has cumbersome steps and difficult operation, which is also unfavorable for industrial production.

However, the traditional bromination reagents have many shortcomings, such as bromine, hydrobromic acid, etc. are highly irritating and corrosive, which will pollute the environment, and the utilization rate of bromine atoms is not high.

Other bromination methods also have the disadvantages of poor selectivity or harsh reaction conditions, and cannot be used for industrial production of halogenated phenols

[0005] In summary, no matter the halogenated products of aromatic amines, carbazoles or phenolic compounds have a wide range of application values, but there are various problems in their known synthetic methods, which restrict their industrial production