Synthetic method of 2-bromocarbazole and intermediate thereof

Abstract

The invention discloses a synthetic method of 2-bromocarbazole and an intermediate thereof. The synthetic method includes the steps of 1) with dichloromethane as a solvent and tert-butyl nitrite as a diazotization reagent, diazotizating o-nitroaniline and performing a coupling reaction to the diazotizated o-nitroaniline and bromobenzene to prepare an intermediate 4-bromo-2'-nitrobiphenyl; 2) adding enough triethyl phosphite to the 4-bromo-2'-nitrobiphenyl to perform a ring closing reaction to the 4-bromo-2'-nitrobiphenyl and the triethyl phosphite; 3) when the ring closing reaction is finished, adding enough hydrochloric acid to damage the triethyl phosphite which is not reacted; and 4) filtering and drying a reaction product to prepare the 2-bromocarbazole.

Description

technical field [0001] The invention relates to a method for synthesizing organic matter, in particular to a method for synthesizing 2-bromocarbazole and its intermediate. Background technique [0002] 2-Bromocarbazole is a very important intermediate of organic light-emitting materials. In recent years, the research on organic optoelectronic materials has been very active. Among them, carbazole derivatives have the characteristics of good photostability, wide spectral absorption range and high photoelectric conversion efficiency. [0003] There are two commonly used synthesis methods: [0004] Method 1, using 2-nitrobiphenyl to synthesize, its chemical reaction formula is as follows: [0005] [0006] The disadvantage of this method is: the material 2-nitrobiphenyl is expensive, and bromine is used when adding bromine in the reaction, and liquid bromine has extremely strong toxicity and corrosiveness, and can volatilize at normal temperature It emits extremely strong ...

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Problems solved by technology

[0006] The disadvantage of this method is: the material 2-nitrobiphenyl is expensive, and bromine is used when adding bromine in the reaction, and liquid bromine has extremely strong toxicity and corrosiveness, and can volatilize at normal temperature It emits extremely strong toxic fumes, irritates the mucous membranes of the eyes and respiratory tract, makes people cry, can burn the skin, produces strong stinging pain that is difficult to treat, has great personal harm, and is not conducive to human health

[0009] The disadvantage of this method is that bromophenylboronic acid is expensive, and the coupling of bromophenylboronic acid and o-bromonitrobenzene Suzuki requires an expensive palladium catalyst, and a large number of side reactions are generated at the same time, which is difficult to purify

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