Preparation method of aliphatic hydrocarbon substituted carbazole

Abstract

The invention provides a preparation method of aliphatic hydrocarbon substituted carbazole. The method comprises the following steps of mixing carbazole, halogenated aliphatic hydrocarbons, an alkaline solution and phase transfer catalysts; performing substitution reaction on the mixed liquid under the microwave radiation at the reaction temperature of 20 to 40 DEG C for 30 to 60 min; after the reaction is completed, obtaining an organic phase which is the aliphatic hydrocarbon substituted carbazole. The microwave radiation is introduced to promote the reaction proceeding; the preparation method of the novel aliphatic hydrocarbon substituted carbazole is obtained; the microwave radiation can effectively improve the intermolecular impingement rate between reactant molecules; the reaction activation energy is reduced, so that the reaction temperature required by the preparation method is only 20 to 40 DEG C; the reaction time only needs 30 to 60 min; the yield of the obtained product ofthe aliphatic hydrocarbon substituted carbazole can reach 99.6 percent; the preparation of the aliphatic hydrocarbon substituted carbazole can be realized at high efficiency in environmental-friendlyand energy-saving manners. The preparation method is applicable to further popularization and use.

Description

technical field [0001] The invention belongs to the field of organic synthesis, in particular to a preparation method of aliphatic hydrocarbon-substituted carbazole. Background technique [0002] Heterocyclic aromatic hydrocarbon compound carbazole and its derivatives are important intermediates for the preparation of dyes, spices or drugs, among which, aliphatic hydrocarbon-substituted carbazole is a compound produced by the substitution reaction between carbazole and halogenated aliphatic hydrocarbons , representative compounds such as N-ethylcarbazole, etc., are important intermediates for the synthesis of dye vat blue and pigment permanent violet. However, the preparation of the above products requires higher purity N-ethylcarbazole to obtain high The purity of N-ethylcarbazole mainly has two ways, one is through the separation and purification of petroleum cracking products, and the other is through organic synthesis. [0003] Because the purification process of carbaz...

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Problems solved by technology

Ethyl chloride method has the highest reaction temperature for synthesizing N-ethylcarbazole, and needs pressurization in the reaction process, which has higher requirements for equipment, and the operation is complicated, and the production cost is too high; although the simple method has simple process, it requires more equipment. Low, but the synthesis cycle is long and the yield is very low; the diethyl sulfate used in the diethyl sulfate method is toxic and does not meet the requirements of green chemistry; the solvent used in the phase transfer method is mainly N,N-dimethylformaldehyde Amide and acetone, the solvents of which are toxic and require post-treatment of the remaining toxic solvent after the reaction, are not suitable for industrial production; the induction method requires the participation of catalysts with complex structures, and is not suitable for industrial mass production

[0005] There is also a problem in the existing organic synthesis method for preparing aliphatic hydrocarbon-substituted carbazole, that is, the reaction takes too long, for example, a kind of preparation method of N-ethyl carbazole is disclosed in CN102115457A, by adding carbazole In an aqueous solution of 20-70% proton-removing agent and 0.1-1% phase-transfer catalyst, conduct a salt-forming reaction at 50-60°C for 20-40 minutes to generate carbazole salt, and then add 2- 8 times excess bromoethane, react to generate N-ethyl carbazole, divide into two phases after the reaction, obtain N-ethyl carbazole after the organic phase is distilled, the N- and carbazole productive rate that above-mentioned method obtains can reach More than 98%, but the reaction process is too long, even after adding excess raw material ethyl bromide, the reaction still needs several hours to complete, it is difficult to meet the industrial needs