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CN-122010676-A - Synthesis method of 9-bromoanthracene

CN122010676ACN 122010676 ACN122010676 ACN 122010676ACN-122010676-A

Abstract

The invention discloses a synthesis method of 9-bromoanthracene, and belongs to the technical field of organic synthesis. The method takes anthracene as a raw material, takes inorganic bromine salt as a bromine source and hydrogen peroxide as an oxidant under the catalysis of composite Lewis acid, synthesizes 9-bromoanthracene with high selectivity in a mixed solvent, and obtains a high-purity product by stepwise fractional recrystallization and purification of a crude product. The invention suppresses the generation of the difficult-to-remove 9, 10-dibromoanthracene byproducts from the source through the synergistic effect of the composite catalytic system and the mixed solvent, and can realize the high-efficiency separation of the product and the key impurities without column chromatography by combining with a gradient cooling fractional crystallization process. The preparation method disclosed by the invention is green and safe in process, simple to operate, low in cost and easy to industrialize, and the prepared 9-bromoanthracene can meet the application requirements of high-end fields such as OLED photoelectric materials and the like.

Inventors

  • ZHAO YINGHAI
  • MA WENZHI
  • LIANG JIANLONG

Assignees

  • 甘肃维世诺新材料有限公司

Dates

Publication Date
20260512
Application Date
20260403

Claims (10)

  1. 1. The synthesis method of 9-bromoanthracene is characterized by comprising the following steps: (1) Under the protection of inert gas, anthracene, inorganic bromine salt and composite Lewis acid are added into a mixed solvent, the mixture is stirred uniformly, the temperature is controlled at 25-45 ℃, hydrogen peroxide aqueous solution is slowly added dropwise, the temperature fluctuation in the dropwise adding process is not more than +/-2 ℃, and the mixture is stirred for 3-6 hours after the dropwise adding is finished; (2) After the reaction is finished, adding saturated sodium sulfite aqueous solution into a reaction system to quench excessive hydrogen peroxide, stirring for 15-30 min, standing for layering, separating an organic phase, extracting an aqueous phase with an extraction solvent for 1-2 times, combining the organic phases, washing the organic phases to be neutral by saturated saline solution, drying by an anhydrous desiccant, and concentrating under reduced pressure to remove the solvent to obtain crude 9-bromoanthracene; (3) Purifying the crude 9-bromoanthracene according to a purification process to obtain pure 9-bromoanthracene; The inorganic bromine salt refers to any one of potassium bromide, sodium bromide or ammonium bromide; The composite Lewis acid refers to a composite system of a main catalyst and a cocatalyst, wherein the main catalyst is selected from any one of ferric trichloride, aluminum trichloride and ferric bromide, and the cocatalyst is selected from any one of quaternary ammonium salt phase transfer catalysts and crown ether phase transfer catalysts; The mixed solvent is a mixed system of halogenated hydrocarbon and alkane, wherein the halogenated hydrocarbon is selected from any one of 1, 2-dichloroethane, dichloromethane and chloroform, the alkane is selected from any one of cyclohexane, n-hexane and n-heptane, and the volume ratio of the halogenated hydrocarbon to the alkane is 2-4:1.
  2. 2. The method for synthesizing 9-bromoanthracene according to claim 1, wherein the inorganic bromine salt is potassium bromide, the main catalyst of the composite Lewis acid is ferric trichloride, and the cocatalyst is any one of tetrabutylammonium bromide, benzyl triethylammonium chloride and 18-crown-6.
  3. 3. The method for synthesizing 9-bromoanthracene according to claim 1, wherein the inert gas in (1) is nitrogen, and the temperature is controlled at 30-40 ℃.
  4. 4. The method for synthesizing 9-bromoanthracene according to claim 1, wherein the molar ratio of anthracene, inorganic bromine salt and hydrogen peroxide in (1) is 1:1.05-1.5:1.1-1.8, the molar ratio of main catalyst and cocatalyst in anthracene and composite lewis acid is 1:0.08-0.42:0.02-0.1, and the solid ratio of anthracene and mixed solvent is 1g:10ml-20 ml.
  5. 5. The method for synthesizing 9-bromoanthracene according to claim 1, wherein the concentration of the aqueous hydrogen peroxide solution in (1) is 20 to 30wt%.
  6. 6. The method for synthesizing 9-bromoanthracene according to claim 1, wherein the extraction solvent in (2) is consistent with the halogenated hydrocarbon component in the mixed solvent, and the single extraction solvent is used in an amount of 1/5-1/3 of the volume of the aqueous phase to be extracted.
  7. 7. The method for synthesizing 9-bromoanthracene according to claim 1, wherein the anhydrous desiccant in (2) is any one of anhydrous sodium sulfate and anhydrous magnesium sulfate.
  8. 8. The method for synthesizing 9-bromoanthracene according to claim 1, wherein the purification process in (3) comprises the steps of: S1, adding crude 9-bromoanthracene into a recrystallization solvent, heating to 60-80 ℃, and stirring until the crude 9-bromoanthracene is completely dissolved to obtain a crude solution; s2, carrying out heat preservation and hot filtration on the crude product solution at 60-80 ℃ to obtain clear filtrate; S3, cooling the clarified filtrate to 40-45 ℃ at the rate of 5-10 ℃ per hour, carrying out heat preservation and stirring for 1-2 hours, filtering to remove impurities to obtain primary filtrate, cooling the primary filtrate to 20-25 ℃ at the rate of 4-6 ℃ per hour, carrying out heat preservation and stirring for 0.5-1 hour, cooling to 10-20 ℃ at the rate of 2-3 ℃ per hour, and carrying out heat preservation and stirring for 2-3 hours to obtain 9-bromoanthracene crystal slurry; S4, centrifugally filtering the 9-bromoanthracene crystal slurry, washing a filter cake with a cold recrystallization solvent at 0-5 ℃ for 1-2 times, and drying to obtain the pure 9-bromoanthracene.
  9. 9. The method for synthesizing 9-bromoanthracene according to claim 8, wherein the solid-to-liquid ratio of the crude 9-bromoanthracene in S1 to the recrystallization solvent is 1 g/3 ml-6 ml.
  10. 10. The method for synthesizing 9-bromoanthracene according to claim 8, wherein the recrystallization solvent in S1 is a mixed system of aromatic hydrocarbon and alcohol, the volume ratio of the aromatic hydrocarbon to the alcohol is 1-3:1, the aromatic hydrocarbon is selected from any one of toluene and xylene, and the alcohol is selected from any one of ethanol and isopropanol.

Description

Synthesis method of 9-bromoanthracene Technical Field The invention relates to the technical field of organic synthesis, in particular to a method for synthesizing 9-bromoanthracene. Background 9-Bromoanthracene is a polycyclic aromatic hydrocarbon functional intermediate with high reactivity, is widely applied to a plurality of fields such as organic photoelectric materials, medical intermediates, functional dye synthesis and the like by virtue of excellent conjugated photoelectric performance of an anthracycline and flexible modifiable property of a 9-position bromine atom, and particularly in the organic electroluminescent diode (OLED) industry, 9-bromoanthracene is a core raw material for synthesizing a blue light main material, a hole transport material and a luminescent layer functional auxiliary agent, and is an indispensable key basic chemical in novel display and flexible electronic industry chains. In recent years, with the rapid development of global OLED display, vehicle-mounted electronics and wearable equipment industries, the demand of the market for high-purity 9-bromoanthracene is continuously increased, and meanwhile, a downstream high-end application scene is more severely required for the product quality, which also provides higher challenges for the synthesis process and purification technology of the 9-bromoanthracene. At present, a plurality of technical routes are formed for the synthesis and preparation of 9-bromoanthracene in the industry, wherein the most widely applied electrophilic bromination reaction routes taking anthracene as a starting material are mainly processes including a liquid bromine direct bromination method, an N-bromosuccinimide (NBS) bromination method and various oxidation bromination improved processes. The liquid bromine direct bromination method is a traditional process for realizing industrial application at the earliest, realizes 9-position bromination through direct electrophilic substitution reaction of liquid bromine and anthracene, has the characteristics of short route and easily available raw materials, is a basic production process adopted by most chemical enterprises at present, and aims to avoid the problems of severe toxicity and strong corrosiveness of liquid bromine, a mild bromination process taking NBS as a bromine source is developed in the industry, so that the operation safety risk is greatly reduced, the method becomes a mainstream method for preparing 9-bromoanthracene in a laboratory, along with the promotion of a green chemical idea, an oxidizing bromination process taking inorganic bromine as a bromine source and various oxidants as an activation system becomes a research and development hot spot, the process thoroughly abandons the use of elemental bromine, realizes bromination reaction through in-situ generation of active bromine species by the oxidants, realizes remarkable improvement in terms of environmental protection and operation safety, and simultaneously aims at the purification of 9-bromoanthracene in two ways, and column chromatography is mainly adopted in the industry, wherein the column chromatography is used for preparing high-purity samples in the laboratory, and the recrystallization is the only feasible purification in industrial production. Although the prior art forms a relatively perfect synthetic and purification route, a plurality of technical defects and industry pain points which cannot be considered exist in the actual industrial production and high-end application adaptation process. Firstly, the traditional liquid bromine direct bromination method has serious hidden danger of safety and environmental protection, liquid bromine has extremely high requirements on corrosion resistance and sealing performance of production equipment, great leakage risk in the operation process, a large amount of extremely toxic hydrogen bromide tail gas as a byproduct, high environmental protection treatment cost, extremely poor reaction selectivity of the process, extremely small difference of the reactivity of 9 and 10 positions of an anthracene ring, extremely easy generation of 9, 10-dibromoanthracene byproducts, high homology of the byproducts with the structure of a main product, extremely close physical and chemical properties, difficult removal of conventional means, incapability of reducing the byproducts to below a threshold value required by OLED application even through repeated recrystallization, and great loss of product yield. In addition, the NBS bromination method and the existing oxidizing bromination improvement process still have the bottleneck that the industrial landing is difficult, the bromine source cost of the NBS bromination method is high, dibromo byproducts are still unavoidable in the reaction process, the purity and the yield of the product are obviously reduced after the amplification production, the industrial economy is extremely poor, the disclosed oxidizing bromination patent technology adopt