Background and overview[1]
At present, liquid crystal displays are widely used because of their small size and energy saving. However, due to the limitations of the characteristics of liquid crystals themselves, they can no longer meet current needs; organic electroluminescent materials (OLED), as a new type of liquid crystal display technology, Gaining importance. 3-iodo-9-phenylcarbazole is an intermediate of (OLED). 3-iodo-9-phenylcarbazole is (OLED). The existing production process is relatively complex, the yield is low, and the production cost is high. And the pollution is serious.
Preparation[1]
Synthesis method of 3-iodo-phenylcarbazole:
Using carbazole as the starting material, 9-phenylcarbazole is synthesized through Ullmann reaction with iodobenzene under the action of cuprous oxide catalyst. The reflux temperature in the reaction is 144℃~146℃. When the raw material carbazole is When the azole GC is less than 1.5%, stop the reaction and cool to 90°C. Dissolve the obtained crude product with dichloroethane and filter. The filter cake is washed with dichloroethane. The eluate and filtrate are combined and passed through the column at normal temperature and pressure. Filter, drain, and dry the solid. 9-Phenylcarbazole and iodine undergo an iodo reaction under the catalysis of iodic acid and concentrated sulfuric acid. The iodo reaction involves adding iodic acid alternately and raising the temperature to 70 to 75°C. When the product is 3 When -iodo-9-phenylcarbazole GC>78% and diiodide GC<8%, the reaction was stopped and the temperature was naturally cooled to 20°C to synthesize the target compound 3-iodo-phenylcarbazole. Using carbazole as the starting material, 9-phenylcarbazole is synthesized through Ullmann reaction with iodobenzene under the action of catalyst cuprous oxide. 9-phenylcarbazole and iodine are catalyzed by iodic acid and concentrated sulfuric acid. The iodine reaction occurs under the conditions, thus changing the existing process, using raw materials with less pollution and easy recovery, reducing the discharged pollution, and using the Ullmann reaction and iodine reaction at the same time. The reaction process is highly controllable and suitable for industrial production. The efficiency is more than 30% higher than that of existing technology, which greatly reduces production costs.
Main reference materials
[1] CN200910019160.Synthesis method of X3-iodo-phenylcarbazole
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