Add the catalyst and p-bromoaniline to the dilute sulfuric acid, and add glycerol dropwise while controlling the temperature to 140-145°C. After the dropwise addition is completed, the dehydration reaction occurs at 140-145°C for 3 hours. Add the above reaction liquid dropwise to ice water, and then add ammonia water dropwise to adjust the pH of the system. Extract the reaction solution with toluene, concentrate the toluene phase at 150~155℃/15mmHg, and then distill the crude product to obtain the product 6-bromoisoquinoline.
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