2,3,5-Tribromothiophene

188290-36-0

3141-24-0

a. Add 35 L of chloroform, thiophene and 16.8 kg of copper bromide to Reactor 1 and stir for 10 minutes. Reactor 1 was cooled to -5°C, followed by the slow dropwise addition of 65.0 kg of bromine. b. Upon start of the reaction, pass air or oxygen into Reactor 1. After completion of the bromine addition, the reaction was slowly heated to reflux and the reaction gas was condensed through reflux condenser 8 and returned to reactor 1. The reaction lasted for 3.5 hours and then cooled to 23-25°C. c. A drop of bromine was added to reactor 1 and the reaction was cooled to -5°C for 10 minutes. c. Add 10 L of 0.05 mol/L ethanol solution of sodium hydroxide dropwise to reaction kettle 1 to decompose unreacted bromine and stir for 30 min. d. Transfer the reaction mixture to autoclave 2, add 35 L of water, stir for 30 minutes and leave to stand. The lower organic phase was separated for atmospheric pressure distillation. During distillation, the solvent was first recovered by condensing through distillation condenser 9 and distillation condenser 10, and the solvent was recovered to solvent recovery tank 4. Subsequently, the distillation was carried out under reduced pressure at 15 mmHg, and again condensed through distillation condenser 9 and distillation condenser 10, and the fraction at 112-116 °C/15 mmHg was collected to the product fraction collection tank 5, which ultimately yielded 52.6 kg of colorless liquid 2,3,5-tribromo thiophene.