Synthesis
The general procedure for the synthesis of 4-bromodibenzothiophene from dibenzothiophene: Dibenzothiophene was dissolved in tetrahydrofuran (THF) at -40°C, and 2.5 M n-butyllithium (n-BuLi) solution was slowly added and reacted for 1 hour. Subsequently, the temperature of the reaction mixture was raised to 0 °C and 1,2-dibromoethane was slowly added dropwise at -78 °C. After completion of the dropwise addition, the reaction mixture was gradually warmed to room temperature and stirred for 12 hours. Upon completion of the reaction, the solvent was removed by reduced pressure distillation and the residue was separated by extraction with water and chloromethane (MC). The organic phase was collected, concentrated and recrystallized from chloromethane (MC) and hexane to give a white solid intermediate in 95% yield.
References
[1] Patent: KR101578475, 2015, B1. Location in patent: Paragraph 0090; 0091; 0092; 0093; 0095
[2] Organometallics, 2012, vol. 31, # 21, p. 7447 - 7452,6
[3] Patent: KR101497123, 2015, B1. Location in patent: Paragraph 0083; 0084; 0085; 0086; 0087
[4] Patent: EP2762478, 2014, A1. Location in patent: Paragraph 0187; 0188
[5] Journal of the American Chemical Society, 1954, vol. 76, p. 5783,5784
