6-Bromo-8-fluoroquinoline

Synthesis

General procedure for the synthesis of 6-bromo-8-fluoroquinoline from 4-bromo-2-fluoroaniline and glycerol: 3-nitrobenzenesulfonic acid sodium salt (0.48 g, 2.132 mmol) and glycerol (0.516 ml, 7.06 mmol) were added to a concentrated H2SO4 (0.63 ml, 11.82 mmol) and H2O (0.48 ml, 26.6 mmol) solution to form a thick gray suspension. The mixture was heated to 110°C. 4-Bromo-2-fluoroaniline was added in batches over a period of 10 min, during which the temperature was raised to 95°C. The reaction mixture was then heated to 140 °C and stirred overnight. Upon completion of the reaction, the reaction mixture was cooled, poured into water and the pH was adjusted with ammonia to 7. The brown precipitate formed was collected by filtration and partially dried. The resulting solid (0.63 g) was purified by fast column chromatography to afford 6-bromo-8-fluoroquinoline (0.4 g, 1.77 mmol, 88% yield).

References

[1] Patent: WO2009/50204, 2009, A1. Location in patent: Page/Page column 15; 48-49
[2] Patent: WO2018/116072, 2018, A1. Location in patent: Page/Page column 97; 98
[3] Patent: CN105968115, 2016, A. Location in patent: Paragraph 0449-0451
[4] Patent: WO2010/20363, 2010, A1. Location in patent: Page/Page column 131-132
[5] Journal of Medicinal Chemistry, 2010, vol. 53, # 10, p. 4066 - 4084