Synthesis
General procedure for the synthesis of 7-bromo-4-chloroquinazoline from 7-bromo-3,4-dihydroquinazolin-4-one: 20.4 mL (0.12 mol) of N-ethyl diisopropylamine was added slowly and dropwise to 55.0 g (0.24 mol) of 7-bromo-3H-quinazolin-4-one suspended in 300 mL of phosphorus trichloride. The reaction mixture was stirred at 115 °C for 3 hours and subsequently cooled to room temperature. After conventional post-processing, 48.0 g of the target product 7-bromo-4-chloroquinazoline was obtained as a solid as confirmed by HPLC/MS analysis ([M+H]+ = 244).
References
[1] Patent: US2013/12489, 2013, A1. Location in patent: Paragraph 0183
[2] Patent: WO2010/146173, 2010, A1. Location in patent: Page/Page column 16-17
[3] Patent: WO2005/42498, 2005, A2. Location in patent: Page/Page column 43
[4] Chemical Biology and Drug Design, 2018, vol. 92, # 5, p. 1859 - 1866
