167158-70-5

102393-82-8

167158-70-5

Step C: Synthesis of 6-bromo-2-chloroquinazolin-4(3H)-one 6-Bromo-2,4-dichloroquinazoline (2.0 g, 7.20 mmol) was dissolved in THF (17.99 mL), 1N NaOH solution (17.99 mL, 17.99 mmol) was added, and the reaction was stirred for 2.5 h at room temperature. Upon completion of the reaction, the reaction solution was cooled to 0 °C and the pH was adjusted with AcOH to 5. The precipitated light yellow solid was collected by filtration and washed with water. The resulting solid was azeotropized by toluene (3×) to remove residual water to afford 6-bromo-2-chloroquinazolin-4(3H)-one (1.625 g, 87%). The product was analyzed by ES-LCMS: m/z 259.0, 261.0 [M+H]+.