Step 1: 6-Bromoquinolin-2(1H)-one (1.0 g, 4.4 mmol, 1.0 eq.) was dissolved in phosphoryl chloride (15 mL), stirred and heated to 100 °C, and reacted for 15 hours. Upon completion of the reaction, the solvent was removed by distillation under reduced pressure and water was added to the residue. The precipitated solid was collected by filtration and dried under vacuum to give 6-bromo-2-chloroquinoline as a pink solid (1.0 g, 92% yield).LC-MS (ES) m/z = 241.0, 243.0 [M + H]+.1H NMR (400 MHz, DMSO-d6) δ ppm: 7.41 (d, J = 8.4 Hz, 1H), 7.79-7.82 ( m, 1H), 7.89 (d, J = 9.2 Hz, 1H), 7.98-7.99 (m, 1H), 8.02 (d, J = 8.8 Hz, 1H).
