A suspension of 8-bromo-N-(tert-butyl)-3-chloroquinoxalin-2-amine (Example 304a (˜2.5:1 mixture with 5-bromo-N-(tert-butyl)-3-chloroquinoxalin-2-amine); 119.0 mg, 0.378 mmol), phenylboronic acid (Aldrich; 46.1 mg, 0.378 mmol), Na2CO3 (200 mg, 1.891 mmol), and Pd(PPh3)4 (Strem Chemicals, Inc.; 21.85 mg, 0.019 mmol) in a mixture of MeCN (3.0 mL) and water (1.000 mL) was stirred under argon at 80° C. for 17.5 h. The reaction mixture was cooled to RT and concentrated onto silica gel. Chromatographic purification (silica gel, 0-10% EtOAc/hexanes) furnished 8-bromo-N-(tert-butyl)-3-phenylquinoxalin-2-amine (83.0 mg, 0.233 mmol, 62% yield) as an off-white solid. 1H NMR (400 MHz, CDCl3) δ ppm 7.85 (1H, dd, J=4.5, 1.2 Hz), 7.83 (1H, dd, J=5.1, 1.4 Hz), 7.67-7.72 (2H, m), 7.51-7.59 (3H, m), 7.20 (1H, t, J=7.8 Hz), 5.23 (1H, br. s.), 1.57 (9H, s). m/z (ESI, +ve) 355.9/358.0 (M+H)+.
