7-Bromo-4-phenyl-4,5-dihydroimidazo[1,5,4-de][1,4]benzoxazin-2(1H)-one (100 mg, 0.3 mmol) was dissolved in 1,4-dioxane (2.4 mL). A solution of 1-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (94 mg, 0.45 mmol) and potassium phosphate (100 mg, 0.6 mmol) in water (0.60 mL) was added. Reaction was deoxygenated with nitrogen. Dicyclohexyl(2′,4′,6′-triisopropylbiphenyl-2-yl)phosphine-(2′-aminobiphenyl-2-yl)(chloro)palladium (1:1) (7 mg, 0.009 mmol) was added and deoxygenated with nitrogen. The reaction mixture was stirred at 100° C. for 4 h. Water and EtOAc were added and the layers were separated. The organic layer was concentrated under reduced pressure. Purification on silica using EtOAc/hexanes gave the title compound (61 mg). LCMS calc. for C19H17N4O2 (M+H)+: m/z=333.1. found: 333.2. 1H NMR (300 MHz, DMSO-d6): d 7.40 (s, 1H); 7.31 (m, 3H); 7.13 (m, 2H); 6.92 (m, 1H); 6.79 (m, 1H); 6.22 (s, 1H); 5.49 (s, 1H); 4.59 (m, 1H); 4.41 (m, 1H); 3.60 (s, 3H).
