A mixture of 4-bromo-3-chloro-7-(2-hydroxypropan-2-yl)-9H-carbazole-1-carboxamide [Intermediate 3] (1.11 g, 2.91 mmol), 5-chloro-2-(2-methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1H-pyrido[1,2-c]pyrimidine-1,3(2H)-dione [Intermediate 33] (1.00 g, 2.42 mmol) and Cs2CO3 (1.58 g, 4.85 mmol) in THF (8 mL) and water (2 mL) was bubbled with argon for three min. The mixture was treated with PdCl2(dppf) DCM adduct (0.099 g, 0.121 mmol) and heated at 60° C. overnight. The cooled mixture was diluted with EtOAc and washed sequentially with water and brine. The combined aqueous layers were extracted with DCM containing a small amount of MeOH. The combined organic layers were dried and concentrated until a tan precipitate formed, which was removed by filtration. The filtrate was concentrated and purified by column chromatography on silica gel (120 g), eluting with EtOAc-DCM (sequentially 70%, 80%, and 100%), to give 3-chloro-4-(3-(5-chloro-1,3-dioxo-1H-pyrido[1,2-c]pyrimidin-2(3H)-yl)-2-methylphenyl)-7-(2-hydroxypropan-2-yl)-9H-carbazole-1-carboxamide (mixture of four atropisomers) as a yellow solid (993 mg, 69% yield). The material was separated by chiral super-critical fluid chromatography as follows: column: CHIRALPAK® AD-H (3×25 cm, 5 μm); Mobile Phase: CO2-IPA (50:50) at 150 mL/min, 45° C., 100 bar; sample preparation: 5.6 mg/mL in MeOH-DCM (1:1); injection: 3 mL. The second peak eluting from the column provided 3-chloro-4-(R)-(3-(R)-(5-chloro-1,3-dioxo-1H-pyrido[1,2-c]pyrimidin-2(3H)-yl)-2-methylphenyl)-7-(2-hydroxypropan-2-yl)-9H-carbazole-1-carboxamide [Example 32]. Mass spectrum m/z 587 (M+H)+. 1H NMR (400 MHz, DMSO-d6) δ 11.50 (s, 1H), 8.27 (s, 2H), 8.14 (s, 1H), 7.84 (d, J=1.1 Hz, 1H), 7.59 (d, J=6.8 Hz, 1H), 7.56-7.46 (m, 2H), 7.29 (dd, J=7.4, 1.2 Hz, 1H), 7.01 (dd, J=8.4, 1.5 Hz, 1H), 6.64 (d, J=8.6 Hz, 1H), 6.55 (t, J=7.3 Hz, 1H), 5.98 (s, 1H), 5.75 (s, 1H), 4.98 (s, 1H), 1.71 (s, 3H), 1.46-1.42 (m, 6H).
