In a flask was added Pd2(dba)3 (0.094 g, 0.10 mmol) and di-tert-butyl(2′,4′,6′-triisopropylbiphenyl-2-yl)phosphine (0.087 g, 0.21 mmol) in 1,4-dioxane (10 mL). The mixture was heated to about 80° C. for about 10 min. 2-Bromo-6-(5-methoxy-1-methyl-1H-indol-3-yl)-5-((2-(trimethylsilyl)ethoxy)methyl)-5H-pyrrolo[2,3-b]pyrazine (0.500 g, 1.03 mmol, Preparation #C.1), tert-butyl carbamate (0.180 g, 1.54 mmol) and NaOt-Bu (0.148 g, 1.54 mmol) were then added and heating was continued for about 45 min. The mixture was cooled to rt and diluted with EtOAc (20 mL), washed with water (15 mL) and dried over MgSO4. The mixture was filtered and concentrated in vacuo and purified by a 12 g silica column eluting with 0 to 30% EtOAc/DCM to provide tert-butyl 6-(5-methoxy-1-methyl-1H-indol-3-yl)-5-((2-(trimethylsilyl)ethoxy)methyl)-5H-pyrrolo[2,3-b]pyrazin-2-ylcarbamate (0.224 g, 42%): LC/MS (Table 2, Method g) Rt=1.99 min; MS m/z 524 (M+H)+.
