[N:1]1[CH:6]=[CH:5][N:4]=[CH:3][C:2]=1[NH2:7].Br[C:9]1[C:10](=[O:17])[N:11]([CH3:16])[CH:12]=[C:13]([Br:15])[CH:14]=1.CC1(C)C2C(=C(P(C3C=CC=CC=3)C3C=CC=CC=3)C=CC=2)OC2C(P(C3C=CC=CC=3)C3C=CC=CC=3)=CC=CC1=2.C(=O)([O-])[O-].[Cs+].[Cs+]>C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].[Pd].O1CCOCC1>[Br:15][C:13]1[CH:14]=[C:9]([NH:7][C:2]2[CH:3]=[N:4][CH:5]=[CH:6][N:1]=2)[C:10](=[O:17])[N:11]([CH3:16])[CH:12]=1A 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser was charged with pyrazin-2-amine (500 mg, 5.3 mmol), 3,5-dibromo-1-methylpyridin-2(1H)-one (1335 mg, 5.3 mmol), Pd2(dba)3 (229 mg, 0.25 mmol), XantPhos (289 mg, 0.50 mmol), cesium carbonate (3.26 g, 10 mmol) and 1,4-dioxane (50 mL). After three cycles of vacuum/argon flush, the mixture was stirred at 100° C. for 2 h. It was then filtered and the filtrate was evaporated in vacuo. The residue was purified by silica-gel column chromatography eluting with 50:1 dichloromethane/methanol to afford 162a (420 mg, 30%) as a yellow solid. MS-ESI: [M+H]+ 281.0.
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