Cl[C:2]1[C:3]([NH2:8])=[N:4][CH:5]=[CH:6][N:7]=1.C(=O)([O-])[O-].[Na+].[Na+].[F:15][C:16]1[CH:25]=[C:24](B2OC(C)(C)C(C)(C)O2)[CH:23]=[CH:22][C:17]=1[C:18]([O:20][CH3:21])=[O:19].C(Cl)Cl>COCCOC.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.Cl[Pd]Cl.[Fe+2]>[NH2:8][C:3]1[C:2]([C:24]2[CH:23]=[CH:22][C:17]([C:18]([O:20][CH3:21])=[O:19])=[C:16]([F:15])[CH:25]=2)=[N:7][CH:6]=[CH:5][N:4]=1To 3-chloropyrazin-2-amine (27 g, 208 mmol) in DME (391 mL) and sodium carbonate (66.3 g, 625 mmol) was added methyl 2-fluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoate (64.2 g, 229 mmol) and PdCl2(dppf).CH2Cl2 adduct (8.51 g, 10.42 mmol). The reaction mixture was purged with N2 and heated in oil bath at 100° C. for 3h. The reaction mixture was partitioned between EtOAc and water. The organic layer was separated, washed with brine, dried over sodium sulfate, filtered and evaporated. The crude product was recrystallized by EtOAc and heptane (2:3) to give methyl 4-(3-aminopyrazin-2-yl)-2-fluorobenzoate in 84% yield. LCMS (m/z): 248.1 (MH+), 0.58 min.
読み込み中…
