Cl[C:2]1[C:3](=[O:16])[N:4]([C:9]2[CH:14]=[CH:13][C:12]([F:15])=[CH:11][CH:10]=2)[CH:5]=[C:6]([Cl:8])[N:7]=1.[CH3:17][O-:18].[Na+].Cl>CO>[Cl:8][C:6]1[N:7]=[C:2]([O:18][CH3:17])[C:3](=[O:16])[N:4]([C:9]2[CH:14]=[CH:13][C:12]([F:15])=[CH:11][CH:10]=2)[CH:5]=13,5-dichloro-1-(4-fluorophenyl)pyrazin-2(1H)-one (13.0 g, 50.2 mmol; prepared according to the general methods described by M. Tutonda, et al., Tetrahedron, 1990, 46, 5715) dissolved in absolute methanol (100 mL) was treated with NaOMe (6.78 g, 125 mmol). The reaction mixture was stirred at room temp for 1 hour, neutralized with 2N HCl (Et2O solution), and evaporated the solvent under reduced pressure. The residue was treated with EtOAc, washed with 0.5N HCl solution, dried over MgSO4, and concentrated under reduced pressure to give the desired product (12.8 g, 100%). LRMS (ESI pos) m/e 254.9, 256.9 (M+1, Cl pattern). 1H-NMR (400 MHz, CDCl3) δ 7.39 (m, 2H), 7.20 (t, 2H), 6.95 (s, 1H), 4.05 (s, 3H); 19F-NMR (376 MHz, CDCl3) δ −111.5.
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