[CH2:1]([O:3][C:4]([CH2:6][N:7]1[C:12]([CH3:13])=[CH:11][N:10]=[C:9](O)[C:8]1=[O:15])=[O:5])[CH3:2].P(Br)(Br)([Br:18])=O.[NH4+].[OH-]>C(Cl)(Cl)Cl>[Br:18][C:9]1[C:8](=[O:15])[N:7]([CH2:6][C:4]([O:3][CH2:1][CH3:2])=[O:5])[C:12]([CH3:13])=[CH:11][N:10]=1A stirred slurry of 505 mg (2.38 mmol) of 1-(ethoxycarbonyl-methyl)-3-hydroxy-6-methylpyrazinone and 756 mg (2.64 mmol) of phosphorous oxybromide in 1.7 ml of CHCl3 was stirred at 50° C. under a slow stream of Ar for 1.5 h, then allowed to cool to rt overnight. The reaction mixture was diluted with CHCl3 and ice water, basified with NH4OH, and extracted with CHCl3. The combined organic layers were dried over Na2SO4, treated with activated carbon, filtered and concentrated to give 2-5 as an orange colored solid: 1H NMR (CDCl3) δ7.06 (s, 1H), 4.77 (s, 2H), 4.27 (q, 2H, 7.2 Hz), 2.24 (s, 3H), 1.31 (t, 3H, 7.2 Hz).
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