[CH2:1]([O:3][C:4]1[N:5]=[CH:6][C:7]([C:10]([O:12]CC)=[O:11])=[N:8][CH:9]=1)[CH3:2].O.O.[OH-].[Li+].C([O-])(O)=O.[Na+]>O1CCOCC1.CCOCC>[CH2:1]([O:3][C:4]1[N:5]=[CH:6][C:7]([C:10]([OH:12])=[O:11])=[N:8][CH:9]=1)[CH3:2]Ethyl 5-ethoxypyrazine-2-carboxylate (0.65 g, approx. purity 85%) was dissolved in dioxan (3 mL) and water (3 mL) was added, followed by lithium hydroxide monohydrate (255 mg, portionwise over 10 mins). After stirring at RT for 24 h, Et2O (25 mL) and NaHCO3 (sat., aq., 25 mL) were added. The layers were separated and the organic layer was extracted with NaOH (1 N, aq., 25 mL). The combined aqueous portions were acidified with 6N HCl to pH 2, and the mixture extracted with EtOAc (3×40 mL). The combined EtOAc extracts were dried over MgSO4 and evaporated to afford the title compound as an off-white powder. 1H NMR (400 MHz, CDCl3) δ ppm 1.47 (t, J=7.1 Hz, 3H), 4.53 (q, J=7.1 Hz, 2H), 8.16 (d, J=1.2 Hz, 1H), 8.98 (d, J=1.2 Hz, 1H)
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