3-Acetylpyridine → Methyl 2,4-dioxo-4-(pyridin-3-yl)butanoate

Beteiligte Stoffe

Reaktionsschritte

Sodium methoxide (5.4 g, 100 mmol) and dimethyloxalate (11.8 g, 100 mmol) were dissolved in anhydrous methanol (700 mL) and stirred at room temperature under nitrogen until a suspension was formed. To this mixture, 3-acetylpyridine (5.5 mL, 50 mmol) was added and the stirring was continued for 3 days at room temperature. The reaction was quenched with enough 5% aqueous KHSO4 until all solids have dissolved. The methanol was removed under reduced pressure, and the residue was extracted with ethyl acetate (3×200 mL). The combined organic layers were washed with water (2×200 mL), brine and dried (NaSO4) followed by the removal of solvent under reduced pressure to give the title compound (8.67 g, 84% yield) as a yellow solid. 1H NMR (CDCl3, 300 MHz) δ 9.21–9.20 (m, 1H), 8.84–8.82 (m, 1H), 8.30–8.26 (m, 1H), 7.50–7.45 (m, 1H), 7.08 (s, 1H), 3.96 (s, 3H). 13C NMR (CDCl3, 75 MHz) δ 188.5, 170.4, 162.2, 153.9, 149.0, 135.2, 130.5, 123.8, 98.0, 53.3. mass spectrum (APIMS) m/z 208 (M+1)+.

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