Acetic Anhydride → 4-ethoxy-1H-pyridin-2-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 4-ethoxypyridine 1-oxide (5 g, 35.9 mmol) in acetic anhydride (36.7 g, 359 mmol) was heated to reflux for 4 h. Then the solvent was removed in vacuo, and the residue was dissolved in MeOH (25 mL) and H2O (25 mL) and stirred at 25° C. for 16 h. The mixture was concentrated. The crude material was purified by silica column chromatography (DCM/MeOH=10:1). All fractions found to contain product by TLC (DCM/MeOH=10:1, Rf=0.6) were combined and concentrated to yield a dark yellow solid of 4-ethoxypyridin-2-ol (2.5 g, 16.17 mmol, 45.0% yield): 1H NMR (400 MHz, CD3OD) δ 7.28 (d, J=7.6 Hz, 1H), 6.07 (d, J=3.2, 7.2 Hz, 1H), 5.86-7.85 (d, J=2.4 Hz, 1H), 4.06-4.01 (m, 2H), 1.38 (t, J=7.2 Hz, 3H); ES-LCMS m/z 140.0 (M+H).

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