4-ethoxy-1-oxidopyridin-1-ium

反応条件: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A mixture of 4-ethoxypyridine 1-oxide (20 g, 144 mmol) in Ac2O (200 mL, 7.836 mol) was heated to refluxed for 4 h. Then, the solvent was removed in vacuo, and the residue was dissolved in MeOH (50 mL) and water (50 mL) and stirred at 25° C. for 16 h. The mixture was then concentrated and 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 (17 g, 104 mmol, 72% yield). 1H NMR (400 MHz, MeOH-d4) δ 8.20 (d, J=7.6 Hz, 2H), 7.12 (d, J=7.6 Hz, 2H), 4.18 (q, J=7.2 Hz, 2H), 1.42 (t, J=6.8 Hz, 3H); ES-LCMS m/z: 140.0 (M+H). was heated to refluxed for 4 h Then, the solvent was removed in vacuo the residue was dissolved in MeOH (50 mL) The mixture was then concentrated the crude material was purified by silica column chromatography (DCM/MeOH=10:1) concentrated

反応条件: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a mixture of 4-nitropyridine 1-oxide (28 g, 200 mmol) in THF (50 mL) was added sodium ethanolate (40.8 g, 600 mmol). The mixture was stirred at 25° C. for 16 h. The reaction residue was then concentrated and the crude material was purified by silica column chromatography (DCM/MeOH=25:1). All fractions found to contain product by TLC (DCM/MeOH=25:1, Rf=0.6) were combined and concentrated to yield a dark red solid of 4-ethoxypyridine 1-oxide (20 g, 101 mmol, 50% yield). 1H NMR (400 MHz, MeOH-d4) δ 8.20 (d, J=7.6 Hz, 2H), 7.12 (d, J=7.6 Hz, 2H), 4.18 (q, J=7.2 Hz, 2H), 1.42 (t, J=6.8 Hz, 3H); ES-LCMS m/z: 140.0 (M+H). The reaction residue was then concentrated the crude material was purified by silica column chromatography (DCM/MeOH=25:1) concentrated

反応条件: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 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). was heated to reflux for 4 h Then the solvent was removed in vacuo the residue was dissolved in MeOH (25 mL) The mixture was concentrated The crude material was purified by silica column chromatography (DCM/MeOH=10:1) concentrated

反応条件: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a mixture of 4-nitropyridine 1-oxide (50 g, 357 mmol) in THF (500 mL) was added sodium ethanolate (48.6 g, 714 mmol). The mixture was stirred at 25° C. for 16 h. The reaction residue was concentrated. The crude material was purified by silica column chromatography (DCM/MeOH=25:1). All fractions found to contain product by TLC (DCM/MeOH=25:1, Rf=0.6) were combined and concentrated to yield a dark red solid of 4-ethoxypyridine 1-oxide (25 g, 162 mmol, 45.3% yield): 1H NMR (400 MHz, CD3OD) δ 8.20-8.18 (m, 2H), 7.11-7.10 (m, 2H), 4.21-4.15 (m, 2H), 1.42 (t, J=7.2 Hz, 3H); ES-LCMS m/z 140.0 (M+H). The reaction residue was concentrated The crude material was purified by silica column chromatography (DCM/MeOH=25:1) concentrated

反応条件: temp:110.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 4-nitropyridine-N-oxide (12 g) was dissolved in ethanol, sodium ethoxide (8.8 g) was added to the mixture, and the mixture was stirred for 40 hours at 50° C. After allowing the mixture to be cooled to room temperature, the precipitates were filtered, the solvent was removed under reduced pressure, and the obtained residue was purified by silica gel column chromatography, to give 4-ethoxypyridine-N-oxide (11.8 g). To 4-ethoxypyridine-N-oxide (11.8 g) was added dimethyl sulfate (8.56 ml), and the mixture was stirred for 1 hour at 110° C. After diluting with methanol (180 ml), the mixture was heated to reflux for 1 hour, an aqueous solution (18 ml) of ammonium peroxodisulfate (20.6 g) was added dropwise to the solution under heat reflux, and the mixture was heated to reflux for 1 hour. After allowing the mixture to be cooled to room temperature, the solvent was removed under reduced pressure, and the obtained residue was purified by silica gel column chromatography, to give (4-ethoxy-2-pyridinyl)methanol (2.8 g). the mixture was heated to reflux for 1 hour under heat reflux the mixture was heated to reflux for 1 hour to be cooled to room temperature the solvent was removed under reduced pressure the obtained residue was purified by silica gel column chromatography

反応条件: temp:110.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 4-nitropyridine-N-oxide (12 g) was dissolved in ethanol, sodium ethoxide (8.8 g) was added to the mixture, and the mixture was stirred for 40 hours at 50° C. After allowing the mixture to be cooled to room temperature, the precipitates were filtered, the solvent was removed under reduced pressure, and the obtained residue was purified by silica gel column chromatography, to give 4-ethoxypyridine-N-oxide (11.8 g). To 4-ethoxypyridine-N-oxide (11.8 g) was added dimethyl sulfate (8.56 ml), and the mixture was stirred for 1 hour at 110° C. After diluting with methanol (180 ml), the mixture was heated to reflux for 1 hour, an aqueous solution (18 ml) of ammonium peroxodisulfate (20.6 g) was added dropwise to the solution under heat reflux, and the mixture was heated to reflux for 1 hour. After allowing the mixture to be cooled to room temperature, the solvent was removed under reduced pressure, and the obtained residue was purified by silica gel column chromatography, to give (4-ethoxy-2-pyridinyl)methanol (2.8 g). the mixture was heated to reflux for 1 hour under heat reflux the mixture was heated to reflux for 1 hour to be cooled to room temperature the solvent was removed under reduced pressure the obtained residue was purified by silica gel column chromatography

反応条件: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 4-nitropyridine-N-oxide (12 g) was dissolved in ethanol, sodium ethoxide (8.8 g) was added to the mixture, and the mixture was stirred for 40 hours at 50° C. After allowing the mixture to be cooled to room temperature, the precipitates were filtered, the solvent was removed under reduced pressure, and the obtained residue was purified by silica gel column chromatography, to give 4-ethoxypyridine-N-oxide (11.8 g). To 4-ethoxypyridine-N-oxide (11.8 g) was added dimethyl sulfate (8.56 ml), and the mixture was stirred for 1 hour at 110° C. After diluting with methanol (180 ml), the mixture was heated to reflux for 1 hour, an aqueous solution (18 ml) of ammonium peroxodisulfate (20.6 g) was added dropwise to the solution under heat reflux, and the mixture was heated to reflux for 1 hour. After allowing the mixture to be cooled to room temperature, the solvent was removed under reduced pressure, and the obtained residue was purified by silica gel column chromatography, to give (4-ethoxy-2-pyridinyl)methanol (2.8 g). to be cooled to room temperature the precipitates were filtered the solvent was removed under reduced pressure the obtained residue was purified by silica gel column chromatography

反応条件: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 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). was heated to reflux for 4 h Then the solvent was removed in vacuo the residue was dissolved in MeOH (25 mL) The mixture was concentrated The crude material was purified by silica column chromatography (DCM/MeOH=10:1) concentrated

反応条件: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 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). was heated to reflux for 4 h Then the solvent was removed in vacuo the residue was dissolved in MeOH (25 mL) The mixture was concentrated The crude material was purified by silica column chromatography (DCM/MeOH=10:1) concentrated

反応条件: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a mixture of 4-nitropyridine 1-oxide (50 g, 357 mmol) in THF (500 mL) was added sodium ethanolate (48.6 g, 714 mmol). The mixture was stirred at 25° C. for 16 h. The reaction residue was concentrated. The crude material was purified by silica column chromatography (DCM/MeOH=25:1). All fractions found to contain product by TLC (DCM/MeOH=25:1, Rf=0.6) were combined and concentrated to yield a dark red solid of 4-ethoxypyridine 1-oxide (25 g, 162 mmol, 45.3% yield): 1H NMR (400 MHz, CD3OD) δ 8.20-8.18 (m, 2H), 7.11-7.10 (m, 2H), 4.21-4.15 (m, 2H), 1.42 (t, J=7.2 Hz, 3H); ES-LCMS m/z 140.0 (M+H). The reaction residue was concentrated The crude material was purified by silica column chromatography (DCM/MeOH=25:1) concentrated

反応条件: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 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). was heated to reflux for 4 h Then the solvent was removed in vacuo the residue was dissolved in MeOH (25 mL) The mixture was concentrated The crude material was purified by silica column chromatography (DCM/MeOH=10:1) concentrated

反応条件: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a mixture of 4-nitropyridine 1-oxide (50 g, 357 mmol) in THF (500 mL) was added sodium ethanolate (48.6 g, 714 mmol). The mixture was stirred at 25° C. for 16 h. The reaction residue was concentrated. The crude material was purified by silica column chromatography (DCM/MeOH=25:1). All fractions found to contain product by TLC (DCM/MeOH=25:1, Rf=0.6) were combined and concentrated to yield a dark red solid of 4-ethoxypyridine 1-oxide (25 g, 162 mmol, 45.3% yield): 1H NMR (400 MHz, CD3OD) δ 8.20-8.18 (m, 2H), 7.11-7.10 (m, 2H), 4.21-4.15 (m, 2H), 1.42 (t, J=7.2 Hz, 3H); ES-LCMS m/z 140.0 (M+H). The reaction residue was concentrated The crude material was purified by silica column chromatography (DCM/MeOH=25:1) concentrated