Acetic Acid → 2-Methyl-4-methoxypyridine-N-oxide
反応式
[Na].[N+]([C:5]1[CH:10]=[CH:9][N+:8]([O-:11])=[C:7]([CH3:12])[CH:6]=1)([O-])=O.[C:13](O)(=[O:15])C.C([O-])(O)=O.[Na+]>CO.O>[CH3:13][O:15][C:5]1[CH:10]=[CH:9][N+:8]([O-:11])=[C:7]([CH3:12])[CH:6]=1[Na].[N+]([C:5]1[CH:10]=[CH:9][N+:8]([O-:11])=[C:7]([CH3:12])[CH:6]=1)([O-])=O.[C:13](O)(=[O:15])C.C([O-])(O)=O.[Na+]>CO.O>[CH3:13][O:15][C:5]1[CH:10]=[CH:9][N+:8]([O-:11])=[C:7]([CH3:12])[CH:6]=1With stirring, sodium pellets (3.95 g, 0.172 mol), maintained dry under hexane, were added to 540 ml dry methanol, under N2. Following dissolution, the mixture was diluted with 900 ml methanol, 4-nitro-2-methylpyridine N-oxide (26.0 g, 0.169 mol) was added, and the mixture heated at reflux for 1 hour, cooled to room temperature and acidified with 18 ml glacial acetic acid. After stirring 15 minutes, the reaction mixture was stripped of solvent, the orange residue taken up in 300 ml of H2O, neutralized with saturated NaHCO3, reconcentrated to dryness, and the residue triturated 5×50 ml of ethanol. The ethanol triturates were combined, stripped to dryness, and the residue restripped 3×50 ml toluene to yield solids (36.1 g) which were chromatographed on silica gel using 6:1 CH2Cl2 :CH3OH as eluant to yield purified title product, 21.14 g; MS 139 (M+).
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