3-bromo-2-(hydroxymethyl)-6-methyl-4H-pyrido[1,2-a]pyrimidin-4-one → 3-bromo-6-methyl-4-oxo-4H-pyrido[1,2-a]pyrimidine-2-carbaldehyde
反応式
[Br:1][C:2]1[C:7](=[O:8])[N:6]2[C:9]([CH3:13])=[CH:10][CH:11]=[CH:12][C:5]2=[N:4][C:3]=1[CH2:14][OH:15]>C1(C)C=CC=CC=1.[O-2].[Mn+4].[O-2]>[Br:1][C:2]1[C:7](=[O:8])[N:6]2[C:9]([CH3:13])=[CH:10][CH:11]=[CH:12][C:5]2=[N:4][C:3]=1[CH:14]=[O:15]参加物
4
実験手順
A mixture of 3-bromo-2-(hydroxymethyl)-6-methyl-4H-pyrido[1,2-a]pyrimidin-4-one (2.7421 g, 10.19 mmol, Prepared in Example 1) and manganese(IV) oxide (8.86 g, 102 mmol) in toluene (67.9 mL) was heated to reflux. After 3 h, the mixture was cooled to rt and filtered through a pad of Celite™, The filtrate was concd under reduced pressure to give 3-bromo-6-methyl-4-oxo-4H-pyrido[1,2-a]-pyrimidine-2-carbaldehyde as a bright yellow solid: 1H NMR (400 MHz, DMSO-d6) δ ppm 10.07 (1 H, s), 7.81 (1 H, dd, J=9.0, 7.0 Hz), 7.60 (1 H, dd, J=9.0, 0.8 Hz), 7.10-7.15 (1 H, m), 2.96 (3 H, s); Mass Spectrum (ESI) m/e=267.0 [M+1 (79Br)] and 268.9 [M+1 (81Br)].