1,4-Dioxane → 5-Nitropyridine-2-carbaldehyde
Reaction equation
[CH3:1][C:2]1[CH:7]=[CH:6][C:5]([N+:8]([O-:10])=[O:9])=[CH:4][N:3]=1.[O:11]1CCOCC1>>[N+:8]([C:5]1[CH:6]=[CH:7][C:2]([CH:1]=[O:11])=[N:3][CH:4]=1)([O-:10])=[O:9]Participants
3
Conditions
- Temperature
- 80 °C
Procedure
To a stirred solution of compound 2-methyl-5-nitropyridine (30) (10 g, 72.5 mmol) in 1,4-dioxane (150 mL) was added SeO2 (9.5 g, 87.0 mmol) at room temperature. The resulting reaction mixture was stirred at 80° C. for 16 h. The reaction mixture was evaporated, the residue was diluted with water (100 mL), the resulting precipitate was separated by filtration and the filtrate was extracted with ethyl acetate (3×100 mL). The combined organic layer was washed with water (100 mL), brine (100 mL), the organic layer was dried over Na2SO4 and concentrated to give 31 (6.4 g, 58%) as a brown solid. Rf: 0.7 (30% EtOAc/pet-ether); 1H NMR (400 MHz, CDCl3): δ 10.18 (1H, s), 9.59 (1H, d, J=2.0 Hz), 8.68-8.65 (1H, m), 8.16 (1H, d, J=8.4 Hz)