反应详情

To a solution of N-(3-hydroxymethylphenyl)-α-(3-nitrophenyl)nitrone (92) (1.38 g, 5.1 mmol) in dimethyl sulfoxide (50 mL) was added active manganese dioxide82 (15 g). The resulting mixture was stirred at room temperature for 21/2 h. The mixture was filtered and the solvent was slowly poured into water (200 mL), and the precipitate product was collected. The crude product was dissolved in dichloromethane, and the solution was washed with water (50 mL). The solution was then dried (MgSO4), and the solvent was removed with a rotary evaporator. Recrystallization from dichloromethane/petroleum ether afforded 0.95 g (3.5 mmol, 69%) of 89 as a yellow crystalline solid: mp 195°-197° C.; IR (Nujol) 1690, 1525, 1340, 1150, 1060, 790 cm-1 ; 1H NMR (Me2SO-d6) δ 7.77-8.74 (m, 7H), 8.93 (s, 1H), 9.53 (s, 1H), 10.10 (s, 1H); 13C NMR (Me2SO-d6) δ 122.44, 123.26, 125.58, 127.64, 130.67, 130.85, 131.76, 132.73, 133.15, 135.48, 137.54, 148.34, 149.15, 192.78; mass spectrum, m/e (relative intensity) 270 (M+, 13.1), 254 (19.8), 119 (100), 91 (72.6), 77 (146.4); high resolution mass spectrum, m/e 270.0644 (calcd for C14H10N2O4, 270.0640).

1. filtrationThe mixture was filtered
2. additionthe solvent was slowly poured into water (200 mL)
3. customthe precipitate product was collected
4. dissolutionThe crude product was dissolved in dichloromethane
5. washthe solution was washed with water (50 mL)
6. dry with materialThe solution was then dried (MgSO4)
7. customthe solvent was removed with a rotary evaporator
8. customRecrystallization from dichloromethane/petroleum ether