[Br:1][C:2]1[CH:3]=[CH:4][C:5]([O:10][CH3:11])=[C:6]([CH:9]=1)[CH:7]=[O:8].[N+:12]([O-])([OH:14])=[O:13]>S(=O)(=O)(O)O>[Br:1][C:2]1[CH:3]=[C:4]([N+:12]([O-:14])=[O:13])[C:5]([O:10][CH3:11])=[C:6]([CH:9]=1)[CH:7]=[O:8]5-Bromo-2-methoxybenzaldehyde (29.65 g, 138 mmol) was added to stirred concentrated sulfuric acid (160 mL) at −15° C. Nitric acid (70% w/w) (16 g) was added dropwise. Further stirring was allowed for 15 mins at this temperature before the mixture was poured onto crushed ice (2 L). The resulting precipitate was collected by filtration and partitioned between dichloromethane (800 mL) and saturated sodium hydrogen carbonate (1 L). The organic layer was dried (Na2SO4) and evaporated in vacuo to give the title compound (20.5 g) as a crude solid.
불러오는 중…