[N+:1]([C:4]1[CH:11]=[CH:10][C:7]([CH:8]=[O:9])=[CH:6][CH:5]=1)([O-:3])=[O:2].[CH2:12](O)[CH2:13][OH:14].C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[N+:1]([C:4]1[CH:5]=[CH:6][C:7]([CH:8]2[O:14][CH2:13][CH2:12][O:9]2)=[CH:10][CH:11]=1)([O-:3])=[O:2]A stirred solution of p-nitrobenzaldehyde (101.5 g, 672 mmol), ethylene glycol (112 mL) and p-toluenesulfonic acid (12.8 g, 67.2 mmol) in toluene (800 mL) was heated in flask equipped with a Dean-Stark trap at 120° C. for 4 h. After cooling to room temperature, the reaction mixture was concentrated under reduced pressure. To the residue was added saturated aqueous sodium bicarbonate (800 mL) and this mixture was stirred at room temperature for 15 min. The resulting solid was isolated by filtration and dried under vacuum to give the title compound (121.8 g, 92% yield) as a yellow solid.
Wird geladen…