[O:1]=[CH:2][C:3]1[CH:11]=[CH:10][C:8]([OH:9])=[C:5]([O:6][CH3:7])[CH:4]=1.C([O-])([O-])=O.[K+].[K+].[CH2:18](Br)[CH:19]([CH3:21])[CH3:20]>CN(C)C=O>[CH3:18][CH:19]([CH3:21])[CH2:20][O:9][C:8]1[CH:10]=[CH:11][C:3]([CH:2]=[O:1])=[CH:4][C:5]=1[O:6][CH3:7]In 250 ml three necked flask, equipped with reflux condenser, mechanical stirrer, 30.4 g (200 mmol) of vanillin, 28 g (200 mmol) of dry K2CO3 and 150 ml of abs. dimethylformamide are placed in the flow of argon. The mixture is stirred for 20 min in argon condition, then 34.3 g (250 mmol) of isobutyl bromide is added. The mixture is refluxed with stirring in argon condition for 20 h at 90÷100° C., and concentrated in vacuum at 50÷80° C. to dryness. Then 200 ml of water is added to the residue, the mixture is extracted with (4×100 ml) of dichloromethane. The combined organic fraction is washed with 7% NaOH solution, dried over magnesium sulfate, filtered off, concentrated in vacuum at 50÷80° C. The residue (15 g of brown oil)-crude 4-(2-methylpropyloxy)-3-methoxybenzaldehyde is used on the next step without further purification.
불러오는 중…