Trimethyl orthoformate → 1-Bromo-2-(dimethoxymethyl)-4,5-dimethoxybenzene
Reaktionsgleichung
[Br:1][C:2]1[C:7](C=O)=[CH:6][C:5]([O:10][CH3:11])=[C:4]([O:12][CH3:13])[CH:3]=1.[CH:14]([O:19][CH3:20])([O:17][CH3:18])OC>CO>[CH3:20][O:19][CH:14]([O:17][CH3:18])[C:7]1[C:2]([Br:1])=[CH:3][C:4]([O:12][CH3:13])=[C:5]([O:10][CH3:11])[CH:6]=1Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
6-Bromo-3,4-dimethoxybenzaldehyde (470 g) is suspended in methanol (600 ml), and thereto are added trimethyl orthoformate (1025 ml) and IRA-120 (H+-type, 10 g), and the mixture is refluxed for one hour. The mixture is cooled to room temperature, and the insoluble materials are removed by filtration, and the filtrate is concentrated under reduced pressure. The resulting residue is dissolved in ether, washed, dried, evaporated to remove the ether, and distilled under reduced pressure to give 6-bromo-3,4-dimethoxybenzaldehyde dimethyl acetal (522 g) as a main distillate (133-138° C./1 Torr).