Reaktion #168922

Reaktionsgleichung

dichloromethoxymethane

1-bromo-4-isopropyl-2-methoxy-benzene

1-bromo-2-isopropyl-4-methoxy-benzene

HCl

→

5-bromo-2-isopropyl-4-methoxy-benzaldehyde

5-bromo-4-isopropyl-2-methoxy-benzaldehyde

Lösungsmittel

1,2 dichloroethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe mixture was warmed to reflux
2. 2
   TemperaturAfter 3 hours the mixture was cooled
3. 3
   workup.ADDITIONpoured over ice
4. 4
   ExtraktionThe resulting slurry was extracted with CH2Cl2
5. 5
   Waschenwashed with brine
6. 6
   TrocknenThe combined organics were dried over MgSO4
7. 7
   Filtrationfiltered
8. 8
   Einengenconcentrated in vacuo
9. 9
   Sonstigeto give a dark-green oil
10. 10
    SonstigePurification via flash chromatography (96:4 hexane/ethyl acetate)

Vorschrift

To a solution of 1-bromo-4-isopropyl-2-methoxy-benzene and 1-bromo-2-isopropyl-4-methoxy-benzene from step 2 (6.621 g, 28.9 mmol) in 100 mL 1,2 dichloroethane was added TiCl4 (6.3 mL, 57.8 mmol) at 0° C. After 10 minutes, dichloromethoxymethane (Cl2CHOMe) (2.6 mL, 28.9 mmol) was added and the mixture was warmed to reflux. After 3 hours the mixture was cooled poured over ice and acidified with 50 mL 2 M HCl. The resulting slurry was extracted with CH2Cl2, and washed with brine. The combined organics were dried over MgSO4, filtered and concentrated in vacuo to give a dark-green oil. Purification via flash chromatography (96:4 hexane/ethyl acetate) afforded 5-bromo-2-isopropyl-4-methoxy-benzaldehyde and 5-bromo-4-isopropyl-2-methoxy-benzaldehyde (2.876 g, 39%, 6.621 g, 72%) as a 1:1 mixture of inseparable isomers in the form of an orange oil, which was used directly in step 4.

Quelle