反応 #168922

反応方程式

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

溶媒

1,2 dichloroethane

反応条件

後処理

1. 1
   温度the mixture was warmed to reflux
2. 2
   温度After 3 hours the mixture was cooled
3. 3
   workup.ADDITIONpoured over ice
4. 4
   抽出The resulting slurry was extracted with CH2Cl2
5. 5
   洗浄washed with brine
6. 6
   乾燥The combined organics were dried over MgSO4
7. 7
   ろ過filtered
8. 8
   濃縮concentrated in vacuo
9. 9
   その他to give a dark-green oil
10. 10
    その他Purification via flash chromatography (96:4 hexane/ethyl acetate)

実験手順

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.

出典