反应详情

Bromine (1.1 mL, 22 mmol) in acetic acid (10 mL) was slowly added into a vigorously stirred solution of 2-(3,4-dimethoxyphenyl)ethylamine (3.4 mL, 20 mmol) in 50 mL acetic acid. 2-bromo-4,5-dimethoxylbenzeneethanamine precipitated out after 15 minutes. The mixture was stirred for another two hours, filtered, and washed with dichloromethane 10 mL×3 and petroleum ether 10 mL×3. The resulting solid was taken up in water and the pH was brought to 10 with aqueous KOH solution. Extraction with dichloromethane followed by evaporation of the solvent yielded 4.12 g (78%) 2-Bromo-4,5-dimethoxylbenzeneethanamine. The crude product was dried under dynamic vacuum overnight and used without further purification.

1. custom2-bromo-4,5-dimethoxylbenzeneethanamine precipitated out after 15 minutes
2. filtrationfiltered
3. washwashed with dichloromethane 10 mL×3 and petroleum ether 10 mL×3
4. extractionExtraction with dichloromethane
5. customfollowed by evaporation of the solvent