反应详情

温度

-78 °C

3,5-Dimethoxyaniline (7.55 g) was dissolved in CH2Cl2 (100 mL) under N2 and the solution was cooled to −78° C. A solution of tetrabutylammonium tribromide (25 g) in CH2Cl2 (100 mL) was added and the mixture was stirred at that temperature for 45 min. The mixture was allowed to warm up to room temperature, stirred for 1.5 h and extracted with 1N HCl. The extract was neutralized with 3 N NaOH and extracted with AcOEt. The extract was dried (MgSO4), filtered and evaporated. The residue was purified by column chromatography (silica gel; eluent: hexane/AcOEt 4:1 to 2:3) to give 4-bromo-3,5-dimethoxyaniline (3.76 g).

1. temperatureto warm up to room temperature
2. stirringstirred for 1.5 h
3. extractionextracted with 1N HCl
4. extractionextracted with AcOEt
5. dry with materialThe extract was dried (MgSO4)
6. filtrationfiltered
7. customevaporated
8. customThe residue was purified by column chromatography (silica gel; eluent: hexane/AcOEt 4:1 to 2:3)