反应详情

To a stirred solution of 5-bromo-3-methylbenzene-1,2-diamine (4 g) in DMF (80 ml) was added NaH (40% oil dispersion, 800 mg) at 0° C., and the reaction mixture was stirred for another 30 min at the same temperature. A solution of ethyl chloroformate (1.9 g) in DMF (10 ml) was added dropwise thereto at 0° C. and then the resulting reaction mixture was stirred at room temperature for 1 h. The reaction mixture was poured into saturated NH4Cl solution, and extracted with EtOAc. The extract was washed with brine, dried over Na2SO4 and concentrated in vacuo. The residue was purified by silica gel column chromatography (hexane/EtOAc) to give the title compound (2.5 g) as a yellow solid.

1. customat 0° C. and then the resulting reaction mixture
2. stirringwas stirred at room temperature for 1 h
3. extractionextracted with EtOAc
4. washThe extract was washed with brine
5. dry with materialdried over Na2SO4
6. concentrationconcentrated in vacuo
7. customThe residue was purified by silica gel column chromatography (hexane/EtOAc)