反应详情

DMAP (50 mg) and acetic anhydride (3.9 g, 37.9 mmol) were added sequentially and dropwise to a cold solution of 5-chloro-benzene-1,3-diamine (4.5 g, 31.6 mmol) in pyridine (22 mL) keeping the internal temperature below 0° C. The reaction mixture was allowed to warm to rt, stirred for 2 h, cooled to 0° C., quenched by addition of ice cooled water, and extracted with EtOAc. The organic phase was washed with brine, dried (Na2SO4), filtered, and concentrated. The crude material was purified by silica gel column chromatography (CH2Cl2/MeOH, 99:1) to afford the title compound. tR: 0.18 min (LC-MS 2); ESI-MS: 184.9 [M+H]+ (LC-MS 2); Rf=0.32 (hexane/EtOAc, 1:4).

1. customthe internal temperature below 0° C
2. temperaturecooled to 0° C.
3. customquenched by addition of ice
4. temperaturecooled water
5. extractionextracted with EtOAc
6. washThe organic phase was washed with brine
7. dry with materialdried (Na2SO4)
8. filtrationfiltered
9. concentrationconcentrated
10. customThe crude material was purified by silica gel column chromatography (CH2Cl2/MeOH, 99:1)