反应详情

77.5 g (0.3 mol) of 1-chloro-N-(2-chloro-4-fluorophenyl)methanesulfonamide were dissolved in 204.2 g (2 mol) of acetic anhydride and refluxed for 4 hours. The excess acetic anhydride was distilled off under reduced pressure at 100° C. To the still hot residue was added ethanol with stirring and the product precipitated (seeding may aid in crystallization). The crude product was filtered off and washed with cold ethanol and dried to yield 72 g (80%) of the title compound as a solid melting at 89-92° C.

1. temperaturerefluxed for 4 hours
2. distillationThe excess acetic anhydride was distilled off under reduced pressure at 100° C
3. additionTo the still hot residue was added ethanol
4. customthe product precipitated
5. custom(seeding may aid in crystallization)
6. filtrationThe crude product was filtered off
7. washwashed with cold ethanol
8. customdried