反应详情

4-amino-N-(3,4-dimethyl-5-isoxazolyl)benzenesulfonamide (545 mg, 2.0 mmol) was dissolved in dry dimethylformamide (10 ml). Ethyl isocyanatoacetate (463 ml, 4.0 mmol) was added. The reaction was stirred at room temperature for 3 h and then heated at 80° C. for an additional 8 h. Dimethylformamide was removed under reduced pressure and the residue was recrystallized from acetonitrile/water to give 807 mg (90% yield) brownish solid, m.p. 115°-125° C.

1. temperatureheated at 80° C. for an additional 8 h
2. customDimethylformamide was removed under reduced pressure
3. customthe residue was recrystallized from acetonitrile/water