反应详情

3.56 g of 3-cyano-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-one, 970 mg of hydroxylamine hydrochloride, 1.5 ml of water, 7 ml of N,N-dimethylformamide and 150 ml of ethanol were mixed, and subjected to refluxing for 3 hours. The reaction mixture was cooled, and thereafter, the precipitated crystals were collected by filtration and then recrystallized from acetonitrile to obtain 2.8 g (yield: 72%) of 2-amino-3-carbamoyl-7-methylsulfonylamino-6-phenoxy-4H-1-benzopyran-4-one having a melting point of >250° C.

1. temperatureto refluxing for 3 hours
2. temperatureThe reaction mixture was cooled
3. filtrationthe precipitated crystals were collected by filtration
4. customrecrystallized from acetonitrile