反应详情

A suspension of 1.0 g (2.1 mmol) of N-[4-[(3,4-dimethoxyphenyl)methyl]phenyl]-3,4-dihydro-4-oxo-2H-1-benzothiopyran-3-carboxamide, 1,1-dioxide and BBr3.S (CH3)2 (4.0 g, 12.6 mmol) in 150 ml of dichloromethane was heated under reflux under nitrogen for 18 hours. The resulting yellow suspension was poured onto 600ml of ice water, stirred for one and one-half hours and then filtered. The crude product was recrystallized from isopropanol-water to yield 544 mg (59%) of N-[4-[(3,4-dihydroxyphenyl)methyl]phenyl]-3,4-dihydro-4-oxo-2H-1-benzothiopyran-3-carboxamide, 1,1-dioxide, mp 216°-218° C.

1. temperatureunder reflux under nitrogen for 18 hours
2. filtrationfiltered
3. customThe crude product was recrystallized from isopropanol-water