Réaction #62613

Équation de réaction

N-[4-[(3,4-dimethoxyphenyl)methyl]phenyl]-3,4-dihydro-4-oxo-2H-1-benzothiopyran-3-carboxamide

BBr3

→

N-[4-[(3,4-dihydroxyphenyl)methyl]phenyl]-3,4-dihydro-4-oxo-2H-1-benzothiopyran-3-carboxamide

Rendement 63.9%

Solvants

dichloromethane

Conditions de réaction

Traitement

1. 1
   Températureunder reflux under nitrogen for 18 hours
2. 2
   Filtrationfiltered
3. 3
   AutreThe crude product was recrystallized from isopropanol-water

Mode opératoire

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 600 ml 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.

Source