Hydrogen Bromide → 7-Hydroxy-1,1-dioxo-2,3-dihydro-1-benzothiepine-4-carboxylic acid
反応式
C[O:2][C:3]1[CH:4]=[CH:5][C:6]2[S:12](=[O:14])(=[O:13])[CH2:11][CH2:10][C:9]([C:15]([O:17]C)=[O:16])=[CH:8][C:7]=2[CH:19]=1.Br>C(O)(=O)C>[OH:2][C:3]1[CH:4]=[CH:5][C:6]2[S:12](=[O:14])(=[O:13])[CH2:11][CH2:10][C:9]([C:15]([OH:17])=[O:16])=[CH:8][C:7]=2[CH:19]=1参加物
4
実験手順
A mixture of methyl 7-methoxy-1,1-dioxo-2,3-dihydro-1-benzothiepine-4-carboxylate (300 mg), 48% hydrobromic acid (3 ml) and acetic acid (3 ml) was heated at reflux for 4 hours. After concentration under reduced pressure, 48% hydrobromic acid (3 ml) and acetic acid (3 ml) were further added to the reaction mixture, which was heated at reflux for 8 hours. After concentration under reduced pressure, the precipitated crystals were collected by filtration. The crystals were washed with diisopropyl ether to obtain 7-hydroxy-1,1-dioxo-2,3-dihydro-1-benzothiepine-4-carboxylic acid (224 mg) as light yellow crystals.