Hydrochloric Acid → Methyl 7-bromo-5-oxo-2,3,4,5-tetrahydro-1-benzothiepine-4-carboxylate
Reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[S:11][CH2:10][CH2:9][CH2:8][C:7](=[O:12])[C:6]=2[CH:13]=1.C[O-].[Na+].Cl.[C:18](=O)([O:21]C)[O:19][CH3:20]>>[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[S:11][CH2:10][CH2:9][CH:8]([C:18]([O:19][CH3:20])=[O:21])[C:7](=[O:12])[C:6]=2[CH:13]=1Participants
5
Procedure
To a solution of 7-bromo-2,3,4,5-tetrahydro-1-benzothiepin-5-one (13.5 g) in dimethyl carbonate (200 ml) was added at room temperature sodium methoxide (14.2 g), and the mixture was refluxed for 8 hours under nitrogen atmosphere. To the mixture was added 1N hydrochloric acid, and the mixture was extracted with ethyl acetate. The organic layer was washed with water and saturated brine, and dried with magnesium sulfate. Under reduced pressure, the solvent was evaporated to give brown prism of methyl 7-bromo-5-oxo-2,3,4,5-tetrahydro-1-benzothiepine-4-carboxylate (11.5 g).