[CH3:1][O:2][C:3]1[CH:4]=[CH:5][C:6]2S[CH2:11][CH2:10][C:9]([C:13]([O:15][CH3:16])=[O:14])=[CH:8][C:7]=2[CH:17]=1.ClC1C=CC=C(C(OO)=O)C=1.[S:29]([O-:33])([O-])(=[O:31])=S.[Na+].[Na+]>C1COCC1>[CH3:1][O:2][C:3]1[CH:4]=[CH:5][C:6]2[S:29](=[O:33])(=[O:31])[CH2:11][CH2:10][C:9]([C:13]([O:15][CH3:16])=[O:14])=[CH:8][C:7]=2[CH:17]=1Into a solution of methyl 7-methoxy-2,3-dihydro-1-benzothiepine-4-carboxylate (3.00 g) in THF (30 ml) was added at 0° C. 70% 3-chloroperbenzoic acid (6.5 g), and the resulting mixture was stirred at 0° C. for 0.5 hour and at room temperature for one hour. The reaction mixture was mixed with an aqueous solution of sodium thiosulfate, was stirred for a few minutes and was then extracted with ethyl acetate. The organic layer was washed with an aqueous saturated solution of sodium bicarbonate (3 times) and an aqueous saturated solution of sodium chloride, and was dried with magnesium sulfate. After concentration under reduced pressure, the precipitated crystals were collected by filtration. The crystals were washed with diisopropyl ether to obtain methyl 7-methoxy-1,1-dioxo-2,3-dihydro-1-benzothiepine-4-carboxylate (3.15 g) as colorless crystals.
Wird geladen…
