Hydrochloric Acid → 3-methylthio-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-one

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Reaction Steps

A solution of sodium sulfite (3.31 g, 47.94 mmol) in water (5 ml) was added dropwise to a mixture of 3-amino-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-one (8.00 g, 45.65 mmol) and 35% hydrochloric acid (20 ml) under ice-cooling and stirred under ice-cooling for 20 minutes. Sodium acetate trihydrate (33 g) was added to the reaction mixture and the resulting mixture was added dropwise to a 15% aqueous sodium thiomethoxide solution (42.67 g, 91.31 mmol). The reaction mixture was stirred at 80° C. for 1.5 hours, adjusted to pH 9 with an aqueous sodium hydroxide solution and then extracted with ethyl acetate. The extract solution was washed with water and a saturated aqueous sodium chloride solution and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure and the resulting residue was purified by a silica gel column chromatography (eluent: ethyl acetate/n-hexane=1/30) to obtain 4.33 g of 3-methylthio-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-one.

Provenance & Evidence