反应详情

Ethyl 4,5,6,7-tetrahydro-3-methylthio-4-oxobenzo[c]thiophene-1-carboxylate (25.12 g) was dissolved in chloroform (400 ml); a solution of bromine (15.59 g) in chloroform (20 ml) was added dropwise at room temperature over a period of 30 minutes. After the reaction mixture was stirred at room temperature for 40 minutes, it was washed with a 2% aqueous solution of sodium sulfite (400 ml), water, a saturated aqueous solution of sodium hydrogen carbonate and water in that order, and dried (MgSO4), after which the solvent was distilled off to yield ethyl 5-bromo-4,5,6,7-tetrahydro-3-methylthio-4-oxobenzo[c]thiophene-1-carboxylate (28.27 g, 87.1%), which was then recrystallized from ethyl acetate-hexane. Light-yellow prisms. Melting point 147-148° C.

1. washit was washed with a 2% aqueous solution of sodium sulfite (400 ml), water
2. dry with materiala saturated aqueous solution of sodium hydrogen carbonate and water in that order, and dried (MgSO4)
3. distillationafter which the solvent was distilled off