Bromine → Ethyl 5-bromo-4,5,6,7-tetrahydro-3-methylthio-4-oxobenzo[c]thiophene-1-carboxylate
Reaction equation
[CH3:1][S:2][C:3]1[S:7][C:6]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[C:5]2[CH2:13][CH2:14][CH2:15][C:16](=[O:17])[C:4]=12.[Br:18]Br>C(Cl)(Cl)Cl>[Br:18][CH:15]1[CH2:14][CH2:13][C:5]2=[C:6]([C:8]([O:10][CH2:11][CH3:12])=[O:9])[S:7][C:3]([S:2][CH3:1])=[C:4]2[C:16]1=[O:17]Participants
Procedure
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.
Workup
- washit was washed with a 2% aqueous solution of sodium sulfite (400 ml), water
- dry with materiala saturated aqueous solution of sodium hydrogen carbonate and water in that order, and dried (MgSO4)
- distillationafter which the solvent was distilled off
Sources & evidence
- ORD record
- ord-8b3b15f138fa43e692f93ff67c76e182
- Source dataset
- uspto-grants-2000_05
- Patent number
- US06066658
Reaction notes
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