Bromine → HCID 18388324, compound
Reaction equation
[O:1]=[C:2]1[C:10]2[C:6](=[C:7]([C:15]([O:17][CH2:18][CH3:19])=[O:16])[S:8][C:9]=2[S:11][CH2:12][CH2:13][CH3:14])[CH2:5][CH2:4][CH2:3]1.[Br:20]Br>C(Cl)(Cl)Cl>[Br:20][CH:3]1[CH2:4][CH2:5][C:6]2=[C:7]([C:15]([O:17][CH2:18][CH3:19])=[O:16])[S:8][C:9]([S:11][CH2:12][CH2:13][CH3:14])=[C:10]2[C:2]1=[O:1]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
Ethyl 4,5,6,7-tetrahydro-4-oxo-3-propylthiobenzo[c]thiophene-1-carboxylate (25.29 g) was dissolved in chloroform (380 ml); a solution of bromine (13.81 g) in chloroform (20 ml) was added dropwise at room temperature over a period of 20 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-4-oxo-3-propylthiobenzo[c]thiophene-1-carboxylate (29.07 g, 90.9%), which was then recrystallized from ethyl acetate-hexane. Light-yellow prisms. Melting point 93-94° C.