Chlorine → 3,7-Dichloro-6-methoxy-1-benzothiophene-2-carbonyl chloride
Reaction equation
[Cl:1]Cl.[Cl:3][C:4]1[C:5]2[CH:15]=[CH:14][C:13]([O:16][CH3:17])=[CH:12][C:6]=2[S:7][C:8]=1[C:9]([Cl:11])=[O:10]>C(Cl)(Cl)Cl>[Cl:3][C:4]1[C:5]2[CH:15]=[CH:14][C:13]([O:16][CH3:17])=[C:12]([Cl:1])[C:6]=2[S:7][C:8]=1[C:9]([Cl:11])=[O:10]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
Chlorine (24 g) is bubbled into a stirred suspension of 3-chloro-6-methoxy-benzo[b]thiophene-2-carbonyl chloride (9.2 g, 35 mmoles) in chloroform (200 mls) over a period of 30 minutes. After an additional 45 minutes of stirring at room temperature the mixture is stripped of volatiles under reduced pressure. The residue is recrystallized from tetrahydrofuran (100 mls) to afford the pure product (6.6 g): mp=174°-175° C.