Reaction #8198

Reaction equation

3-Methylbenzo[b]thiophene

n-bromosuccinimide

2,2′Azobisisobutyronitrile

→

3-Bromomethylbenzo[b]thiophene

Yield 42.2%

Solvents

carbon tetrachloride

Conditions

Workup

1. 1
   Temperaturethe resulting mixture is refluxed for two hours
2. 2
   TemperatureAfter cooling
3. 3
   Filtrationthe reaction mixture is filtered through a glass-fritted funnel
4. 4
   Concentrationthe filtrate is concentrated
5. 5
   OtherThe residue is triturated with petroleum ether and toluene

Procedure

3-Methylbenzo[b]thiophene (9.9 g, 67 mmol) is heated in carbon tetrachloride (133 ml ) to near reflux in the presence of n-bromosuccinimide (11.9 g, 67 mmol, 1.0 eq.). 2,2′Azobisisobutyronitrile (2.2 g, 13.3 mmol, 0.2 eq.) is added and the resulting mixture is refluxed for two hours. After cooling, the reaction mixture is filtered through a glass-fritted funnel, and the filtrate is concentrated. The residue is triturated with petroleum ether and toluene to afford 6.42 g of 3-Bromomethylbenzo[b]thiophene (42%).

Source