Reaction #549683

Reaction equation

sulphur trioxide

4-(3-methyl-2-pyridyl)butylamine hydrobromide

bromine

→

4-(5-bromo-3-methyl-2-pyridyl)-butylamine

Yield 46.1%

Solvents

1,1,2-trifluorotrichloroethane

1,1,2-trifluorotrichloroethane

Conditions

Workup

1. 1
   TemperatureThe mixture was heated
2. 2
   Temperatureunder reflux for ca 16 hr
3. 3
   OtherThe solvent was removed by distillation
4. 4
   Otherwas removed by acetylation

Procedure

A solution of sulphur trioxide (150 ml) in 1,1,2-trifluorotrichloroethane (550 ml) was added over 30 min to a suspension of 4-(3-methyl-2-pyridyl)butylamine hydrobromide (14.2 g) [prepared by reacting 4-(3-methyl-2-pyridyl)butylamine with hydrobromic acid (0.89M)] in 1,1,2-trifluorotrichloroethane and to this mixture was added liquid bromine (5.56 g). The mixture was heated under reflux for ca 16 hr. The solvent was removed by distillation and unbrominated starting material was removed by acetylation as described in Example 1(b) to yield 4-(5-bromo-3-methyl-2-pyridyl)-butylamine (6.49 g) as an oil.

Source