Preparation of Tribromoaniline

Tribromo aniline can be prepared by dissolving anilineĀ  in glacial acetic acid and then treating it with bromine dissolved in glacial acetic acid in the cold.

C6H5NH2 + 3Br2 => C6H2(Br)3NH2 (2,4,6-tribromoaniline)+ 3HBr

About 2 ml of aniline is dissolved in 5 mL of glacial acetic acid taken in an Erlenmeyer flask. The solution of bromine in glacial acetic acid is added in drops from a burette with constant stirring. Use a teflon coated magnetic stirrer for the purpose. The stirring should be continued until you get a pale yellow liquid.The mixture is then added to 75 mL of water. The crystallized 2,4,6-tribromoaniline is washed with cold water, dried and yield noted.About 1 gram of the sample can be recrystallized from dilute ethanol and melting point can be determined.

The approximate yield expected in this experiment is 3.0 grams and the melting point of the compound is 119oC.