ORGANIC cHEMISTRY - II

Experiment 4

Aim of the Experiment

To prepare 2, 4, 6-tribromo aniline from aniline

Materials required

Chemicals:

Aniline- 4 ml

Bromine -6.4 ml

Dilute hydrochloric acid,

Rectified spirit

Apparatus: beaker, filtration set, glass rod, conical flask

Procedure

A solution is prepared by adding 8.4 ml of bromine in 20 ml glacial acetic acid. Another second solution is prepared adding 5 ml of aniline in 20 ml of glacial acetic acid in a conical flask. The first solution is added drop wise to the second solution from a dropping funnel. During addition, the flask is shaken time to time and cooled in ice. A yellow colored mass is obtained. It is poured into excess of water. The separated product is filtered, washed with water and recrystallised from rectified spirit. The yield is about 10 g (55.6 %)

Observation:

i) Amount of aniline taken = g.

ii) Amount of 2,4,6-tribromo aniline formed = g.

iii) Melting point of 2,4,6-tribromo aniline = ⁰C.

Calculation:

93g of aniline with 3 g of bromine yields 329.8 g of Tribromoaniline

i. e. 4 g of aniline yields 4 x329.8 / 93 g of Tribromoaniline

Thus,

Theoretical yield of Tribromoaniline = g

Experimental yield = g

^{%Yield =} x 100 %

Result & Conclusion

i) Yield of Tribromoaniline = %

ii) Melting point of Tribromoaniline = ⁰C. (Reported value = 120°C)

Reference Material:

Tribromoaniline

Questions:

Explain mechanism of the reaction.