Name of the Experiment: PREPARATION OF ACETANILIDE FROM ANILINE
Chemicals required:
1. Aniline(freshly distilled) = 5 mL.
2. Glacial acetic acid = 7 mL
3. Acetic anhydride = 5mL.
Theory: Acetanilide is prepared when aniline is refluxed with a mixture of acetic acid and acetic anhydride.
Procedure: Take 5 mL of aniline in a dry round-bottomed flask and then add 7 mL acetic acid and 5 mL acetic anhydride. Introduce one or two pieces of porcelain and fit the flask with an air-condenser. Heat the mixture on the wire gauge so that the liquid gently boils under reflux. Adjust the heating in such a way such that no vapour of the liqiud escapes through the air-condenser. Continue heating for about 30-45 minutes. Stop the heating and test for completion of the reaction by adding 2-3 drops of reaction mixture in a test tube full of water. If the reaction mixture solidifies then the reaction is complete, otherwise continue heating until the reaction is complete. Now take about 100-150 mL of water in a beaker and at once pour the hot mixture into this beaker with constant stirring with a glass rod. It is then filtered through Buchner funnel under suction. Wash with cold water.
The crude product is purified by recrystallizations. Dissolve the crude product in a minimum volume of boiling water. If the solution is dark coloured, add a pinch of bone charcoal to the solution and continue boiling for a few minutes. Filter the hot solution through Buchner funnel under suction. Allow the filtrate to cool to room temperature and then filter through Buchner funnel under suction and then wash with a little cold water. Dry the crystals by pressing between the folds of a blotting paper. Acetanilide will be obtained as white shining flakes. The yield is about 5 g and m.p. is 113° C.
Chemicals required:
1. Aniline(freshly distilled) = 5 mL.
2. Glacial acetic acid = 7 mL
3. Acetic anhydride = 5mL.
Theory: Acetanilide is prepared when aniline is refluxed with a mixture of acetic acid and acetic anhydride.
Procedure: Take 5 mL of aniline in a dry round-bottomed flask and then add 7 mL acetic acid and 5 mL acetic anhydride. Introduce one or two pieces of porcelain and fit the flask with an air-condenser. Heat the mixture on the wire gauge so that the liquid gently boils under reflux. Adjust the heating in such a way such that no vapour of the liqiud escapes through the air-condenser. Continue heating for about 30-45 minutes. Stop the heating and test for completion of the reaction by adding 2-3 drops of reaction mixture in a test tube full of water. If the reaction mixture solidifies then the reaction is complete, otherwise continue heating until the reaction is complete. Now take about 100-150 mL of water in a beaker and at once pour the hot mixture into this beaker with constant stirring with a glass rod. It is then filtered through Buchner funnel under suction. Wash with cold water.
The crude product is purified by recrystallizations. Dissolve the crude product in a minimum volume of boiling water. If the solution is dark coloured, add a pinch of bone charcoal to the solution and continue boiling for a few minutes. Filter the hot solution through Buchner funnel under suction. Allow the filtrate to cool to room temperature and then filter through Buchner funnel under suction and then wash with a little cold water. Dry the crystals by pressing between the folds of a blotting paper. Acetanilide will be obtained as white shining flakes. The yield is about 5 g and m.p. is 113° C.
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