Acetanilide is the acetyl derivative of aniline. It is widely used in industry for the preparation of a number of important organic compounds. It is usually prepared by acetylation of aniline with acetic anhydride and glacial acetic acid. The reaction involved is

How To Perform Experiment

Preparation of acetanilide

(i) Take a 100 ml clean and dry R.B. flask and pour 5 ml of aniline into it followed by 5 ml of acetic anhydride and 5 ml of glacial acetic acid. Also add about 0.1 g of zinc dust and a few boiling chips.

(ii) Attach a reflux condenser to the flask and heat the reaction mixture gently on a sand bath for about 30 minutes.

(iii) Remove the flask and pour the hot liquid in a thin stream into 125 ml of cold water with continuous stirring.

(iv) Cool the flask in ice and filter the crude acetanilide at the suction pump using a Buchner funnel.

(v) Wash the crude solid with little cold water and dry upon filter paper in the air.

Crystallization

Place the crude acetanilide in a 250 ml beaker and add gradually 100-125 ml of boiling water. Add 2-3 ml of alcohol to help the dissolution of acetanilide. Heat the contents of the beaker to boiling to get a clear solution. Now keep the beaker undisturbed for slow cooling. White crystals of acetanilide will soon separate out. Filter off the crystals at the pump, wash with little cold water and dry.