Synthesis of benzil From benzoin

1. BABA FARID COLLEGE OF PHARMACY
(Department of Pharmaceutical Chemistry)
Synthesis of benzil From benzoin
Requirements :-
Chemicals - Benzoin , Conc. nitric acid, Methylated or rectified spirit, Ice cold water
Apparatus - Round Bottom Flask (RBF), Beaker, Glass rod, Measuring cylinder, Funnel, Filter paper
Weighing scale, Condenser
1. Place 10 gm of powdered benzoin
and 25 ml of conc. nitric acid in a
150 ml RBF & mixed properly by
using glass rod.
4. Then pour the mixture into a
beaker of cold water, when on
vigorous stirring the oil will
crystallize into a yellow solid
2. Now fitted the RBF with the
reflux condenser & heat the flask on
a boiling water bath for 1.5 hour.
After 15 minutes of heating nitrous
fumes evolves from the reaction.
Which is very toxic to inhale.
3. After 1.5 hours turn off the water
bath & wait for 5-10 minutes to
settle down the nitrous fume
Prepared By:- Mr. Pankaj Kumar Maurya (Asst. Prof.)
5. Product is filtered & washed with
cold water to ensure complete
elimination of acid. Recrystallized
the product with methylated or
rectified spirit
6. Benzil separates as clear yellow
crystals & Calculate Percentage
yield.