PREPARTION OF DI-BENZYLIDINE ACETONE FROM BENZALDEHYDE
AIM:
Prepare Di-Benzylidine acetone from benzaldehyde by condensation process.
PRINCIPLE:
When an ethanoic solution containing acetone and two equivalents of benzaldehyde is
made alkaline with sodium hydroxide rapid condensation occurs with a formation of Di-
Benzylacetone or Di-Benzylidine acetone.This is the example of CLAISEN-SCHMDTH
reaction.
Claisen explains that aldehyde under the influence of NaOH condenses with another
alkaline or acetone with the elimination of water.In this preparation two moles of
benzaldehyde condensed with one mole of acetone to give Di-Benzylidine acetone.
CHEMICALS REQUIRED:
Benzaldehyde = 2.6ml
Acetone = 1.0 ml
3M NaOH = 20.0 ml
Ethanol =15.0 ml
PROCEDURE:
Measure out 20.0 ml of 3M NaOH and 15.0ml of ethanol into a clean conical
flask.Separately prepare a mixture of 2.6ml Benzaldehyde and 1ml of acetone in a testube
and add one half of benzaldehydeinto the clean reflux the solution on water bath for 15
minutes and add the remaining solution to the same conical flask and continue to reflux for
another 30 minutes. The solid mass of Di – benzylidine is formed.
Filter the solid,wash to eliminate alkaline products,dry,weigh and calculate the percentage
yield is produced.
, CALCULATIONS:
MOLECULAR WEIGHT OF BENZALDEHYDE
C = 7 x 12 = 84
H=6x 1 = 6
O = 1 x 16 =16
=106
MOLECULAR WEIGHT OF DI-BENYLIDINE ACETONE
C = 17 x 12 =204
H = 14 x 1= 14
O = 1 x 16 = 16
=234
THEORTICAL = MOL WT OF THE PRODUCT X WEIGHT OF
YIELD MOL WT OF THE REACTANT REACTANT TAKEN
=------g
PRACTICAL YIELD =------g
PERCENTAGE YIELD = PRACTICAL YIELD X 100
THEORITCAL YIELD
=--------%
AIM:
Prepare Di-Benzylidine acetone from benzaldehyde by condensation process.
PRINCIPLE:
When an ethanoic solution containing acetone and two equivalents of benzaldehyde is
made alkaline with sodium hydroxide rapid condensation occurs with a formation of Di-
Benzylacetone or Di-Benzylidine acetone.This is the example of CLAISEN-SCHMDTH
reaction.
Claisen explains that aldehyde under the influence of NaOH condenses with another
alkaline or acetone with the elimination of water.In this preparation two moles of
benzaldehyde condensed with one mole of acetone to give Di-Benzylidine acetone.
CHEMICALS REQUIRED:
Benzaldehyde = 2.6ml
Acetone = 1.0 ml
3M NaOH = 20.0 ml
Ethanol =15.0 ml
PROCEDURE:
Measure out 20.0 ml of 3M NaOH and 15.0ml of ethanol into a clean conical
flask.Separately prepare a mixture of 2.6ml Benzaldehyde and 1ml of acetone in a testube
and add one half of benzaldehydeinto the clean reflux the solution on water bath for 15
minutes and add the remaining solution to the same conical flask and continue to reflux for
another 30 minutes. The solid mass of Di – benzylidine is formed.
Filter the solid,wash to eliminate alkaline products,dry,weigh and calculate the percentage
yield is produced.
, CALCULATIONS:
MOLECULAR WEIGHT OF BENZALDEHYDE
C = 7 x 12 = 84
H=6x 1 = 6
O = 1 x 16 =16
=106
MOLECULAR WEIGHT OF DI-BENYLIDINE ACETONE
C = 17 x 12 =204
H = 14 x 1= 14
O = 1 x 16 = 16
=234
THEORTICAL = MOL WT OF THE PRODUCT X WEIGHT OF
YIELD MOL WT OF THE REACTANT REACTANT TAKEN
=------g
PRACTICAL YIELD =------g
PERCENTAGE YIELD = PRACTICAL YIELD X 100
THEORITCAL YIELD
=--------%
