ALDOL

CONDENSATION
EXPERIMENT
Name- Sonam Amarghade
Roll No-7269
Organic Chemistry
  Condensation between two molecule of an
aldehyde or ketone to form a beta-
hydroxyaldehyde Or beta-hydroxyketone is
Aldol known as ALDOL CONDENSATION.
condensation  Aldol condensation is possible only when
reaction. the carbonyl compound contains at least
one alpha-hydrogen group.
Mechanism of
aldol
condensation:
 TO CARRY OUT THE SOLVENT FREE
ALDOL CONDENSATION BETWEEN
AIM: 3,4-DIMETHOXYBENZALDEHYDE AND
I-INDANONE.
 The reaction is carried out in absolute ethanol
powdered reactants and dissolved in absolute
ethanol and powdered NaOH is added.
THEORY: The reaction mixture is stirred overnight. During
Conventional that time products separates from the reaction
method of mixture.
preparation. 1 ml aq. HCl is added to the slurry, this reaction
leads of the formation of precipitate.
The precipitate is faltered off and it is
recrystallised in appropriate solvent.
 Some solvent free aldol condensation
relationship between acetophenone derivatives
and benzaldehydes are known.
Green method In many reactions, one of the reagent in a liquid
of preparation. at room temperature, and in all the cases
aldehyde without alpha-hydrogen are used to
ensure single aldol condensation process is
possible.
 1. In the reaction between 3,4-
dimethoxybenzaldehyde and I-Indanone, a
single condensation product is expected as
the aldehyde bears no alpha-hydrogen and
Advantages of can’t act as a carbon nucleophille.
Green method: 2. Both reactants are solid at room
temperature. This is done simply by grinding
the solid reagent together with solid NaOH.
3. A remarkable high degree of conversion and
a single product is obtained.
REACTION
INVOLVED:
MECHANISM:
 1. 0.25 g of 3,4-dimethoxybenzaldehyde was
taken and grind into a mortor and pastle. It
was then transferred into a china dish.
2. 0.2g of I-Indanone was grinded and
transferred into the same china dish.
3. They were mixed together and crushed with
PROCEDURE: a glass rod till it become a yellowish-brown
liquid.
4. 0.05g of finally grinded solid NaOH was
added to it. The reaction mixture was
scraped till it become solid. It was kept like
this for 15 min.
5. 2 ml of 10% aq. HCl was added to the reaction
mixture. This HCl was added to nutralise excess
of NaOH.
6. It was made sure that the solution was acidic
by checking it with litmus paper.
7.The product was washed with water. It was
dried, weighed, recrystallised with 90% ethanol
and it’s melting point was determined.
  Experimental yeild of the crystal=____g
 Colour of the crystal- pale yellow.
RESULT:  Literature melting point of the crystal- 183-
185°C.
  SAFETY PRECAUTIONS: Avoid contact with the NaOH as it is caustic.
 Wear gloves when doing this experiment.
 Take a small sample of 3,4-dimethoxybenzaldehyde and a small sample of 1-
indanone and determine their melting points.
 Using weighing paper, weigh 0.25 g of 3,4-dimethoxybenzaldehyde and 0.20 g of
1-indanone and place them in a small beaker.
 Crush and scrape the two solids together with a metal spatula until they become a
darkly colored oil. Be patient, as the mixing will take some time. Note that
pressing harder will not speed the process, but may break the beaker.
Precautions:  Once the oil has formed add 0.05 g of finely ground solid NaOH (prepared using a
mortar and pestle). Continue mixing and scraping until the mixture becomes solid.
Let the mixture stand for 15 minutes to allow the reaction to come to a stop.
 Add about 2 mL of 10% aqueous HCl solution. Scrape the beaker thoroughly to
make sure that all the solid is mixed with the solution.
 Check the pH of the solution by dipping your spatula in the solution and then
touching it to the pH paper. Confirm that the solution is acidic, if not add more
acid and mix again.
THANK
YOU.