The Diels-Alder Reaction of Anthracene with ... - Franklin College

SYNT 717: The Diels-Alder Reaction of Anthracene with Maleic
Anhydride
Linsey J. Page
February 19 th – February 21 st , 2002
Organic Chemistry Laboratory II
Abstract:
This experiment allows one to perform a diels-alder reaction using anthracene and
maleic anhydride. We also see different ways to determine the purity of products gained
from a diels-alder reaction. The melting point process allows us to compare the boiling
points of our product with the melting point of another molecule to determine how
closely it relates to it. For example my recrystallization showed that my product was a
pure 9,10-dihydroanthracene-9,10-A,B-succinic acid. The DRIFT infrared spectroscopy
allowed us to look at a spectrum for 9,10-dihydroanthracene-9,10,-A,B-siccinic acid and
compare the peaks with our own products.

SYNT 717: The Diels-Alder Reaction of Anthracene with Maleic Anhydride
Introduction:
During this experiment students used the Diels-Alder reactions of Anthracene and
Maleic Anhydride to form a bridge polycyclic anhydride. The product gained from this
reaction was then recrystallized. Afterwards, it was characterized by taking the melting
points and an Infrared Spectroscopy using the DRIFT method.
Materials Used
• 150-ml beaker
• boiling chip
• 2 Erlenmeyer flasks, 10-ml
• 25-ml filter flask with vacuum
tubing
• filter paper
• Hirsch Funnel
• 2 melting point capillary tubes
• microspatula
• 1-ml pipets
• sand bath
• support stand
• thermometer
• 13 x 100-mm test tube
Reagents and Products Properties:
Substance Quantity used Molar mass Melting Point
(g/mol)
( o Boiling Point
C)
( o Density
C)
anthracene
9,10dihydroanthrac
106 mg 178.23 216-218 340 ----ene-9,10,A,B,succinic
anhydride
----- 276.29 262-264 ----- -----
Maleic
anhydride
58-mg 98.06 54-56 200 1310 kg/m 3
Potassium
bromide
100 mg 119.1 730 ----- 2.753 g/cc
xylene 6-ml 106.17 13.4 - -47* 137-144 -----
* The melting points differ between para, meta, and ortho configuration. (13.4-para, -25-ortho, -47-meta)

Procedure:
Place a 10x100-mm reaction tube into a small flask. Place them both onto a scale
and tare them. Weigh out approximately 100-g of anthracene and approximately 55-g of
maleic acid. Place both into the 10x100-mm reaction tube. Then add 1.0-ml of xylene to
the reaction tube along with the anthracene and maleic acid. Place a boiling chip into the
solution. Place the reaction tube onto a support stand and wrap a cold kim wipe around
the top of the tube. Place it into a heat bath that is around 200 o C and reflux the solution
for 30 minutes.
After 30 minutes, remove the solution from the heat and allow it to cool to room
temperature. Then place it into an ice bath for five minutes. While your original solution
is in the ice bath, measure out 2-ml of xylene into another tube and place it in the ice
bath. While these tubes are in an ice bath, set up a filtration apparatus. Place a Hirsch
funnel into a 25-ml filter flask and add a vacuum tube that runs from the flask to the
vacuum. Once the original solution has been in the ice bath for five minutes run it
through this filtration apparatus. Rinse it with 1-ml of xylene and allow them to dry.
Weigh the crystals collected and set aside a portion for melting point analysis later.
Place the crystals from part one and place it into a 10-ml flask. Add 1-2-ml of
xylene to the crystals. Heat this solution in the flask, and allow it to boil. Once it has
boiled for a while remove it from the heat, allow it to cool, and place it into an ice bath.
Collect the new crystals by the same vacuum filtration method mentioned above. Rinse
the crystals with 1-ml of xylene. Allow the crystals to dry, overnight if possible.
Take the crystals that were formed in the first part of the experiment and the
recrystallized crystals from the second part of the experiment and place a small amount of
them into two separate melting point capillary tubes. Place the tubes into the melting

For this experiment I used 106-mg of anthracene and 58-mg of maleic anhydride.
The theoretical yields for each of these only differed slightly. Anthracene was .1643g
and the maleic acid was .1634g. Maleic acid is the limiting reagent in this experiment.
In the first crystallization I recovered .128g with a melting point of 259-262 o C. This
boiling point showed that there are slight impurities in the final product. The percent
yield is 78.34%.
For the recrystallization, I recovered .106g of product. The percent yield for this
was 64.87%. It had a boiling point of 260-263 o C. This is very similar to the melting
point of 9,10-dihydroanthracene-9,10-A,B-succinic acid which is 262-264 o C. This
showed that my final product was very pure. The loss in percent yield was because we
had to remove part of the product in the first part of the experiment. A small amount was
saved from the first crystallization in order to do a melting point on it. Overall, I had a
fairly good percent yield knowing that I lost some of it to the removal from the first
crystallization. The only other things that might have effected the percent yield was loss
of solution to the environment during reflux.
Reference:
Wade, L.G., Jr. SYNT 717: The Diels-Alder Reaction of Anthracene with Maleic
Anhydride 33-43