MDC Calculating Percent Yield Before & After Recrystallization Report

Instructions:

THE VIDEO THAT YOU MUST SUMMARIZE IS THIS ONE :

https://youtu.be/_sO6at1VcCs

Compounds Amounts

anthracene 0.520 g

maleic anhydride 0.320 g

crude Diels Alder product 0.623 g

recrystallized Diels Alder product 0.550 g

Experimental melting point of recrystallized product 266 – 268 Celsius

Xylenes (solvent) 35 mL

Post-Laboratory Questions

1. Calculate the percent yield for your product, before and after recrystallization.

2. Calculate the percent recovery from the recrystallization.

3. The product of this reaction can be hydrolyzed by water. Show the product of hydrolysis.

4. Recrystallizing an anhydride (such as the product of this reaction) from water or from an alcohol is rarely a good idea. Explain why.

5. (a) Compare the carbonyl region of your IR spectrum with that of maleic anhydride. What are the similarities? What are the differences? (b) Does your IR spectrum allow you to confirm that the structure of the product is a combination of the two reactants? Briefly explain.

USE APA EDITION 7 FORMAT

YOU MUST WRITE ON YOUR OWN, USE THE HANDOUT PAPER AND THE VIDEOS AS A REFERENCE TOO. DO NOT ADD CITATIONS OR QUOTATIONS PLEASETHIS VIDEOS BELOW ARE ADDITIONAL INFORMATION:

https://youtu.be/z9KGlRNgnbE

https://youtu.be/sfWmd5fAo5w

https://youtu.be/HdvrTQpzfjc

https://youtu.be/_sO6at1VcCs 12
modular
publisher:
. laboratory.
program
SYNT
in
chemistry
717
organic editor: Joe Jeffers
H.A. Neidig
The Diels-Alder Reaction
of Anthracene with
Maleic Anhydride
prepared by L. G. Wade, Jr., Whitman College
PURPOSE OF THE
EXPERIMENT
Use the Diels-Alder reaction to form a bridged polycyclic anhydride.
Recrystallize the product and characterize it by using melting point and
infrared spectroscopy.
BACKGROUND REQUIRED
You should be familiar with reflux techniques, vacuum filtration, recrystallization, melting point measurement, and infrared spectroscopy.
EXPERIMENTAL OPTIONS
Semi-Microscale Diels-Alder Reaction
Microscale Diels-Alder Reaction
BACKGROUND
INFORMATION
Otto Diels, Professor of Chemistry at the University of Kiel, Germany,
and his student Kurt Alder published a paper in 1928 on additions of
electron-poor alkenes and alkynes to electron-rich dienes to form cyclohexenes and cyclohexadienes. These [4 + 2] cycloadditions came to be
known as Diels-Alder reactions. Diels and Alder received the 1950 Nobel Prize in chemistry for this work.
The Diels-Alder reaction is one of the most useful synthetic reactions in organic chemistry. In one step the reaction forms a sixmembered ring with one or two double bonds from an open-chain compound, as shown in Equations 1 and 2 on the next page. A diene is the
4-1t-electroncomponent. It is electron-rich, like a nucleophile in a Lewis
acid-base reaction. Simple dienes like 1,3-butadiene are sufficiently
electron-rich to react, but electron-releasing groups such as alkyl groups
(-R) or alkoxy groups (-OR) enhance a diene’s reactivity.
The 2-1t-electron component is called a dienophile (“lover of dienes”). Good dienophiles contain relatively electron-poor double bonds
or triple bonds; at least one strongly electron-withdrawing group (W) is
needed. Therefore, ethylene and acetylene are not good dienophiles.
Because the reaction is concerted-that is, bond breaking and bond
forming take place in the same step-the
stereochemistry of the
Copyright @ 1998 by Chemical Education Resources,
Inc., P.O. Box 357, 220 S. Railroad, Palmyra, Pennsylvania
17078
No part of this laboratory program may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Printed in the United
States of America
156
SYNT 717: The Diels-Alder ReaCtion of Anthracene with Maleic Anhydride
(
+
diene
(W
(Eq.l)
adduct
dienophile
(alkene)
W
I
(
+
diene
C
(Eq. 2)
III
C
I
H
dienophile
(alkyne)
adduct
reactants and the symmetry of their molecular orbitals control the
stereochemistry of the products. Using well-chosen reactants, a chemist
can control the stereochemistry of a Diels-Alder product at up to four
carbon atoms, as shown in Figure 1.
o
II
( (
~
+
~ COOCH3
-+-
I
a
H
C-OCH3
I
:
C-OCH3
II
o
= COOCH3
H
(cis, but not trans)
(trans, but not cis)
but not
(endo)
OCH3
(
CH30.
+
(exo)
H
(=N_ a~N
(cis
-1,2)
and not
(trans -1,2)
(1,3)
Figure 1 Stereochemical patterns of Diels-Alder reactions
In this experiment, maleic anhydride is used as the dienophile.
Maleic anhydride is an excellent dienophile because two strongly
electron-withdrawing groups are attached to the double bond.
The diene is anthracene, which is commonly thought of as an aromatic compound, and not as a diene. However, in polynuclear aromatic
compounds like anthracene, each individual ring may not be as well stabilized as an isolated benzene ring. Anthracene has only 141t electrons,
compared with 18 needed for three fully independent aromatic rings.
@ 1998 Chemical Education Resources
156
SYNT 717: The Diels-Alder ReaCtion of Anthracene with Maleic Anhydride
(
+
diene
(W
(Eq.1)
adduct
dienophile
(alkene)
W
I
(
C
+
diene
(Eq. 2)
III
C
I
H
dienophile
(alkyne)
adduct
reactants and the symmetry of their molecular orbitals control the
stereochemistry of the products. Using well-chosen reactants, a chemist
can control the stereochemistry of a Diels-Alder product at up to four
carbon atoms, as shown in Figure 1.
o
II
( (
~
+
~ COOCH3
-+-
I
a
H
C-OCH3
I
:
C-OCH3
II
o
= COOCH3
H
(cis, but not trans)
(trans, but not cis)
but not
(endo)
OCH3
(
CH30.
(exo)
H
CH3~H
+
(=N_ 6