Preparation of Maleimide
11
PREPARATION OF MALEIMIDE Lecture by: Dotsha J. Raheem Assistant Lecturer Department of Chemistry College of Science University of Salahadin 2010
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Preparation of Maleimide, preparation of imide from amic acid
Transcript of Preparation of Maleimide
PREPARATION OF MALEIMIDE
Lecture by: Dotsha J. RaheemAssistant Lecturer
Department of ChemistryCollege of Science
University of Salahadin 2010
1. Amic acid
O
O
O + NH2
aniline
O
O
NH
OH
N-phenylmaleamic acid
maleic anhydride
O
O
N
N-phenylmaleimide
Dehydeation
- H2O
2. Imide
O
O
NH
OH
N-phenylmaleamic acid
*O
ClH3C
acetyl chloride
*CH3
O
H3C
O
O
acetic anhydride
,H3C
O
O-Na+
sodium acetate
Or:
- H2ODehydeation
O
O
N
N-phenylmaleimide
An Imide is a compound of the general formula
(a nitrogen atom bonded to two carbonyl groups), Where R= alkyl, aryl or hydrogen. An Imide may be saturated or unsatd., open chain or cyclic.
Definition
R C
O
N
R
C
O
R
Mechanism of the Reaction
1. Formation of Na-salt of Amic acid
O
O
NH
OH
N-phenylmaleamic acid
+ H3C
O
O- Na+
sodium acetate
O
O
NH
O-Na+
+ H3C
O
OH
Mechanism of the Reaction
2. Nucleophilic Attack
O
O
HN
O
Na
+
H3C C
O
O
C
OH3C
ph
O
O
HN
O
ph
C
O
O
CH3
C
O
CH3
O
O
HN
O
ph
C
O
CH3+ H3C
O
O Na
Na
Mechanism of the Reaction
3. Cyclization
C
O
O
N
O
ph
C
O
CH3C
H
C
O
O
N
O
ph
C
O
CH3
C
HC
O
O
N
ph
C
+H3C
O
OH
N-phenylmaleimide
Uses of Imides:
N-bromosuccinimide is a good brominating agent
1.
O
O
NH
succinimide
Br2
O
O
N Br
N-bromosuccinimideNBS
2. Utilized in the preparation of pesticides and herbicides, to control diseases on fruits and vegetables.
Uses of Imides:
Used to give a fresh and bright look to many fruits.
3.
4. In the preparation of polyimides (a polymer with a high chemical and thermal stability used instead of glass and metal).
Uses of Imides:
A mixture of substituted succinamic acid-succinimide is used in transmission fluids composition.
5.
Procedure:
In a round bottomed flask, place 0.3g of sodium acetate, 1.0ml of acetic anhydride, 5.0ml of acetic acid and 1.0g of amic acid.
Reflux the mixture for 40 minutes. Pour the mixture into a beaker
containing 25g of ice with stirring Filter the formed precipitate, dry and
calculate the percent of yield.
