Method of Preparation of Amines.ppt

Method of preparation of amines are discussed.

1. AMINES: Method of
Preparation
By
Dr. Nidhi Gupta
M.M. College of Pharmacy
Mullana, Ambala, India

2. Amines
(organic ammonia) :NH
3
:NH
2Ror RNH
2 1
o
amine (R may be Ar)
:NHR
2or R
2NH 2
o
amine
:NR
3or R
3N 3
o
amine
NR
4
+
4
o
ammonium salt

3. NB amines are classified by the class of the nitrogen, primary
amines have one carbon bonded to N, secondary amines have
two carbons attached directly to the N, etc.
Nomenclature.
Common aliphatic amines are named as “alkylamines”CH
3NH
2
methylamine
1
o
(CH
3)
2NH
dimethylamine
2
o
(CH
3)
3N
trimethylamine
3
o
CH
3CH
2NHCH
3
ethylmethylamine
2
o
CH
3CH
2CHCH
3
NH
2
sec-butylamine
1
o
CH
3CCH
3
CH
3
NH
2
tert-butylamine
1
o

4. NH
2
cyclohexylamine
1
o
Complex amines are named by prefixing
"amino"-" ( or N-methylamino, N,N-dimethyl
amino-, etc.) to the parent chain:
CH
3CH
2CHCH
2CH
2CH
3
NH
2
3-aminohexane
CH
3NHCH
2CH
2OH
2-(N-methylamino)ethanol
CH
2NH
2
benzylamine

5. NH
2 NH
2
NH
2
NH
2
CH
3
CH
3
CH
3
aniline o-toluidine m-toluidine
p-toluidine
N
CH
3H
3C
N,N-dimethylaniline
H
N
diphenylamine

6. Salts of amines: change amine ammonium + anion
change aniline anilinium + anion
CH
3CH
2CH
2NH
3
+
Cl
-
n-propylammonium chloride
(C
6H
5NH
3)
2SO
4
anilinium sulfate

7. Amines, physical properties:
Nitrogen is sp
3
hybridized, amines are polar
and can hydrogen bond.
mp/bp are relatively high for covalent substances
amines are basic and will turn litmus blue
insoluble in water (except for four-carbons or less)
soluble in 5% HCl
“fishy” smell N

8. 1. Ammonolysis of 1
o
or methyl halides.R-X
NH
3 RNH
2
R-X
R
2NH
R-X
R
3N
R-X
R
4N
+
X
-
1
o 2
o 3
o
4
o
salt
R-X must be 1
o
or CH
3
CH
3CH
2CH
2CH
2Br
NH
3
CH
3CH
2CH
2CH
2NH
2
n-butylamine
Method of preparation of amines