AZIRINE
One of the simplest heterocyclic compound or azacyclo propene. It could
have structure 1 or II
H
1
1
N
N
2
3
2
3
1-Azirine
2-Azirine
Azirine found natmaly as a part of some compound such as III and IV
Which are used as an antibiotic and could be synthesis.
N H
COOH
Me
H
Azirinomycin
H
COOMe
Disidiaziridine
Which are used as an antibiotic and could be synthesis.
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Reactions:1.
Methanol reacted by addition with 1- azririne to give 2- Methoxy azirine in
presence of sodmethoxide as a catalyst.
H
- +
Me-OH
2.
N
+
R
OMe
R
R
N
R
3,3 – dimethyl -2- phynyl -1- azirine react with sulphonic acid.
N
Ph
H
O3SH
Me
+
Me
H3C
Ph N
O4SH4C6Me
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Me
Me
2
3.
Reaction with acetic acid and acetic anhydride.
AC
AC2O
N
R
Me
N Me
R-CH-CO-Me
ACOH
R
4.
NHAC
OAC
n
Reaction with Grignard reagent.
H
N
Ph
Ph
+
Et
EtMgBr
Ph
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N
H
Ph
3
Synthesis:1.From thermal analysis of Ethanyl azide which can be prepared from
alkenes.
R-CH=CH2
Br2
R-CH-CH2-Br
NaN3
Br
- +
N-N=N
R-CH-CH2-Br
: N:
N
NoOH
-HBr
R-C=CH2
-N2
R-C-=CH2
R
N3
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Oxirane
Oxirane or ethylene oxide (1) it was first obtain by wartz in 1859. in 1931 P
taent was taken out on direct oxidation of ethylene to okirane by oxygen.
Oxiranes found naturally in a plant, animal and insect. Orapetene (2) was
oxirane separated from natural source. In general orxirane ring found as a part
of structure of many compound specially prostalandine.
O
MeO
O
O
Some oxirane drevative use as an antibiotic and its effective in treatment of
malignant toummer.
- It is colourless liquide misible with water
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Chemical properties:1. When oxirane heated its rearranged to aldehyde.
O
O
CH3-C
H
2. Ring opening:The most important reaction of oxirane is the ring opening became
its very important in organic synthesis.
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3. Nucleophillic reagent:It react with oxirane such as ammonia to give mono ethanolamine in
excess of oxirane it give diethanol amine and triethanol amine.
a-
..
NH3
+
NH3-CH2-CH2-O
O
+
NH2-CH2-CH2-OH
ethanolamine
O
O
NH(CH2 CH2OH)2
N(CH2 CH2OH)3
triethano lamine
b - With Grignard reagent it give alcohol
CH3 CH2 MgBr
:
+
O
CH3 CH2 CH2 CH2OMgBr
+
H
CH3 CH2 CH2 CH2OH
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c – with halogen in presence of ph3p or lix give B- halo alcohol
Ph3 P
I
+
+
O
I2
+
Ph3 PI
ICH2 CH2O
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+
I
H2O
ICH2 CH2OH
8
1.Reduction
Oxirane reduce to alcohol
O
O
H2 / Pd
Sod,borohyd
give mix true
R
CH2 CH2OH
RCH2CH2OH
OH
‫يراجع الترتيب‬
+
RCH-CH3
OH
LiALH4
CH3-CH
Sec-alcohol
O
H3C
CH3
LiALH4
ALCL3
H2 / Ni
pri-alcohol
CH2-CH2-CH3
OH
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2. Electrophillic reactions:H
R
O
+
H
R2
R
R2
O
or
R3
R1
R3
R1
OH
+
RR1-C-CR2 R3
RR1-C-CR2 R3
OH
OH
O
Hcl
CH3-C-CH2-CL
H3 C
+
CH3-CH-CH2OH
major
CL
3. Polymarisation:+
H
O
OH
H
O
+
O
CH2-CH2 +
O
O
polymer
n
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Synthesis:1. From B- Halo alcohol by elimination of hydrogen halide by base
OH
O
O
+
CL
CL
CL
2. Darzen reaction:halo ester with carbonyl compound in presence of sod. Ethoxide.
CL-CH2-COOEt
+
CL-CH-COOEt
NaOEt
O
+
C
CH-COOEt
R1
CL
R1
R1
R2
EtOH
O
C-CH-COOEt
R2 CL
R2
O
+
+
CL
COOEt
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Thirane
It is known also as ethylene sulphide its highly strain ring less stable than
oxirane. Substituted thirane more stable than un-substituted one.
It is colourless liquid in sulible in water but dissolve in organic solvent, boil
at 55Co
Chemical reactions:1. it react with ammonia to give drevative of B- aminothiol
S
RNH2
RNH-CH2-CH2-SH
+
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2. Nucleophilic reagent always attack carbon atom but in thirane it
attack carbon atom but in thirane it attack the sulphur atom leading to
alkene formation.
Bu
S-
S
Me
Me
+
Li
BuLi
Me
Me
+
BuSLi
n
3. It react with sodium periodate to give thirane okide.
O
S
NaIO4
S
CH2=CH2
S=O
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4. Reduction
Me-CH(SH)CH3
S
LiALH4
Me
HCL
Me-CH(SH)CH2-CL
major
+
Me-CHCl-CH2SH
This became the proton added to sulphur and carbonium ion formed.
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Synthesis:
-1-
CH2
SH
CH2
OH
S
200 C
Na2CO3
-H2O
1. From chlorothiol cyclised by sod. Bicarbonate
CL
OH
HCL
SH
SH
n
SH
SH
2. From okirane when treated with pot. Thiocyanate.
O
NaNCS
O
O
C
S
SH
+
NCO
C
N
n
S
N
n
O CN
S
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Heterocyclic analogues of cyclobutane
Four membered ring are not highly strained as the corresponding
three-membered rings. But are more difficult to prepare by the direct
cyclisation of straight chain intermediate. The most important of four
membered ring are Azetidine, oxetane and thietane.
O
S
NH
Oxetanes:Synthesis
By cyclo addition of two double bond.
CH2
CH2
C
O
ZnCL2
10 C
O
O
O
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Reaction
They are susceptible to acid catalyzed ring-opening reaction (like
three membered ring analogues.
trace
O
+
C2H5OH
H2SO4
C2H5-O-CH2CH2CH2OH
It react with nucleophilic reagent but are less reactive than
the analogues three membered ring compounds.
O
+
- +
C6H5CH2SNa
H2O
100 / 6 hr
C6H5CH2SCH2CH2CH2OH
Sod.salt of benzylthioalcohol
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3-benzyl thiopropane
17
Azetidine
Synthesis:Similar to oxetanes preparation
O
Ph
C
C
Ph
CHPh
Ph
O
N
Ph
N
Ph
( Ph)3
C=C=O
(ph)-C=C-O
..
Ph-HC=N- Ph
PH-HC=N- Ph
+
Ph
Ph
O
N
Ph
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Thietanes
Syntesis:By ring closure similar to azetidine
CL-CH2-CH2-CH2-CL
+
Na2S
C2H5OH
S
1,3- dichloropropane
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