PHENOLS
OH -
more
likely to undergo electrophilic substitution than
Acidity :
-
benzene as oxygen's lone pair can overlap with the OH 0
delocalised electron
density
+
r-ring ,
So
greater +
Hz0 + Hz0
Phenol
Stronger C-O bond than in aliphatic compounds
O-Nat
OH
Solubility : +
NaOH +
H20
Sparingly soluble in water part of the
-
as
Sodium Phenoxide
molecule can form H-bonds with water
-
Soluble in NaOH as it forms an ion dipole
-
Not acidic enough to react with NazCOz & NatCOz
Test to aliphatic acid & laq)
which is a
stronger force than
H-bonding distinguish between phenol :
add NazCOz
aliphatic acid will
give CO2 bubbles
, phenol will not .
Test for phenol : Ethano Pheno Ethanois acid
NaOH X V V
Will react with /yellow/orange) iron (111) chloride to produce purple
·
Naz(Oz X X V
colour ag Solution
in .
·
Reaction with bromine : Reaction w/ dilute HNOz :
70 %
30 %
Substitution only
OH OH in 2
,
4, 6 positions
OH OH OH
Br Br
-NOz
+
3Brz(aq) + 3 HBr + HNOz/dilute) 7 t
/no catalyst) I
Br NOz
Poly substitution doesn't be
Selectrophilic substitution occur
-
2 4 , 6-triobromopheno "
reduces the electron
NO,
density
,
-
Phenol decolourises bromine water & forms a white ppt .
With ethanoyl chloride:
(basic so
HCI)
OH
Forming
,
removes
esters :
(sHgN)
O O
Pyridine CHzC HCl
-
Alcohols & phenols can act as nucleophiles due to
oxygen's lone pair + CHzC Y
+
- H20
.
-
delocalised, it is harder& won't
However as
phenol's is
partially ethanoyl chloride
react with a
carboxylic acid .
(expensive)
Ethanoic anhydride :
(less reactive than
ethanoyl Chloride)
OH
CH3-cX0 (increases ROR)
O
Y (H2SOn) +
Reaction + > CHzC CHzCOOH
with acyl chloride:
CH3-C- O
Yo
OHX ethanoate
Phenyl
ethanoic
anhydride
t NaOH 10 + Hz0 + NaCl
Y
Cheaper & less dangerous
, 4. 6 Amines
t
Basicity :
R
Reactions with Nitric (III) acid
: FN (H-O-N O)
> H
·
N has a lone pair Nitric (IIIacid/nitrous acid is not
very stable .
=
NaNOz + HCl < HNOz +
NaCl
e .
.
g methylammonium ion -
diazonium ion is unstable
Aliphatic amines : at ANY temperature quickly decomposes
So : CHzNHz +H2O [CHzNHz]OH NHz
+
HNOz OH
+
Nz
↑
+ H, 0
/ pour yield ,
effervescence
usually mixture
Weak base
(equilibrium lies to LHS) (volume can used be
to find moles of amine)
·
methylaminefishy ammonia' smell Aromatic reactions : Diazotisation
stabilises
=
< 10 % #
More Basics Greater availability of lone pair NHz + HNOz + H(l(aq) N = NCI + 2H20
H H H benzenedizonium
↑
NH
↑ H
C i
-
Chloride
-
H - c - -
-
H 1
HH
I H
H H
-
Aromatic amines :
Nitrogen's lone pair is
partially delocalised
-
Stable intermediate because of delocalisation of
charge caused
electron
density p orbitals the NEN with the r-bond
onto 2-electron
ring ,
so on the
nitrogen decreases
, by in
group system
it less attracted
making to HI OH
= NCI +
H20
Warm
7 +
Nz + HC
-
Aliphatic amines :
alkyl groups a re electron
releasing ,
so donate
Y
effervescence
electrons to the lone pair This increases .
nitrogen's electron
density
> more
-
attractive to HT
Coupling : benzenediazonium compounds are v reactive
to make
ionic
↑
= NCI + OH
NaOH
L
v -
-
OH + NaCl + Hz0
form ammonium Salts with acids (4-phenylazo) phenol
e CHgNHz + HCl >
-
CcHgNHz'Cl (yellowppt)
.
.
g
CHy
+
-
Nz + ~ 7
in -
(Hz
H20
CHz - +
Ethanoylation of Amines
Primary
CHz
·
(rea)
lone pair o n enables amines to act OH
nitrogen nucleophiles
·
as
Y
5
t = NCI- NaOH
, = H
Acyl Chloride
I sto ethanoylation O
O C C - c
HC)
- -
+
-
-
-
12 Sultan 1
+ NaCl + Hz0
-C
RC I N -
CHz ↳ steamy fumes
C H Cred solid used
/H N-methylethanamide
to colour curry)
peptide linkage
OH
·
If amine added , Salt To form diazonium ion benzene has to
excess
ring
-
Iv
ammonium a
,
H
be activated -
has to have an electron
withdrawing
N-
c
-C (e g OH)
c CH3 group NHz
-
. .
-
or -
>
NHz +
"
-
-
I
N-phenlethanamine
, in
NENCI + NHz 7 ·
-
NHz + HG)
·
fN N-) = Azo bridge links 2 aromatic
rings to
give extended delocalized system
Chromophore :
group of atoms in a compound responsible for its colour
#
With the -N
N-System , electrons be excited to
higher energy levels
·
pi p
=
can :
44
. . Aldehydes & Ketones Reductio n.
.
Use NaBHG
Distinguishing between an aldehyde & Ketone: based on the fast that
aldehyde can be further oxidised
·
Tollen's reagent : ·
Fehling's reagent :
-
CNaOH +
2AgNOz-AgzO(s) +
NaNOz +
H20 -
Fehling's A & B solution a re mixed,
forming a deep blue
Agz0(s) +
NHz(aq) until it dissolves (Agt solution containing a complex copper (11) ion
-
Carbonyl heated w/ solution
-
When heated with aldehyde ,
blue Cutions are reduced to
Aldehyde : Silver mir ror coats inside of tube (Ag- Ag(s) Cut forming
,
an
orange-red precipitate of Cu > O (s)
Ketone won't : reduce Tollen's reagent
-
Doesn't react w/ aromatic aldehydes
F
·
yAldehyde :
* Aldehyde :
* Cred brown)
Ag (aq)
+
Cut complex CuzO(s)
Nucleophilic Addition :
·
2 , 4-dinitrophenylhydrazine (2 4-DNPH) ,
-
dissolved in an acid to
form 'Brady's reagent'
* Ri
R -
H
, 1 o o
C= O HEN 7 C + = N :
- With aldehyde o r Ketone solid
1
REN orange-red
-
y gives an
Rz C= :
Rz :
CENT hydroxynitrile This is purified & melting temp used .
to
identify original
·
Important reaction as increases carbon chain molecule
-
Nucleophilic addition elimination /Condensation reaction
Hydrolysis of hydroxynitrile
P
Riy
R2 CN
C
OH Dilute
Reflux
e .
g .
H2SO4
>
Ric
R
C
, COOH
-
OH
·
Triiodomethane (iodoform)
-
test for methyl Ketones
reaction
& their precursors
: R2-C-CH3
R
or
Rache
hydroxynitrile hydroxy acid
-
Heat :
Organic compound +
Iz/NaOH
↑
or + IYOCI
alkaline iodine (clourless)
&
-
Result :
+ve when CHI , yellow ppt forms .
-
wo
CHIz(s)
liodoform)
OH -
more
likely to undergo electrophilic substitution than
Acidity :
-
benzene as oxygen's lone pair can overlap with the OH 0
delocalised electron
density
+
r-ring ,
So
greater +
Hz0 + Hz0
Phenol
Stronger C-O bond than in aliphatic compounds
O-Nat
OH
Solubility : +
NaOH +
H20
Sparingly soluble in water part of the
-
as
Sodium Phenoxide
molecule can form H-bonds with water
-
Soluble in NaOH as it forms an ion dipole
-
Not acidic enough to react with NazCOz & NatCOz
Test to aliphatic acid & laq)
which is a
stronger force than
H-bonding distinguish between phenol :
add NazCOz
aliphatic acid will
give CO2 bubbles
, phenol will not .
Test for phenol : Ethano Pheno Ethanois acid
NaOH X V V
Will react with /yellow/orange) iron (111) chloride to produce purple
·
Naz(Oz X X V
colour ag Solution
in .
·
Reaction with bromine : Reaction w/ dilute HNOz :
70 %
30 %
Substitution only
OH OH in 2
,
4, 6 positions
OH OH OH
Br Br
-NOz
+
3Brz(aq) + 3 HBr + HNOz/dilute) 7 t
/no catalyst) I
Br NOz
Poly substitution doesn't be
Selectrophilic substitution occur
-
2 4 , 6-triobromopheno "
reduces the electron
NO,
density
,
-
Phenol decolourises bromine water & forms a white ppt .
With ethanoyl chloride:
(basic so
HCI)
OH
Forming
,
removes
esters :
(sHgN)
O O
Pyridine CHzC HCl
-
Alcohols & phenols can act as nucleophiles due to
oxygen's lone pair + CHzC Y
+
- H20
.
-
delocalised, it is harder& won't
However as
phenol's is
partially ethanoyl chloride
react with a
carboxylic acid .
(expensive)
Ethanoic anhydride :
(less reactive than
ethanoyl Chloride)
OH
CH3-cX0 (increases ROR)
O
Y (H2SOn) +
Reaction + > CHzC CHzCOOH
with acyl chloride:
CH3-C- O
Yo
OHX ethanoate
Phenyl
ethanoic
anhydride
t NaOH 10 + Hz0 + NaCl
Y
Cheaper & less dangerous
, 4. 6 Amines
t
Basicity :
R
Reactions with Nitric (III) acid
: FN (H-O-N O)
> H
·
N has a lone pair Nitric (IIIacid/nitrous acid is not
very stable .
=
NaNOz + HCl < HNOz +
NaCl
e .
.
g methylammonium ion -
diazonium ion is unstable
Aliphatic amines : at ANY temperature quickly decomposes
So : CHzNHz +H2O [CHzNHz]OH NHz
+
HNOz OH
+
Nz
↑
+ H, 0
/ pour yield ,
effervescence
usually mixture
Weak base
(equilibrium lies to LHS) (volume can used be
to find moles of amine)
·
methylaminefishy ammonia' smell Aromatic reactions : Diazotisation
stabilises
=
< 10 % #
More Basics Greater availability of lone pair NHz + HNOz + H(l(aq) N = NCI + 2H20
H H H benzenedizonium
↑
NH
↑ H
C i
-
Chloride
-
H - c - -
-
H 1
HH
I H
H H
-
Aromatic amines :
Nitrogen's lone pair is
partially delocalised
-
Stable intermediate because of delocalisation of
charge caused
electron
density p orbitals the NEN with the r-bond
onto 2-electron
ring ,
so on the
nitrogen decreases
, by in
group system
it less attracted
making to HI OH
= NCI +
H20
Warm
7 +
Nz + HC
-
Aliphatic amines :
alkyl groups a re electron
releasing ,
so donate
Y
effervescence
electrons to the lone pair This increases .
nitrogen's electron
density
> more
-
attractive to HT
Coupling : benzenediazonium compounds are v reactive
to make
ionic
↑
= NCI + OH
NaOH
L
v -
-
OH + NaCl + Hz0
form ammonium Salts with acids (4-phenylazo) phenol
e CHgNHz + HCl >
-
CcHgNHz'Cl (yellowppt)
.
.
g
CHy
+
-
Nz + ~ 7
in -
(Hz
H20
CHz - +
Ethanoylation of Amines
Primary
CHz
·
(rea)
lone pair o n enables amines to act OH
nitrogen nucleophiles
·
as
Y
5
t = NCI- NaOH
, = H
Acyl Chloride
I sto ethanoylation O
O C C - c
HC)
- -
+
-
-
-
12 Sultan 1
+ NaCl + Hz0
-C
RC I N -
CHz ↳ steamy fumes
C H Cred solid used
/H N-methylethanamide
to colour curry)
peptide linkage
OH
·
If amine added , Salt To form diazonium ion benzene has to
excess
ring
-
Iv
ammonium a
,
H
be activated -
has to have an electron
withdrawing
N-
c
-C (e g OH)
c CH3 group NHz
-
. .
-
or -
>
NHz +
"
-
-
I
N-phenlethanamine
, in
NENCI + NHz 7 ·
-
NHz + HG)
·
fN N-) = Azo bridge links 2 aromatic
rings to
give extended delocalized system
Chromophore :
group of atoms in a compound responsible for its colour
#
With the -N
N-System , electrons be excited to
higher energy levels
·
pi p
=
can :
44
. . Aldehydes & Ketones Reductio n.
.
Use NaBHG
Distinguishing between an aldehyde & Ketone: based on the fast that
aldehyde can be further oxidised
·
Tollen's reagent : ·
Fehling's reagent :
-
CNaOH +
2AgNOz-AgzO(s) +
NaNOz +
H20 -
Fehling's A & B solution a re mixed,
forming a deep blue
Agz0(s) +
NHz(aq) until it dissolves (Agt solution containing a complex copper (11) ion
-
Carbonyl heated w/ solution
-
When heated with aldehyde ,
blue Cutions are reduced to
Aldehyde : Silver mir ror coats inside of tube (Ag- Ag(s) Cut forming
,
an
orange-red precipitate of Cu > O (s)
Ketone won't : reduce Tollen's reagent
-
Doesn't react w/ aromatic aldehydes
F
·
yAldehyde :
* Aldehyde :
* Cred brown)
Ag (aq)
+
Cut complex CuzO(s)
Nucleophilic Addition :
·
2 , 4-dinitrophenylhydrazine (2 4-DNPH) ,
-
dissolved in an acid to
form 'Brady's reagent'
* Ri
R -
H
, 1 o o
C= O HEN 7 C + = N :
- With aldehyde o r Ketone solid
1
REN orange-red
-
y gives an
Rz C= :
Rz :
CENT hydroxynitrile This is purified & melting temp used .
to
identify original
·
Important reaction as increases carbon chain molecule
-
Nucleophilic addition elimination /Condensation reaction
Hydrolysis of hydroxynitrile
P
Riy
R2 CN
C
OH Dilute
Reflux
e .
g .
H2SO4
>
Ric
R
C
, COOH
-
OH
·
Triiodomethane (iodoform)
-
test for methyl Ketones
reaction
& their precursors
: R2-C-CH3
R
or
Rache
hydroxynitrile hydroxy acid
-
Heat :
Organic compound +
Iz/NaOH
↑
or + IYOCI
alkaline iodine (clourless)
&
-
Result :
+ve when CHI , yellow ppt forms .
-
wo
CHIz(s)
liodoform)
