Organic Chemistry – chemistry of aromatics History · Organic Chemistry – chemistry of...

Organic Chemistry – chemistry of aromatics

History

- discovery of benzene (M.Faraday – 1825)

- structure of benzene (F.A.Kekulé – 1864)

- conjugation, resonance structures

C6H6

HBHA

X

HA

X

Y HBY

X

substitution +

H

H

H

H

H

Hα = 120 °C-H = 108,4 pmC-C = 139,7 pm


Aromaticity

H

HH

H

HH

H= 6 x

Delocalisation of π – electrons

- is it favourfable process ???


energy

ΔHh = 96 kJ mol-1

ΔHh = 410 kJ mol-1

ΔHh = 120 kJ mol-1

ΔHh = 208 kJ mol-1

ΔHh = estimated delocalisation energy

of benzene


Aromaticity

„Hückel rule“

Aromatic compounds have to have

- cyclic structure

- conjugated systém of double bonds

- 4n + 2 (n = 1,2,3,4….. Π – electrons

- planar structure (shape) of aromatic part


Aromaticity – π - orbital picture

energy

LUMO

HOMO bonding MO

antibonding MO

benzene 1,3-cyclobutadiene


Aromatic compounds

[10]-annulene [18]-annulene naphthalene anthracene fenanthrene

H H

H

FeH H

H+


Heteroaromatic compounds

N

NH

N

NH

N NN

O SNH

pyridine quinoline isoquinoline

pyrrole furane thiophene

porfyrine


Aromatic compounds - reactivity

O

H

H

Br

BrBr2/CCl4

OH

OH

vs.RCO3HRCO3H

Br2/CCl4

OsO4OsO4

no reaction

no reaction

no reaction


Aromatic compounds – reactivity – SE aromatic

NO2HO3S

Br

CO-CH3C

CH3

CH3

CH3

ClCH2

HNO3/H2SO4

nitration

SO3/H2SO4

sulfonation

Br2/FeBr3

halogenation

CH3COCl3/AlCl3

F-C acylation

(CH3)3CCl/AlCl3

F-C alkylation

CH2=O/HCl

chloromethylation


Aromatic compounds – retention of aromatic character

HBr

+

Br

Br

Br

Br

+ Br-Br

addition

substitution



H

H

E+

H

E+

H

E+

E

E+

"base"

σ-complex σ-complex



CN

CNNC

NCNO2

NO2O2N

X2

π – complexes

C-T (charge-transfer) complexes



energy

TS-1TS-2

Eactivation

σ - complex



σ - complex

reakční koordináta

energie

C6H6 + Br2 + FeBr3

H Br

+

FeBr4-

Br2

+ FeBr3 C6H5Br + HBr + FeBr3

Br

HBr

+ FeBr3

TS1 TS2

reakční koordináta

energie

C6H6 + Br2 + FeBr3

H Br

+

FeBr4-

Br2

+ FeBr3 C6H5Br + HBr + FeBr3

Br

HBr

+ FeBr3

TS1 TS2

Reaction coordinate

energy

σ -complex

π -complex

π -complex


Aromatic compounds – SE aromatic - halogenation

H

Br+

BrFeBr3 BrH

FeCl3

Cl2Cl

HNO3

I2I

Br BrFeBr3

Br Br+

FeBr3-

Br FeBr3-

+ +

bromobenzene

chlorobenzene(83%)

iodobenzene(86%)


Aromatic compounds – SE aromatic - nitration

H

NO2+

NO2

OH2OH NO2

H OSO3H

O+

H

H NO2 NO2+ +

nitrobenzene

-OSO3H

-H2SO4

stable salts NO2+ X - (X = BF4 , ClO4 , PF6)


Aromatic compounds – SE aromatic - sulfonation

H

SO3H+

SO O

OH

OH2OH SO3H

H OSO3H

O+

H

H SO2 OHO

SOO

H

SO O

O Na+

+

O

SOO

H+

+

benzenesulfonic acid

-OSO3HNaCl

natrium-benzenesulfonate


Aromatic compounds – SE aromatic – F-C alkylation

H

CH2CH3+

CH2CH3

AlCl3

CH3CH2 ClAlCl3

CH3CH2 Cl AlCl3+

CH3CH2+ Cl AlCl3

-

-

ethylbenzene

+ +

CH3CH2+[AlCl4]-

HCl



CH2OH

H2SO4

cyclohexylbenzene

HF

diphenylmethane

+

+



C(CH3)3CH3 CHCH3

CH2Cl

CH3 CH2 CH2Cl CH(CH3)2CH2CH2CH3

tert-butylbenzene

propylbenzene

AlCl3

AlCl3

isopropylbenzene

+


Aromatic compounds – SE aromatic – F-C acylation

C ClCH3CH2

OAlCl4-

H

C CH2CH3

O

C CH2CH3

O

CH3CH2 Cl AlCl3CO

CH3CH2 C O AlCl3

Cl

Cl AlCl3-C CH3CH2O

+

C+

CH3CH2 O

CCH3CH2 O+

AlCl3

+HCl AlCl3

stabilized acylium cation

δ+ δ−

δ+ δ−

+ +1-phenylpropane-1-one

+


Aromatic compounds – SE aromatic – F-C acylation

CH3CH2CH2COCl C

O

CH2CH2CH3CH2CH2CH2CH3

AlCl3

Zn(Hg)x

HCl

1-phenylbutane-1-one butylbenzene

C

O

CH2

CH2

COOH

OO O CH2CH2

CH2

COOH OAlCl3

reduction P2O5

H3PO4


Aromatic compounds – SE aromatic – varia

CH3 CH3

CH=O

OH

OHOH C NH+R

CH3 C N

OH

OHOH

O

CH3

CH3

CH2OH

CH3

CH2 OH+CH2Cl

CH3

C O

C+

OH

C+

NHR

CH2 OH

C O+

H+HCl

AlCl3, CuCl

electrophile formed

p-methylbenzaldehyde

+2) H2O

1) HCl/Zn(CN)2

2,4,6-trihydroxyacetophenone

CH2=O/HCl

p-methylbenzylchloride

HCl

+


Aromatic compounds – varia

(CH3CH2CH2CH2)2CuLi I CH2CH2CH2CH3+ ether

lithiumdibutylcuprate butylbenzene (75%)

(CH3)2CuLi CH3(CH2)8CH2I CH3(CH2)8CH2CH3ether

-30 °C

(C6H5)2CuLi CH3(CH2)6CH2I CH3(CH2)6CH2C6H5

R2CuLi + R´X + RCu + LiXR-R

+lithiumdimethylcuprate 1-iododekane undekane (90%)

+lithiumdiphnylcuprate 1-iodooktane 1-phenyloktane (99%)

ether



I CO2CH3 ZnI CO2CH3+

methyl-4-jodobenzoate phenylzinc iodide methyl-biphenyl-4-carboxylate

+ ZnI2Pd0[P(C6H5)3]4

Negishi reaction:



I CO2CH3

Pd CO2CH3

P(C6H5)3

I

P(C6H5)3

ZnI

Pd CO2CH3

P(C6H5)3

P(C6H5)3

CO2CH3Pd0[P(C6H5)3]2

II

oxidative addition

transmetallation

reductiveelimination

ZnI2

-2P(C6H5)3Catalytic circle:

Pd0[P(C6H5)3]4

+2P(C6H5)3

II


Aromatic compounds – SE aromatic – directive effect

CH3 CH3

NO2

CH3 NO2CH3

NO2

HNO3

H2SO4

CF3 CF3

NO2

CF3 NO2CF3

NO2

HNO3

H2SO4

+ +

2-nitrotoluene(63%)

3-nitrotoluene(3%)

4-nitrotoluene(34%)

2-nitro(trifluoro-methyl)benzene

(6%)


(91%)


(3%)

+ +



CH3 CF31.0

relative velocity of nitration

44

2,4

59

4,6 x 10-6

4,5 x 10-6

69 x 10-6



CH3H

NO2+

CH3H

NO2+

CH3

H NO2

+

CH3

H NO2

+

CH3

H

NO2

+

CH3

H

NO2

+

CH3 Ar

+ICH3

H NO2

+

CH3H

NO2

+

CH3

H

NO2

+

ortho substitution

para substitution

meta substitution



CF3H

NO2+

CF3H

NO2+

CF3H

NO2

+

CF3

H NO2

+

CF3

H NO2

+

CF3

H NO2

+

CF3

H

NO2

+

CF3

H

NO2

+

CF3

H

NO2

+

C Ar

F

F

F

-I

ortho substitution

para substitution

meta substitution



CH2CH3 CH(CH3)2 C(CH3)3CH3

47%

53%

31%

69%

18%

82%

61%

39%

Steric effect



- I +M substituents

H

Br

OH

+

OHH

Br+

OHH

Br+

OH

H Br

+

OH

H Br

+

H Br

OH

+

OHH

Br

+

H Br

OH+



Velocity of SEAr Substituent Name Oriention super activating NH2

amino ortho/para

NR2

R1

alkylamino (R1=H) dialkylamino (R1,R2≠H)

ortho/para

OH hydroxy ortho/para Strongly activating

NH C

O

R acylamino ortho/para

O R alkoxy ortho/para

O C

O

R acyloxy ortho/para

activating -R, -Ar alkyl, aryl ortho/para -CH=CR2 alkenyl ortho/para

reference H


Velocity SEAr Substituent Name Oriention reference H

weakly deactivating X (X=F, Cl, Br, I)

halogen ortho/para

CH2 X halogenmethyl ortho/para

strongly deactivating

C

O

Y

acyl (Y=R) acylchloride (Y=Cl)

carboxylic acid (Y=OH)ester (Y=OR)

meta

C N cyano meta SO3H sulfonic acid meta

Very strongly deactivating CF3 trifluormethyl meta

NO

O

+

-

nitro meta


NO O

+

+

NO O

+

+

NO O

+

NOO

+

+



H

Br

NO O

+ +

+

+ +

+ +NO O

H

Br

NO O

H

Br

+

NO O

H Br

NO O

H Br

NO O

H Br

+ ++

+


Aromatic compounds – SE aromatic – multiple effect

CH3

CH3

CH3

CH3

BrCH3

C(CH3)3

CH3

C(CH3)3

Br

CH3

NO2

CH3

NO2

NO2

Cl

NHCOCH3

Cl

NHCOCH3

SO3H

Br2

FeBr3

Br2

FeBr3

a) b)

HNO3

H2SO4

c) d)

H2SO4


Aromatic compounds – SE aromatic – naphthalene

Br2

FeBr3

BrBr

NO2

NO2

1

2

3

456

7

8

+

1-bromonaphthalene(99 %)

2-bromonaphthalene(1 %)

+

1-nitronaphthalene(90 %)

2-nitronaphthalene(10 %)

HNO3

H2SO4


Aromatic compounds – SE aromatic – naphthalene

SO3H

H2SO4

165 °C

SO3H

EH

naphthalene-1-sulfonic acidacid (98 %)

H2SO4

75 °C

naphthalene-2-sulfonicacid (88 %)


Aromatic compounds – SE aromatic – naphthaleneOMe OMe

SO3HOMe

SO3H

NO2NO2SO3H NO2

SO3H8-nitronaphthalene-1-sulfonic acid

H2SO4

H2SO4

5-nitronaphthalene-1-sulfonic acid

this nucleus is activated

+

+

this nucleus is deactivated

Me = CH3


Aromatic compounds – SE aromatic – reduction

3 H2 (0,3 MPa)/Pt

AcOH, 30 °C(100%)

3 H2/Rh

30 °C



H

H

H

H

H

H H

H

H

H

HH H

H

HH

HH H

H H

HH

HH H

H

H

H

H

H

H

H

H

H -

-

H

H

H

H

HH H

-H

H

H

H

HH H

Na EtOH

-EtONa

Na+ Na+

EtOH -EtONa

++ 2 Na + 2 EtOHNH3 (l)

overall reaction

Na

Na+

Et = C2H5

+ 2 EtONa



COOEt

-

-

H

COOEt

H

COOEt

H H

H COOEt

OMe

-

-

OMe

H

H

OMe

H

HOMe

HH

HH

Na

Na+ Na+

Na

Na+ Na+

Me = CH3, Et = C2H5


Aromatic compounds – SE aromatic – oxidation

O

O

O

O

O

O

vzduch

V2O5, 400 °C

ftalanhydride maleinanhydride


Aromatic compounds – SE aromatic – oxidation

CH3

O2N O2N

COOH

CH2CH2CH3

CH3

COOH

HOOC

Na2Cr2O7

H2SO4/H2O

p-nitrobenzoic acid

Na2Cr2O7

H2SO4/H2O

benzene-1,4-dicarboxylic acid(tereftaphthalic acid)


Aromatic compounds – technically important

CH2 CH2

CH2CH3 CH CH2

CH3CH CH2

OHCH3COCH3

+dehydrogenation

Cr2O3.Al2O3

styrene

+

kumenephenol

HF

HF+

CH3 O2N

CH3

CH3

NO2

CH3

NO2

NO2

CH3

NO2

NO2O2NHNO3/H2SO4

110 °C+

TNT

HNO3/H2SO4

30 °C

HNO3/H2SO4

65 °C


Phenols - SN on aromatic halogen

Cl OH1. NaOH, H2O, 370°C

2. H+

chlorobenzene phenol (97%)

ClO2N O2N OCH3+ NaOCH3

CH3OH85 °C

4-chloronitrobenzene methyl(4-nitrophenyl)ether (92%)

+ NaCl


Phenols - SN on aromatic skeleton

Cl

NO2

NO2O2N

Cl

Cl

NO2

Cl

NO2

NO2

Relative velocityreaction with NaOCH3:

1,0 7x1010 2,4x1015 too high to bedetermined

2,4,6-trinitro-chlorobenzenechlorobenzene

1-chloro-4-nitrobenzene

1-chloro-2,4-dinitrobenzene


Phenols - SN on aromatic skeleton - mechanism

Cl

NO2

H

H

H

H

NO2

H

H

H

ClH

OCH3

1. step:

+ OCH3-

slow-

4-chloronitrobenzene cyclohexadienyl anion

NO2

H

H

H

ClH

OCH3

NO2

H

H

H

H

OCH3

2. step:

-

cyclohexadienyl anion

quick

+ Cl -

methyl(4-nitrophenyl)ether


Phenols - SN on aromatic skeleton - mechanism

NO O

H

H

H

ClH

OCH3

NO O

H

H

H

ClH

OCH3

NO O

H

H

H

ClH

OCH3

NOO

H

H

H

ClHH3CO

H

H

ClH

OCH3

H

N

O

O N

O

O

H

H

ClH

OCH3

H

N

O

OH

HCl

HH3CO

H

-

-

-

The most stable mesomeric structure (negative charge on oxygen)

Negative charge can be located on carbon atoms only

4-nitrochlorobenzene:

3-nitrochlorobenzene:

- -+ +--

+ +-

-

-+ -

-+

-

-+


SN on aromatic skeleton – addition-elimination mechanism

Cl NH2KNH2, NH3

-33 °C

chlorobenzene aniline (52%)


CH3

Br

CH3

Br

CH3

Br

CH3

NH2

CH3

NH2

CH3

NH2

CH3

NH2

CH3

NH2

CH3

NH2

CH3

NH2

+

+

+ +

o-bromotoluene

p-bromotoluene

m-bromotoluene o-methylaniline

o-methylaniline m-methylaniline

m-methylaniline

m-methylanilinep-methylaniline

p-methylaniline

KNH2, NH3

-33 °C

KNH2, NH3

-33 °C

KNH2, NH3

-33 °C



H

H

H

H Cl

H

H

H

H

H

Cl-

NH2-

chlorobenzene benzyne

+ NH3 +

1. step - elimination:

H

H

H

H


H

H

H

HH

H

H

H

NH2

H

H

H

H

NH2

H NH2

H

H

H

H

NH2

H

2. step - addition amide anion:

benzyne

NH2-

-

aryl anion

3. step - protonation:

-

aryl anion

+ NH2-

aniline



CH3

CH3

Cl

CH3

NH2

CH3

NH2

+KNH2

NH3

KNH2

NH3

o-chlorotoluene 3-methylbenzyne o-methylaniline m-methylaniline


Phenols – acidity – stabilisation od anion by resonance

O-

O

-

O

-

O

-

Compounds pKa Compounds pKa

Phenol 10,0 3-nitrophenol 8,4

2-methylphenol 10,3 4-nitrophenol 7,2

3-methylphenol 10,1 2.4-dinitrophenol 4,0

4-methylphenol 10,3 3,5-dinitrophenol 6,7

2-nitrophenol 7,2 2,4,6-trinitrophenol 0,4


Phenols – are extremely reactive aromatics

OH OH

Br

Br

BrH2O25°C+ 3Br2 + 3 HBr

phenol 2,4,6-tribromophenol

OH OH

Br

ClCH2CH2Cl

0°C+ Br2 + HBr

phenol 4-bromophenol (93%)


Phenols – are extremely reactive aromaticsOH

NaNO2

H2SO4, H2O

N O

OH

phenol 4-nitrosophenol

OHC

Cl

OCH3

OC

O

CH3C

Cl

OCH3

AlCl3

CO CH3

OHC

CH3

OOH

phenol

+

phenyl-acetate 4-hydroxyaceto- phenone (74%)

2-hydroxyaceto- phenone (16%)


Phenols – are extremely reactive aromatics

ONa OH

CO2Na

H+ OH

CO2H

CO2

sodium phenoxide sodium salicylate salicylic acid (79%)

125°C, 10 Mpa

O - O

O

C

O

O

C

O

OH

-OH

C

O

O

-

-+

phenoxide anion salicylate anion oxoform of salicylate anion


Phenols – oxidation to quinonesOH

OH

Na2Cr2O7

H2SO4, H2O

O

O

OH

CH3

OH

O

CH3

OAg2O

hydroquinone p-benzoquinone (81%)

4-methylbenzene-1,2-diol 4-methylbenzo-1,2-quinone (68%)


Phenols – oxidation to quinones and cleavage of ethers

CH2CH CCH2(CH2CH2CHCH2)3H

CH3 CH3

O

O

CH3

O

O

CH3O

CH3O

CH3

(CH2CH CCH2)

CH3

n = 6-10nH

ubiquinone (koenzyme Q) vitamine K

O CH3HI O

H

CH3

I-

OH+

no reaction here SN2

+ CH3I

phenyl(methyl)ether (anisole) phenol iodomethane


Phenols – Claisen rearrangement of allylarylethers

OCH2CH=CH2200°C

OH

CH2CH=CH2

allyl(phenyl)ether 2-allylphenol (75%)

C14

O

C14

O

H

OH

C14C14

O

allyl(phenyl)ether transition state 6-allylcyclohexa-2,4-diene-1-one

(enolform of product)2-allylphenol

oxo-enol


Aromatic amines – preparation –reduction of nitrocompounds

C6H5 N O C6H5 NH OHNO

OC6H5 + C6H5 NH2

redukceredukce redukce

nitrobenzenenitrosobenzene N-phenylhydroxylamine aniline

Cl NO2 Cl NH21. Fe, HCl2. NaOH

CH(CH3)2

NO2

CH(CH3)2

NH2H2, Nimethanol

4-chloronitrobenzene 4-chloroaniline (95%)

2-isopropyl-1-nitrobenzene 2-isopropylaniline (92%)


Aromatic amines – preparation –reduction of nitrocompounds

NO2 NHOH

N-phenylhydroxylamine

Zn, NH4Cl

H2O

C6H5 NHOH O N C6H5

-H2O

C6H5 N N C6H5

C6H5 N

O

N C6H5

+

C6H5 NH NH C6H5C6H5 N

O

N C6H5

+

C6H5 N H2

O

Zn, OH Zn, OH

+N-phenylhydroxylamine nitrosobenzene

azoxybenzene

azoxybenzeneazobenzene 1,2-diphenylhydrazine

+


Aromatic amines - structure

H

H

H

H

H

NH

-

+

H

H

H

H

NH2

H

H

H

H

H

H

NH

-

+

H

H

H

H

H

NH

-

+

anilinebenzenamineaminobenzenephenylamine


Aromatic amines - structure

N

HH

sp3

N HH

sp2

N

HHCH3

125°

N

HH

142.5°

N

125°

N

180°

sp3 hybridisationace on N sp2 hybridisation on Nmethylamine

aniline

aniline - conjugation of nonbonded electrons


Aromatic amines – structure, chirality

CH3

N

CH2CH3

C6H5CH2

C6H5

CH3

N

CH2CH3

CH2C6H5

C6H5

I I

mirror plane

++

CH3

CH2CH3

HN

CH3CH2

H3C

NH

CH3CH2

H3C

NH

CH3

CH2CH3

H

N

CH3

CH2CH3

HN

mirror plane


Amines – natural compounds

NCH3N

H

N

H

N

OHH C

ONCH3

OOCH3

CO

C6H5

OH

OH

CH3

NHOH H

NH

CH2CH2NH2OH CO2H

NH2 H

nicotine quinine cocaine

adrenaline serotonine L-phenylalanine


Amines – basicity

R3N H O H R3N H+

O H-

[R3NH+][OH-]

[R3N]Kb = pKb = -log Kb

+ +

Amine pKb Amine pKb

amoniak 4,7 secondary aminesprimary amines (CH3)2NH 3,3CH3NH2 3,4 (CH3CH2)NH 2,9CH3CH2NH2 3,2 C6H5NHCH3 9,2(CH3)2CHNH2 3,4 Tertiary amines(CH3)3CNH2 3,6 (CH3)3N 4,3C6H5NH2 9,4 (CH3CH2)3N 3,2

C6H5N(CH3)2 8,9


Aromatic amines – basicity – role of substituent

NH2X NO

ONH2 NH2N

O

O

+++

X pKb

H 9,4CH3 8,7CF3 11,5O2N 13,0


Amines – as acids – deprotonation of them

H O HR NH2H H

O

H+R NH+ +

pKa = -log KaKa =

Ka

[RNH-][H3O+]

[RNH2]= ~ 10-35 = ~ 35

-

(CH3)2CH NH

CH(CH3)2

CH3CH2CH2CH2Li

- CH3CH2CH2CH3(CH3)2CH N CH(CH3)2

Li+

diisopropylamine lithium-diisopropylamide, LDA


Aromatic amines – reactivity SEAr

NH2

Br2

H2O

NH2

Br

Br

Br

NH2

CH3COCl

nebo(CH3CO)2O

CH3

CNH

O

CH3

CNH

O

Br

NaOHH2O

NH2

Br

Br2

aniline 2,4,6-tribromoaniline (quantitative)

acetanilide 4-bromoacetanilide (main product)

4-bromoaniline

aceticacid


Aromatic amines – reactivity SEArNHCOCH3

CH(CH3)2CH(CH3)2

NH2 NHCOCH3

CH(CH3)2

NO2HNO3

20°C

NH2

CH(CH3)2

NO2KOHH2O

protection groupremoval

4-isopropylaniline 4-isopropylacetanilide (98%)

4-isopropyl-2-nitroacetanilide (94%)

4-isopropyl-2-nitroaniline (100%)

(CH3CO)2O

protection

NH2 NH2

NO2

H2SO4 HNO3

H2SO4

NaOHH2O

NH3 HSO4

+NH3

NO2

HSO4

+

hydrogensulphate of aniline

hydrogensulphate of 3-nitroaniline

3-nitroaniline



O N O H+O N OH H+ -H2O

O N OH

H

+N O+

nitrous anion nitrous acid nitrosyl cation

N(CH2CH3)2

1. NaNO2, HCl, H2O, 8°C

2. OH-

NO

N(CH2CH3)2

N,N-diethylaniline

N,N-diethyl-4-nitrosoaniline (95%)



N O+

H

R2N R2N

H

N O-H+

R2N N O

(CH3)2NHNaNO2, HCl

H2O(CH3)2N N O

NH

CH3

NCH3

NO

NaNO2, HClH2O, 10°C

++

N-nitrosoamine

N-nitrosodimethylamine (90%)

N-methylaniline N-methyl-N-nitrosoaniline (90%)



NCH3

CH3

NO

NO

N

NON

N

N-nitrosodimethylamine(found e.g. in beer)

N-nitrosopyrrolidine(in roasted beans)

N-nitrosonornicotin(i tobacco smoke)


Amines – reactivity – diazonium salt formation

N N OHRNaNO2

H+ NN O

HR

-H2O

H+ -H+

H+

R NH2 NN O

H

HR

OH2N NRN NR

alkyldiazohydroxide

diazonium cation

N-nitrosoalkylamine (not isolated)

+

++


Amines – reactivity – diazonium salt formation

CH3CH2CH2NH2

CH3CH2CH2OH CH2 CHCH3CH3 CH

CH3

OH

CH3CH2CH2 N N+ N N- CH3CH2CH2

+NaNO2

Cl

CH3CH2CH2Cl CH3 CH

CH3

Cl

+ +

HCl, H2O

+ +

NH2

NaNO2, HCl, H2O0 - 5°C

N

N

+

benzendiazoniumchloride

Cl


Amines – reactivity - diazonium salt synthetic utilisation – SN(R)

Ar N N+

Ar OH H+

Ar+-N2 H2O

(CH3)2CH NH2

1. NaNO2, H2SO4, H2O2. H2O, zahřátí

(CH3)2CH OH

+

4-isopropylaniline 4-isopropylphenol (73%)

NH2

Br

I

Br2-bromoaniline 1-bromo-2-iodobenzene (72-83%)

1. NaNO2, HCl, H2O, 0-5°C2. KI, ambient temperature



CH3

NH2 1. NaNO2, HCl, 0°C

2. CuCl, 60°C

CH3

Cl

NH2

Cl

Br

Cl1. NaNO2, HBr, 0°C

2. CuBr, 100°C

2-methylaniline 2-chlorotoluene (79%)

2-chloroaniline 1-bromo-2-chlorobenzene (73%)



NH2

CH3 CH3

CN

4-methylaniline 4-methylbenzonitrile (70%)

1. NaNO2, HCl, 0°C

2. CuCN, NaCN, 50°C

BF4Δ Ar F BF3 N2Ar N N

+

CH2CH3

O

NH2

1. NaNO2, H2O,2. HBF4

3. ΔCH2CH3

O

F

+ +

1-(3-aminophenyl)propane-1-one 1-(3-fluorophenyl)propane-1-one (68%)



Ar H N2Ar N N+

CH3

Br

NH2

1. NaNO2, HCl, H2O2. H3PO2, H2O

CH3

Br

CH(CH3)2

NH2

NO2

CH(CH3)2

NO2

H3PO2 +

2-bromo-4-methylaniline

3-bromotoluene (85%)

4-isopropyl-2-nitroaniline1-isopropyl-3-nitrobenzene (59%)

1. NaNO2, HCl, H2O2. CH3CH2OH



NH2

Br2

H2O

NH2

Br

Br

Br Br

Br

Br1. NaNO2, H2SO4, H2O

2. CH3CH2OH

2,4,6-tribromoaniline (100%) 1,3,5-tribromobenzene (75%)

OH

O2N N N OHO2N N2

+ Cl-

+

4-(4-nitrophenyldiazenyl)-1-naphtol



-H+

(CH3)2N H NN N NH

(CH3)2N

N N(CH3)2N

+ +

4-(dimethylamino)azobenzene

Organic Chemistry – chemistry of aromatics History · Organic Chemistry – chemistry of...

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