2 t 06 Aromatic Transparencies

8/12/2019 2 t 06 Aromatic Transparencies

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Aromatic compounds1. Benzene 2. Salicylic Acid

O H

C O O H

3. Acetyl Salicylic Acid (Aspirin)

O C C H 3

C O O H

O

4.Ibuprofen (Advil !otrin)

" "

C O O H

#. $A%&'

NH

O

O

O

O H O H O

O O

OO

O HO

O

O

. 1 1 1 $ric*loro 2 2 bis(pc*lorop*enyl)et*ane (++$)

Cl C l

C lC l

C l

,. $etra*ydrocannabinol

O

O H

-. !et*yl salicylate (flavor forinter/reen)

C O O C H 3

O H


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0. anillin.O

O H

O C H 3

1 . ap*t*alene

11. +iazepam (valium)

N

NH O

12. apro en

C O O H

C H 3 O

13. +iet*yl m toluamide

C

O

N(CH 2 CH 3 )2

H3 C

14. 5ocaine

N O

O

O

O

H 3 C

1#. icotine

N

N

CH 3

1 . Benzo6a7pyrene


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Aromatic Compounds

5onditions t*at must be satisfied to considered aromatic8 $*e

1. 5yclic

2. 9lanar 3. All atoms in t*e cyclic structure must *ave an un*ybridized p orbital4. must follo :uc;el pi electrons *ere n> 1 2?.

( *ole number)

Nomenclature:

A. !onosubstituted Benzene8

S&3:5&&: & : 2 5 & 2Br

B. +isubstituted Benzene

5&&:

5l

: 2

& 2

5: 3

Br

5. 9olysubstituted Benzene

S&3:

& 2&2

&

5l

5l

5

5l

&2


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Reactions:

1. @lectrop*ilic Aromatic Substitution

= :

@

@==

:

@lectrop*iles enerated from

Al%3

5%

&

%

Al%3

S&3: 2S&4

: & 3

: 2S&4

5 =&

=

S&3:=

& 2=

%=%2

Ce%3


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Electrophilic Aromatic Substitution

A. :alo/enation

= :%Ce%3

%2%

A. itration

= : 2&: 2S&4

& 2: & 3

B. Sulfonation

: 2S&4

S&3S&3:

5. Criedel 5raft


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Limitations of Friedel Crafts Reactions1. $*ere is dan/er of polysubstitution2. earran/ement may occur 3. Aryl can not be used as t*e *alide component because t*ey do not form

carbocations readily.

4. Aromatic rin/s less reactive t*an *alobenzene do not under/o Criedel5rafts reactions.

#. Aromatic rin/s it* : 2 : and D 2 do not under/o Criedel5rafts

eactions

Substituent Effects in Electrophilic Aromatic Substitution (EAS)

1. Substituents affect reactivity to ards @ASActivatin/ roups electron releasin/+eactivatin/ roups electron it*dra in/

2. Substituents affect t*e orientation of t*e reactiono, p +irectorsm- +irectors

3. Substituents can be classified asActivatin/ o, p +irectors+eactivatin/ o, p +irectors+eactivatin/ m- +irectors


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&t*er eactions

2. & idation of Al;yl benzene

: 2&

E!n& 45&&:

3. eduction

*i/* $ *i/* 9

: 2F9t

4. eduction of Aryl Eetone

a. 5lemmensen eduction

:5l

Gn(:/)

&

b. Holff Eis*ner eduction

base

: 2 : 2

&


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#. Al;ali Cusion of Aromatic SulfonatesS&3:

a&:1.

2.: 3&=

&:

= a:S& 3

. eduction of Aromatic itro /roup

: 2 & 2

=: 3&2.

1. Sn5l 2 :3&=

,. ucleop*ilic Aromatic Substitution(a) Addition @limination to activated aryl *alide

& 2

& 2

&2

5l

1. &: *i/* $ 9

2. : 3&=

& 2

& 2

&2

&:

(b) via benzyne intermediate for unactivated aryl *alides

-. Benzylic Bromination


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5: Br 5: 2

BS

(9*5& 2)2 55l 4

BS8

&

&

Br

Bromosuccinimide


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Substituent @ffects in @lectrop*ilic Aromatic Substitution

Activatin/ o,p directors

Stron/ly Activatin/ : 2 : 2&: &

!oderately Activatin/ & :5&

Hea;ly Activatin/ 9* (p*enyl)

+eactivatin/ o,p directors

Hea;ly +eactivatin/C5lBr I

+eactivatin/ m directors

!oderately +eactivatin/

5:&

5&2 5&2:5& S&3:

Stron/ly +eactivatin/5

&2 3 5C3 55l3

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2 t 06 Aromatic Transparencies