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650 Chapter 18
Copyright © 2017 Pearson Education, Inc.
105.
Notice that the Friedel–Crafts reaction can be done on a ring with a sulfonic acid group because its deacti-
vation is offset by the activating amide group. The sulfonic acid group is put on the ring to block the para
position and thereby force the methyl groups to go to the ortho positions. Notice that the Friedel–Crafts
alkylation reaction can be done because the deactivating effect of the meta director is offset by the activat-
ing effect of the amide. Also notice that because some (or all) of the amide may be hydrolyzed when the
sulfonic acid group is removed, the acyl chloride is added to reform the amide.
N
HO
3
S
Cl
H
N
Cl
H
N
Cl
H
C
O
C
O
C
O
N
N
H
C
O
NO
2
HNO
3
H
2
SO
4
H
2
Pd/C
NH
2
ClCH
2
CCl
O
N
H
Cl
C
O
H
2
SO
4
HO
3
S
excess CH
3
Cl
AlCl
3
CH
3
CH
3
H
2
O
HCl
NH
CH
3
+
3
CH
3
1. HO
−
2. ClCH CCl
O
2
CH
3
CH
3
CH
3
CH
3
(CH
3
CH
2
)
2
NH
106.
Notice that thionyl chloride can replace the OH group of a carboxylic acid and the OH group of a sulfonic
acid with a Cl.
CH
3
CH
3
C
SO
3
O
O
C
S
Cl
O
Cl
S
NH
C
O
O
O
CH
3
Cl
AlCl
3
H
2
SO
4
2 NH
3
excess
SOCl
2
SO
3
H
O
O
1. H
2
CrO
4
,
−
2. HO
−
−