Chemistry Reference
In-Depth Information
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HO
CH
2
CH
2
O
CH
2
CH
2
OCH
2
CH
2
OH
p
o
C
CH
2
OCH
2
CH
2
OH
HO
CH
2
CH
2
O
CH
2
s
r
or
HS
CH
2
CO
O
H
2
C
CH
2
O
OC
CH
2
SH
C
HS
CH
2
CO
O
H
2
C
CH
2
O
OC
CH
2
SH
+
ClCO
COCl
ClCO
CH
2
COCl
n
ortho, meta, para
n = 4, 6, 8, 10
Formula 12.6
and 4,4-bis(4-chlorophenylsulfonyl)biphenyl (Formula
12.7
) were used. The best
results were achieved with the long a
2
monomer although DFDS is more reactive
Hence, it may be concluded that with the short diphenyl sulfones cyclization of
several isomers is sterically hindered.
The second group of a
2
? b
4
polycondensations was conducted with electro-
philic b
4
monomers When pentaerythritol tetrabromide was reacted with tert.-
