Methyl- and fluoro-substituted bis(4'-aminophenoxy)benzenes: A convenient method of synthesis

Article abstract of DOI:10.1055/s-1998-2084

We have synthesised a series of new bis(ether amine)s, primarily 1,2- bis(4'-aminophenoxy)benzene derivatives but including 1,3- and 1,4-bis(4'- aminophenoxy)benzene derivatives, with fluoro and alkyl substituents. These diamines were synthesised by fluoro displacement with 1-fluoro-4-nitrobenzene or its derivatives, or nitro displacement with 1,4-dinitrobenzene, and various phenylenediols and their alkyl- or fluoro-substituted derivatives. The resulting bis(ether nitro) compounds were reduced to the corresponding bis(ether amine)s. Thus, various bis(4'-aminophenoxy)benzenes were prepared which can be used in the synthesis of polyimides, polyamides and poly(azomethine)s with different distributions of alkyl and fluoro substituents and different substituent patterns, enabling a comprehensive study of structure-property relationships to be undertaken.

Full text of DOI:10.1055/s-1998-2084

June 1998
SYNTHESIS
894
¢
Methyl- and Fluoro-Substituted Bis(4 -aminophenoxy)benzenes: A Convenient Method
of Synthesis
G. C. Eastmond,* J. Paprotny
Donnan Laboratories, University of Liverpool, P. O. Box 147, Liverpool L69 7ZD, UK
Fax +44(151)79443534; E-mail: eastm@liv.ac.uk
Received 15 July 1997; revised 19 September 1997
Abstract: We have synthesised a series of new bis(ether amine)s,
primarily 1,2-bis(4¢-aminophenoxy)benzene derivatives but
including 1,3- and 1,4-bis(4¢-aminophenoxy)benzene derivatives,
with fluoro and alkyl substituents. These diamines were synthe-
sised by fluoro displacement with 1-fluoro-4-nitrobenzene or its
derivatives, or nitro displacement with 1,4-dinitrobenzene, and
various phenylenediols and their alkyl- or fluoro-substituted deriv-
atives. The resulting bis(ether nitro) compounds were reduced to
the corresponding bis(ether amine)s. Thus, various bis(4¢-ami-
nophenoxy)benzenes were prepared which can be used in the syn-
thesis of polyimides, polyamides and poly(azomethine)s with
different distributions of alkyl and fluoro substituents and differ-
ent substituent patterns, enabling a comprehensive study of struc-
ture–property relationships to be undertaken.
nitrophenoxy)benzenes, precursors to the diamines, can
be synthesised easily by halo displacement from 4-halo-
nitrobenzenes, or by nitro displacement using 1,4-dini-
trobenzene.
Our previous finding that modifying substitution patterns,
especially by incorporating catechol and substituted moi-
eties, modified the processability of both poly(ether
imide)s and poly(ether amide)s from solution or melt, es-
pecially when combined with alkyl and fluoro sub-
stituents,7, 8 led us to become interested in bis(4¢-
aminophenoxy)benzenes bearing different numbers of
methyl or fluoro substituents. We wished to synthesise di-
amines with the substituents distributed in different ways
in the molecules and present in either the central or termi-
nal rings of the diamine moiety or, alternatively, distribut-
ed more evenly throughout the molecule. No diamines of
this type are reported in the Beilstein database.9 Recently,
another specific diamine with p-phenoxyamine units
linked ortho to an aromatic residue, 2,3-bis(4¢-aminophen-
oxy)naphthalene, has been synthesised by Yang and
Chen;10 the diamine was prepared by a chloro displace-
ment reaction between 1-chloro-4-nitrobenzene and 2,3-
dihydroxynaphthalene followed by reduction of the re-
sulting dinitro compound. This diamine and 1,2-bis(4¢-
aminophenoxy)benzene have been used in the synthesis
of polyamides.10, 11
Key words: fluoro displacement, dihydroxybenzenes, 3,4-difluo-
ronitrobenzene, synthesis, fluoronitrotoluene, bis(4-aminophen-
oxy)benzenes
Bis(4¢-aminophenoxy)benzenes with the general formula:
are aminophenyl derivatives of simple aromatic diols, i.e.
hydroquinone, resorcinol, catechol and certain dihydroxy-
naphthalenes. These diamines are of considerable interest
to the polymer chemist, because their incorporation into
relatively stiff aromatic polymer chains may provide flex-
ibility and enhance processability. The synthesis of 1,4-
bis(4¢-aminophenoxy)benzene was described by Arcoria
and Passerini1 while 1,3-bis(4¢-aminophenoxy)benzene
was subsequently prepared by Williams et al. using a sol-
vent-assisted Ullmann synthesis.2 These compounds, de-
rivatives of hydroquinone and resorcinol and known as
TPE-Q and TPE-R diamines, respectively, are now wide-
ly used in the polymer field. The use of both TPE-Q3 and
TPE-R4 diamines in polyimides was described several
years ago. Much later, diamines derived from catechol,
namely 1,2-bis(2¢- and 4¢-aminophenoxy)benzene and re-
lated substances with aminopyridyl units, were described
by Kurita and Williams;5 synthesis was by chloro dis-
placement in the presence of potassium tert-butoxide and
reported yields were low, extensive purification was need-
ed and the diamines were not widely used. The use of 1,2-
bis(2¢- and 3¢-aminophenoxy)benzene in the synthesis of
polyimides has been reported.6 Now, with a better under-
standing of nucleophilic aromatic displacement reactions,
we are able to demonstrate that the synthesis of pure 1,2-
bis(4¢-aminophenoxy)benzenes and their derivatives, as
well as corresponding 1,3- and 1,4-bis(4¢-aminophen-
oxy)benzenes, has become a relatively easy task. Bis(4¢-
Here we report the synthesis of a number of methyl- and
fluoro-substituted diamines based on simple aromatic di-
ols and principally 1,2-dihydroxybenzenes; some new di-
amines were also prepared from derivatives of
hydroquinone and resorcinol for use in comparative stud-
ies of polymer properties. Diamines in which the central
ring had alkyl or fluoro substituents were synthesised
from variously substituted diols and 1-fluoro-4-nitroben-
zene, with subsequent reduction of the product. Diamines
with methyl substituents in the outer rings were similarly
synthesised from fluoronitrotoluenes and either unsubsti-
tuted or substituted diols. Fluoro substitution in the outer
rings was achieved by employing 1,2-difluoro-4-ni-
trobenzene; the nomenclature scheme adopted is a self-
consistent scheme which allows us to identify reactants
used and products formed unambiguously, see the
Scheme. The fluorine in the 2¢-position, i.e. meta to the ni-
tro group, is practically unreactive under the conditions
used, in dimethylformamide solution in the presence of
potassium carbonate at 130°C, and remains intact. This
contrasts with the synthesis of related dinitriles and diac-
ids where we found that fluoro meta to nitrile is very reac-
tive relative to the corresponding nitro compounds.12 This

June 1998
SYNTHESIS
895
Scheme
melting points and yields of the products are given in Ta-
bles 1, 3 and 5. In all cases results of C,H,N analyses were
in excellent agreement with calculated values. In one case,
the synthesis of 3aBii from 2-methylresorcinol, the dis-
placement was undertaken with 1,4-dinitrobenzene; this
reaction was also highly efficient and gave a high yield of
product after two hours reaction.
study therefore generalises and completes the syntheses of
substituted bis(4¢-aminophenoxy)benzenes from hydro-
quinone, resorcinol and catechol derivatives from com-
mercially available diols in order to provide monomers for
studies of structure–property relationships in several
types of polymers.
For all syntheses of dinitrophenoxy ethers reported here
we preferred to use fluoro-displacement reactions from
fluoronitrobenzenes rather than the less expensive chlo-
ronitrobenzenes, used in some previous cases, because of
the higher yields and purity of the products.
Fluoro displacements from 1a,c,d are relatively straight-
forward, only one mode of displacement and formation of
ether linkage is possible. With 1b two modes of displace-
ment are potentially feasible. It is normally considered
that the nitro group will activate a para fluorine and not a
meta fluorine for nucleophilic displacement. However,
we recently demonstrated that a nitrile group will activate
meta fluorine towards displacement in the presence of po-
tassium carbonate in aprotic solvents, albeit at a higher
temperature than was necessary for efficient para-fluoro-
displacement reactions.12 In supplementary experiments
we have demonstrated that fluoro displacement from 1-
fluoro-4-nitrobenzene is efficient but displacement from
1-fluoro-3-nitrobenzene does not occur under comparable
conditions. Thus, the fluoro displacement from 1,2-diflu-
oro-4-nitrobenzene should be selective with only the
para-fluoro group being displaced. This proved to be the
case in displacement reactions involving 1b where with
2Ai, 2Bi, 2Ci, and 2Cv only one fluorine was displaced,
see NMR data later.
The diamines described in this paper have now been used
in the synthesis of poly(ether imide)s, poly(ether amide)s
and poly(azomethine)s with a variety of dianhydrides, di-
acids and dialdehydes, respectively. The synthesis and
properties of those polymers will be presented separately
where the effects of different substitution patterns (i.e.
ortho-, meta- and para-linkages), as well as the influences
of alkyl and fluoro substituents, on polymer properties
will be compared.
Results and Discussion
The overall reaction scheme employed for the synthesis of
bis(ether amine)s is summarised in the Scheme where, in
the first step, 1-fluoro-4-nitrobenzene (1a) or a derivative
1b–d is reacted with a dihydroxybenzene or substituted All of the bis(4¢-nitrophenoxy)benzenes prepared were
derivative 2A,B,C,i–viii, in the presence of potassium readily reduced by hydrazine in the presence of palladi-
carbonate, to produce a bis(4¢-nitrophenoxy)benzene de- um on charcoal catalyst; yields of the corresponding di-
rivative 3. Reactions were carried out with hydroquinone amines were mostly in excess of 90% and always greater
derivatives 2Ai, 2Aii, 2Aviii, resorcinol derivatives 2Bi, than 80%. Melting points, crystallisation solvents and
2Bii, and catechol derivatives 2Ci, 2Ciii, 2Civ, 2Cv, yields are presented in Tables 2, 4 and 5 ; C, H, N analy-
2Cvi, 2Cvii. In all cases the reactions proceeded readily to ses, in all cases, gave results in excellent agreement with
give high yields, often greater than 90%, of bis(4¢-nitro- calculated values. Identification of compounds by ele-
phenoxy)benzene compound; crystallisation solvents and mental analysis data were confirmed by accurate mass

896
Papers
SYNTHESIS
the syntheses detailed, that is the syntheses of 1,2-bis(4¢-nitrophen-
oxy)benzene and of 1,2-bis(4,-aminophenoxy)benzene, and the pro-
cedures used for other combinations were in the recrystallisation
solvents used, which are given in the tables detailing the mps and
yields of the products.
determinations; the results for three compounds are giv-
en in Table 6.
That, in the case of fluoro displacement from 1,2-difluoro-
4-nitrobenzene, only the para fluorine was displaced
while the meta fluorine remained intact was confirmed by
analysis of NMR spectra. Tables 6 and 7 present the re-
sults of an analysis of NMR spectra for bis(4¢-amino-
phenoxy)benzenes produced from the products of fluoro
displacement from 1,2-difluoro-4-nitrobenzene and hyd-
roquinone, resorcinol and catechol, i.e. 4bAi, 4bBi, and
4bCi, respectivelly. The assignments are based on 1H (400
and 300 MHz), 19F (235 and 280 MHz) and 13C (100 and
75 MHz) spectra with COSY 2-D proton–proton correla-
tions for 4bBi and 4bCi and HECTOR C–H correlations
for 4bAi and 4bBi. In all cases the chemical shifts, split-
ting patterns and coupling constants are consistent with
structures 5 and inconsistent with the isomeric structures
6. For example, F–H couplings are consistent with cou-
pling of F with one ortho, one meta and one para H, as ex-
pected for 5, whereas 6 would require one ortho and two
meta couplings. Other features are also inconsistent with
6, e.g. the calculated chemical shift for C(2¢) in 5 is d =
154.8, with a strong C–F coupling, consistent with the ob-
served doublet at 155.8 and a coupling constant of
242 Hz, while the calculated chemical shift for C(2¢) in (6)
is d = 144.4; there is no peak near this position with strong
coupling to F.
Mps were determined with a Mettler FP-5/FP-50 hot stage attached to
a polarizing microscope using a heating rate of 1°C min–1 and values
1
quoted are uncorrected. H and 13C NMR spectra were recorded (in
Liverpool) on a Bruker AMX-400 spectrophotometer, while 19F spec-
tra were recorded on a Bruker WM250 spectrometer operating at
235 MHz. Accurate molar masses were determined on a VG Analyt-
ical 7070E spectrometer. Masses of molecular ions were also deter-
mined on a TRIO-100 spectrometer.
Synthesis of 1,4-, 1,3- and 1,2-Bis(4¢-nitrophenoxy)benzenes and
Their Derivatives by F1uoro Displacement; General Procedure:
In a three-necked round-bottomed flask, equipped with thermometer,
Dean–Stark trap, magnetic stirring bar and nitrogen inlet, were placed
DMF (100 mL) and the required diol (0.05 mol). The solution was
thoroughly deoxygenated with a stream of N2. Anhyd K2CO3 (12 g)
was added, followed by sufficient toluene or xylene (usually 10–
15 mL) to enable the solution to boil at 130–135°C. Under a stream
of N2, the mixture was brought to the boil and was dewatered (1–
1.5 h). After cooling to 60–70°C, 1-fluoro-4-nitrobenzene (0.1 mol,
plus 10% excess)(or fluoronitrotoluene, in relevant examples) was
added and the mixture was again brought to the boil. The mixture was
Table 1. Characteristics and Analytical Data for 1,2-Bis(4¢-nitro-
phenoxy)benzene and Derivativesa
Substance
Structure
3aCi
mp (°C)
(Solvent)
Yield
(%)
Designation
1,2-bis(4¢-nitrophen-
oxy)benzene
134–135
(EtOH)
98
85
73
94
92
96
3aCv
3-fluoro-1,2-bis(4¢-nitro-
phenoxy)benzene
128.8–130.0
(EtOH)
3aCiii
3aCiv
3aCvi
3aCvii
3-methyl-1,2-bis(4¢-nitro-
phenoxy)benzene
117.5–119.0
(EtOH)
4-methyl-1,2-bis(4¢-nitro-
phenoxy)benzene
112–113
(EtOH)
4-tert-butyl-1,2-bis(4¢-
nitrophenoxy)benzene
147.2–147.9
(EtOH)
Thus, we have established an efficient route to a wide va-
riety of new diamines which can be used as monomers in
the synthesis of several varieties of aromatic polymers,
namely polyimides, polyamides and poly(azomethine)s.
The various aromatic substitution patterns on the central
aromatic ring and the dispositions of different numbers
and locations of alkyl and fluoro substituents gives rise to
a considerable family of materials which are being used in
the assessment of structure–property relationships.
3,5-di-tert-butyl-1,2-
bis(4¢-nitrophenoxy)ben-
zene
170.8–171.4
[EtOH/toluene
(90:10)]
3cCi
1,2-bis(2¢-methyl-4¢-nitro-
152.4–152.8
(EtOH)
91
83
61
phenoxy)benzene
3dCi
3dCiv
1,2-bis(3¢-methyl-4¢-nitro-
phenoxy)benzene
105.6–107.7
(EtOH)
4-methyl-1,2-bis(3¢-meth-
yl-4¢-nitrophenoxy)ben-
zene
82–84 (EtOH)
All chemicals were used as supplied by major companies including
Aldrich, Fluka and Fluorochem.
3bCi
1,2-bis(2¢-fluoro-4¢-nitro-
phenoxy)benzene
149–151
(EtOH)
90
The procedures used for the synthesis of the dinitro compounds 3 and
subsequent conversion to diamines 4 were identical for all combina-
tions of fluoronitrobenzenes and diols used. The details of a single re-
action sequence are described below. The only differences between
a
Satisfactory elemental analysis obtained: C ± 0.29, H ± 0.04, N ±
0.08.

June 1998
SYNTHESIS
897
Table 2. Characteristics and Analytical Data for 1,2-Bis(4′-amino- refluxed for 3–4 h. Subsequently, some toluene (or xylene) was dis-
phenoxy)benzene and Derivativesa
tilled off and the mixture was poured into a stirred ice-water mixture
(1.5 L). Stirring was continued for a few hours or overnight; the prod-
ucts sometimes solidified very slowly. The product, as a solid crystal-
line mass, was filtered off and washed a few times with water. The
wet cake was dissolved in boiling EtOH, with added Norit decolouris-
ing agent, and was crystallised. This crystallisation procedure applies
to all 1,2- and 1,3-diols used. In the case of the nitrophenoxy deriva-
tives of 1,4-diols the crude product was washed with MeOH (on a fil-
ter) and was recrystallised (boiling BuOH) after decolourisation.
Most dinitro compounds so synthesised were pale yellow, highly
crystalline substances; the resorcinol derivatives were colourless.
Yields and melting points are presented in Tables 1, 3 and 5. The
same procedure was used in the reaction of 2-methylresorcinol with
1,4-dinitrobenzene.
Substance
mp (°C)
(Solvent)
Yield
(%)
Structure
Designation
4aCi
1,2-bis(4¢-aminophen-
oxy)benzene
135–136
(EtOH)
94
(85
pure)
137–138b
4aCv
1,2-bis(4¢-aminophen-
oxy)-3-fluorobenzene
99–l01
(MeOH)
86
93
85
88
82
4aCiii
4aCiv
4aCvi
4aCvii
1,2-bis(4¢-aminophen-
114.3–115.5
(MeOH)
oxy)-3-methylbenzene
Synthesis of 1,4-, 1,3- and 1,2-Bis(4,-aminophenoxy)benzenes and
Their Derivatives; General Procedure:
1,2-Bis(4¢-nitrophenoxy)benzene (0.03 mol), synthesised as de-
scribed above, was dissolved, or partially dissolved/suspended, in
EtOH (800–l200 mL). For 1,4- and 1,3-bis(4¢-nitrophenoxy)ben-
zenes, or derivatives, less EtOH was satisfactory. To the boiling solu-
1,2-bis(4¢-aminophen-
oxy)-4-methylbenzene
164.4–165.0
(EtOH)
1,2-bis(4¢-aminophen-
oxy)-4-tert-butylbenzene
131–132
(EtOH)
1,2-bis(4¢-aminophen-
oxy)-3,5-di-tert-butyl-
benzene
166–167 [(1)
EtOH, (2) cy-
clohexane]
Table 4. Characteristics and Analytical Data for 1,4-Bis(4¢-amino-
phenoxy)benzenesa
Substance
Structure
4aAii
mp (°C)
(EtOH)
Yield
(%)
4cCi
Ci 1,2-bis(4¢-amino-2¢-
126.5–127.0
(cyclohexane/
toluene)
93
methylphenoxy)benzene
Designation
1,4-bis(4¢-aminophen-
oxy)-2-methylbenzene
102–l03
190–191
92
99
4dCi
1,2-bis(4¢-amino-3¢-
methylphenoxy)benzene
123–124
(EtOH)
94
94
4aAviii
1,4-bis(4¢-aminophen-
oxy)-2,3,5-trimethylben-
zene
4dCiv
1,2-bis(4¢-amino-3¢-
methylphenoxy)-4-
methylbenzene
128–130
(MeOH)
4bAi
1,4-bis(4¢-amino-2¢-fluo-
226.5–227
230.4–231
95
93
4bCi
1,2-bis(4¢-amino-2¢-fluo-
51–l52
(MeOH)
93
rophenoxy)benzene
rophenoxy)benzene
a
4cAviii
1,4-bis(4¢-amino-2¢-
methylphenoxy)-2,3,5-
trimethylbenzene
Satisfactory elemental analysis obtained: C ± 0.18, H ± 0.15, N ±
0.26.
b Lit. ref 5.
a Satisfactory microanalysis obtained: C ± 0.19, H ± 0.01, N ± 0.04.
Table 5. Characteristics and Analytical Data for 1,3-Bis(4¢-nitrophen-
oxy)benzenes and 1,3-Bis(4¢-aminophenoxy)benzenesa
Table 3. Characteristics and Analytical Data for 1,4-Bis(4¢-nitrophen-
oxy)benzenesa
Substance
Structure
3aBii
mp (°C)
(Solvent)
Yield
(%)
Substance
Structure
3aAii
mp (°C)
(Solvent)
Yield
(%)
Designation
Designation
2-methyl-1,3-bis(4¢-nitro-
phenoxy)benzene
155.0–155.7
(EtOH)
83b
80
85
82
2-methyl-1,4-bis(4¢-nitro-
phenoxy)benzene
201–202
(BuOH)
92
92
4aBii
3bBi
4bBi
1,3-bis(4¢-aminophen-
oxy)-2-methylbenzene
52.2–152.6
(MeOH)
3aAviii
2,3,5-trimethyl-1,4-
bis(4¢-nitrophenoxy)ben-
zene
193–194
(BuOH)
1,3-bis(2¢-fluoro-4¢-nitro-
phenoxy)benzene
81–82
(MeOH)
3bAi
1,4-bis(2¢-fluoro-4¢-nitro-
phenoxy)benzene
192–193
(BuOH)
92
96
1,3-bis(4¢-amino-2¢fluo-
ro-phenoxy)benzene
113.4–114.1
[toluene/cyclo-
hexane (1:3)]
3cAviii
2,3,5-trimethyl-1,4-
bis(2¢-methyl-4¢-nitro-
phenoxy)benzene
24–225
(BuOH/EtOH)
a Satisfactory microanalysis obtained: C ± 0.13, H ± 0.03, N ± 0.06.
b Synthesised by nitro displacement from 1,4-dinitrobenzene in DMF
in the presence of K2CO3 at 130°C, 2 h.
a Satisfactory microanalysis obtained: C ± 0.17, H ± 0.07, N ± 0.05.

898
Papers
SYNTHESIS
1
Table 6. Accurate Molar Masses, H and 19F NMR Chemical Shifts
(d) and Coupling Constants
tion/suspension, 10% Pd/C (0.3 g) was added. To the mixture, boiling
under reflux, hydrazine monohydrate (35 mL) was added over a peri-
od of 1 h. Refluxing was continued for a period of 3 h after which the
catalyst was filtered off from the colourless hot solution of diamine.
The volume of the solution was reduced to 10% by rotary evapora-
tion. The diamine was precipitated by addition of water and was fil-
tered off and washed twice with water. The wet diamine cake was
recrystallised from the smallest possible volume of EtOH to yield,
usually, snow-white diamine of monomer purity. Some diamines
based on methyl-substituted catechols are very soluble and were re-
crystallised (MeOH) and the mother liquor was worked up to recover
the full yield of product. Yields and mps are presented in Tables 2, 4
and 5.
Accurate Mass (Dalton) Observed
Calculated
4bAi
4bBia
4bCia
328.1017
328.1017 328.1020 328.1023
d
H (2, 3, 5, 6)
H (2)
H (4, 6)
H (5)
6.89
6.72
6.56
6.52
7.13
6.37
6.42
7.07
6.72
6.77
6.12
6.20
6.56
H (3, 6)
H (4, 5)
H (3¢)
~6.82
~6.92
6.50
6.40
6.92
6.63
6.53
6.94
6.49
6.40
6.91
The authors wish to thank EPSRC for financial support (GR/K80235)
and Dr M. Gibas and M. Sowa of The Technical University, Gliwice,
Poland for assistance with some of the NMR spectroscopy.
H (5¢)
H (6¢)
F (2¢)
–127.9
J (Hz)
(1) Arcoria, A.; Passerini, R. Atti. accad. Gioenia sci. nat. Catania
1957, 11, 184.
(2) Williams, A. L.; Kinney, R. E.; Bridger, F. J. Org. Chem. 1967,
32, 2501.
(3) Koton, M. M.; Rudakov, A. P.; Frenkel, S. Ya. Vestn. Akad.
Nauk SSSR. 1966, 36, 56.
J2-4,6
J5-4.6
J3¢ 5¢
J5¢ 6¢
J3¢ F
J5¢ F
J6¢ F
~2.3
~8.1
2.69
8.55
11.96
1.23
2.53
8.69
13.34
1.23
2.69
8.79
11.96
1.22
Dr Beck and Co. GmbH Br. Patent 1030026, 1966; Chem. Ab-
str. 1966, 65, 10807.
9.38
8.78
8.79
(4) Gall, W. G. Fr. Patent 1365545, 1964; Chem. Abstr. 1965, 62,
7898.
a See ref 13.
Enderey, A. L. U. S. Patent 3179631, 1965 ; Chem. Abstr. 1965,
63, 16503.
(5) Kurita, K.; Williams, R. L. J. Polym. Sci., Polym. Chem. Ed.
1974, 12, 1809.
(6) Gannett, T. P.; Gibbs, H. H. U. S. Patent 4576857, 1986; Chem.
Abstr. 1990, 112, 57047.
(7) Eastmond, G. C.; Paprotny, J. Polymer 1994, 35, 5148.
Eastmond, G. C.; Paprotny, J. Macromolecules 1996, 29, 1382.
(8) Eastmond, G. C.; Paprotny, J. U. S. Patent filed 1995; WO 97/
00903, 1996.
(9) Beilstein CrossFireplusReactions Database from Beilstein In-
formationssysteme GmbH, Frankfurt Germany.
(10) Yang, C.-P.; Chen, W.-T. Macromolecules 1993, 26, 4865.
(11) Yang, C.-P.; Cherng, J.-J. J. Polym. Sci., Part A, Polym. Chem.
1995, 33, 2209.
(12) Eastmond, G. C.; Paprotny, J. J. Mater. Chem. 1997, 7, 1321.
(13) NMR spectra were recorded and analysed by M. Gibas and M.
Sowa at The Technical University, Gliwice, Poland with the aid
of a Varian 300 MHz spectrometer.
Table 7. 13C NMR Chemical Shifts (d) and Coupling Constants
Observed
Calculated
4bAi
4bBia
4bCia
d
C (1, 4)
C (2, 3, 5, 6)
C (1, 3)
C (2)
C (4, 6)
C (5)
154.7
117.4
152.6
120.7
157.7
109.7
114.0
131.7
148.3
120.7
125.0
135.0
154.8
103.9
143.6
112.3
121.4
159.9
104.4
109.4
129.9
C (1, 2)
C (3, 6)
C (4, 5)
C (1¢)
148.0
117.2
123.0
135.3
154.7
103.8
144.0
110.7
123.0
133.1
155.8
102.6
148.4
110.8
124.2
134.1
155.2
103.7
144.6
110.8
123.9
C (2¢)
C (3¢)
C (4¢)
C (5¢)
C (6¢)
J (Hz)
J1¢-F
J2¢-F
J3¢-F
J4¢-F
J5¢-F
J6¢-F
12.8
242
20.8
9.4
1.6
3.2
11.7
240.6
21.2
9.6
11.3
240.2
21.7
9.1
2.9
a See ref 13.