Model reactions for preparing poly(imino-tetrafluoro-1,4-phenylene)

Article abstract of DOI:10.1016/j.jfluchem.2006.06.019

2,3,4,5,6-Pentafluoroformanilide was prepared giving, in addition, two new compounds 4,5,6,7-tetrafluoro-1-pentafluorophenyl-benzimidazole and 2,3,4,5-tetrafluoro-6-[(pentafluorophenyl)amino]formanilide. Sodium 2,3,4,5,6-pentafluoro-formanilide was reacted with hexafluorobenzene in a molar ratio of 1:4 to give oligomers of α-pentafluorophenyl-ω-fluoro-poly(imino-tetrafluoro-1,4-phenylene). Some of the oligomers were isolated. The results indicate that poly(imino-tetrafluoro-1,4-phenylene) could be formed. Model reaction on hexafluorobenzene with sodium acetanilide, molar ratio 1:2, gave a low yield of N,N′-diacetyl-diphenyl-tetrafluoro-1,4-phenylenediamine.

Full text of DOI:10.1016/j.jfluchem.2006.06.019

Journal of Fluorine Chemistry 127 (2006) 1505–1509
www.elsevier.com/locate/fluor
Model reactions for preparing poly(imino-tetrafluoro-1,4-phenylene)
*
Rolf Koppang
Section for Biomaterials Science, Institute of Clinical Dentistry, University of Oslo, Box 1052 Blindern, 0316 Oslo, Norway.
Received 13 March 2006; received in revised form 27 June 2006; accepted 28 June 2006
Available online 4 July 2006
Abstract
2,3,4,5,6-Pentafluoroformanilide was prepared giving, in addition, two new compounds 4,5,6,7-tetrafluoro-1-pentafluorophenyl-benzimidazole
and 2,3,4,5-tetrafluoro-6-[(pentafluorophenyl)amino]formanilide. Sodium 2,3,4,5,6-pentafluoro-formanilide was reacted with hexafluorobenzene
in a molar ratio of 1:4 to give oligomers of a-pentafluorophenyl-v-fluoro-poly(imino-tetrafluoro-1,4-phenylene). Some of the oligomers were
isolated. The results indicate that poly(imino-tetrafluoro-1,4-phenylene) could be formed. Model reaction on hexafluorobenzene with sodium
acetanilide, molar ratio 1:2, gave a low yield of N,N0-diacetyl-diphenyl-tetrafluoro-1,4-phenylenediamine.
# 2006 Elsevier B.V. All rights reserved.
Keywords: Synthesis; 2,3,4,5,6-Pentafluoroformanilide; Oligomers of poly(imino-tetrafluoro-1,4-phenylene)
1. Introduction
isolated together with 1 from the previously described reaction
[6] (Scheme 1). 3 and 4 seemed to be formed from a nucleophilic
attack by lithium pentafluoroanilide on pentafluoroformanilide.
The lithium pentafluoroformanilide will not form a nucleophile
strong enough to react with itself. The sodium pentafluorofor-
manilidedidnotreactwithhexafluorobenzeneintetrahydrofuran
until dimethylformamide was added (Scheme 3). In contrast,
lithium pentafluoroanilide reacted readily with hexafluoroben-
zeneintetrahydrofuranindicatingthatlithiumpentafluoroanilide
is a stronger nucleophilic reagent than lithium pentafluorofor-
manilide or sodium pentafluoroformanilide [7].
Poly(imino-1,4-phenylene) has attracted growing attention
as a material used in electrochemical devices and for battery
electrodes [1–3]. Reacting hexafluorobenzene with sodium N-
methylformamide or sodium formanilide gave 1,4-disubsti-
tuted compounds in good yields [4,5] indicating that
poly(imino-tetrafluoro-1,4-phenylene) ought to be formed by
reacting hexafluorobenzene with sodium 2,3,4,5,6-pentafluor-
oformanilide.
It has previously been shown that some solvents strongly
influence the direction of substitution in some pentafluor-
ophenyl compounds [8,9].
2. Results and discussion
2.1. Preparation of 2,3,4,5,6-pentafluoroformanilide
Dimethylformamide, as a good dipolar aprotic solvent, may
have interfered with the reagents giving an intermediate
complex, Scheme 2. Compound 3 has probably been formed
through that complex.
2,3,4,5,6-Pentafluoroformanilide (1) was prepared from
pentafluoroaniline and lithium amide in dimethylformamide
as previously described (Scheme 1) [6]. The amount of starting
materials was increased compared to the previous report,
resulting in the isolation of two new compounds, 4,5,6,7-
tetrafluoro-1-pentafluorophenyl-benzimidazole (2) and 2,3,4,5-
tetrafluoro-6-[(pentafluorophenyl)amino]formanilide (3). The
yield of 3 was better than that of 2,3,5,6-tetrafluoro-4-
[(pentafluorophenyl)amino]formanilide (4), the only compound
Only traces of 2 were isolated. This compound is believed to
have been formed by a cyclization of 3. 1,2,3,4,6,7,8,9-
Octafluoro-5-formyl-10-hydrophenazine was not formed from
the lithium compound of 3, believed to be present during the
reaction. An attempt at chemical cyclization of 2-aminonona-
fluorodiphenylamine, using sodium hydride and n-butyl lithium
to give 1,2,3,4,6,7,8,9-octafluoro-5,10-dihydrophenazine, was
unsuccessful [10]. Nevertheless, 4,5,6,7-tetrafluoroimidazole
was formed by reacting 3,4,5,6-tetrafluoro-1,2-phenylenedia-
mine with formic acid or formaldehyde and hydrochloric acid
* Tel.: +47 22 84 03 01; fax: +47 22 84 03 02.
E-mail address: koppang@odont.uio.no.
0022-1139/$ – see front matter # 2006 Elsevier B.V. All rights reserved.
doi:10.1016/j.jfluchem.2006.06.019

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R. Koppang / Journal of Fluorine Chemistry 127 (2006) 1505–1509
Scheme 1.
rafluoro-1,4-phenylenediamine (6) could be isolated together
with traces of a-pentafluorophenyl-v-fluoro-tri(imino-tetra-
fluoro-1,4-phenylene) (7), N-formyl-N,N0-decafluorodiphenyl-
tetrafluoro-1,4-phenylenediamine (8), and N-formyl-4,40-bis
[(pentafluorophenyl)amino]-2,20,3,30,5,50,6,60-octafluorodiphe-
nylamine (9) (Scheme 3). Hydrolyzed or partially hydrolyzed
compounds seem to have been formed during the quenching of
the reaction mixture. Thin layer chromatography of the rest from
the reaction mixture contained 7 and a series of other compounds
believed to belong to the same series of compounds as isolated.
No 2,3,4,5,6-pentafluoroformanilide was recovered from the
reaction mixture.
Scheme 2.
[11]. The results described in this paper seem to be in
agreement with those of Professor Tatlow’s group [10,11].
2-Aminononafluorodiphenylamine was not obtained from
the hydrolyzed reaction mixture. This indicates that the
formyl compound is relatively stable. Attempts to hydrolyze
4 in a mixture of ethanol and sodium hydroxide were
unsuccessful.
The results indicate that a poly(imino-tetrafluoro-1,4-
phenylene) could be formed.
2.3. Hydrolysis of separated formyl compounds
2.2. Preparation of the oligomers
Hydrolysis of 8 and 9 gave the linear compounds 6 and 7
(Scheme 3).
No reaction seemed to take place between sodium
pentafluoroformanilide and hexafluorobenzene in tetrahydro-
furan. Dimethylformamide was therefore added to the reaction
mixture. The addition of sodium pentafluoroformanilide to
hexafluorobenzene seemed to be the rate dependent reaction.
When N,N-decafluorodiphenylformamide was formed, the
further substitution reactions seemed to run smoothly. To obtain
as large a proportion of oligomers as possible for separation, a
four-fold amount of hexafluorobenzene was used to the reaction
(Scheme 3).
Dissolving a sample of 6 relativelyquickly resultedin a strong
reddishcolor of the solution. Thediscolorationof6in solid, dried
form was slow. 7 gave a bluish tint to the red. Purification of a
colored, dissolved sample of 6 on a silicate column gave almost
no red material, which is believed to be an oxidation product.
2.4. Reaction of hexafluorobenzene with acetanilide
A reaction between hexafluorobenzene and sodium acet-
anilide, molar ratio 1:2, resulted in 2.8% 2,3,4,5,6-pentafluoro-
N-phenylacetanilide (10) and 14.4% N,N0-diacetyl-N,N0-diphe-
nyl-tetrafluoro-1,4-phenylenediamine (11) (Scheme 4). No
reaction occurred between lithium acetanilide and hexafluor-
obenzene in tetrahydrofuran [13].
In an attempt to prevent hydrolysis of the compounds formed,
the reaction mixture was cooled to 0 8C and a 20% (v/w)
hydrogen chloride solution was added as quickly as possible. It
has previously been shown that N,N-decafluorodiphenylforma-
mide is stable in an acidic solution [12]. When hexafluor-
obenzene was reacted with the sodium N-methylformamide or
sodium formanilide, the N,N0-disubstituted compounds could be
obtained along with hydrolyzed and partially hydrolyzed
compounds after hydrolysis of the reaction mixture [4,5]. From
the hydrolyzed reaction mixture as pure compounds, only
decafluorodiphenylamine (5) and N,N0-decafluorodiphenyl-tet-
The use of sodium 2,3,4,5,6-pentafluoro-acetanilide to
obtain poly(imino-tetrafluoro-1,4-phenylene) after hydrolysis,
therefore seems little fruitful.
2.5. Spectroscopic results
Mass spectra of the formanilides concurred with the normal
pattern [M+ ꢀ CO]. 3 gave a strong peak at m/z 355.9989
Scheme 3.
Scheme 4.

R. Koppang / Journal of Fluorine Chemistry 127 (2006) 1505–1509
1507
indicating the presence of 2[+] (m/z calc.: 355.9996) and the
strongest peak at m/z 326.0093, which is believed to indicate the
presence of 5,10-dihydrooctafluorophenazine [+] (m/z calc.:
326.0085) (obtained by electrolysis of 2-aminononafluorodi-
phenylamine [10]) in the mass spectrum.
Hydrolysis of 8 and 9 was performed by a slow elution from a
neutral alumina column (approximately 30 cm high and 2 cm in
diameter) with a mixture of acetone and light petroleum (3:1).
When hydrolysis was not complete, for 9, the material was
added to the same column again.
1H NMR of pentafluoroformanilide did not show any
presence of cis and trans isomers in acetone-d6 [6,14]. This
has been attributed to a very strong hydrogen bonding
between the acetone-d6 and the solute [6]. The same situation
is possible with the new formyl compounds. The fluorine
shifts of the formyl compounds showed two isomers
indicative of the presence of cis and trans isomers. Based
on previous findings [4,6], the signals at the lowest field
seemed to be the trans isomer, i.e. when the carbonyl and the
heaviest groups have a trans relationship to each other. For
compound 9, 19F NMR indicated that only one of the isomers
was present. It has previously been reported that only one of
the isomers could be observed in the solution when the
solubility of a formanilide was too low [15]. In one report
only one of the isomers of 4 was identified [6]. From a new
19F NMR-spectrum of 4, the presence of both cis and trans
isomers at room temperature could be shown. NMR analyses
at different concentrations were not performed, as the focus
only was to confirm that the formyl compounds, 8 and 9, were
linear, which was also demonstrated for the hydrolyzed
compounds 6 and 7.
3.2. Reaction of pentafluoroanilide with
dimethylformamide
Lithium amide (0.28 mol, 6.4 g) was added to pentafluor-
oaniline (0.12 mol, 22.0 g) in dried tetrahydrofuran (40 ml) at
0 8C, and then dimethylformamide (30 ml) was added after
20 min. The mixture was slowly heated and refluxed for 4 h,
cooled and worked up.
Pentafluoroformanilide was extracted from the crude
products with hot water, extracted with diethyl ether, dried
and chromatographed giving in the following equation.
3.2.1. 10.8 g (49.0%) 2,3,4,5,6-Pentafluoroformanilide (1)
[6]
IR (KBr): n 3212(s,br), 1682(s), 1651(m), 1550(m), 1526(s),
1499(s), 1395(m), 1211(s), 1117(s), 1018(w), 1000(s), 972(s),
865(s), 694(m).
Remaining compounds on the column was washed off with
acetone, dried and added to the rest of the dried crude materials.
Further work-up on silica gel columns gave yet three more
compounds.
3. Experimental
The NMR spectra were obtained with a Varian Gemini 200
and a Varian VXR 300 S spectrometer at 24 8C. The 19F
chemical shifts are reported with respect to CCl3F [with C6F6
and C6H6CF3 as secondary references (ꢀ164.9 and
ꢀ63.732 ppm[16])]. The accuracy of the shifts is ꢁ0.01. The
1H chemical shifts are reported with reference to SiMe4. All
spectra were recorded in deuterated acetone unless otherwise
stated. The fluorines in the ortho positions belonging to
AA0XX0M and AA0XX0 spin systems have been given as
doublets (d), as shown in the spectra, and not as pseudo-
doublets (ps-d). Mass spectroscopy data were obtained with a
VG Micromass 7070E instrument with data system VG 11–
250J. IR spectra were obtained from a FT-IR spectrometer, Bio-
Rad Laboratories, Digilab Merlin 3.4.
3.2.2. (0.15 g) 4,5,6,7-Tetrafluoro-1-pentafluorophenyl-
benzimidazole (2) (nc) mp 92–93.5 8C (sublimed)
EIMS 70 eV, m/z (rel. int.): 357(15), 356(100), 337(7),
310(13), 279(7), 156(13), 117(11). HRMS: C13H1F9N2 requires
355.9996, Found 355.9990.
19F NMR:
d
ꢀ144.09(d), ꢀ149.57(t), ꢀ151.61(t),
ꢀ159.30(m), ꢀ159.85(t), ꢀ162.58(t), rel. int.: 2:1:1:3:1:1.
1H NMR: d 8.51.
IR (KBr): n 3140(w), 3093(w), 1547(s), 1520(s), 1478(m),
1314(w), 1288(w), 1223(m), 1155(w), 1056(m), 995(s), 835(w),
810(m).
3.2.3. 1.9 g (8.5%) 2,3,4,5-Tetrafluoro-6-
[(pentafluorophenyl)amino]formanilide (3) (nc) mp 160–
161.5 8C
3.1. General methods
EIMS 70 eV, m/z (rel. int.): 375(20), 374(85), 357(32),
356(96), 346(32), 327(24), 326(100), 325(55), 307(30),
306(32), 179(23), 156(21), 152(19). HRMS: C13H3F9N2O
requires 374.0102, Found 374.0102.
19F NMR: (trans) d ꢀ147.89(m), ꢀ153.95(m), ꢀ156.74(d),
ꢀ161.75(t), ꢀ166.43(m), ꢀ169.14(t), rel. int.: 1:1:2:1:3:1 (2F
from the cis isomer is included in the multiplet centered at
ꢀ166.43), (cis) d ꢀ151.48(m), ꢀ153.18(m), ꢀ156.17(d),
ꢀ162.11(t), ꢀ165.34(t),ꢀ166.43(m),ꢀ168.65(t), rel. int.:
1:1:2:1:1:2:1 (3F from the trans isomer is included in the
multiplet centered at ꢀ166.43). 1H NMR: d (>NH) 7.3 (broad),
(–CHO) 8.39, 8.31, (–NHCHO) 9.3 (broad).
All reactions were performed under oxygen-free nitrogen.
Reaction mixtures were cooled on an ice bath, and diethyl ether
was added (30–50 ml), followed by hydrolysis with HCl (10%
or 20% v/w) to give an acidic mixture, extracted with diethyl
ether, dried with anhydrous sodium sulfate, concentrated and
chromatographed on silica (230–400 mesh) starting with light
petroleum (bp 60 8C) as the elution solvent. When no more
could be eluted from the mixture, increasing amounts diethyl
ether or acetone were added to the light petroleum. When
necessary, additional chromatography or recrystallization was
performed using a mixture of light petroleum and diethyl ether.

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R. Koppang / Journal of Fluorine Chemistry 127 (2006) 1505–1509
IR (KBr): n 3289(s), 1675(s), 1521(s), 1497(w), 1431(m),
1395(m), 1220(w), 1116(m), 1034(s), 1007(s), 976(w), 954(w),
870(m).
3.3.4. 0.97 g (27.2%) N-Formyl-N,N0-decafluorodiphenyl-
tetrafluoro-1,4-phenylene-diamine (8) (nc) mp 143.5–
145.5 8C
EIMS 70 eV, m/z (rel. int.): 541(11), 540(51), 513(21),
512(100), 345(30), 256(11). HRMS: C19H2F14N2O requires
539.9944, Found 539.9969. (Ionization with methane gave a
trace signal at 569(0.67) which could indicate N,N0-diformyl-
N,N0- dipentafluorophenyl-tetrafluoro-1,4-phenylenediamine.)
19F NMR: (trans) d ꢀ141.88(d), ꢀ146.56(d), ꢀ148.78(d),
ꢀ151.86(t), ꢀ153.46(d), ꢀ159.63(t), ꢀ160.35(t), ꢀ161.86(m),
rel. int.: 2:2:2:1:2:1:2:2, (cis) d ꢀ143.89(d), ꢀ144.64(d),
ꢀ148.97(d), ꢀ152.10(t), ꢀ153.73(d), ꢀ159.92(m), ꢀ161.86
3.2.4. 1.1 g (4.9 %) 2,3,5,6-Tetrafluoro-4-
[(pentafluorophenyl)amino]formanilide (4) [6]
19F NMR: (trans) d ꢀ148.35(m), ꢀ154.52(d), ꢀ157(m),
ꢀ166.09(m) rel. int.: 2:2:2:3 (3F from the cis isomer is included
in the multiplet centered at ꢀ166.09), (cis) d ꢀ153.48(m),
ꢀ154.70(d), ꢀ156.28(m), ꢀ166.09(m), rel. int.: 2:2:2:3 (3F
from the trans isomer is included in the multiplet centered at
ꢀ166.09).
1
(m), rel. int.: 2:2:2:1:2:3:2. H NMR: d (>NH) 8.63, (–CHO)
1H NMR: d (>NH) 7.9 (broad), (–CHO) 8.47, (–NHCHO)
9.1 (broad).
8.66.
IR (KBr): n 3240(br,m), 3005(w), 1714(s), 1653(m), 1555
(w), 1514(br,s), 1467(w), 1329(m),1256(s), 1162(m), 1113(m),
1065(s), 1030(m), 981(s), 924(m), 807(m).
IR (KBr): n 3429(m), 3208(m), 1682(s), 1655(m), 1549(s),
1530(s), 1515(s), 1495(s), 1445(m), 1397(m), 1212(m), 1182
(m), 1117(m), 1034(s), 1001(m), 976(m), 959(m), 861(m),
814(w).
3.3.5. 0.36 g (10.2%) N-Formyl-4,40-
bis[(pentafluorophenyl)amino]-2,20,3,30,5,50,6,60-
octafluorodiphenylamine (9) (nc) mp 142–144 8C
EIMS 70 eV, m/z (rel. int.): 705(2), 704(12), 703(41,),
677(4), 676(27), 675(100), 674(7), 508(9), 507(1), 493(2),
474(1), 473(2),347(2), 346(2), 345(13), 340(1.6), 338(4.4),
337.4(16), 311(2.3), 310(3.2), 280(2.0), 279(2.0)248(2.4).
HRMS: C25H3F18N3O requires 702.9989, Found 702.9961.
19F NMR: d ꢀ144.05(d), ꢀ146.82(d), ꢀ148.87(d), ꢀ149.09
(d), ꢀ153.36(d), ꢀ153.67(d), ꢀ159.87(t), ꢀ160.25(t), ꢀ161.88
(m), rel. int.: 2:2:2:2:2:2:1:1:4. 1H NMR: d (>NH) 8.11, (–CHO)
8.65.
3.3. Reaction of pentafluoroformanilide with
hexafluorobenzene
Sodium hydride (0.022 mol, 0.96 g, 55% in oil) was added
to pentafluoroformanilide (0.02 mol, 4.22 g) in tetrahydro-
furan (35 ml) at 0 8C and the mixture was stirred overnight at
ambient temperature. Hexafluorobenzene (0.08 mol, 14.88 g)
in tetrahydrofuran (5 ml) was added in a single portion at
0 8C. The mixture was stirred for 1 h followed by the
addition of dimethylformamide (10 ml). The temperature
was raised to light reflux and maintained for 3.5 h. The
mixture was cooled to 0 8C, diethyl ether (50 ml) was added,
followed by 20% HCl (50 ml) in one portion, and worked up.
From the reaction mixture some of the lower oligomers were
isolated.
IR (KBr): n 3432(m), 3315(m), 1715(s), 1652(m), 1514(s),
1247(m), 1175(w), 1071(s), 1021(s), 1021(s), 978(s), 822(w),
793(w).
3.4. Hydrolysis of isolated formyl compounds
Hydrolysis of N-formyl-N,N0-dipentafluorophenyl-1,4-tetra-
fluorophenylenediamine (0.14 g) gave (0.08 g) N,N0-dipenta-
fluorophenyl-1,4-tetrafluorophenylene-diamine (6).
Hydrolysis of N-formyl-4,40-bis[(pentafluorophenyl)amino]-
2,20,3,30,5,50,6,60-octafluorodiphenylamine (0.15 g) gave
(0.08 g) a-pentafluorophenyl-v-fluoro-tri(imino-tetrafluoro-1,
4-phenylene) (7) (nc) mp 245–246 8C.
3.3.1. 0.32 g (9.2%) Decafluorodiphenylamine (5)
This compound has previously been described [7].
3.3.2. 0.60 g (17.6%) N,N0-decafluorodiphenyl-tetrafluoro-
1,4-phenylenediamine (6) (nc) mp 183–184 8C
EIMS 70 eV, m/z (rel. int.): 513(23), 512(100), 345(32),
256(12). HRMS: C18H2F14N2 requires 511.9994, Found
512.0003.
19F NMR (Gemini 200): d ꢀ157.41(s), ꢀ158.49(m),
ꢀ168.29(m), ꢀ170.24 (t of t), rel. int.: 4:4:4:2. 1H NMR
(tetrahydrofuranD): d 7.77.
19F NMR: d ꢀ151.81(m), ꢀ152.70(d), ꢀ152.86(d), ꢀ162.28
(t), ꢀ164.31(t), rel. int.: 4:4:4:4:2. 1H NMR: d (>NH) 7.58.
IR (KBr): n 3429(m), 1561(m), 1522(s), 1511(s), 1478(w),
1447(m), 1314(w), 1258(w),1062(m), 1040(m), 968(m), 788
(w), 651(w).
IR (KBr): n 3430(m), 1559(m), 1522(s), 1511(s), 1470(w),
1445(m), 1313(w), 1260(w),1056(m), 1034(m), 967(m), 800
(w), 650(w).
3.5. Reaction of acetanilide with hexafluorobenzene
To acetanilide (0.042 mol, 5.68 g) in tetrahydrofuran (30 ml)
at0 8Csodiumhydride (0.042 mol, 2.03 g, 55%inoil)wasadded
giving sodium acetanilide. The temperature was raised slowly to
ambient whereupon the mixture was cooled in a bath with tap
water. Then hexafluorobenzene (0.02 mol, 3.72 g) in tetrahydro-
furan (10 ml) and dimethylformamide (10 ml) was added in one
3.3.3. Traces of a-pentafluorophenyl-v-fluoro-tri(imino-
tetrafluoro-1,4-phenylene) (7) (nc)
mp and IR were in accordance with the hydrolyzed
compound obtained from N-formyl-4,40-bis[(pentafluorophe-
nyl)amino]-2,20,3,30,5,50,6,60-octafluorodiphenylamine (9).

R. Koppang / Journal of Fluorine Chemistry 127 (2006) 1505–1509
1509
portion to the sodium acetanilide. The temperature in the mixture
wasslowlyraised(1 h)tolightrefluxandthemixturewasrefluxed
for 3 h, cooled, hydrolyzed and worked up to give the following.
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3.5.1. 0.17 g, (2.8%) 2,3,4,5,6-Pentafluoro-N-
phenylacetanilide (10)
This compound has previously been described [14].
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[5] R. Koppang, J. Fluorine Chem. 74 (1995) 177–179.
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1254.
3.5.2. 1.2 g, (14.4%) N,N’-diacetyl-N,N’-diphenyl-
tetrafluoro-1,4-phenylenediamine (11) (nc) mp 252–
252.5 8C.
EIMS 70 eV, m/z (rel. int.): 418(2), 417(5), 416(24),
375(16), 374(69), 334(3), 333(22), 332(100),331(8), 292(4),
291(7), 255(3), 254(5), 241(3), 240(6), 43(20). HRMS:
C22H16N2O2F4 requires 416.1148, Found, 416.1132.
19F NMR (CDCl3): d ꢀ144.10(br. band), ꢀ145.97(s),
ꢀ146.34(br. band) (amount: 1.00:4.84:1.00) 1H NMR (CDCl3):
d (ꢀC6H5) 7.40, 7.37, 7.24, (ꢀCH3) 2.04(s) (amount 5:3).
IR (KBr): n 1691(s), 1595(m), 1497(s), 1371(m), 1325(w),
1302(s), 1248(w), 1067(w), 1030(w), 977(m), 969(m), 751(m),
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