Selective synthesis and radical polymerization of N-vinyl-2-(1-naphthyl)- and N-vinyl-2-(2-naphthyl)pyrroles

Full text of DOI:10.1134/S001250081009003X

ISSN 0012ꢀ5008, Doklady Chemistry, 2010, Vol. 434, Part 1, pp. 219–222. © Pleiades Publishing, Ltd., 2010.
Original Russian Text © M.V. Markova, L.V. Morozova, I.V. Tatarinova, A.I. Mikhaleva, Sang Heon Hyun, E.Yu. Shmidt, N.V. Zorina, G.F. Myachina, B.A. Trofimov, 2010,
published in Doklady Akademii Nauk, 2010, Vol. 434, No. 1, pp. 65–69.
CHEMISTRY
Selective Synthesis and Radical Polymerization
of NꢀVinylꢀ2ꢀ(1ꢀnaphthyl)ꢀ
and NꢀVinylꢀ2ꢀ(2ꢀnaphthyl)pyrroles
M. V. Markovaa, L. V. Morozovaa, I. V. Tatarinovaa,
A. I. Mikhalevaa, Sang Heon Hyunb,
E. Yu. Shmidta, N. V. Zorinaa, G. F. Myachinaa, and Academician B. A. Trofimova
Received March 4, 2010
DOI: 10.1134/S001250081009003X
Rapid development of the chemistry of pyrroles in
2ꢀ(1ꢀNaphthyl)pyrrole is used for preparing boraꢀ
recent decades is caused by their large biological and diazaindacene derivatives with good fluorescence [8].
technical potentiality. Pyrroles are known biologically
A wide range of substituted
becomes available owing to a systematic development
of efficient oneꢀpot synthesis of ꢀvinylpyrroles from
ketoximes and acetylene in superbasic media (the Troꢀ
fimov reaction [9–11]).
Nꢀvinylpyrroles
active compounds and pharmacophores and provide a
basis for preparing various pharmaceuticals, including
antitumor drugs [1–3]. They are of interest as materiꢀ
als for new technologies and design of semiconductors
with prescribed properties [4].
N
With the aim to obtain polymers promising for
designing new electrically conducting materials, we
have developed selective methods for the synthesis of
The presence of the Nꢀvinyl group in the structure
of pyrrole derivatives opens new prospects for the synꢀ
thesis of polymeric materials for contemporary techꢀ
Nꢀvinylꢀ2ꢀ(1ꢀnaphthyl)pyrrole and Nꢀvinylꢀ2ꢀ(2ꢀ
nologies. Thus,
aration of electrically conducting ladder polymers [5].
Poly( ꢀvinylpyrrole) shows high optical absorption in
Nꢀvinylpyrrole was used for the prepꢀ
naphthyl)pyrrole and studied their radical polymerꢀ
ization. These monomers were obtained in 49 and 62%
yields, respectively, from oximes of 1ꢀ and 2ꢀacetylꢀ
N
the visible region and strong luminescence both in
solution and in solid state [6]. A large number of polyꢀ
naphthalenes (1a
molar ratio oxime : KOH = 1 : 1, initial acetylene presꢀ
sure of 12 atm, 90 , 1 h, the target product was
, 1b) and acetylene (KOH/DMSO,
mers of
vinylꢀ and
bis[2ꢀ( ꢀvinyl)pyrrolyl]benzene,
nylpyrrole, 9ꢀmethylꢀ3ꢀ( ꢀvinylpyrrolꢀ2ꢀyl)carbaꢀ
zole, and ꢀvinylꢀ2ꢀ(1ꢀanthracenyl)ꢀ and ꢀvinylꢀ2ꢀ
N
N
ꢀvinylpyrroles and
ꢀvinylꢀ4,5ꢀdihydrobenzo[
ꢀvinylꢀ2,5ꢀdipheꢀ
N
ꢀvinylindoles—
Nꢀ
°
С
g]indoles, 1,4ꢀ
extracted with diethyl ether) [12]. The reaction mixꢀ
ture contained the corresponding NHꢀpyrroles and
the starting oximes along with the target Nꢀvinylpyrꢀ
N
N
N
N
N
roles. This fact hampered the isolation and purificaꢀ
tion of the monomers. In this paper, we describe two
new modifications of this method developed with the
aim to increase the yield and purity of the monomers
intended for polymerization.
(2ꢀanthracenyl)pyrroles—are patented as promising
conducting electrochromic layers of electrooptical
devices (thinꢀfilm displays, fluorescent sensors) [7].
a Favorsky Irkutsk Institute of Chemistry, Siberian Branch,
Russian Academy of Sciences, ul. Favorskogo 1, Irkutsk,
664033 Russia
b Samsung Advanced Institute of Technology,
Display Device & Material Lab. San 14ꢀ1, NongseoꢀDong,
GiheungꢀGu, Yongin, GyeonggiꢀDo 446ꢀ712, Korea
The first modification consists in the preliminary
preparation of oximates 2a and 2b from oximes 1a and
1b and NaOH in a DMSO medium followed by their
treatment with acetylene (Scheme 1).
219

220
MARKOVA et al.
Me
Me
N
CH≡CH
NaOH
DMSO
+ H2O
120°C, 1 h
N
N
ONa
OH
1a
2a
3a
Yield 61%
NaOH
DMSO
CH≡CH
+ H2O
120°C, 1 h
Me
Me
N
N
N
ONa
OH
1b
2b
3b
Yield 64%
Scheme 1.
The second modification is based on the direct use of 2ꢀacetylnaphthalene
NH2OH · HCl–NaHCO3 system and then, after addition of one equivalent of KOH, with acetylene (Scheme 2).
4
, which was initially treated with
1. NH2OH · HCl–NaHCO3/DMSO
2. CH≡CH
Me
N
KOH/DMSO
120°C, 1 h
O
4
3b
Yield 71%
Scheme 2.
nꢀHexane was used as an extractant instead of and 2ꢀarylazoꢀNꢀvinylpyrroles—readily undergo
diethyl ether in both modifications, it allows one to
extract selectively ꢀvinylpyrroles 3a and 3b from
polymerization in the presence of radical initiators to
form linear oligomers containing pyrrole rings in the
side chain (yield 80–90%) [1, 13, 14]. We have found
that, under conditions of freeꢀradical polymerizations
N
reaction mixtures containing residual amount of interꢀ
mediate (not vinylated) 2ꢀ(1ꢀnaphthyl)ꢀ and 2ꢀ(2ꢀ
naphthyl)ꢀNHꢀpyrroles, initial oximes, and acetylꢀ
naphthalenes. These modifications provide a possibilꢀ
ity to obtain monomers 3a and 3b in 99.9% purity in 61
and 71% yields, respectively, which are 11–12%
higher than the yields reported in [12].
(5% of azobis(isobutyronitrile) (AIBN), 80 C, 50–
°
75 h), the yield of oligomers 5a and 5b is 17–30%,
while molecular weight is 2100–2500 (table,
Scheme 3). Reduction in AIBN concentration to 2%
sharply decreases the yield of the oligomers (down
It is known that
methylpyrrole,
Nꢀvinylpyrroles—Nꢀvinylꢀ2ꢀ
ꢀvinylꢀ4,5,6,7ꢀtetrahydroindole, to 4%).
N
AIBN
80°C, 50–75 h
N
N
n
3a
5a
AIBN
80°C, 50–75 h
N
N
n
3b
5b
Scheme 3.
DOKLADY CHEMISTRY Vol. 434
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2010

SELECTIVE SYNTHESIS AND RADICAL POLYMERIZATION
221
Polymerization of Nꢀvinylꢀ2ꢀ(1ꢀnaphthyl)pyrrole (3a) and Nꢀvinylꢀ2ꢀ(2ꢀnaphthyl)pyrrole (3b) and the properties of oligomers
(5a, 5b)
σ
, S/cm
Oligomer
Time, h
Yield, %
Molecular weight
undoped
doped I2
5.3
10–10 d
seec
5aꢀ1a
5aꢀ2a
5bꢀ1a
5bꢀ2a
5bꢀ3a
5bꢀ4b
50
70
50
70
75
70
17
20
20
26
30
4
2100
2200
2300
2400
2500
seec
1.2
4.0
4.2
×
10–14
seec
10–14
×
×
4.3
×
10–8 e
seec
seec
×
10–14
4.7
×
10–8
seec
seec
Notes:The numbers 1–4 in the first column correspond to different polymerization times.
a
b
c
d
e
5% of AIBN, 80°C. 2% of AIBN. Not determined. Content of I is 29.10%. Content of I is 46.19%.
2
2
The obtained oligomers are meltable powders soluꢀ lowed by degradation of the macromolecule at 640–
ble in benzene, chloroform, and THF, insoluble in 660 C. The first exothermic maximum (410 C,
hexane and acetonitrile. The reduced activity of 3a 10 C) accompanied by 50% weight loss is detected for
and 3b in polymerization in comparison with the oligomer 5bꢀ2 in the range of 380–450 C. Destruction
above ꢀvinylpyrroles seems to result from steric facꢀ up to 700 C occurs successively with the second exoꢀ
tors: the bulky naphthyl substituent produces steric thermic maximum in the DTA curve (~600 C,
hindrance for the radical center in the growing macroꢀ 80 C), and the degradation of the molecule completes
radical. at 680–720 C.
Thus, we have developed selective methods for the
synthesis of ꢀvinylꢀ2ꢀ(1ꢀnaphthyl)pyrrole and
°
°
Δ
Т =
°
°
N
°
°
Δ
Т =
°
°
The structure of the obtained oligomers was conꢀ
firmed by 1H NMR and IR spectroscopy. All signals in
the H NMR spectra of compounds 5a and 5b are
N
Nꢀ
1
vinylꢀ2ꢀ(2ꢀnaphthyl)pyrrole, studied for the first time
their radical polymerization, and showed the semiꢀ
conductor properties of the resultant polymers.
broadened, the proton signals of vinyl group (4.45–
4.66, 5.07–5.16, and 6.46–6.92 ppm) disappear; the
wide proton signals of the CH and CH2 groups of the
main polymer chain appear at 3.90 and 4.20 ppm. The
protons of the pyrrole ring (Hꢀ3, Hꢀ4) appear as a
wide signal with a maximum at 6.29–6.31 ppm, and
the proton signals from the fused benzene rings are
detected at 7.88–7.43 and 7.79–7.42 ppm (for 5a and
5b, respectively). The IR spectra of oligomers 5a and
5b show the lack of absorption bands of vinyl group
(3132, 1645, 1312, 1351 (for 5a), 682–687, and
667 cm–1), but the presence of the bands of CH2 and
CH stretching vibrations of the polymer chain at 2955,
2918, 2868, and 2976, 2923, 2858 cm–1 for oligomers
5a and 5b, respectively.
EXPERIMENTAL
The IR spectra of the obtained compounds within
400–4000 cm–1 range were recorded on a Bruker IFS
25 (Germany) spectrophotometer; H NMR spectra
were recorded on a Bruker DPX 400 spectrometer
operating at 400.13 MHz (1H) and 100.6 MHz (13C)
using CDCl3 as a solvent and HMDS as an internal
reference. The thermogravimetric analysis of the polyꢀ
mers was performed on a MOM Qꢀ1500 derivatograph
1
(Hungary), the highest temperature was 700 C, the
°
heating rate in air was 5 K/min, and the sensitivity of
DTA was 1/10. The electrical conductivity of the polyꢀ
mers was measured with the use of an E6ꢀ13A standard
teraohmmeter. Studied specimens were prepared by
pressing pellets at a pressure of 700 kg/cm2.The polyꢀ
mers were doped with iodine by the diffusion method
from a gas phase. The molecular weight of the polyꢀ
mers was determined by the isopiestic method in benꢀ
Oligomers 5a and 5b are highꢀresistance organic
semiconductors (electrical conductivity
σ
= 1.2
×
10⎯ 14 to 4.2
iodine increases the electrical conductivity up to
5.3
10–10–4.7 10–8 S/cm (the content of I2 in the
×
10⎯ 14 S/cm). Doping the oligomers with
×
×
samples is 29.10 and 46.19%).
Differential thermal analysis (DTA) shows that oliꢀ
zene at 60
Monomers 3a and 3b were purified by distillation
prior to polymerization, bp 168–170 C (2 mmHg),
99.9% purity (monitoring by GLC, IR and NMR
°
C [15].
gomers 5aꢀ2 and 5bꢀ2 are stable up to 250 and 350
respectively. Degradation (10% weight loss) begins at
320 and 380 C. The destruction of oligomer 5aꢀ2 proꢀ
ceeds smoothly up to 440 C (weight loss is 55%). The
first exothermic maximum (370 C, = 15 C) is
detected within this temperature range. The second
exothermic maximum ( = 60 C) is detected in the
range of 500–570 C; it results in 80% weight loss folꢀ from oxime 1a. A mixture of 5.00 g (27 mmol) of oxime
°
C,
°
°
°
spectroscopy). AIBN (mp 102
from methanol.
°
C) was recrystallized
°
Δ
Т
°
Δ
Т
°
Synthesis of Nꢀvinylꢀ2ꢀ(1ꢀnaphthyl)pyrrole (3a)
°
DOKLADY CHEMISTRY Vol. 434
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2010

222
MARKOVA et al.
1a and 1.08 g (27 mmol) of NaOH was dissolved in
100 mL of DMSO, heated for 30 min at 100–105
For C16H13N anal. calcd. (%): C, 87.63; H, 5.98;
N, 6.39.
°
C
with vigorous stirring. The resultant homogeneous
solution of sodium oximate was transferred into a
0.5ꢀL steel rotating autoclave, acetylene was supplied,
Found (%): C, 87.36; H, 5.85; N, 6.79.
The polymerization of pyrrole 3b was conducted by
a similar procedure. The polymerization of 3.38 g
(15.4 mmol) of pyrrole 3b in the presence of 0.17 g
and the mixture was heated to 120
After cooling, the reaction mixture was extracted with
hexane (15 30 mL), the extracts were washed with
°
C and kept for 1 h.
(1.0 mmol, 5%) of AIBN after 75 h (at 80
1.01 g (30%) of polymer 5b as a white powder, mp
190–200 C.
For C16H13N anal. calcd. (%): C, 87.64; H, 5.98;
C. The constants agree well N, 6.39.
°
C) gave
×
water and dried with K2CO3. The solvent was
removed, the residue was distilled in a vacuum to give
3.93 g (61%) of 3a as yellow crystals, bp 165–170
(2 mmHg), mp 49–51
°
°
C
°
with the literature data [1, 12].
Found (%): C, 87.56; H, 6.00; N, 6.31.
For C16H13N anal. calcd. (%): C, 87.63; H, 5.98;
N, 6.39.
ACKNOWLEDGMENTS
Found (%): C, 87.52; H, 6.14; N, 6.28.
This work was supported by the Russian Foundaꢀ
Synthesis of
Nꢀvinylꢀ2ꢀ(2ꢀnaphthyl)pyrrole (3b) tion for Basic Research (project no. 08–03–00002).
from oxime 1b. Pyrrole 3b was obtained by the similar
procedure from 5.00 g (27 mmol) of oxime 1b and
1.08 g (27 mmol) of NaOH in 100 mL of DMSO.
Yield, 4.12 g (64%). The constants of the monomer
agree well with the literature data [1, 12].
REFERENCES
1. Trofimov, B.A. and Mikhaleva, A.I., NꢀVinilpirroly (Nꢀ
Vinylpyrroles), Novosibirsk: Nauka, 1984.
For C16H13N anal. calcd. (%): C, 87.63; H, 5.98;
N, 6.39.
2. Trofimov, B.A., in The Chemistry of Heterocyclic Comꢀ
pounds, part 2: Pyrroles, Jones, R.A., Ed., New York:
Wiley, 1992, vol. 48, pp. 131–298.
Found (%): C, 87.50; H, 6.05; N, 6.45.
3. Baraldi, P.G., Bovero, A., Fruttarolo, F., et al., Med.
Res. Rev., 2004, vol. 24, pp. 475–528.
Oneꢀpot threeꢀcomponent synthesis of pyrrole 3b.
A mixture of 1.88 g (27 mmol) of NH2OH · HCl and
2.27 g (27 mmol) of NaHCO3 was dissolved in DMSO
4. Cagnolati, R., Lucehesi, M., Rolla, P.A., et al., Synth.
Met., 1992, vol. 46, no. 1, pp. 127–131.
(50 mL), 5.00 g (27 mmol) of 2ꢀacetylnaphthalene (
was added with stirring. The reaction mixture was
heated at 60 C for 3 h, purged with acetylene to
4)
5. Ruggeri, G., Bianchi, M., Puncioni, G., and
Ciardelli, F., Pure Appl. Chem., 1997, vol. 69, no. 1,
pp. 143–149.
°
remove CO2, placed into 0.5ꢀL steel rotating autoꢀ
clave, 2.66 g (41 mmol) of KOH was added, and acetꢀ
ylene was supplied. The reaction was conducted at
6. Wang, W., Yu, D., and Tian, F., Synth. Met., 2008,
vol. 158, pp. 717–721.
7. Park, J.ꢀJ., Choi, B.ꢀK., Noh, T.ꢀY., et al., US Patent
Application no. 0185294, 2007.
120
(100 mL) and extracted with hexane (15
The extracts were washed with water (3 25 mL) and
°
C for 2 h. The mixture was diluted with water
×
25 mL).
8. Loudet, A. and Burgess, K., Chem. Rev., 2007, vol. 107,
×
pp. 4891–4932.
dried with K2CO3. After removal of hexane, the resiꢀ
due was distilled in a vacuum to give 4.57 g (71%)
9. Abele, E. and Lucevics, E., Heterocycles, 2000, vol. 53,
pp. 2285–2336.
of pyrrole 3b as yellow crystals, bp 160–165
(2 mmHg), mp 52–54 C. The constants of the monoꢀ
mer agree well with the literature data [1, 12].
°
C
°
10. Tedeschi, R.J., in Encyclopedia of Physical Science and
Technology, Meyers, R.A., Ed., San Diego: Academic,
2001, vol. 1, pp. 55–89.
For C16H13N anal. calcd. (%): C, 87.63; H, 5.98;
N, 6.39.
11. Wang, Z., in Comprehensive Organic Name Reactions
and Regents, London: Wiley, 2009, part 3, pp. 2793–
2796.
Found (%): C, 87.56; H, 6.00; N, 6.31.
12. Korostova, S.E., Trofimov, B.A., Sobenina, L.N., et al.,
Polymerization of pyrrole 3a (typical experiment).
The polymerization of 6.00 g (27.6 mmol) of pyrrole
3a in the presence of AIBN (0.30 g, 1.8 mmol, 5%)
was carried out in sealed ampules in argon atmosphere
Khim. Geterotsikl., 1982, no. 10, pp. 1351–1353.
13. Trofimov, B.A., Mikhaleva, A.I., and Morozova, L.V.,
Usp. Khim., 1985, vol. 54, no. 6, pp. 1034–1050.
(80 C, 50 h). The oligomer was dissolved in benzene 14. Trofimov, B.A., Markova, M.V., Morozova, L.V., et al.,
°
Vysokomol. Soedin., Ser. B, 2007, vol. 49, no. 12,
and precipitated into hexane, washed three times with
the precipitating solvent and dried in a vacuum until
constant weight to give 1.02 g (17%) of oligomer as a
pp. 2200–2205 .
15. Rabek, J.F., Experimental Methods in Polymer Chemisꢀ
try, New York: Wiley, 1980.
white powder, mp 135–145 C.
°
DOKLADY CHEMISTRY Vol. 434
Part 1
2010