Synthesis of new sulfur-containing vinyl monomers derived from tetrazole-5-thiols

Full text of DOI:10.1134/S1070428012060255

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2012, Vol. 48, No. 6, pp. 877–879. © Pleiades Publishing, Ltd., 2012.
Original Russian Text © P.A. Aleshunin, V.A. Ostrovskii, 2012, published in Zhurnal Organicheskoi Khimii, 2012, Vol. 48, No. 6, pp. 879–880.
SHORT
COMMUNICATIONS
Synthesis of New Sulfur-Containing Vinyl Monomers
Derived from Tetrazole-5-thiols
P. A. Aleshunin and V. A. Ostrovskii
St. Petersburg State Institute of Technology, Moskovskii pr. 26, St. Petersburg, 190013 Russia
e-mail: apa-ti@mail.ru
Received December 15, 2011
DOI: 10.1134/S1070428012060255
1
Polyvinyltetrazoles are high-molecular compounds
which were used to prepare nitrogen-rich composite
materials [1–3]. Monomers for the synthesis of poly-
vinyltetrazoles are C- and N-vinyltetrazoles, including
those containing various aliphatic, aromatic, or other
substituents on the heteroring [2–3]. There are no pub-
lished data on vinyltetrazoles having a sulfur-contain-
ing substituent. On the other hand, it is known that
sulfur-containing monomers are quite promising from
the viewpoint of preparation of polymeric materials
widely used in modern technologies and medicine [4].
Therefore, synthesis and further study of monomers
containing a nitrogen-rich tetrazole ring, sulfur atom,
and vinylic double bond constitute an important
problem.
bromide. According to the H NMR data, the ratio of
1- and 2-vinyl derivatives III and IV in the reaction
mixture was 70:30. Vinylation of 1-phenyl-1H-tetra-
zole-5-thiol (II) gave 1-phenyl-5-vinylsulfanyl-1H-
tetrazole (V) and 1,2-bis(1-phenyl-1H-tetrazol-5-yl-
sulfanyl)ethane (VI) at a ratio of 75:25. By Heck
arylation [6] of tetrazole IV we synthesized 5-methyl-
sulfanyl-2-[(E)-2-phenylethenyl]-2H-tetrazole (VII)
(Scheme 2).
Tetrazoles III–VI (general procedure). A solution
of 58.8 mmol of 1,2-dibromoethane in 10 ml of aceto-
nitrile was heated to the boiling point, a solution of
29.4 mmol of tetrazole I or II and 115 mmol of
triethylamine in 30 ml of acetonitrile was added under
vigorous stirring over a period of 2 h, and the mixture
was heated for 5 h under reflux. The resulting suspen-
sion was cooled to 5°C, the precipitate of triethylamine
hydrobromide was filtered off, the filtrate was evap-
orated to dryness under reduced pressure, and 30 ml of
chloroform was added to the residue. The solution was
washed with water (28 ml) and dried over anhydrous
Na2SO4, and the solvent was removed under reduced
We were the first to synthesize vinyl-substituted
derivatives of 5-methylsulfanyl-1H-tetrazole (I) and
1-phenyl-1H-tetrazole-5-thiol (II) (Scheme 1). Vinyl-
tetrazoles III–VI were obtained according to [5] by
alkylation of tetrazoles I and II with 1,2-dibromo-
ethane in the presence of triethylamine in acetonitrile,
followed by elimination of triethylamine hydro-
Scheme 1.
CH2
H
MeS
MeS
MeS
CH2
N
N
N
N
i
+
N
N
N
–2Et3N·HBr
N
I
N
N
N
N
III
IV
N
Ph
Ph
Ph
N
H2C
S
HS
N
N
N
N
S
i
+
N
S
N
N
N
–2Et3N·HBr
N
N
N
N
N
N
Ph
II
V
VI
i: Br(CH2)2Br, Et3N, MeCN, Δ.
877

ALESHUNIN, OSTROVSKII
878
Scheme 2.
MeS
Ph
N
i
N
IV
+ PhI
N
N
VII
i: Pd(OAc)2, PPh3, CuI, Cs2CO3, DMF, 100°C.
pressure. The product ratio in the residue was deter-
mined by H NMR. Regioisomeric vinyltetrazoles III
spectrum (DMSO-d6), δ, ppm: 3.79 s (4H, CH2), 7.60–
7.66 m (10H, Ph). 13C NMR spectrum, δC, ppm: 32.32
(CH2); 124.57, 129.96, 130.64, 132.97 (Ph); 153.71
(C5). Mass spectrum: m/z 383.51 [M + H]+. M 382.47.
1
and IV were isolated and purified by column chroma-
tography on silica gel using hexane–chloroform–ethyl
acetate (8:1:1) as eluent. A mixture of tetrazoles V
and VI was treated with 60 ml of boiling 70% aqueous
ethanol, the mixture was heated for 10 min under
reflux and filtered, and the precipitate (tetrazole VI)
was recrystallized from 40 ml of carbon tetrachloride.
The filtrate was cooled, and the precipitate (tetrazole
V) was filtered off and dried in a stream of air over
a period of 1 h.
5-Methysulfanyl-2-[(E)-2-phenylethenyl]-2H-
tetrazole (VII). A suspension of 0.2 g (1.4 mmol) of
tetrazole IV, 0.28 g (1.4 mmol) of CuI, 0.7 g
(2.2 mmol) of Cs2CO3, 0.013 g (0.056 mmol) of
Pd(OAc)2, 0.044 g (0.17 mmol) of PPh3, and 1.5 g
(7 mmol) of iodobenzene in 2 ml of DMF was heated
to 100°C and was kept for 6 h at that temperature
under argon. The mixture was cooled to 25°C and
poured into 10 ml of water, and the resulting suspen-
sion was filtered through celite. The filtrate was
extracted with ethyl acetate (3×15 ml), the combined
extracts were dried over anhydrous Na2SO4 and
evaporated under reduced pressure, the residue was
dispersed in 20 ml of hexane, and the precipitate was
filtered off. Yield 0.3 g (85%), colorless crystals,
mp 60–61°C, Rf 0.2 (hexan–ethyl acetate, 9:1).
1H NMR spectrum (DMSO-d6), δ, ppm: 2.72 s (3H,
CH3), 7.37–7.42 m (3H, Ph), 7.58 d (1H, CHPh, J =
14.4 Hz), 7.74–7.76 m (2H, Ph), 8.48 d (1H, 2-CH, J =
14.4 Hz). 13C NMR spectrum, δC, ppm: 14.44 (CH3),
123.39 (CHPh); 124.96, 128.07, 129.37 (Ph); 129.74
(2-CH), 133.36 (Ph), 165.21 (C5). Mass spectrum:
m/z 219.31 [M + H]+. M 218.28.
5-Methylsulfanyl-1-vinyl-1H-tetrazole (III).
Yield 1.1 g (25%), light yellow oily liquid, Rf 0.3
1
(hexane–ethyl acetate, 7 : 3). H NMR spectrum
(DMSO-d6), δ, ppm: 2.79 s (3H, CH3), 5.52 d.d (1H,
=CH2, J = 1.5, 8.8 Hz), 5.90 d.d (1H, =CH2, J = 1.5,
15.4 Hz), 7.32 d.d (1H, CH=, J = 8.8, 15.4 Hz).
13C NMR spectrum, δC, ppm: 15.50 (CH3), 110.90
(=CH2), 126.76 (CH=), 154.59 (C5). Mass spectrum:
m/z 143.21 [M + H]+. M 142.18.
5-Methylsulfanyl-2-vinyl-2H-tetrazole (IV). Yield
2.7 g (65%), colorless crystals, mp 40–41°C, Rf 0.7
1
(hexane–ethyl acetate, 7 : 3). H NMR spectrum
(DMSO-d6), δ, ppm: 2.68 s (3H, CH3), 5.48 d.d (1H,
=CH2, J = 1.4, 8.7 Hz), 6.06 d.d (1H, =CH2, J = 1.5,
15.5 Hz), 7.79 d.d (1H, CH=, J = 8.7, 15.5 Hz).
13C NMR spectrum, δC, ppm: 14.37 (CH3), 109.51
(=CH2), 130.40 (CH=), 165.41 (C5). Mass spectrum:
m/z 143.20 [M + H]+. M 142.18.
1
The H and 13C NMR spectra were recorded on
a Bruker DPX-300 spectrometer at 300.1 and
75.5 MHz, respectively, using the solvent as reference
(DMSO-d5, δ 2.50 ppm; DMSO-d6, δC 39.52 ppm).
The mass spectra were obtained on a Thermo Scientific
TSQ Quantum Access MAX LC/MS instrument. The
melting points were determined on a PTP melting
point apparatus; samples were heated at a rate of
1 deg/min near the melting point. The purity of the
isolated compounds was checked by TLC on Kieselgel
60F254 plates (Merck); spots were detected under UV
light (λ 254 nm). The properties of initial tetrazoles I
and II were consistent with published data [7].
1-Phenyl-5-vinylsulfanyl-1H-tetrazole (V). Yield
4.1 g (70%), colorless crystals, mp 56–57°C, Rf 0.8
1
(hexane–ethyl acetate, 7 : 3). H NMR spectrum
(DMSO-d6), δ, ppm: 5.69 d (1H, =CH2, J = 1.2 Hz),
5.72 d.d (1H, =CH2, J = 1.2, 9.8 Hz), 6.92 m (1H,
CH=, J = 1.3, 9.8, 16.7 Hz), 7.66 s (5H, Ph). 13C NMR
spectrum, δC, ppm: 120.85 (=CH2), 124.61 (CH=);
125.25, 129.76, 130.42, 130.61, 131.27, 132.94 (Ph);
152.27 (C5). Mass spectrum: m/z 205.15 [M + H]+.
M 204.25.
1,2-Bis(1-phenyl-1H-tetrazol-5-ylsulfanyl)ethane
(VI). Yield 1.9 g (18%), colorless crystals, mp 143–
144°C, Rf 0.2 (hexane–ethyl acetate, 7:3). H NMR
This study was performed under financial support
by the Russian Foundation for Basic Research (project
no. 11-08-00757-a).
1
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 48 No. 6 2012

SYNTHESIS OF NEW SULFUR-CONTAINING VINYL MONOMERS
879
4. Nedel’kin, V.I., Zachernyuk, B.A., and Andrianova, O.B.,
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