New derivatives of 2-mercaptobenzotellurazole

Article abstract of DOI:10.1134/S1070363216040125

New derivatives of 2-mercaptobenzotellurazole at the three reaction centers, the thiol group, nitrogen atom and tellurium atom, have been synthesized.

Full text of DOI:10.1134/S1070363216040125

ISSN 1070-3632, Russian Journal of General Chemistry, 2016, Vol. 86, No. 4, pp. 830–834. © Pleiades Publishing, Ltd., 2016.
Original Russian Text © А.М.М. Ali, P.А. Ramazanova, G.М. Abakarov, А.V. Tarakanova, А.V. Anisimov, 2016, published in Zhurnal Obshchei Khimii,
2016, Vol. 86, No. 4, pp. 643–647.
New Derivatives of 2-Mercaptobenzotellurazole
А. М. М. Alia, P. А. Ramazanovaa, G. М. Abakarova,
А. V. Tarakanovab, and А. V. Anisimovb
a Dagestan State University, Makhachkala, Dagestan, Russia
b Lomonosov Moscow State University, Moscow, 119991 Russia
e-mail: aurume1958@mail.ru
Received October 8, 2015
Abstract—New derivatives of 2-mercaptobenzotellurazole at the three reaction centers, the thiol group,
nitrogen atom and tellurium atom, have been synthesized.
Keywords: 2-mercaptobenzotellurazole, ethyl bromide, allyl bromide, propargyl bromide, acetyl bromide,
synthesis, heterocyclic compounds
DOI: 10.1134/S1070363216040125
The chemistry of organotellurium compounds is
still much less studied than the chemistry of other
chalcogens: the derivatives of oxygen, sulfur and
selenium. Organotellurium heterocycles are used as
inhibitors of acid corrosion of metals, insecticides,
phlotoreagents, photoconductors, photosensibilizers,
etc. [1, 2]. Tetratellurofulvalenes are promising donors
for preparation of charge transfer complexes and ion-
radical salts possessing high conductivity and even
superconductivity [3]. In some cases, organotellurium
compounds have advantages over the organoselenium
reagents widely used in organic chemistry. For example,
adducts of tellurium tetrachloride with propargyl
alcohol and some other substituted acetylenes show
high antioxidant and anti-leishmaniasis activity [4, 5].
Earlier, we have synthesized 2-mercaptobenzo-
tellurazole 1 and 2-methylmercaptobenzotellurazole 2
by the reaction of the corresponding 2,2-diaminodi-
phenylditellurides with sodium borohydride and
Scheme 1.
N
C2H5Br
S
S
C2H5
C2H5ONa
Te
3
N
BrCH2CH=CH2
H
CH2
C2H5ONa
Te
N
4
C
S
CH
Te
N
BrCH2C≡CH
1
S
NaOH, H2O
Te
5
O
C
N
AcBr
CH3
S
C2H5ONa
Te
6
830

831
NEW DERIVATIVES OF 2-MERCAPTOBENZOTELLURAZOLE
Scheme 2.
CH3
I−
N+
CH3I
C S
CH3
CH3
Te
7
H
N
+ Cl−
C S
N
HCl
C S CH3
Te
C2H5OH
Te
8
2
H
O−(NO2)3C6H2
N+
HO(NO2)3C6H2
C2H5OH
C S
CH3
Te
9
Scheme 3.
HgCl2
N
C S
CH3
C2H5OH
Te
HgCl2
10
N
N
Br2
C S CH3
Te
C S
Te
CH3
CH3
C2H5OH
2
Br
Br
11
N
S
C S
S
12
carbon disulfide in hexamethylphosphoramide solution
[6, 7]. Taking into account the presence of several
highly reactive centers in the molecule of 2-
mercaptobenzotellurazole, in this work we have tried
to elaborate preparative methods of the synthesis of
new derivatives of 2-mercaptobenzotellurazole by
functionalization at the thiol group, tellurium atom and
nitrogen atom.
The structure of the synthesized compounds was
proved by the data of NMR spectroscopy and mass
spectrometry. A specific feature of mass spectra of
compounds 3–6 is the absence of the peak of
molecular ion and the presence of the most intensive
peak with m/z 135 originating from the elimination
from the molecules of the tellurium atom.
Quaternization on the nitrogen atom of 2-mercapto-
benzotellurazole 2 was performed by its reaction with
methyl iodide, hydrochloric acid, and picric acid,
leading to salts 7–9 (Scheme 2).
The products of substitution at the thiol group, 2-ethyl-
mercaptobenzotellurazole 3, 2-allylmercaptobenzo-
tellurazole 4, 2-propargylmercaptobenzotellurazole 5,
and 2-acetylmercaptobenzotellurazole 6 were prepared
in 50–78% yields by the reaction of heterocycle 1 in
aqueous or aqueous-alcoholic alkaline medium with
ethyl bromide, allyl bromide, propargyl bromide, and
acetyl bromide, respectively, by the modified
procedures described earlier [8–14] (Scheme 1).
The third reaction site in 2-mercaptobenzo-
tellurazole, which was functionalized, was the tellu-
rium atom. As a result, compounds 10–12 have been
synthesized in 34–89% yield by the reactions of
benzotellurazole 2 with mercury(II) chloride, bromine
and sulfur, respectively (Scheme 3).
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 86 No. 4 2016

832
ALI et al.
All derivatives of 2-mercaptobenzotellurazole syn-
anhydrous ethanol and 0.53 g (2.3 mmol) Na, 6 g
(2.3 mmol) of 2-mercaptobenzotellurazole 1 was
added in small portions in the course of 30 min. The
mixture was cooled to 0°С, 1.8 mL (2.1 mmol) of
freshly distilled allyl bromide was slowly added,
stirred at 0°С for 1 h, then for 5 h at room temperature.
The reaction mixture was filtered, the crystalline
precipitate was washed several times with water, dried
in air, crystallized from the mixture ether : hexane (1 : 9).
Yield 3.7 g (1.2 mol, 58 %), white needle crystals, mp
115–117°С. IR spectrum, ν, cm–1: 3100–3090 (NH),
3100–3048 (CH=CH2), 2858–2817 (CHAr), 1645–1570
thesized in this work are stable in air and readily
soluble in conventional organic solvents. The structure
of all synthesized compounds 3–12 was proved by the
data of IR, NMR, mass spectra and the data of
elemental analysis.
EXPERIMENTAL
1H and 13С NMR spectra were registered in DMSO-
d6 solutions on Avance-400 (Bruker) instrument with
TMS as internal reference. IR spectra were obtained in
KBr on a VERTEX-70 (Bruker) spectrometer in the
range 400–4000 cm–1. Elemental analysis was per-
formed on a CHN analyzer Carlo-Erba. Chromato-
mass spectrometry analysis was done on a Maestro
7820А instrument with mass-selective detector Agilent
5975 (Agilent Tеchnologies) in the electron impact
mode at electron ionization energy of 70 eV, with
capillary column HP-5ms (l = 30 m, d = 0.25 mm) in
the isothermal mode at 45°С and in the temperature
programming mode from 45 to 250°С, heating rate
15°С/min, gas-carrier helium. Melting points were
determined in open capillaries.
1
(N=C), 1600–1530, 1480–1380 (Аr). H NMR spec-
trum, δH, ppm: 8.00 d (1H, CH7, J = 8.0 Hz), 7.88 d
(1H, CH4, J = 8.4 Hz), 7.37 d.d (1H, CH6, J = 8.0,
7.2 Hz), 7.11 d.d (1H, CH5, J = 8.4, 7.2 Hz ), 6.65 d.d
(2H, =СH2, J = 17.0, 11.6 Hz), 6.43–6.19 m (1H,
СH=), 3.40 d (2H, СH2, J = 7.2 Hz). 13С NMR
spectrum, δС, ppm: 123.56 (C4), 124.2 (C8), 126.8 (C5),
132.1 (C7), 133.3 (C6), 140.6 (C9), 161.5 (C2), 120.3
(C11), 18.5 (С12), 15.1 (С13). Mass spectrum, m/z (Irel,
%): 175 (37), 135 (100), 102 (90), 76 (92). Found, %:
C 39.63; Н 2.95; N 4.68; S 10.55. C10H9NSTe.
Calculated, %: C 39.66; Н 2.99; N 4.63; S 10.59.
2-Ethylmercaptobenzotellurazole (3). To the
solution of sodium ethoxide prepared from 0.11 g
(5 mmol) of sodium metal and 30 mL of anhydrous
ethanol 1.31 g (5 mmol) of 2-mercaptobenzo-
tellurazole 1 was added at stirring in small portions. To
the obtained solution 0.44 g (5 mmol) of the solution
of ethyl iodide in 20 mL of anhydrous ethanol was
added, stirred at room temperature for 1.5 h, filtered,
the filtrate was diluted with 20 mL of cold water, the
precipitate formed was dried and crystallized from
ethanol. Yield 0.58 g (71%). Dark-maroon needle
crystals, mp 69–71°С. IR spectrum, ν, cm–1: 3100–
3055 (CHAr), 2960–2840 (CH3), 1610–1590 (N=C),
2-Propargylmercaptobenzotellurazole (5). To the
solution of 0.16 g (3.8 mmol) of NaOH in 30 mL of
water 1.0 g (3.8 mmol) of 2-mercaptobenzotellurazole
1 was added in small portions. To the obtained solution
0.5 mL (3.88 mmol) of freshly distilled propargyl
bromide was added and the mixture was stirred for 2 h
at room temperature. The precipitate formed was
filtered off, washed with water to neutral reaction,
dried, and crystallized from the mixture hexane :
ether : benzene (8 : 1 : 2). Yield 0.57 g (1.9 mmol,
50%), brown crystals, mp 78–80°С. IR spectrum, ν,
cm–1: 3080–3050 (CHarom), 2150–2050 (С≡С), 1580–
1
1540, 1485–1430 (Аr), 1645–1590 (N=C). H NMR
1
spectrum, δH, ppm: 7.74 d (1H, CH7, J = 8.0 Hz), 7.36
d (1H, CH4, J = 8.4 Hz), 7.30 d.d (1H, CH6, J = 7.9,
7.2 Hz) 7.10 d.d (1H, CH5, J = 8.4, 7.3 Hz), 3.49 d
(2H, СH2, J = 2.6 Hz), 2.14 t (1H, ≡СH, J = 2.6 Hz).
13С NMR spectrum, δС, ppm: 114.9 (C4), 120.8 (C8),
124.0 (C5), 127.3 (C7), 132.4 (C6), 146.8 (C9), 195.7
(C2), 97.5 (C11), 18.5 (С12), 15.1 (С13). Mass spectrum,
m/z (Irel, %): 173 (100), 161 (20), 134 (67), 102 (30),
76 (27). Found, %: C 39.90; Н 2.38; N 4.68; S 10.64.
C10H7NSTe. Calculated, %: C 39.92; Н 2.35; N 4.66; S
10.66.
1555–1490 (Аr). H NMR spectrum, δH, ppm: 7.98 d
(1H, CH7, J = 8.0 Hz), 7.82 d (1H, CH4, J = 8.4 Hz),
7.35 d.d (1H, CH6, J = 8.0, 7.3 Hz), 7.09 d.d (1H, CH5,
J = 8.5, 7.2 Hz), 1.38 t (3H, СH3, J = 7.1 Hz), 3.23 d
(2H, SСH2, J = 8.1 Hz). 13С NMR spectrum, δС, ppm:
123.7 (C4), 123.6 (C8), 126.7 (C5), 132.1 (C7), 133.2
(C6), 160.2 (C9), 167.1 (C2), 28.5 (C11), 14.6 (С12).
Mass spectrum, m/z (Irel, %): 163 (51), 135 (100), 102
(35), 76 (31). Found, %: C 37.21; Н 3.09; N 4.81; S
11.05. C9H9NSTe. Calculated, %: C 37.17; Н 3.12; N
4.82; S 11.02.
2-Allylmercaptobenzotellurazole (4). To the
solution of sodium ethoxide prepared from 30 mL of
2-Acetylmercaptobenzotellurazole (6). To the
solution of 0.16 g (3.8 mmol) of NaOH in 30 mL of
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 86 No. 4 2016

833
NEW DERIVATIVES OF 2-MERCAPTOBENZOTELLURAZOLE
ethanol 1 g (3.8 mmol) of 2-mercaptobenzotellurazole
1 was added in small portions and then 0.33 mL
(3.8 mmol) of freshly distilled acetyl bromide was
added. The precipitate starts to form in 10 min. The
mixture was stirred for 1 h at room temperature. The
formed precipitate was filtered off, washed with water
to neutral reaction, and chromatographed (eluent
benzene : hexane : acetone, 5 : 5 : 1.5). Yield 0.86 g
(2.7 mmol, 74%), red crystals, mp 234–236°С. IR
spectrum, ν, cm–1: 3106–3034 (CHAr), 2961–2897
(CH3), 1698–1577, 1453–1425 (Аr), 1653–1600 (С=О).
1H NMR spectrum, δ, ppm: 7.72 d (1H, СH7, J =
7.9 Hz), 7.36 d (1H, СH4, J = 7.9 Hz), 7.32 d.d (1H,
CH6, J = 8.0, 7.2 Hz), 7.20 d.d (1H, CH5, J = 8.4,
7.2 Hz), 2.49 s (3H, CH3). 13C NMR spectrum, δС,
ppm: 169.2 (C2), 166.6 (C12), 159.7 (C9), 133.9 (C8),
132.0 (C7), 126.5 (C6), 123.6 (C4), 123.6 (C5), 37.3
(C11). Mass spectrum, m/z (Irel %): 135 (100), 263 (61),
76 (39), 91 (13). Found, % С 35.48; Н 2.33; N 4.63; S
10.47 С9Н8N2ОSTе. Calculated, % С 35.46; Н 2.31; N
4.59; S 10.52.
1452–1433 (Ar), 1120–1100, 780–730 (N–C), 610–
600, 570–550 (С–S). H NMR spectrum, δ, ppm: 8.28
1
s (1H, СH6), 7.82 d.d (1H, CH5, J = 8.6, 7.3 Hz), 7.44
d (1H, CH7, J = 8.0 Hz), 7.19 d (1H, CH4, J = 8.7 Hz),
2.79 s (3H, CH3), 1.13 s (1H, NH+). 13C NMR
spectrum, δС, ppm: 18.6 (C11), 121.6 (C5), 124.0 (C4),
127.2 (C6), 132.6 (C7), 136.3 (C8), 140.6 (C9), 162.2
(C2). Mass spectrum, m/z (Irel, %): 279 (100), 149 (55),
76 (4), 102 (4). Found, % C 30.74; Н 2.64; N 4.49; S
10.20 С8Н8NSClTе. Calculated, % C 30.67; Н 2.57; N
4.47; S 10.23.
2-Methylmercaptobenzotellurazolium picrate (9).
To the solution of 0.692 g (2.5 mmol) of 2-methyl-
mercaptobenzotellurazole in 25 mL of benzene the
solution of 0.58 g (2.5 mmol) of picric acid in 10 mL
of benzene was added at room temperature with
stirring. The mixture was stirred for 1 h at room
temperature, the formed precipitate was filtered off,
washed with ethanol, and dried. Yield 1.08 g
(2.1 mmol, 85%), yellow crystals, mp 176–178°С. IR
spectrum, ν, cm–1: 3450–3350, 1697, 1550–1515, 875–
850 (N–H), 3120–3059 (N=C), 3040–3020 (CHAr),
2960–2895 (CH3), 1680–1610, 1497, 1452–1424 (Аr),
1117, 1075, 741 (N–C), 1577–1550, 1320–1250, 873,
855 (NO2), 1313, 1281, 1250 (С-О), 609, 536 (С–S).
1H NMR spectrum, δ, ppm: 8.77 s (2Н, H14,16), 8.16
d.d (1H, СH6, J = 7.9, 7.3 Hz), 7.98 d.d (1H, CH5, J =
8.5, 7.3 Hz), 7.00 d.d (1H, CH7, J = 8.0 Hz), 6.98 d
(1H, CH4, J = 8.6 Hz), 2.39 s (3H, CH3). 13C NMR
spectrum, δС, ppm: 17.5 (C11), 114.4 (C5), 118.8 (C9),
126.3 (C14), 126.2 (C16), 129.2 (C7), 134.4 (C8), 135.2
(C6), 137.8 (C4), 138.3 (C15), 139.2 (C13), 139.1 (C17),
151.7 (C2), 155.8 (C12). Mass spectrum, m/z (Irel, %):
149 (100), 279 (29), 76 (21), 134 (17), 102 (15).
Found, %: C 33.14; Н 1.83; N 11.04; S 6.37.
C14H10N4O7SТe. Calculated, %: C 33.23; Н 1.99; N
11.07; S 6.34.
N-Methyl-2-methylmercaptobenzotellurazolium
iodide (7) [22]. A sealed tube with 1.05 g (2.5 mmol)
of 2-methylmercaptobenzotellurazole and 10 mL of
methyl iodide was heated for 6 h on a boiling water
bath. After cooling the content of the tube was filtered,
washed with ether, dried. Yield 0.966 g (2.1 mmol,
92%), yellow crystals, mp 177–179°С. IR spectrum, ν,
cm–1: 3050–3000 (CHarom), 2955–2890 (CH3), 1697–
1630, 1443–1378 (Аr), 1565 (N=C). 1H NMR
spectrum, δ, ppm: 8.96 d.d (1H, СH6, J = 7.9, 7.4 Hz),
8.52 d.d (1H, CH5, J = 8.6, 7.3 Hz), 8.16 d (1H, CH7,
J = 8.0 Hz), 7.96 d (1H, CH4, J = 8.6 Hz), 3.79 s (3H,
NCH3), 2.94 s (3H, CH3). 13C NMR spectrum, δС,
ppm: 168.2 (C2), 148.0 (C9), 132.8 (C8), 128.6 (C7),
126.0 (C6), 122.5 (C4), 118.9 (C5), 31.5 (C12), 22.1
(C11). Mass spectrum, m/z (Irel %): 279 (100), 149 (55),
76 (4), 102 (4). Found, % C 23.81; Н 2.53; N 3.38; S
7.64; С9Н10NSITе. Calculated, % C 23.62; Н 2.48; N
3.35; S 7.66;
(2-Methylmercaptobenzotellurazole)mercury
chloride (10). To the solution of 0.692 g (2.5 mmol) of
2-methylmercaptobenzotellurazole 2 in 10 mL of
ethanol the solution of 0.68 g (2.5 mmol) of mercury
(II) chloride in 5 mL of ethanol was added dropwise at
stirring. The precipitate formed was filtered off,
washed with ether, and dried. Yield 0.975 g (1.8 mmol,
89%), yellow crystals, mp 205–207°С. IR spectrum, ν,
cm–1: 3045 (N=C), 2950 (CH3), 2901 (CHAr), 1613,
1577, 1455, 1425 (Аr), 1720–1680, 2960–1163, 1112,
2-Methylmercaptobenzotellurazolium hydrochlo-
ride (8). Through the solution of 0.692 g (2.5 mmol)
of 2-methylmercaptobenzotellurazole in 30 mL of
benzene the flow of dry HCl was passed until the
formation of the precipitate ceased. The precipitate
was filtered off, washed with ether, and dried. Yield
0.65 g (2 mmol, 83%), white crystals, mp 196–198°С.
IR spectrum, ν, cm–1: 3600-3200, 1697, 1513 (N+–H),
3120–3060 (N=C), 3056–2980 (CHAr), 2962–2874
(CH3), 1735–1700, 1513, 853–830 (N–H), 1680–1590,
1
753, 713 (N–C); 655, 605, 560–550 (С–S). H NMR
spectrum, δ, ppm: 7.98 s (1H, СH6), 7.84 d.d (1H,
CH5, J = 8.3, 7.1 Hz), 7.38 d (1H, CH7, J = 8.0 Hz),
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 86 No. 4 2016

834
ALI et al.
7.10 d (1H, CH4, J = 8.5 Hz), 2.69 s (3H, CH3). 13C
NMR spectrum, δС, ppm: 160.4 (C2), 133.1 (C9), 132.0
(C8), 126.6 (C7), 123.6 (C6), 123.4 (C4), 117.7 (C5),
17.1 (C11). Mass spectrum, m/z (Irel, %): 149 (100), 279
(34), 76 (27), 102 (20), 134 (17), 264 (15). Found, %:
C 17.59; Н 1.33; N 2.59; S 5.82. C8H7NSCl2HgTe.
Calculated, %: C 17.52; Н 1.29; N 2.55; S 5.85.
NMR spectrum, δС, ppm: 168.1 (C2), 153.5 (C9), 135.2
(C8), 126.1 (C6), 124.1 (C4), 121.4 (C7), 121.0 (C5),
17.1 (C11). Mass spectrum, m/z (Irel, %): 181 (100), 136
(27), 102 (16), 122 (13), 166 (12), 90 (10). Spectral
characteristics coincide with the literature data [15, 16].
ACKNOWLEDGMENTS
1,1-Dibromo-2-methylmercaptobenzotellurazole
(11). To the solution of 0.692 g (2.5 mmol) of 2-
methylmercaptobenzotellurazole 2 in 20 mL of CCl4
the solution of 0.80 g (5 mmol) of bromine in 5 mL of
CCl4 was slowly added dropwise. The formed
precipitate was filtered off, washed with ether, and
crystallized from ethanol. Yield 0.86 g (2 mmol, 78%)
orange-yellow crystals, mp 176–178°С IR spectrum, ν,
cm–1: 1755, 1730, 1722, 1697, 3100, 3050 (N=C),
2950 (CH3), 2925 (CHAr), 2850, 1540, 1520 (C–H),
1653, 1630, 1583, 1465, 1420 (Аr), 1229, 1196, 1115,
754, 710 (N–C), 650, 609, 590, 540 (С–S), 465, 450,
The authors are grateful to A.V. Khoroshutin
(Lomonosov Moscow State University) for assistance
in discussing and interpretation of the spectral data.
REFERENCES
1. Irgolic, K.J., The Organic Chemistry of Tellurium, New
York: Gordon and Breach, 1974.
2. Sadekov, I.D., Maksimenko, А.А., and Minkin, V.I.,
Khimiya tellurorganicheskikh soedinenii (Chemistry of
Organotellurium Compounds), Rostov-on-Don: RSU, 1983.
3. Todres, Z.V., Ion-radikaly v organicheskom sinteze
(Radical Ions in Organic Synthesis), Мoscow: Khimiya,
1986, p. 5.
4. Tiekink, E.R.T., Dalton Trans, 2012, vol. 41, p. 6390.
DOI: 10.1039С2DT12225A.
5. Sailer, B.L., Liles, N., Dickerson, S., and Chasteen, T.G.,
Arch. Toxicol., 2003, vol. 77, p. 30. DOI: 10.1007/
s00204-002-0407-x.
1
400 (NTeC), (NTeBr). H NMR spectrum, δ, ppm:
7.72 s (1H, СH6), 7.36 d.d (1H, CH5, J = 7.9, 7.2 Hz),
7.30 d (1H, CH7, J = 7.6 Hz), 7.10 d (1H, CH4, J =
7.9 Hz), 2.29 s (3H, CH3). 13C NMR spectrum, δС,
ppm: 160.4 (C2), 153.1 (C9), 132.0 (C8), 126.6 (C7),
123.6 (C6), 123.4 (C4), 117.7 (C5), 17.1 (C11). Mass
spectrum, m/z (Irel, %): 149 (100), 279 (32), 76 (25),
102 (16), 264 (13). Found, %: C 21.65; Н1.62; N 3.26;
S 7.39. C8H7NSBr2Te. Calculated, %: C 21.72; Н 1.73;
N 3.21; S 7.41.
6. RU Patent 2546674.
7. Ali, A.M.M., Ramazanova, P.A., Abakarov, G.M.,
Tarakanova, A.V., and Anisimov, A.V., Russ. J. Gen.
Chem., 2015, vol. 85, no. 3, p. 770. DOI: 10.1134/
S107036321503041X
8. USA Patent 4678735, Ref. Zh. Khim., 1988, 10 N264.
9. Bagrii, О.K., Galenko, G.F., and Kochergin, P.M.,
Dopovidi Akad. Nauk Ukr. SSR, Ser. B, 1975, no. 9, p. 801.
10. Sarhan, A.A.O., Hozien, Z.A., El-Sherief, H.A.H., and
Mahmoud, A.M., Pol. J. Chem., 1995, vol. 69, p. 1479,
C. A., 1996, vol. 124, 232318s.
11. Sarhan, A.A.O., El-Sherief, H.A.H., and Mahmoud, A.M.,
J. Chem. Res. Synop., 1996, vol. 1, p. 4; C. A., 1996,
vol. 124, 343197w.
12. USA Patent 5093132, Ref. Zh. Khim., 1993, 10 075 P.
13. USA Patent 5091399, Ref. Zh. Khim., 1993, 10 0287 P.
14. Skora, W., Rusek ,D., Ecrstein, Z., and Tippe, A.,
Przem. Chem., 1983, vol. 62, p. 223, , Ref. Zh. Khim.,
1984, no. 3, p. O330.
2-Methylmercaptobenzothiazole (12). A well ground
mixture of 0.70 g (2.5 mmol) of 2-methylmercapto-
benzotellurazole 2 and 0.16 g (5 mmol) of sulfur was
placed in a one-neck flask equipped with a Vigreux
column and the mixture was heated for 6 h at 150–
180°С. The reaction mixture turns dark-red and
tellurium metal is formed as a grey fine-crystalline
powder. The reaction mixture was cooled, dissolved in
20 mL of benzene, filtered from tellurium, the
precipitate was washed with benzene and dried. 0.11 g
(0.86 mmol, 34%) of tellurium was isolated. The
filtrate was treated with activated charcoal, filtered,
and chromatographed on silica gel with the mixture of
hexane and benzene 2 : 8 as an eluent. The solvent was
removed, the residue crystallized from ethanol. Yield
0.13 g (7 mmol, 34%), yellow crystals, mp 45–47°С.
IR spectrum, ν, cm–1: 3070–3045 (CHarom), 2960–2840
(CH3), 1670–1640 (N=C), 1615–1590 (Аr), 536 (С–S).
1H NMR spectrum, δ, ppm: 7.86 s (1H, СH6), 7.65 d
(1H, CH5, J = 7.9 Hz), 7.40 d (1H, CH7, J = 8.0 Hz),
7.22 d (1H, CH4, J = 7.9 Hz), 2.76 s (3H, CH3). 13C
15. Yu, Y., Li, Z., and Jiang, L., Phosphorus, Sulfur,
Silicon, Rel. Elem., 2012, vol. 187, p. 632. DOI:
10.1080/10426507.2011.636229.
16. Dalal, D.S., Pawar, N.S., and Mahulikar, P.P., Org.
Prep. Proc. Int., 2005, vol. 37, no. 6, p. 539. DOI:
10.1080/ 00304940509354982.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 86 No. 4 2016