N,N′-bis(trimethylsilylmethyl)thiocarbamide and N,N′-bis(trimethylsilylmethyl)-λ6-thiocarbamide S,S-Dioxide

Article abstract of DOI:10.1007/s11176-005-0334-7

N,N′-Bis(trimethylsilylmethyl)-λ⁶-thiocarbamide S,S-dioxide was synthesized by oxidation of N,N′-bis(trimethylsilylmethyl)thiocarbamide with hydrogen peroxide. The synthesized dioxide is a less active reducing agent than previously studied S,S-

Full text of DOI:10.1007/s11176-005-0334-7

Russian Journal of General Chemistry, Vol. 75, No. 6, 2005, pp. 860 861. Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 6, 2005,
pp. 912 914.
Original Russian Text Copyright
2005 by Vlasova, Grigor’eva, Voronkov.
N,N -Bis(trimethylsilylmethyl)thiocarbamide
6
and N,N -Bis(trimethylsilylmethyl)- -thiocarbamide S,S-Dioxide
N. N. Vlasova, O. Yu. Grigor’eva, and M. G. Voronkov
Favorskii Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
Received January 27, 2004
Abstract N,N -Bis(trimethylsilylmethyl)- 6-thiocarbamide S,S-dioxide was synthesized by oxidation of
N,N -bis(trimethylsilylmethyl)thiocarbamide with hydrogen peroxide. The synthesized dioxide is a less active
reducing agent than previously studied S,S-dioxides of organosilicon thiocarbamides in which the silicon atom
is separated from the thiocarbamide fragment by a CH CH CH bridge.
2
2
2
We previously reported the first synthesis of
organosilicon derivatives of thiocarbamide dioxide
Thiocarbamide I, like its analog N,N -bis-[3-(tri-
ethylsilyl)propyl]thiocarbamide [1], is easily oxidized
with 50% hydrogen peroxide in dioxane at (-5)- 0 C
[
X SiCH CH CH NH] CSO , X Si = (C H ) Si,
N(CH CH O) Si, and O Si] [1 3]. With the purpose
3 2 2 2 2 2 3 2 5 3
6
to give N,N -bis(trimethylsilylmethyl)- -thiocarba-
2
2
3
1.5
of preparing analogs of the general formula [X Si
mide S,S-dioxide (IV) as a white solid (mp 197
199 C) almost insoluble in organic solvents and
readily soluble in water.
3
CH NH]CSO , we have synthesized formerly un-
2
2
known
N,N -bis(trimethylsilylmethyl)thiocarbamide
(
I) and studied its oxidation to N,N -Bis(trimethyl-
6
silylmethyl)- -thiocarbamide S,S-dioxide.
I + 2H O2
Me SiCH NHC(SO )NHCH SiMe + H O.
3 2 2 2 3 2
2
IV
Organosilicon thiocarbamide I was prepared ana-
logously to N,N -bis(triorganylsilylpropyl)thiocar-
bamides [4] by condensation of (aminomethyl)tri-
methylsilane (II) with thiourea in the presence of a
catalytic amount of ammonium sulfate at 150 160 C.
The IR spectrum of compound IV has no absorp-
tion band in the range 1695 1660 cm , characteristic
of (C=N), which distinguishes it from the spectra of
previously prepared organosilicon thiocarbamide S,S-
dioxides [1, 3]. In this connection compound IV can
not be regarded as an organosilicon derivative of
1
2
Me SiCH NH + H NC(S)NH
3 2 2 2 2
cat
formamidinesulfinic acid Me SiCH NHC(SOOH)=
Me SiCH NHC(S)NHCH SiMe + 2NH .
3
2
3
2
2
3
3
NCH SiMe .
2
3
The starting (aminomethyl)trimethylsilane (II) was
prepared by the procedure described in [5].
At the same time, like thiocarbamide S,S-dioxide
6], dioxide IV evidently has a zwitterionic structure.
[
N,N -Bis(trimethylsilylmethyl)thiocarbamide (I) is
thermally labile. It easily decomposes when heated
above 160 C to form compound II and (isothiocyana-
tomethyl)trimethylsilane (III).
Me SiCH HN
NH CH SiMe
2 3
3
2
+
C
S
I
O
O
I
Me SiCH NH + SCNCH SiMe .
3 2 2 2 3
II
III
Evidence for this proposal is provided by the ab-
sence of the [ (C=S)] band at 1000 cm 1 [7], that is
present in the IR spectrum of starting thiocarbamide
I. At the same time, the IR spectrum of compound IV
displays absorption bands at 3060 [ (NH)], 1430
The composition and structure of compound I were
confirmed by elemental analysis and IR and H NMR
spectroscopy. The IR spectrum contains absorption
1
bands at 3196 [ (NH)], 1420 [ (NH)], 1260 [ (Me Si)],
[ (NH)], 1260 [ (Me Si)], 1080 [ as(SO)], 1040
3
3
1
1
1
000 [ (C=S)], and 850 cm [ (Me Si)] and lacks
[ (SO)] and 850 cm [ (Me Si)], confirmatory of
3
s
3
1
the (N=C=S) band at 2100 2000 cm .
its structure.
1
070-3632/05/7506-0860 2005 Pleiades Publishing, Inc.

N,N -BIS(TRIMETHYLSILYLMETHYL)THIOCARBAMIDE
861
6
S,S-dioxide (IV), like previously studied organosilicon
thiocarbamide S,S-dioxides [1 3], is a reducing agent.
It reacts with cyclohexanone to give cyclohexanol.
N,N -Bis(trimethylsilylmethyl)- -thiocarbamide
S,S-dioxide (IV). To a solution of 2.0 g of thiocarb-
amide I in 15 ml of dioxane, 0.2 ml of 50% hydrogen
peroxide was added at 5 to 0 C over the course of
30 min. A precipitate formed and was crystallized
from acetone and washed with ether to obtain 1.1 g
[
Me SiCH NH] CSO + (CH ) CHCO + 2NaOH
3 2 2 2 2 5
[
Me SiCH NH]C=O + (CH ) CHOH + Na SO .
3 2 2 5 2 3
(
49%) of compound IV as colorless needle-like crys-
1
The reactions of compound IV with potassium per-
tals, mp 197 199 C. H NMR spectrum, , ppm:
0.19 s (18H, CH ), 2.33 s (4H, CH Si), 4.8 s (2H,
NH). Found, %: H 9.14; N 10.78; S 13.02. C H
manganate in alkaline, neutral, or acidic media in-
3
2
volve reduction of Mn+ to Mn .
7
+4
9 24
N O SSi . Calculated, %: H 8.57; N 10.00; S 11.42.
2
2
2
3
[Me SiCH NH] CSO + 2KMnO + 4NaOH
3 2 2 2 4
Reduction of cyclohexanone. To a mixture of
3
[Me SiCH NH] C=O + 2MnO + K SO
3 2 2 2 2 3
solutions of 0.21 g of cyclohexanone in 16 ml of
ethanol and 0.05 g of sodium hydroxide in 6 ml of
water, 0.6 g of dioxide IV was added. The reaction
mixture was heated at 80 C for 6 h after that the
ethanol was removed by distillation, and the residual
aqueous solution was extracted with ether. After that
the ether was distilled off, and the residue was
analyzed by GLC to identify cyclohexanol.
+
2Na SO + 2H O.
2 3 2
The fastest reduction of Mn+7 with dioxide IV
takes place in alkaline medium (1 2 h). At the
same time, the same reaction in neutral and acidic
media completes in 24 and 36 h, respectively. These
data are nicely consistent the reductive ability of thio-
carbamide S,S-dioxide [8].
Hence, N,N -bis(trimethylsilylmethyl)thiocarba-
Reduction of Mn(VII). To a solution of 0.1 g of
compound IV in 100 ml of distilled water, 0.1 N
mide (I), like its analogs containing an [X SiCH2
3
CH CH NH] fragment [1 3], is fairly easy oxidized
KMnO was added dropwise from a burette until a
2
2
2
4
without side processes. However, dioxide IV is a less
stable pink color appeared. The same operation was
carried out with a solution of compound IV with
10 ml of 0.1 N H SO or 0.2 g of NaOH added.
active reducing agent than its silicon-containing
+
7
-
analog [1]. The latter reduces Mn within 10 30
2
4
min at any pH of the medium. This fact suggests that
compounds with the silicon atom and the dioxothio-
carbamide group intervened with a methylene bridge
are more difficultly reduced that compounds with a
CH CH CH bridge. This effect evidently arises
ACKNOWLEDGMENTS
The work was financially supported by the Leading
Scientific Schools Program (project no. NSh-1129-
2003.3).
2
2
2
from the difference in the electronic and steric effects
of the R SiCH and R SiCH CH CH groups.
REFERENCES
3
2
3
2
2
2
1
. Vlasova, N.N., Raspopina, O.Yu., Kashik, T.V., and
Voronkov, M.G., Zh. Obshch. Khim., 2000, vol. 70,
no. 10, p. 1754.
EXPERIMENTAL
The IR spectra were recorded on a UR-20 spec-
1
2. Vlasova, N.N., Grigor’eva, O.Yu., and Voronkov, M.G.,
trometer in thin layer. The H NMR spectra were ob-
Zh. Obshch. Khim., 2001, vol. 71, no. 12, p. 2057.
tained on a Bruker DPX-400 spectrometer (400 MHz)
3
4
. Vlasova, N.N., Raspopina, O.Yu., Pozhidaev, Yu.N.,
and Voronkov, M.G., Zh. Obshch. Khim., 2002, vol. 72,
no. 1, p. 61.
. Vlasova, N.N., Pestunovich, A.E., and Voronkov, M.G.,
Izv. Akad. Nauk SSSR, Ser. Khim., 1979, no. 9,
p. 2105.
in D O against internal HMDS. Gas chromatography
2
was performed on an LKhM-8MDP chromatograph
equipped with a thermal conductivity detector, carrier
gas helium, column 1000x4 mm, packing 5% SE-30
on Chromaton N-AW-HMDS (0.2 0.25 mm).
N,N -Bis(trimethylsilylmethyl)thiocarbamide (I).
A mixture of 3.3 g of trimethylsilylamine, 1.2 g of
thiocarbamide, and 0.01 g of ammonium sulfate was
heated in a sealed ampule for 5 6 h at 150 160 C.
Compound I, 2.5 g (63%), was frozen out from the
5. Sommer, L. and Rocket, J., J. Am. Chem. Soc., 1965,
vol. 73, p. 5130.
6. Makarov, S.V., Kolobov, V.V., and Budanov, V.V.,
Izv. Vyssh. Uchebn. Zaved., Khim. Khim. Tekhnol.,
1988, vol. 31, no. 11, p. 3.
1
reaction mixture at 5 to 0 C, mp 24 25 C. H NMR
7. Gattow, G. and Manz, W., Z. Anorg. Allg. Chem., 1988,
vol. 561, no. 6, p. 66.
spectrum, , ppm: 0.1 s (18H, CH Si), 2.6 s (4H,
2
CH Si), 7.15 s (2H, NH). Found, %: H 9.70; N 12.18;
8. Budanov, V.V. and Makarov, S.V., Khimiya seroso-
derzhashchikh vosstanovitelei (Chemistry of Sulfur-
containing Reducing Agents), Moscow: Khimiya, 1994.
2
S 13.95. C H N SSi . Calculated, %: H 9.67; N
9
24
2
2
1
1.29; S 12.90.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 75 No. 6 2005