Synthesis of novel dithiocarbamyl-containing organosilicon compounds

Article abstract of DOI:10.1080/17415993.2014.953163

Aldehydes-bearing dithiocarbamate moieties were generated via highly efficient and simple method based on the one-pot reaction of amines, CS₂, and 4-(bromoalkoxy)benzaldehydes with the use of K₂CO₃ as a catalyst under solv

Full text of DOI:10.1080/17415993.2014.953163

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Synthesis of novel dithiocarbamyl-
containing organosilicon compounds
Kazem D. Safaa, Sama Tavakkoli Osgoeia & Maryam Alyaria
a Organosilicon Research Laboratory, Faculty of Chemistry,
University of Tabriz, 5166616471 Tabriz, Iran
Published online: 12 Sep 2014.
To cite this article: Kazem D. Safa, Sama Tavakkoli Osgoei & Maryam Alyari (2014) Synthesis of
novel dithiocarbamyl-containing organosilicon compounds, Journal of Sulfur Chemistry, 35:6,
683-690, DOI: 10.1080/17415993.2014.953163
To link to this article: http://dx.doi.org/10.1080/17415993.2014.953163
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Journal of Sulfur Chemistry, 2014
Vol. 35, No. 6, 683–690, http://dx.doi.org/10.1080/17415993.2014.953163
Synthesis of novel dithiocarbamyl-containing organosilicon
compounds
Kazem D. Safa∗, Sama Tavakkoli Osgoei and Maryam Alyari
Organosilicon Research Laboratory, Faculty of Chemistry, University of Tabriz, 5166616471 Tabriz, Iran
(Received 25 June 2014; accepted 6 August 2014)
Aldehydes-bearing dithiocarbamate moieties were generated via highly efficient and simple method based
on the one-pot reaction of amines, CS2, and 4-(bromoalkoxy)benzaldehydes with the use of K2CO3
as a catalyst under solvent-free conditions. The mild reaction conditions, high yields, and broad scope
of the reaction, illustrate the good synthetic utility of this method. The newly synthesized aldehydes
were converted to 1,1-bis(trimethylsilyl)-1-alkenes via the Peterson olefination reaction and produced
dithiocarbamate-based organosilane compounds.
Keywords: dithiocarbamate; carbon disulfide; tris(trimethylsilyl)methyllithium; 1,1-bis(silyl)-1-alkene;
Peterson olefination
1. Introduction
Organic dithiocarbamates have become a field of increasing interest during the past few
years.[1,2] They are intensively used as agrochemicals and pharmaceuticals and as interme-
diates in organic synthesis.[3,4] They can also be found in a variety of biologically active
compounds.[5,6] Syntheses of dithiocarbamates involve reactions of amines with CS2 and alkyl
halides or acrylates.[7]
∗Corresponding author. Email: dsafa@tabrizu.ac.ir
c
ꢀ 2014 Taylor & Francis

684 K.D. Safa et al.
1,1-bis(silyl)-1-alkenes are useful reagents in organic synthesis because of the presence
of Csp2-Si bonds that undergo numerous transformations. Their use as precursors for the
preparation of ketones and isoxazoline derivatives, as well as variety of organosilicon interme-
diates such as acylsilanes, epoxysilanes, 1-halosilanes, silylenol ethers, (E)-alkenylsilanes, and
silylenolacetates, stimulates interest in their synthesis.[8,9] In our previous work, we described
the synthesis of β-aminoketones containing bis(trimethylsilyl)ethenyl groups.[10] We have now
synthesized a series of dithiocarbamyl-containing organosilicon compounds.
2. Result and discussion
Efficient and safe methods for the synthesis of dithiocarbamates with various substitution pat-
terns at the thiol chain have recently been reported.[11] One method involves the addition of
amine to carbon disulfide in the presence of electrophilic reagents,[12] but it suffers from several
disadvantages such as the use of strong bases, unsatisfactory yields, high reaction tempera-
tures, and prolonged reaction times. Herein we report a novel, efficient and green synthesis
of these compounds under solvent-free conditions by the three-component reaction of amines,
carbon disulfide, and 4-(bromoalkoxy)benzaldehydes 2 and 3. The required starting materials,
4-(3-bromopropoxy)benzaldehyde 2, and 4-(4-bromobutoxy)benzaldehyde 3 were obtained by
the reaction of 4-hydroxy-benzaldehyde and 1,3-dibromopropane or 1,4-dibromo-butane with
K2CO3 in dry DMF. Initially, the reaction between piperidine 1a (1 mmol), carbon disulfide
(1 mmol), and 4-(3-bromopropoxy)benzaldehyde 2 (1 mmol) in CH2Cl2 at room temperature for
1 h without any catalyst, afforded the desired dithiocarbamate 4a in 40% yield (Table 1, Entry 1).
In order to improve the reaction efficiency, we varied the molar ratios of the reactants. When a
ratio of 1.5:1:3 (1a/2/CS2) was used, the product was isolated in highest yield (Table 1, Entry 4).
Table 1. Synthesis of 3-(4-formylphenoxy)propyl piperidine-1-carbodithioate (4a) under different conditionsa.
Catalyst
(equiv.)
Molar ratio
1a/2/CS2
Time/
min
Entry
Solvent
Yield (%)b
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
None
None
K2CO3(0.5)
None
K2CO3(0.5)
K2CO3(0.5)
None
1:1:1
1:1:1
CH2Cl2
THF
THF
CH2Cl2
CH2Cl2
60
45
20
40
20
14
8
10
7
9
5
7
18
5
3
40
43
89
75
82
85
86
83
90
87
92
93
63
91
94
1.5:1:3
1.5:1:3
1.5:1:3
1.5:1:3
1.5:1:3
1.5:1:3
1.5:1:3
1.5:1:3
1.5:1:3
1.5:1:3
1:1:1
EtOH
H2O
None
H2O-EtOH(1:1)
H2O
H2O-EtOH(1:1)
H2O(60◦C)
H2O
Solvent-free
Solvent-free
Solvent-free
K2CO3(0.5)
K2CO3(0.5)
K2CO3(0.5)
K2CO3(0.5)
None
None
K2CO3(0.5)
1.5:1:3
1.5:1:3
aAll reactions were carried out at open atmosphere.
bIsolated yield based on 4a.

Journal of Sulfur Chemistry 685
When water was used as the alternative medium of CH2Cl2, a similarly good result was obtained
(Table 1, Entry 7).
With 0.5 mmol K2CO3 as catalyst, the process is driven rapidly to completion (Table 2,
Entry 9) and only one equivalent of amine is required.[11] Without solvent at room tempera-
ture the one-pot reaction gave the dithiocarbamate in excellent yield with K2CO3 as a catalyst.
The reaction conditions were finally established as given in Entry 15 (Table 1). The addition
of amine to CS2 was slow, maintaining the temperature at around 0◦C followed by the addition
of 4-(bromopropoxy)benzaldehyde 2 or 4-(bromobutoxy)benzaldehyde 3 at room temperature.
Generally, the solvent-free reaction is fast, experimentally simple, gives higher selectivity, and
generates virtually no by-products.
To show the generality and scope of this new protocol, structurally diverse amines were treated
with 4-(bromoalkoxy)benzaldehydes and the results are shown in Table 2. By using solvent-free
conditions, the corresponding products were afforded in good to excellent yield (Table 2).
Recently, we have embarked on a program directed toward the use of tris(trimethylsilyl)
methane, (Me3Si)3CH, for the generation of synthetically useful organosilicon compounds.
[13,14] To extend this reaction to the synthesis of dithiocarbamates bearing organosilicon groups,
the newly synthesized aldehydes were treated with (Me3Si)3CLi, and the related 2-aryl-1,1-
bis(silyl)alkenes were produced in good yields (Scheme 1, Table 3). 2-Aryl-1,1-bis(silyl)alkenes
represent an important class of key compounds that have been used for various applications,
especially as synthetic intermediates.[15,16]
The organolithium reagent, (Me3Si)3CLi, was made by deprotonation of (Me3Si)3CH by
MeLi under reflux conditions in THF. The starting precursor tris(trimethylsilyl)methane has been
conveniently prepared by the reaction between CHCl3 and Li with Me3SiCl in THF.[17]
Table 2. One-pot synthesis of (4-formylphenoxy)butyl(propyl) dialkylcarbamodithioate under
solvent-free conditions.
Entry
Amine 1
Aldehyde Product Time/min
Yield (%)a
1
2
3
4
5
6
Piperidine 1a
Piperidine 1a
Dipropylamine 1b
Dipropylamine 1b
Diisopropylamine 1c
Diisopropylamine 1c
2
3
2
3
2
3
4a
5a
4b
5b
4c
5c
3
3
4
4
3
4
94
94
93
92
93
94
aIsolated yield.
Scheme 1. Synthesis of dithiocarbamyl-containing organosilicon compounds.

686 K.D. Safa et al.
Table 3. The results of the preparation of 2-aryl-1,1-bis(silyl)alkenes containing dithiocarbamates.
Entry
Aldehyde
R2N-
Product
Time/min
Yield (%)a
1
2
3
4
5
6
4a
5a
4b
5b
4c
5c
Piperidine
Piperidine
Dipropylamine
Dipropylamine
Diisopropylamine
Diisopropylamine
6a
7a
6b
7b
6c
7c
6
5
7
6
6
5
92
93
91
92
92
93
aIsolated yield.
The reaction is carried out, with stirring, at room temperature. All the newly synthesized com-
1
pounds were characterized through spectroscopic techniques. The H NMR spectra of the 6a
show the complete disappearance of aldehydic proton resonance and the concomitant appearance
=
of signals assigned to HC C at 7.68 ppm and -SiMe3 protons at −0.01 and 0.18 ppm. Similar
results were observed for 6b, 6c and 7a–c.
3. Conclusion
We demonstrated the convenient one-pot and solvent-free preparation of various dithiocarba-
mates by a facile reaction of 4-(3-bromoalkoxy)benzaldehydes, carbon disulfide and a amine
under solvent-free conditions at room temperature. The significant advantages offered by this
protocol are simple operation, easy accessibility of reactants, no solvent, reaction at room tem-
perature (energy efficient), and high yields of products. The newly synthetic dithiocarbamates
containing formyl group were obtained from the reaction of (Me3Si)3CLi with variety of dithio-
carbamates. These compounds might be used as intermediate for the synthesis of attractive
molecules containing organosilicon groups.
4. Experimental
4.1. Solvents and reagents
Reactions involving organolithium reagents were carried out under dry argon. Sol-
vents and CS2 were dried by standard methods. Substrates for the preparation of
tris(trimethylsilyl)methyllithium, namely, Me3SiCl, Li, CHCl3, and substrates for the prepara-
tion of 4-(bromoalkoxy)benzaldehydes, namely, 4-hydroxy-benzaldehyde, 1,4-dibromo-butane,
1,3-dibromo-propane, K2CO3, and DMF were purchased from Merck and Fluka.
4.2. Instrumentation
1
The H NMR and 13C NMR were recorded with a Bruker FT-400 MHz spectrometer at room
temperature and CDCl3 as a solvent. The FTIR spectra were recorded on a Bruker-Tensor 270
spectrometer. Elemental analyses were carried out with a Heareus CHN-ORAPID instrument.
4.3. General procedure for the preparation of 4-(3-bromopropoxy)benzaldehyde 2 and
4-(4-bromobutoxy)benzaldehyde 3
To a stirred solution of 4-hydroxy-benzaldehyde (1 g, 8.2 mmol) in dry DMF (30 mL), K2CO3
(1.70 g, 12.3 mmol) and 1,3-dibromopropane or 1,4-dibromo-butane (81.9 mmol) were added

Journal of Sulfur Chemistry 687
consecutively. The mixture was stirred at room temperature for 24 h. Then DMF was evaporated
in vacuum, and the residue was taken up in CH2Cl2 and washed with H2O. The organic layer
was dried over Na2SO4, filtered, and evaporated under reduced pressure. After filtration, the sol-
vent was evaporated, and the residue was purified by column chromatography (n-hexane/ethyl
acetate, 4:1, Rf = 0.80) for 2 and (n-hexane/ethyl acetate, 4:1, Rf = 0.76) for 3. The compounds
have been described previously.[18,19]
4.4. General procedure for the preparation of 4-(4-formylphenoxy)butyl
dialkylcarbamodithioate and 3-(4-formylphenoxy)propyl dialkylcarbamodithioate
To a well stirred mixture of 4-(3-bromopropoxy)benzaldehyde or 4-(4-bromobutoxy)benzal-
dehyde (1 mmol) with CS2 (1 mmol) was added secondary amine drop-wise over 2 min at 0◦C,
and the stirring was continued for 3 min at 0◦C. The mixture was allowed to warm to room tem-
perature, then stirred until the reaction was shown by TLC to be complete. The reaction mixture
was then poured into distilled water (30 ml) and extracted with dichloromethane. The organic
layer was separated and dried over anhydrous sodium sulfate. The solvent was evaporated and
the residue was purified by preparative TLC on silica gel using n-hexane and dichloromethane
as eluent to give the product.
4.4.1. 3-(4-formylphenoxy)propyl piperidine-1-carbodithioate (4a)
Yellow solid, 94% (Rf = 0.33), m.p. 70–72◦C. FTIR (KBr, cm−1): 2740, 1682 (C O), 1465,
=
1
=
1154 (C S), 1025 (C–S), 837; H NMR (400 MHz, CDCl3): δ 1.62–1.75 (m, 6H), 2.22–2.29
(m, 2H, CH2), 3.51 (t, J = 7.1 Hz, 2H, CH2–S), 3.89 (bs, 2H, CH2–N), 4.15 (t, J = 6.1 Hz, 2H,
CH2–O), 4.29 (bs, 2H, CH2–N), 7.00 (d, J = 8.7 Hz, 2H, Ar), 7.83 (d, J = 8.7 Hz, 2H, Ar),
9.88 (s, 1H, CHO); 13C NMR (100 MHz, CDCl3): δ 23.27, 24.50, 24.98, 27.55, 32.25, 50.31,
=
=
51.93, 65.79, 113.76, 128.89, 130.98, 162.89, 189.83 (C O), 194.09 (C S); Anal. Calcd for
C16H21NO2S2: C, 59.41; H, 6.54; N, 4.33. Found: C, 59.58%; H, 6.63%; N, 4.19%.
4.4.2. 4-(4-formylphenoxy)butyl piperidine-1-carbodithioate (5a)
Yellow solid, 94% (Rf = 0.52), m.p. 44–46◦C. FTIR (KBr, cm−1): 2735, 1687 (C O), 1425,
=
1
=
1158 (C S), 1008 (C–S), 830; H NMR (400 MHz, CDCl3): δ 1.60–1.73 (m, 6H), 1.86–1.97 (m
4H), 3.37 (t, J = 7.0 Hz, 2H, CH2–S), 3.87 (bs, 2H, CH2–N), 4.06 (t, J = 6.0 Hz, 2H, CH2–S),
4.27 (bs, 2H, CH2–N), 6.97 (d, J = 8.6 Hz, 2H, Ar), 7.80 (d, J = 8.6 Hz, 2H, Ar), 9.85 (s, 1H,
CHO); 13C NMR (100 MHz, CDCl3): δ 23.19, 24.41, 24.89, 27.16, 35.48, 50.16, 51.79, 66.66,
=
=
113.65, 128.69, 130.88, 162.94, 189.74 (C O), 194.36 (C S); Anal. Calcd for C17H23NO2S2:
C, 60.50; H, 6.87; N, 4.15. Found: C, 60.65%; H, 6.98%; N, 3.99%.
4.4.3. 3-(4-formylphenoxy)propyl dipropylcarbamodithioate (4b)
Yellow solid, 93% (Rf = 0.40), m.p. 76–78◦C. FTIR (KBr, cm−1): 2736, 1691 (C O), 1480,
=
1
=
1159 (C S), 1029 (C–S), 832; H NMR (400 MHz, CDCl3): δ 0.90–0.96 (m, 6H), 1.70–1.83
(m, 4H), 2.20–2.26 (m, 2H), 3.47 (t, J = 7.1 Hz, 2H, CH2-S), 3.58–3.63 (m, 2H, CH2–N), 3.88–
3.92 (m, 2H, CH2–N), 4.14 (t, J = 6.1 Hz, 2H, CH2-O), 6.99 (d, J = 8.6 Hz, 2H, Ar), 7.82 (d,
J = 8.6 Hz, 2H, Ar), 9.87 (s, 1H, CHO); 13C NMR (100 MHz, CDCl3): δ 10.15, 18.56, 19.60,
=
=
27.43, 32.24, 53.26, 55.78, 65.79, 113.71, 128.83, 130.91, 162.84, 189.75 (C O), 194.58 (C S);
Anal. Calcd for C17H25NO2S2: C, 60.14; H, 7.42; N, 4.13. Found: C, 60.26%; H, 7.58%; N,
3.94%.

688 K.D. Safa et al.
4.4.4. 4-(4-formylphenoxy)butyl dipropylcarbamodithioate (5b)
Yellow solid, 92% (Rf = 0.43), m.p. 49–51◦C. FTIR (KBr, cm−1): 2734, 1691(C O), 1475,
=
1
=
1156 (C S), 1030 (C-S), 831; H NMR (400 MHz, CDCl3): δ 0.91–0.96 (m, 6H), 1.72–1.74 (m,
4H), 1.86–1.98 (m, 4H), 3.36 (t, J = 7.0 Hz, 2H, CH2–S), 3.61 (t, J = 7.9 Hz, 2H, CH2–N), 3.90
(t, J = 7.8 Hz, 2H, CH2–N), 4.08 (t, J = 6.0 Hz, 2H, CH2–O), 6.98 (d, J = 8.7 Hz, 2H, Ar), 7.81
(d, J = 8.7 Hz, 2H, Ar), 9.87 (s, 1H, CHO); 13C NMR (100 MHz, CDCl3): δ 10.17, 18.63, 19.62,
=
24.40, 27.26, 35.61, 53.26, 55.76, 66.74, 113.73, 128.82, 130.93, 163.02, 189.74 (C O), 195.05
=
(C S); Anal. Calcd for C18H27NO2S2: C, 61.15; H, 7.70; N, 3.96. Found: C, 61.28%; H, 7.92%;
N, 3.75%.
4.4.5. 3-(4-formylphenoxy)propyl diisopropylcarbamodithioate (4c)
Yellow solid, 93% (Rf = 0.46), m.p. 73–75◦C. FTIR (KBr, cm−1): 2729, 1689 (C O), 1475,
=
1
=
1155 (C S), 1030 (C–S), 836; H NMR (400 MHz, CDCl3): δ 1.24–1.64 (m, 12H), 1.89–1.98
(m, 2H,–CH2), 2.21–2.28 (m, 2H), 3.48 (bs, 2H, CH2–N), 4.15 (t, 2H, J = 6.2 Hz, CH2–O),
7.00 (d, J = 8.7 Hz, 2H, Ar), 7.82 (d, J = 8.7 Hz, Ar), 9.87 (s, 1H, CHO); 13C NMR (100 MHz,
=
CDCl3): δ 18.74, 27.34, 65.94, 66.74, 113.75, 128.85, 130.95, 162.91, 189.80 (C O), 194.98
=
(C S); Anal. Calcd for C17H25NO2S2: C, 60.14; H, 7.42; N, 4.13. Found: C, 60.29%; H, 7.60%;
N, 3.96%.
4.4.6. 4-(4-formylphenoxy)butyl diisopropylcarbamodithioate (5c)
Yellow solid, 94% (Rf = 0.52), m.p. 41–43◦C. FTIR (KBr, cm−1): 2734, 1689 (C O), 1438,
=
1
=
1162 (C S), 1031 (C–S), 831; H NMR (400 MHz, CDCl3): δ 1.24–1.62 (m, 14H), 1.91–2.00
(m, 4H), 3.38 (bs, 2H), 4.08 (t, J = 6.0 Hz, CH2–O), 6.98 (d, J = 8.7 Hz, 2H, Ar), 7.82 (d,
J = 8.7 Hz, 2H, Ar), 9.87 (s, 1H, CHO); 13C NMR (100 MHz, CDCl3): δ 18.80, 24.19, 27.37,
=
=
66.21, 66.75, 113.72, 128.77, 130.96, 163.04, 189.83 (C O), 194.36 (C S); Anal. Calcd for
C18H27NO2S2: C, 61.15; H, 7.70; N, 3.96. Found: C, 61.32%; H, 7.98%; N, 3.73%.
4.5. General procedure for the preparation of
3-(4-(2,2-bis(trimethylsilyl)vinyl)phenoxy)propyl dialkylcarbamodithioate
To a stirred solution of tris(trimethylsilyl)methyllithium (1 mmol) in THF, 4-(4-formylphenoxy)
butyl dialkylcarbamodithioate or 3-(4-formylphenoxy)propyl dialkylcarbamodithioate (1 mmol)
in 2 mL THF was added at room temperature under argon atmosphere. The progress of the reac-
tion was followed by TLC with n-hexane as eluent. After completion of the reaction, the mixture
is poured into water and extracted with CH2Cl2. The organic layer was washed with water,
dried over Na2SO4, and filtered. The solvent was evaporated and the residue was purified by
preparative TLC on silica gel using n-hexane as eluent to give the product.
4.5.1. 3-(4-(2,2-bis(trimethylsilyl)vinyl)phenoxy)propyl piperidine-1-carbodithioate (6a)
Yellow oil, 92% (Rf = 0.76). FTIR (KBr, cm−1): 2862 ( CH–), 1244 and 837 (C–Si), 1171
=
1
=
(C S); H NMR (400 MHz, CDCl3): δ −0.01 (s, 9H, SiMe3), 0.18 (s, 9H, SiMe3), 1.65–1.75 (m,
6H), 2.18–2.25 (m, 2H), 3.50 (t, J = 7.1 Hz, CH2–S), 3.90 (bs, 2H, CH2–N), 4.07 (t, J = 6.1 Hz,
2H, CH2–O), 4.30 (bs, 2H, CH2–N), 6.82 (d, J = 8.6 Hz, 2H, Ar), 7.11 (d, J = 8.6 Hz, 2H, Ar),
7.68 (s, 1H, 9CH–); 13C NMR (100 MHz, CDCl3): δ −0.402 (SiMe3), 1.091 (SiMe3), 23.31,
24.53, 24.95, 27.55, 27.74, 32.55, 35.82, 50.30, 51.82, 65.42, 66.34, 112.69, 128.18, 134.20,

Journal of Sulfur Chemistry 689
=
143.86, 153.61, 157.07, 194.47 (C S); Anal. Calcd for C23H39NOS2Si2: C, 59.30; H, 8.44; N,
3.01. Found: C, 59.53%; H, 8.67%; N, 2.78%.
4.5.2. 4-(4-(2,2-bis(trimethylsilyl)vinyl)phenoxy)butyl piperidine-1-carbodithioate (7a)
Yellow oil, 93% (Rf = 0.76). FTIR (KBr, cm−1): 2861 ( CH–), 1171 (C S), 1244 and 838
(C–Si), 1014 (C–S); 1H NMR (400 MHz, CDCl3): δ −0.02 (s, 9H, SiMe3), 0.17 (s, 9H, SiMe3),
1.65–1.75 (m, 6H), 1.91–1.92 (m, 4H, CH2), 3.39 (t, J = 6.7 Hz, 2H, CH2–S), 3.90 (bs, 2H), 3.97
(t, J = 5.6 Hz, 2H, CH2–O), 4.301 (bs, 2H), 6.81 (d, J = 8.5 Hz, 2H, Ar), 7.10 (d, J = 8.5 Hz,
2H, Ar), 7.67 (s, 1H, = CH–); 13C NMR (100 MHz, CDCl3): δ −0.41 (SiMe3), 1.08 (SiMe3),
23.31, 24.51, 27.53, 35.80, 66.30, 112.62, 128.16, 134.05, 143.75, 153.62, 157.14, 194.68
=
=
=
(C S); Anal. Calcd for C24H41NOS2Si2: C, 60.07; H, 8.61; N, 2.92. Found: C, 60.27%; H,
8.88%; N, 2.73%.
4.5.3. 3-(4-(2,2-bis(trimethylsilyl)vinyl)phenoxy)propyl dipropylcarbamodithioate (6b)
Yellow oil, 91% (Rf = 0.72). FTIR (KBr, cm−1): 2855 ( CH–), 1172 (C S), 1247 and 836
(C–Si), 1025 (C–S); 1H NMR (400 MHz, CDCl3): δ −0.02 (s, 9H, SiMe3), 0.17 (s, 9H, SiMe3),
1.25–1.33 (m, 6H), 1.51–1.58 (m, 4H), 2.01–2.06 (m, 2H), 3.41 (t, J = 7.3 Hz, 2H, CH2–S),
3.49–3.54 (m, 2H, CH2–N), 3.81–3.89 (m, 2H, CH2–N), 4.10 (t, J = 6.2 Hz, 2H, CH2–O), 6.84
(d, J = 8.5 Hz, Ar), 7.11 (d, J = 8.5 Hz, Ar), 7.68 (s, 1H, 9CH–); 13C NMR (100 MHz, CDCl3):
δ −0.41, 1.06, 10.17, 17.84, 19.70, 29.39, 34.12, 54.01, 56.24, 67.76, 112.87, 116.67, 128.16,
=
=
=
=
133.46, 153.54 (C O), 195.24 (C S); Anal. Calcd for C24H43NOS2Si2: C, 59.82; H, 8.99; N,
2.91. Found: C, 60.02%; H, 9.20%; N, 2.73%.
4.5.4. 4-(4-(2,2-bis(trimethylsilyl)vinyl)phenoxy)butyl dipropylcarbamodithioate (7b)
Yellow sticky solid, 92% (Rf = 0.73). FTIR (KBr, cm−1): 2873 ( CH–), 1172 (C S), 1244
=
=
1
and 836 (C–Si), 1033 (C–S); H NMR (400 MHz, CDCl3): δ −0.02 (s, 9H, SiMe3), 0.17 (s,
9H, SiMe3), 0.92–0.97 (m, 6H), 1.73–1.77 (m, 4H), 1.90–1.92 (m, 4H), 3.36 (t, J = 6.8 Hz,
2H, CH2–S), 3.63 (t, J = 7.8 Hz, 2H), 3.91 (t, J = 7.8 Hz, 2H), 3.99 (t, J = 5.6 Hz, 2H, CH2–
O), 6.81 (d, J = 8.5 Hz, 2H, Ar), 7.10 (d, J = 8.5 Hz, 2H, Ar), 7.68 (s, 1H, CH–); 13C
=
NMR (100 MHz, CDCl3): δ −0.41 (SiMe3), 1.08 (SiMe3), 10.21, 18.65, 19.62, 24.42, 27.57,
=
35.86, 53.28, 55.74, 66.32, 112.63, 128.16, 134.06, 143.76, 153.64, 157.16, 195.22 (C S);
Anal. Calcd for C25H45NOS2Si2: C, 60.55; H, 9.15; N, 2.82. Found: C, 60.68%; H, 9.31%;
N, 2.68%.
4.5.5. 3-(4-(2,2-bis(trimethylsilyl)vinyl)phenoxy)propyl diisopropylcarbamodithioate (6c)
Yellow oil, 92% (Rf = 0.66). FTIR (KBr, cm−1): 2871 ( CH–), 1174 (C S), 1247 and 842
(C–Si), 1036 (C–S); 1H NMR (400 MHz, CDCl3): δ −0.01 (s, 9H, SiMe3), 0.17 (s, 9H, SiMe3),
1.21–1.68 (m, 15H), 2.20–2.23 (m, 2H), 3.48 (bs, 2H), 4.05 (t, J = 6.2 Hz, 2H, CH2–O), 6.82
=
=
(d, J = 8.6 Hz, 2H, Ar), 7.11 (d, J = 8.6 Hz, 2H, Ar), 7.67 (s, 1H, CH–); 13C NMR (100 MHz,
=
CDCl3): δ −0.42 (SiMe3), 1.07 (SiMe3), 18.77, 24.86, 27.64, 65.48, 66.28, 112.61, 128.13,
=
134.08, 143.75, 153.57, 157.03, 194.05 (C S); Anal. Calcd for C24H43NOS2Si2: C, 59.82; H,
8.99; N, 2.91. Found: C, 59.96%; H, 9.13%; N, 2.78%.

690 K.D. Safa et al.
4.5.6. 4-(4-(2,2-bis(trimethylsilyl)vinyl)phenoxy)butyl diisopropylcarbamodithioate (7c)
Yellow oil, 93% (Rf = 0.64). FTIR (KBr, cm−1): 2883 (=CH–), 1246 and 836 (C–Si), 1170
(C=S), 1033 (C–S); 1H NMR (400 MHz, CDCl3): δ −0.02 (s, 9H, SiMe3), 0.17 (s, 9H, SiMe3),
1.41–1.42 (m, 12H), 1.91–1.92 (m, 4H), 2.90 (t, J = 6.2 Hz, 2H, CH2–S), 3.38 (bs, 2H), 4.00
(t, J = 5.9 Hz, 2H, CH2–O), 6.81 (d, J = 8.5 Hz, 2H, Ar), 7.10 (d, J = 8.5 Hz, 2H, Ar), 7.67 (s,
1H, CH–); 13C NMR (100 MHz, CDCl3): δ −0.41 (SiMe3), 1.08 (SiMe3), 19.63, 19.92, 24.20,
=
=
27.67, 66.32, 112.61, 128.15, 134.03, 143.73, 153.63, 157.16, 193.97 (C S); Anal. Calcd for
C25H45NOS2Si2: C, 60.55; H, 9.15; N, 2.82. Found: C, 60.72%; H, 9.30%; N, 2.69%.
Acknowledgements
We thank Dr. N. Arsalani for supplying some of the starting materials.
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