Synthesis and biological evaluation of diastereomeric (E and Z) sulfides, sulfones, sulfide-sulfones, and disulfones

Article abstract of DOI:10.1080/10426507.2010.530629

The addition of p-chlorobenzenethiol to benzyl p-chlorophenylketone resulted in the formation of a mixture of diastereomers (E)-and (Z)-1-p-chlorophenyl-2-phenyl-1-p-chlorophenylthioethylene (1 and 2). These compounds, upon reaction with bromine in acetic acid, yielded a mixture of (E)-and (Z)-1-bromo-2-p-chlorophenyl-1-phenyl-2-p-chlorophenylthioethylenes (5a and 5b). Oxidation of 5a and 5b affords (E)-and (Z)-1-bromo-2-p-chlorophenyl-1- phenyl-2-p-chlorophenylsulfonylethylenes (6a and 6b), which upon reaction with the p-chlorobenzenethiol gave (E)-and (Z)-1-p-chlorophenyl-1-p- chlorophenylsulfonyl-2-phenyl-2-p-chlorophenylthioethylenes (7a and 7b). Oxidation of 7a and 7b yielded (E)-and (Z)-1,2-bis(p-chlorophenylsulfonyl)-2- phenyl-1-p-chlorophenylethylenes (8a and 8b). The final products, 8a and 8b, were also synthesized from a mixture of diastereomers, (E)-and (Z)-2-p-chlorophenyl-1-phenyl-1-p-chlorophenylthioethylenes (3 and 4), yielding the intermediates 9a and 9b, 10a and 10b, and 11a and 11b. The configurations of these compounds were established by elemental analysis, IR, ¹H NMR, and mass spectra, and by their preparation from the corresponding phenylketones and p-chlorophenylphenylacetylene. All these new compounds exhibited pronounced in vitro antibacterial and antifungal activities. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. Copyright Taylor &Francis Group, LLC.

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Synthesis and Biological Evaluation
of Diastereomeric (E and Z) Sulfides,
Sulfones, Sulfide-Sulfones, and
Disulfones
A. Babul Reddy a , A. Hymavathi a , L. Vinay Kumar a , N.
Penchalaiah a , P. Jagan Naik a , M. Naveen a & G. Narayana Swamy a
a Department of Chemistry , Sri Krishnadevaraya University ,
Anantapur, Andhra Pradesh, India
Published online: 11 Aug 2011.
To cite this article: A. Babul Reddy , A. Hymavathi , L. Vinay Kumar , N. Penchalaiah , P. Jagan Naik ,
M. Naveen & G. Narayana Swamy (2011) Synthesis and Biological Evaluation of Diastereomeric (E and
Z) Sulfides, Sulfones, Sulfide-Sulfones, and Disulfones, Phosphorus, Sulfur, and Silicon and the Related
Elements, 186:8, 1721-1732, DOI: 10.1080/10426507.2010.530629
To link to this article: http://dx.doi.org/10.1080/10426507.2010.530629
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Phosphorus, Sulfur, and Silicon, 186:1721–1732, 2011
Copyright ꢀC Taylor & Francis Group, LLC
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426507.2010.530629
SYNTHESIS AND BIOLOGICAL EVALUATION OF
DIASTEREOMERIC (E AND Z) SULFIDES, SULFONES,
SULFIDE-SULFONES, AND DISULFONES
A. Babul Reddy, A. Hymavathi, L. Vinay Kumar,
N. Penchalaiah, P. Jagan Naik, M. Naveen,
and G. Narayana Swamy
Department of Chemistry, Sri Krishnadevaraya University, Anantapur,
Andhra Pradesh, India
GRAPHICAL ABSTRACT
SH
Cl
SH
O
C
O
C
Cl
C
C
H2
Cl
H2
Cl
CH2Cl2
Anhy.AlCl3
CH2Cl2
Anhy.AlCl3
Cl
Cl
Cl
H
H
S
H
S
S
H
S
Cl
Cl
Cl
Cl
Cl
1
2
3
4
C
C
Cl
HS
Cl
Abstract The addition of p-chlorobenzenethiol to benzyl p-chlorophenylketone resulted
in the formation of a mixture of diastereomers (E)- and (Z)-1-p-chlorophenyl-2-phenyl-
1-p-chlorophenylthioethylene (1 and 2). These compounds, upon reaction with bromine
in acetic acid, yielded a mixture of (E)- and (Z)-1-bromo-2-p-chlorophenyl-1-phenyl-2-p-
chlorophenylthioethylenes (5a and 5b). Oxidation of 5a and 5b affords (E)- and (Z)-1-bromo-2-
p-chlorophenyl-1-phenyl-2-p-chlorophenylsulfonylethylenes (6a and 6b), which upon reaction
with the p-chlorobenzenethiol gave (E)- and (Z)-1-p-chlorophenyl-1-p-chlorophenylsulfonyl-
2-phenyl-2-p-chlorophenylthioethylenes (7a and 7b). Oxidation of 7a and 7b yielded (E)- and
(Z)-1,2-bis(p-chlorophenylsulfonyl)-2-phenyl-1-p-chlorophenylethylenes (8a and 8b). The final
products, 8a and 8b, were also synthesized from a mixture of diastereomers, (E)- and (Z)-2-p-
chlorophenyl-1-phenyl-1-p-chlorophenylthioethylenes (3 and 4), yielding the intermediates 9a
and 9b, 10a and 10b, and 11a and 11b. The configurations of these compounds were estab-
lished by elemental analysis, IR, 1H NMR, and mass spectra, and by their preparation from the
Received 25 June 2010; accepted 6 October 2010.
The authors are thankful to the University Grants Commission, New Delhi, for financial help.
Address correspondence to G. Narayana Swamy, Department of Chemistry, Sri Krishnadevaraya University,
Anantapur-515003, Andhra Pradesh, India. E-mail: narayanaswamy.golla@gmail.com
1721

1722
A. B. REDDY ET AL.
corresponding phenylketones and p-chlorophenylphenylacetylene. All these new compounds
exhibited pronounced in vitro antibacterial and antifungal activities.
Supplemental materials are available for this article. Go to the publisher’s online edition of
Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.
Keywords Antimicrobial activity; disulfones; (E)- and (Z)-isomers, sulfide-sulfones; sulfides;
sulfones
INTRODUCTION
Sulfones, an important class of synthetic intermediates, are used for C-C bond forma-
tion and stereo-controlled functional group transformations.1–3 Dimethylsulfone or methyl-
sulfonylmethane is one of the best and safest drugs4 for the relief of arthritis,5 inflammation,
lupus, and other debilitating and disabling pain conditions, and is also effective in amelio-
rating the symptoms of gastrointestinal upset.6 The biological studies on sulfones revealed
that they can be used in chemotherapy, agriculture, dyes, and detergents.7 Vinyl sulfones
have been known for their synthetic utility in organic chemistry, easily participating in 1,4-
addition reactions. This functional group has also recently been shown to potently inhibit a
variety of enzymatic processes, providing unique properties for drug design and medicinal
chemistry.8 Divinyl sulfones and hydroxydiethyl sulfones are used to give crease-resistant
finishes, while other sulfones are used as fuel additives, plasticizers, and anti-icing addi-
tives.9 The recently originated unsaturated disulfones revealed from their biological studies
that they can be used as effective fungicides.7 There are several reports in the literature for
synthesis of sulfones, but not much information is available for the synthesis of disulfones.
We report the synthesis and biological evaluation of diastereomeric (E and Z) sulfides,
sulfones, sulfide-sulfones, and disulfones.
DISCUSSION
Benzylphenyl ketone is known to react with benzenethiol, forming a mixture of (E)-
and (Z)-1-phenylthiostilbenes in which the (E)-isomer predominates.10 Similarly, the reac-
tion of p-chlorobenzenethiol with benzyl p-chlorophenylketone in the present investigation
gave a mixture of (E)- and (Z)-1-p-chlorophenyl-2-phenyl-1-p-chlorophenylthioethylenes
(1 and 2) in which the (E)-isomer was in major proportion. On the other hand, the re-
action of p-chlorobenzenethiol with p-chlorobenzylphenylketone gave a mixture of (E)-
and (Z)-2-p-chlorophenyl-1-phenyl-1-p-chlorophenyl thioethylenes (3 and 4) in which the
(E)-isomer predominated (Scheme 1).
Only a pair of (E)- and (Z)-1-arylthiostilbenes are known to be formed by the ad-
dition of arenethiols to diphenylacetylene.11 But the addition of p-chlorobenzenethiol to
p-chlorophenylphenylacetylene in the present study resulted in the formation of two pairs
of diastereomeric (E)- and (Z)-1-p-chlorophenyl-2-phenyl-1-p-chlorophenylthioethylenes
(1 and 2), and (E)- and (Z)-2-p-chlorophenyl-1-phenyl-1-p-chlorophenylthioethylenes (3
and 4) (Scheme 1). The formation of two pairs of diastereomeric (E)- and (Z)-isomers is
expected because the dissimilar acetylenic carbons in p-chlorophenylphenylacetylene can
be attacked independently by the thio radical, and the addition can be both cis and trans.
The cis-addition of thiol leads to (E)-isomers, and the trans-addition leads to (Z)-isomers.
They were separated by fractional distillation under reduced pressure. The (E)-isomers 1

SYNTHESIS AND BIOLOGICAL EVALUATION OF DIASTEREOMERIC
1723
SH
SH
O
C
O
C
Cl
C
H2
C
H2
Cl
Cl
Cl
CH2Cl2
Anhy.AlCl3
CH2Cl2
Anhy.AlCl3
Cl
Cl
Cl
H
H
S
H
S
S
H
S
Cl
Cl
Cl
Cl
Cl
1
2
3
4
C
C
Cl
HS
Cl
Scheme 1
and 3 were the major products compared to their respective (Z)-isomers 2 and 4. The ad-
dition of thiols to acetylenes was reported to yield primarily the cis-addition products, and
the trans-addition products were obtained in minor proportion.12–15 Thus, the predominant
occurrence of the (E)-isomers 1 and 3 in the present investigation may be, in part, due to
their steric preference over the corresponding (Z)-isomers 2 and 4.
The synthesis of the four isomers was subsequently verified by the reaction of p-
chlrophenylphenylacetylene with p-chlorobenzenethiol. Of the four isomers formed in the
mixture, both the diastereomers 3 and 4 were in a higher proportion when compared to the
diastereomers 1 and 2. This may be attributed to the stabilities of the intermediate radicals
involved (Scheme 2). Thus, the formation of compounds 3 and 4 involves the intermediate
radical I, and those of 1 and 2 involve the intermediate radical II. The radical I is expected
to be more stable than II due to the contribution of a greater number of resonance structures.
The (E)-isomers 1 and 3 obtained from ketone have the same melting point, and there is no
depression in the mixed melting point. Also, the (Z)-isomers 2 and 4 have the same melting
point with no change of mixed melting point. The IR spectra of all the isomers formed
following the two methods were identical.

1724
A. B. REDDY ET AL.
p-ClC6H4S
SC6H4Cl-p
C6H4Cl-p
C C
C C
Cl
C6H5
I
II
Scheme 2
The reaction of 1 and/or 2 with Br2 in AcOH at room temperature gave a mixture of
5a and 5b (Scheme 3). They were separated by fractional crystallization from methanol.
Compound 5a was in a major proportion (64%), while 5b was a minor product (32%). This
is expected because of the formation of a carbocation (Scheme 4).
The carbocations I and II are interconvertable by rotation of a central carbon–carbon
single bond. The expulsion of a proton from carbocation I results in the formation of
(Z)-isomer (5a), and the expulsion of a proton from carbocation II gives (E)-isomer (5b).
In carbocation I, the p-ClC6H4S group is gauche to H on the adjacent carbon, whereas in
carbocation II the p-ClC6H4S group is gauche to C6H5. Since the formation of the (Z)-
isomer involves a more stable carbocation (I) than the (E)-isomer, the (Z)-isomer forms in
a major proportion. The identity of compound (5a) has been confirmed as the (Z)-isomer.
Compound 5a upon irradiation with UV light14 gave 5b. Oxidation of 5a and
5b afforded (E)- and (Z)-1-bromo-2-p-chlorophenyl-1-phenyl-2-p-chlorophenylsulfonyl
ethylenes (6a and 6b), respectively. Compounds 6a and 6b when heated with sodium salt
of p-chlorobenzenethiol yielded (E)- and (Z)-1-p-chlorophenyl-1-p-chlorophenylsulfonyl-
2-phenyl-2-p-chlorophenylthioethylenes (7a and 7b) with retention of configuration.16 Ox-
idation of 7a and 7b afforded 8a and 8b, respectively (Scheme 3). The stereoisomers 3 and
4 also yielded the final compounds 8a and 8b (Scheme 5).
The characterization data of all the newly synthesized compounds are presented in
Table 1. In the IR region, νc mode was not observed for all sulfide-sulfones and bis-
c
sulfones. This may be attributed to the tetrasubstituted nature of the compounds.17 The
strong bands at 1175 and 1356 cm−1 in bis-sulfones were assigned to νas SO2 and νs
SO2 modes, and the bands observed in sulfide-sulfones and bis-sulfones at 1086 cm−1
were assigned to νc-c (aryl) mode.18 Because the compounds 1 through 4 are trisubstituted
1
ethylenes, the H NMR spectra chemical shifts (included in the Supplemental Materials,
available online) are used,19 rather than coupling constants, to differentiate between (E)- and
(Z)-isomers. The chemical shifts of vinyl protons of cis-(E)-thioethylenes 1 and 3 occur at a
lower field strength (δ 7.29 and 7.39) than their corresponding trans-(Z)-thioethylenes 2 and
4 (δ 6.96 and 7.02). A similar observation was made with monosulfides by Hussain et al.,20
wherein all aromatic hydrogens resonated as multiplets at δ 6.99–8.00. The electron impact
mass spectral data of some (E)- and (Z)-monosulfides, bromosulfones, sulfide-sulfones,
and disulfones are presented as Supplemental Materials, available online. A notable feature
observed in the spectra of (E)- and (Z)-bromosulfides, bromosulfones, sulfide-sulfones,
and disulfones is the absence of molecular ion peaks, and this may be due to the thermal
decomposition of the sample during vaporization.12
Antimicrobial Activity
The data related to antibacterial and antifungal activities are presented as Supple-
mental Materials (Tables S1 and S2).

SYNTHESIS AND BIOLOGICAL EVALUATION OF DIASTEREOMERIC
1725
1 and or 2
Br2/AcOH
Cl
Cl
Br
hv
UV
Br
S
S
5a
5b
Cl
Cl
H2O2/AcOH
Cl
H2O2/AcOH
Cl
Br
O
S
O
S
Br
O
O
6a
6b
Cl
Cl
p-ClC6H4SNa/EtOH
p-ClC6H4SNa/EtOH
Cl
Cl
Cl
S
O
S
O
S
S
O
O
7a
7b
Cl
Cl
Cl
H2O2/AcOH
Cl
H2O2/AcOH
Cl
Cl
O
S
O
O
O
S
O
S
S
O
O
O
8a
8b
Cl
Cl
Cl
Scheme 3

1726
A. B. REDDY ET AL.
p- ClC6H4
p- ClC6H4
SC6H4Cl -p
p- ClC6H4S
SC6H4Cl -p
SC6H4Cl -p
-H+
Br2
Br
C6H5
C6H5
C6H5
H
H
1
Br
I
5a
p- ClC6H4S
p - ClC6H4S
p - ClC6H4S
C6H4Cl -p
C6H4Cl -p
C6H4Cl -p
+
Br2
-H
Br
C6H5
C6H5
C6H5
H
H
II
Br
2
5b
Scheme 4
EXPERIMENTAL
All melting points were determined in open capillary tubes on Mel-Temp apparatus
(Laboratory Devices, Cambridge, MA, USA), and are uncorrected. Infrared spectra (νmax in
cm−1) were recorded as KBr pellets on a Perkin-Elmer 283 double beam spectrophotometer.
1H NMR spectra were recorded on an ABX 400 MHz spectrophotometer operating at
1
1
400 MHz for H NMR, using DMSO-d6 as solvent. The H NMR chemical shifts were
referenced to tetramethylsilane (TMS).
General Procedure for the Preparation of 1 and 2 from Benzyl
p-Chlorophenyl Ketone or 3 and 4 from p-Chlorobenzyl Phenyl Ketone
A solution of benzyl p-chlorophenyl ketone (23 g, 100 mmol) or p-
chlorobenzylphenylketone and p-chlorobenzenethiol (23 g, 159 mmol) in methylene
chloride (100 mL) were taken in a 250 mL conical flask fitted with an air-condenser
guarded with a calcium chloride tube. The solution was stirred at room temperature, and
anhydrous aluminium chloride (4.53 g, 34 mmol) was added in small portions over a
period of 10 min. The reaction mixture became turbid as the reaction proceeded. After the
addition, the mixture was further stirred for another 60 min and was poured into water
(75 mL). The resulting mixture was extracted with methylene chloride (100 mL), and the

SYNTHESIS AND BIOLOGICAL EVALUATION OF DIASTEREOMERIC
1727
3 and or 4
Br2/AcOH
Cl
Br
hv
UV
S
Br
S
Cl
9a
9b
Cl
Cl
H2O2/AcOH
H2O2/AcOH
Cl
Br
O
S
O
S
Br
O
O
10a
10b
Cl
Cl
Cl
p-ClC6H4SNa/EtOH
p-ClC6H4SNa/EtOH
Cl
Cl
S
O
S
O
S
S
O
O
Cl
11a
11b
Cl
Cl
Cl
H2O2/AcOH
H2O2/AcOH
8a
8b
extract was washed with brine solution (100 × 2 mL), 2% sodium hydroxide solution
(100 × 2 mL), and water (250 mL). The organic layer was dried over anhydrous MgSO4,
and the solvent was evaporated to give the solid, which was recrystallized from acetic acid
(1 or 3). The yields varied from 65–71%.

1728

SYNTHESIS AND BIOLOGICAL EVALUATION OF DIASTEREOMERIC
1729
The acetic acid solution obtained after separating 1 or 3 on evaporation of the solvent
gave 2 or 4 as solid, which upon recrystallization with 95% ethanol yielded needle-shaped
crystals. The yields varied from 35–39%.
Reaction of p-Chlorobenzenethiol with p-Chlorophenylphenylacetylene
A solution of p-chlorophenylphenylacetylene (21.24 g, 100 mmol) in n-heptane (150
mL) was heated to reflux, and p-chlorobenzenethiol (21.63 g, 150 mmol) was added to
the above solution. The reaction mixture was refluxed for 24 h. The solution was washed
successively with 2% sodium hydroxide solution (100 × 2 mL) and water (250 mL), and
dried over anhydrous calcium chloride. The residue left after the evaporation of the solvent
was subjected to fractional distillation under reduced pressure to get four fractions.
The first fraction was collected at 180–182◦C/30 mm Hg, which upon cooling gave a
solid of 7.05 g (19.8%). It was recrystallized from 95% ethanol to give needle-shaped crys-
tals of (E)-1-p-chlorophenyl-2-pheny-1-p-chlorophenylthioethylene (1), mp 110–112◦C.
There was no change in melting point of this compound when mixed with 1 prepared
earlier from benzyl p-chlorophenylketone.
The second fraction was collected at 188–190◦C/30 mm, which upon cooling be-
came a pasty mass, and upon treatment with petroleum spirit gave a solid of 16.92 g
(47.4%). It was recrystallized from 95% ethanol to give colorless crystals of (E)-2-p-
chlorophenyl-1-phenyl-1-p-chlorophenylethylne (3), mp 139–140◦C. No change in melt-
ing point of this compound was observed upon mixing with 3 synthesized earlier from
p-chlorobenzylphenylketone.
The third fraction was collected at 195–197◦C/30 mm, which upon cooling gave a
solid of 4.96 g (13.7%). It was recrystallized from methanol to give (Z)-1-p-chlorophenyl-
2-phenyl-1-p-chlorophenylthioethylene (2) with a mp of 78–80◦C. When mixed with 2
prepared earlier from benzyl p-chlorophenylketone, there was no change in melting point
of this compound.
The fourth fraction was collected at 198–200◦C/30 mm, which upon cooling gave
a pasty mass, and upon trituration with n-hexane yielded a solid of 3.25 g (8.9%).
It was recrystallized from ethyl acetate to give (Z)-2-p-chlorophenyl-1-phenyl-1-p-
chlorophenylthioethylene (4), mp 172–174◦C. The melting point of this compound also
did not depress on admixture with 4 prepared earlier from benzyl p-chlorophenylketone.
General Procedure for the Bromination of (1 or 2) to (5a and 5b),
or (3 or 4) to (9a and 9b)
1 or 2 or 3 or 4 (9.54 g, 26 mmol) was dissolved in glacial acetic acid (100 mL) in a
250 mL conical flask fitted with a mechanical stirrer. The stirrer was set in motion, and a
solution of bromine (4.37 g, 26 mmol) in glacial acetic acid (15 mL) was added dropwise.
Decolorization was observed during addition, and stirring was continued for 24 h. The
solid separated was filtered and recrystallized from 95% ethanol. The yields varied from
59–63%. The filtrate from the above reaction mixture after separating the 5b or 9b upon
dilution with water gave 5a or 9a as a solid, which was recrystallized from 95% ethanol.
The yields ranged from 35–39%.

1730
A. B. REDDY ET AL.
General Procedure for the Oxidation of 5a to 6a or 5b to 6b or 9a to 10a
or 9b to 10b
A solution of 5a or 5b or 9a or 9b (4.03 g, 9 mmol) in glacial acetic acid (60 mL) was
taken in a 100 mL round-bottomed flask fitted with a reflux condenser. The solution was
heated to boiling, then 30% hydrogen peroxide (50 mL) was added dropwise and refluxed
for 2 h. The product that separated upon cooling was collected, filtered, and recrystallized
from 95% ethanol. The yields varied from 80–98%.
General Procedure for the Conversion of 6a to 7a or 6b to 7b or 10a to
11a or 10b to 11b
p-Chlorobenzenethiol (0.77 g, 5 mmol) was added to an ethanolic solution of sodium
ethoxide, which was prepared from sodium (0.12 mg, 5 mmol) dissolved in absolute ethanol
(10 mL). This solution was then added to a hot solution of 6a or 6b, or 10a or 10b (2.37
g, 5 mmol) in absolute ethanol (200 mL) contained in a 500 mL round-bottomed flask
fitted with a reflux condenser protected with calcium chloride guard tube. The mixture
was refluxed for 24 h. The colorless product that separated upon cooling was filtered and
recrystallized three times from 95% ethanol. They yields ranged from 38–69%.
General Procedure for the Oxidation of 7a or 7b or 11a or 11b to (E)-
and (Z)-1,2-Bis-(p-chlorophenylsulfonyl)-1-p-chlorophenyl-2-phenyl Ethylene
(8a and 8b)
A solution of 7a or 7b, or 11a or 11b (1.07 g, 2 mmol) in glacial acetic acid (50 mL)
was taken in a 100 mL round-bottomed flask fitted with a reflux condenser. The solution
was heated to boiling, and 30% hydrogen peroxide (10 mL) was added slowly. The solution
was refluxed for 1 h, and the colorless crystals that separated upon cooling were filtered
and recrystallized from 95% ethanol. The yields varied from 88–95%.
Spectroscopic Data
Spectral data for 5b, 6b, 7b, and 8b are found as Figures S1–S4 in the Supplementary
Materials.
1
(E)-1-p-chlorophenyl-2-phenyl-1-p-chlorophenylthioethylene (1). H
NMR (400 MHz, CDCl3): δ 7.12–7.14 (m, 4H), 7.29 (s, 1H), 7.32–7.41 (m, 5H), 7.55–7.58
(d, 2H), 7.83–7.89 (d, 2H). LCMS: (m/z) 356 (M++1), 212, 213, 215, 143, 111.
1
(Z)-1-p-Chlorophenyl-2-phenyl-1-p-chlorophenylthioethylene (2). H
NMR (400 MHz, CDCl3): δ 6.96 (s, 1H), 7.23–7.32 (d, 2H), 7.35–7.39 (m, 5H), 7.63–7.68
(m, 4H), 7.92–7.99 (d, 2H). LCMS: (m/z) 356 (M++1), 212, 213, 215, 143, 111.
1
(E)-2-p-Chlorophenyl-1-phenyl-1-p-chlorophenylthioethylene (3). H
NMR (400 MHz, CDCl3): δ 6.99 (d, 2H), 6.99–7.01 (d, 2H), 7.08 (d, 2H), 7.26–7.31 (m,
5H), 7.39 (s, 1H). 7.86 (d, 2H). LCMS: (m/z) 356 (M++1), 212, 213, 215, 143, 111.
1
(Z)-2-p-Chlorophenyl-1-phenyl-1-p-chlorophenylthioethylene (4). H
NMR (400 MHz, CDCl3): δ 7.02 (s, 1H), 7.14–7.20 (m, 4H), 7.11–7.18 (d, 2H), 7.38–7.44
(m, 5H), 7.57–7.65 (d, 2H). LCMS: (m/z) 356 (M++1), 212, 213, 215, 143, 111.
(E)-1-Bromo-2-p-chlorophenyl-1-phenyl-2-p-chlorophenylthioethylene
1
(5b). H NMR (400 MHz, CDCl3): δ 7.01–7.12 (m, 5H), 7.14 (d, 2H), 7.17 (d, 2H),

SYNTHESIS AND BIOLOGICAL EVALUATION OF DIASTEREOMERIC
1731
7.26–7.35 (d, 2H), 7.62–7.73 (d, 2H). LCMS: (m/z) 291, 293, 295, 212, 214, 176, 143,
111.
(E)-1-Bromo-2-p-chlorophenyl-1-phenyl-2-p-chlorophenylsulfonylethy
1
lene (6b). H NMR (400 MHz, CDCl3): δ 7.13 (d, 2H), 7.25 (d, 2H), 7.29-7.38 (m, 5H),
7.42 (d, 2H), 7.89 (d, 2H). LCMS: (m/z) 291, 293, 295, 212, 214, 176, 175, 143, 111.
(E)-1-p-Chlorophenyl-2-phenyl-1-p-chlorophenylsulfonyl-2-p-chlropheny
lthioethylene (7b). NMR (400 MHz, CDCl3): δ 6.99–7.04 (d, 2H), 7.13–7.24 (m, 5H),
7.43 (d, 2H), 7.67–789 (m, 4H), 7.83–7.89 (d, 2H), 7.93–8.00 (d, 2H). LCMS: (m/z) 359,
358, 357, 356, 355, 321, 320, 319, 212, 214,177, 176, 175, 143, 111.
(E)-1,2-Bis(p-chlorophenylsulfonyl)-1-p-chlorophenyl-2-phenylethylene
1
(8b). H NMR (400 MHz, CDCl3): δ 7.11 (d, 2H), 7.18 (d, 2H), 7.26 (d, 2H), 7.32 (d,
2H), 7.36-7.48 (m, 5H), 7.47 (d, 2H), 7.87 (d, 2H), 8.00 (d, 2H). LCMS: (m/z) 387, 357,
323, 212, 177, 176, 175, 139, 111, 105.
Antimicrobial Activity
All the compounds synthesized (1 through 11b) were screened for their antibacterial
activity against human pathogenic bacteria Pseudomonas aeruginosa, Staphylococcus au-
reus, Escherichia coli, Streptococcus faecalis, and Propionibacterium acnes. The minimum
inhibition concentration (MIC) of each compound was determined using the tube dilution
method.21 DMF was used as a blank and ciprofloxacin as a standard. The compounds were
also screened for their antifungal activity against Candida albicans and Aspergillus niger
using the fungicide clotrimazole in DMF22 as a standard.
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