Synthesis, characterization, and antimicrobial evolution of bissydnone based on sulfonamide derivatives

Article abstract of DOI:10.1002/jhet.1094

3,3′-(Sulfonyldi-1,4-phenylene)bis(4-substituted aminosulfonyl) sydnones () were synthesized from the starting material 4,4′- diaminodiphenylsulfone. The synthesized compounds were characterized by IR, NMR, and elemental analysis. Some of the compounds we

Full text of DOI:10.1002/jhet.1094

Month 2013
Synthesis, Characterization, and Antimicrobial Evolution of
Bissydnone Based on Sulfonamide Derivatives
*
Shahrukh T. Asundaria and Keshav C. Patel
Department of Chemistry, Veer Narmad South Gujarat University, Surat, Gujarat 395007, India
*
E-mail: drkeshavpatel@rediffmail.com
Received April 18, 2011
DOI 10.1002/jhet.1094
Published online 00 Month 2013 in Wiley Online Library (wileyonlinelibrary.com).
3,3′‐(Sulfonyldi‐1,4‐phenylene)bis(4‐substituted aminosulfonyl)sydnones (7a–j) were synthesized from
the starting material 4,4′‐diaminodiphenylsulfone. The synthesized compounds were characterized by IR,
NMR, and elemental analysis. Some of the compounds were effectively active against Gram‐positive bacte-
ria (Streptococcus pneumoniae and Staphylococcus aureus) and Gram‐negative bacteria (Escherichia coli
and Pseudomonas aeruginosa).
J. Heterocyclic Chem., 00, 00 (2013).
INTRODUCTION
RESULTS AND DISCUSSION
Sydnones have continued to attract a widespread in-
terest for a long time because of their unusual structure,
chemical properties, and synthetic utility [1]. Kier and
Roche [2] had reviewed in detail the biological impor-
tance of various mesoionic compounds. Since their dis-
covery, sydnones have shown varieties of biological
activities such as anticonvulsant [3], antioxidant [4], an-
algesic [5], antitumor [6], anti‐inflammatory [7], anti-
fungus [8], and antibacterial activity [9]. Sydnones are
used as a versatile synthon in many heterocyclic synthe-
ses [10]. Besides, sulfonamides are also an important
class of compounds exhibiting interesting biological as
well as medical applications [11]. Compounds related
to 4,4′‐diaminodiphenylsulfone have been proved to be
important therapeutic agents [12]. Recently, various bis-
sydnone sulfonamide derivatives have been synthesized
from our laboratory. To extend the work, we report
the synthesis and characterization of novel 3,3′‐(sulfo-
nyldi‐1,4‐phenylene)bis(4‐primary substituted aminosul-
fonyl)sydnones 7(a–j) and evaluated their antibacterial
activity.
Replacement of chlorine atom of sulfonyl chloride by an
amino group is a well‐established strategy for the synthesis
of sulfonamides. Herein, we have described the synthesis,
characterization, and biological evaluation of 3,3′‐(sulfo-
nyldi‐1,4‐phenylene)bis(4‐substituted aminosulfonyl)sydnone
(7a–j). Commercially available 4,4′‐diaminodiphenylsulfone
(1) was taken as the starting material. 3,3′‐(Sulfonyldi‐1,4‐
phenylene)bissydnone (5) was prepared in moderate yield in
four steps through conventional route [13]. Bissydnone
derivative (5) has been prepared by the cyclodehydration of
compound (4). The nitroso glycine has to be dried to remove
traces of water before it reacted with the cyclization reactant
acetic anhydride. The motivating force for the formation of
sydnone ring may be the nucleophilicity of the oxygen atom
of nitroso group for the carbon atom of carboxylic group. As
sydnone compounds are unstable toward both acidic and
basic media, the synthesis must be carried out carefully. The
carbon atom at the fourth position of sydnone ring bears a
fractional negative charge, and therefore, electrophilic substi-
tution takes place with reaction of chlorosulfonic acid. Com-
pound (5) on chlorosulfonation followed by condensation
© 2013 HeteroCorporation

S. T. Asundaria and K. C. Patel
Vol 000
Figure 1. 3,3′‐(Sulfonyldi‐1,4‐phenylene)bis(4‐substituted aminosulfonyl)sydnone (7a–j). (a) R = 4‐ClC6H4; (b) R = CH2(CH2)4CH3; (c) R = CH3; (d) R
= C6H5; (e) R = 3‐ClC6H4; (f) R = 2‐FC6H4; (g) R = CH2(CH2)2CH3; (h) R = 3‐CH3C6H4; (i) R = CH2-C6H5; (j) R = 2‐CH3C6H4.
with different amines formed final compounds 3,3′‐sulfo-
nyldi‐1,4‐phenylene)bis(4‐substituted aminosulfonyl)sydnone
(7a–j). Figure 1 shows the synthetic route of compounds
(7a-j). Thin layer chromatography (TLC) of compounds 6
and (7a–j) showed that single compounds were produced.
The solvent system used for TLC was toluene:ethyl acetate:
isopropyl alcohol (7:2:1). The structures of synthesized com-
pounds were deduced from elemental analysis and spectral
data. IR spectrum shows characteristic band for C═O group
of sydnone between 1727 and 1750 cm−1. Sometimes multiple
peaks of carbonyl group occur due to the Fermi resonance
splitting [14]. The SO2 stretching was observed between
1336–1350 cm−1 and 1129–1168 cm−1. Sulfonamide group
of compound 7a–j also shows N-H stretching band near
3260 cm−1. The IR spectrum of 7a is shown in Figure 2. The
lH‐NMR spectrum of each compound in the series shows char-
acteristic singlet for sulfonamide group about δ = 8.96–10.25
and δ = 4.65–5.75. In the mesoionic structure of sydnone, the
positive charge associated with the ring exerts a very marked
deshielding effect, and therefore, high field for the ring proton
of sydnone ring in compound (5) is observed at δ = 7.80.
The antibacterial screening results have shown that this
activity varies with the substitution on sulfonamide group
(Table 2). Compound 7d possessing phenyl substitution
showed highest activity, whereas compounds 7g, 7i, and
7j having butyl, benzyl, and 2‐methylphenyl substituent,
respectively, showed good activity against Streptococcus
pneumoniae. Compound 7i containing benzyl ring as substitu-
ent showed highest activity against rest of the tested bacterial
organisms. Compounds 7g, 7h, and 7j containing butyl,
3‐methylphenyl, and 2‐methylphenyl substituents, respectively,
were found to show good activity against Staphylococcus
aureus. Compounds 7a and 7j possessing 4‐chlorophenyl and
2‐methylphenyl substituents displayed pronounced activity
against Escherichia coli, whereas compound 7g having butyl
substitution was found to possess higher activity against
Pseudomonas aeruginosa. The rest of the compounds were
found to possess moderate to poor activity against tested organ-
isms. It shows how biological properties influence by minor
structural modification. In general, most of the compounds
were found to possess antibacterial activity. It is noted that
larger zones are co‐related with smaller minimum inhibitory
concentration.
1
Figure 3 shows the H‐NMR spectrum of compound 7a.
13C‐NMR of sydnone carbon at the fourth position reso-
nance near δ = 90.00 and carbonyl carbon of sydnone ring
near δ = 161.00. 13C‐NMR spectrum of the compound 7a
is depicted in Figure 4. Characterization data of the com-
pounds 7(a–j) obtained are given in Table 1.
Biological activity. The preliminary antibacterial testing
has been carried out by Kirby‐Bauer Technique [16] to
estimate the minimum inhibitory concentration of the test
compounds. The following dilutions of compounds were
selected: 400, 200, and 100 μg/mL. The antimicrobial
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

Month 2013
Synthesis, Characterization, and Antimicrobial Evolution of Bissydnone
Based on Sulfonamide Derivatives
activity was done against Gram‐positive bacterial strains
Streptococcus pneumoniae and Staphylococcus aureus
and against Gram‐negative bacterial strains Escherichia
coli and Pseudomonas aeruginosa. The reference drugs
used were streptomycin and penicillin‐G. The sample
drugs were screened at 200 μg/mL under identical
conditions, and the zone of inhibition was measured in
millimeters. A reading of 10 mm indicates no zone. The
activity of the compounds (7a–j) as spectrum is depicted
in Figure 5.
CONCLUSIONS
The sulfonyl chloride derivative of sydnone was reacted
with various amines. Their analytical data provide ade-
quate results. Many of the new products exhibited splendid
activity against tested organisms.
EXPERIMENTAL
Melting points were determined by open capillary method and
are uncorrected. All compounds were analyzed satisfactorily for
C, H, O, N, and S. IR spectra (KBr) were recorded on Shimadzu
FTIR spectrophotometer (Japan). 1H‐NMR and 13C‐NMR spectra
were recorded on Bruker spectrometer at 400 MHz using di-
methyl sulfoxide (DMSO)‐d6 as a solvent and TMS as an internal
standard. Elemental analysis was carried out on a Vairo‐EL
(Elementa) model. Purity of the compounds was checked by
TLC on silica gel plates. Analytical TLC was carried out with
Merck silica gel 60 F254λ aluminum sheets.
Typical procedure for the synthesis of 3,3′‐sulfonyldi‐1,4‐
phenylene)bis(4‐primary substituted aminosulfonyl)sydnones
(7a–j). Synthesis of 2,2′‐[sulfonylbis(1,4‐phenylene imino)]diethyl
acetate (2). To a mixture of 4,4′‐diaminodiphenylsulfone (2.48 g,
0.01 mol) and double molar quantity of ethylchloroacetate in
dry ethanol (10 mL), freshly dried sodium acetate (3.28 g, 0.04
mol) was added, and then the mixture was heated under reflux
for 4–5 h.. The mixture was diluted with water and kept in
refrigerator overnight. Crystalline esters were obtained and
purified by recrystallization from ethanol. The reaction was
monitored by TLC.
Synthesis of 2,2′‐[sulfonylbis(1,4‐phenylene imino)]diacetic
acid (3). 2,2′‐[Sulfonylbis(4,1‐phenyleneimino)]diethylacetate
(4.20 g, 0.01 mol) and sodium hydroxide (1.2 g, 0.03 mol)
were dissolved in distilled water:absolute alcohol (36.0:4.0 mL) in
a
flat‐bottomed flask. The mixture was stirred at reflux
temperature for 30 min. The resultant mixture was cooled and
acidified with hydrochloric acid to get the final product. Pure
product was obtained by recrystallization from ethanol.
Synthesis of 2,2′‐[sulfonylbis{1,4‐phenylene(nitrosoimino)}]
diacetic acid (4). To a well‐stirred solution of 2,2′‐[sulfonylbis(4,1‐
phenylene‐imino)]diacetic acid (5.82 g, 0.016 mol) in water (40 mL),
freshly prepared sodium nitrate solution (3.32 g, 0.049 mol)
was added dropwise at 0–5°C over a period of 40 min [15].
Concentrated hydrochloric acid was added until pH becomes
2-3. The nitroso compound was filtered with suction and
washed with cold water and then was dried and recrystallized
from ethanol.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

S. T. Asundaria and K. C. Patel
Vol 000
Figure 2. IR spectrum of 3,3′‐(sulfonyldi‐1,4‐phenylene)bis(4‐{[(4‐chlorophenyl)amino]sulfonyl}sydnone (7a).
Figure 3. 1H‐NMR spectrum of 3,3′‐(sulfonyldi‐1,4‐phenylene)bis(4‐{[(4‐chlorophenyl)amino]sulfonyl}sydnone (7a).
Figure 4. 13C‐NMR spectrum of 3,3′‐(sulfonyldi‐1,4‐phenylene)bis(4‐{[(4‐chlorophenyl)amino]sulfonyl}sydnone (7a).
Synthesis of 3,3′‐(sulfonyldi‐1,4‐phenylene)bissydnone
(5). The dried 2,2′‐[sulfonylbis{4,1‐phenylene(nitrosoimino)}]
diacetic acid (4) and acetic anhydride were taken in the ratio of
1:5 and stirred for 10 h. The stirred solution was slowly poured
into cold water. The content was neutralized by 10% sodium
bicarbonate solution and washed well with water and dried. The
crude sydnone was recrystallized from benzene–petroleum ether.
Synthesis of 3,3′‐(sulfonyldi‐1,4‐phenylene)bis(4‐
chlorosulfonyl)sydnone (6). Chlorosulfonic acid (2.32 mL, 0.02 mol)
was added dropwise into the mixture of 3,3′‐(4,4′‐diphenyl)
bissydnonyl sulfone (3.86 g, 0.01 mol) and catalytic amount of P2O5
over 30 min with constant stirring at 0–5°C. The temperature of the
well‐stirred mixture was maintained at 5°C. When all the
chlorosulfonic acid has been added (about 1 h), the mixture was
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

Month 2013
Synthesis, Characterization, and Antimicrobial Evolution of Bissydnone
Based on Sulfonamide Derivatives
Table 2
Antibacterial activity of 3,3′‐(sulfonyldi‐1,4‐phenylene)bis(4‐substituted aminosulfonyl)sydnone (7a–j).
Gram‐positive organism
Streptococcus pneumoniae Staphylococcus aureus
Gram‐negative organism
Escherichia coli Pseudomonas aeruginosa
Compd. no.
IZ
MIC
IZ
MIC
64
128
–
64
128
64
32
32
32
32
IZ
MIC
IZ
MIC
64
64
64
7a
7b
7c
7d
7e
7f
7g
7h
13
10
12
17
13
12
16
10
16
16
40
35
64
–
12
11
10
14
12
13
16
15
18
17
40
45
13
11
14
15
11
12
16
13
16
15
28
30
32
128
64
12
12
13
10
10
12
14
10
15
10
34
38
64
16
64
64
32
–
32
32
0.25
0.25
64
–
–
128
128
16
64
16
32
1
0.5
64
32
–
–
7i
7j
32
Streptomycin
Penicillin‐G
0.125
0.125
0.5
0.25
IZ, inhibition of zone; MIC, minimum inhibitory concentration.
refluxed at about 60°C for about 60 min. The solution was then poured
into a mixture of crushed ice and water with vigorous stirring.
Precipitation was collected by filtration, washed thrice with water and
then dried.
Following the above procedure, bissydnone derivatives
(7a–j) were synthesized using p‐chloroaniline, n‐hexylamine,
n‐methylamine, aniline, m‐chloroaniline, o‐floroaniline, n‐butylamine,
m‐toluidine, benzylamine, and o‐toluidine as primary amines. All the
synthesized compounds 7(a–j) are recorded in Table 1.
Condensation of 3,3′‐(sulfonyldi‐1,4‐phenylene)bis
(4‐chlorosulfonyl)sydnone with different primary amines
(7a–j). 3,3′‐(Sulfonyldi‐1,4‐phenylene)bis(4‐chlorosulfonyl)
sydnone (0.011 mol) was dissolved in acetone at room
temperature. A solution of primary amine (0.022 mol) in
acetone was added dropwise into the solution of compound
6 over a period of 5 h with constant stirring. Then 10 mL
of pyridine was added to the well‐stirred solution after 1 and
2 h during the reaction. The solution was poured into ice
with stirring. The precipitate was collected by filtration,
washed thrice with water and then dried. The precipitate was
recrystallized from benzene.
IR, 1H‐NMR (δ, ppm; DMSO), and 13C‐NMR (δ, ppm;
DMSO) of the synthesized compounds. 2,2′‐[Sulfonylbis
(1,4‐phenyleneimino)]diethyl acetate (2). IR (KBr): 2955, 2919,
1
2864, 2845, 1757, 1339, 1320, 1150 cm−1; H‐NMR: δ = 1.33
(t, 6H, J = 7.10 Hz, CH3), 3.70 (s, 2H, CH2), 4.00 (s, 2H, NH),
4.35 (q, 4H, J = 7.10 Hz, COO-CH2), 6.47–7.70 (m, 8H, Ar‐H);
13C‐NMR: δ = 14.46, 44.42, 61.45, 115.08, 128.07, 133.38,
171.49, 149.12.
2,2′‐[Sulfonylbis(1,4‐phenylene imino)]diacetic acid (3). IR
(KBr): 3340–2523, 2948, 2914, 1710, 1343, 1320, 1139 cm−1
;
1H‐NMR: δ = 4.03 (s, 4H, CH2), 6.37 (s, 2H, NH), 6.40 (s, 2H,
140
120
100
80
7a
7b
7c
7d
7e
7f
7g
7h
60
7i
7j
Streptomycin
Penicilline – G
40
20
0
IZ
MIC
IZ
MIC
IZ
MIC
IZ
MIC
S. pneumoniae
S. aureus
E. coli
P. aeruginosa
Figure 5. Minimum inhibitory concentration and zone of inhibition of compounds (7a–j). [Color figure can be viewed in the online issue, which is avail-
able at wileyonlinelibrary.com.]
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

S. T. Asundaria and K. C. Patel
Vol 000
COOH), 6.49–7.45 (m, 8H, Ar‐H); 13C‐NMR: δ = 44.77, 114.56,
128.64, 133.57, 148.96, 171.79.
3,3′‐(Sulfonyldi‐1,4‐phenylene)bis{4‐[(butylamino)sulfonyl]
sydnone (7g). IR (KBr): 3263, 2965, 2930, 2880, 2865, 1750, 1339,
1164 cm−1; 1H‐NMR: δ = 0.94 (t, 6H, J = 7.15 Hz, CH3), 1.35–1.69
(m, 8H, CH2), 3.04 (t, 4H, J = 6.53 Hz, NHCH2), 4.65 (s, 2H,
-SO2NH), 8.15–8.73 (m, 8H, Ar‐H); 13C‐NMR: δ = 13.83, 20.16,
29.72, 41.18, 124.12, 129.58, 132.53, 137.54, 142.26, 167.75.
3,3′‐(Sulfonyldi‐1,4‐phenylene)bis(4‐{[(3‐methylphenyl)
amino]sulfonyl}sydnone (7h). IR (KBr): 3263, 2968, 2950,
2,2′‐[Sulfonylbis{1,4‐phenylene(nitrosoimino)}]diacetic acid (4).
IR (KBr): 2520–3322, 2935, 2917, 1505, 1355, 1347, 1134 cm−1;
1H‐NMR:
δ = 4.79 (s, 4H, CH2), 7.87–8.10 (m, 8H,
Ar‐H), 11.37 (s, 2H, COOH); 13C‐NMR: δ = 49.24, 121.40,
128.92, 134.77, 141.33, 167.77.
3,3′‐(Sulfonyldi‐1,4‐phenylene)bissydnone (5). IR (KBr):
1750, 1339, 1162 cm−1 1H‐NMR: δ = 2.15 (s, 6H, CH3),
;
1745, 1339, 1129 cm−1 1H‐NMR: δ = 7.80 (s, 2H, sydnone),
;
6.89–8.30 (m, 16H, Ar‐H), 9.05 (s, 2H, SO2NH); 13C‐NMR:
δ = 22.03, 118.57, 122.15, 123.76, 125.97, 129.64, 129.75,
132.54, 137.05, 137.96, 141.21, 142.75, 167.28.
8.54–8.06 (m, 8H, Ar‐H); 13C‐NMR: δ = 95.67, 122.82,
128.70, 131.77, 141.98, 169.13.
3,3′‐(Sulfonyldi‐1,4‐phenylene)bis(4‐chlorosulfonyl)sydnone
(6). IR (KBr): 1745, 1410, 1336, 1193, 1138 cm−1; 1H‐NMR:
δ = 8.22–8.54 (m, 8H, Ar‐H); 13C‐NMR: δ = 123.18, 126.16,
128.36, 139.64, 141.66, 168.47.
3,3′‐(Sulfonyldi‐1,4‐phenylene)bis(4‐{[(4‐chlorophenyl)
amino]sulfonyl}sydnone (7a). IR (KBr): 3261, 1750, 1339, 1163,
1055 cm−1; 1H‐NMR: δ = 7.00–8.30 (m, 16H, Ar‐H), 10.25 (s, 2H,
SO2NH); 13C‐NMR: δ = 122.47, 123.11, 129.45, 130.37, 131.26,
132.64, 135.75, 136.30, 142.37, 167.30.
3,3′‐(Sulfonyldi‐1,4‐phenylene)bis{4‐[(benzylamino)sulfonyl]
sydnone (7i). IR (KBr): 3262, 2920, 1750, 1339, 1161 cm−1
;
1H‐NMR: δ = 4.85 (s, 4H, CH2), 5.75 (s, 2H, SO2NH), 7.35–8.50
(m, 18H, Ar‐H); 13C‐NMR: δ = 45.21, 123.46, 127.28, 127.94,
128.30, 129.76, 132.95, 138.44, 142.35, 142.72, 167.34.
3,3′‐(Sulfonyldi‐1,4‐phenylene)bis(4‐{[(2‐methylphenyl)
amino]sulfonyl}sydnone (7j). IR (KBr): 3261, 2968, 2950,
1750, 1339, 1161 cm−1 1H‐NMR: δ = 2.21 (s, 6H, CH3),
;
7.10–8.50 (m, 16H, Ar‐H), 8.96 (s, 2H, SO2NH); 13C‐NMR:
δ = 17.03, 123.42, 124.65, 126.64, 127.79, 129.83, 131.39,
131.94, 132.73, 134.53, 138.27, 143.11, 167.52.
3,3′‐(Sulfonyldi‐1,4‐phenylene)bis{4‐[(hexylamino)sulfonyl]
sydnone (7b). IR (KBr): 3263 (NH), 2965, 2930, 2880, 2865, 1750,
1
1339, 1164 cm−1; H‐NMR: δ = 0.92 (t, 6H, J = 6.72 Hz, CH3),
1.19–1.75 (m, 16H, CH2), 2.84 (t, 4H, J = 7.11 Hz, NH-CH2),
4.98 (s, 2H, SO2NH), 7.50–8.13 (m, 8H, Ar‐H); 13C‐NMR:
δ = 14.97, 22.43, 26.76, 27.65, 30.73, 44.00, 123.87, 128.54,
133.87, 138.53, 143.71, 168.76.
REFERENCES AND NOTES
[1] Badami, B. V. Resonance 2006, 11, 40.
3,3′‐(Sulfonyldi‐1,4‐phenylene)bis{4‐[(methylamino)sulfonyl]
sydnone (7c). IR (KBr): 3262, 2975, 2884, 1727, 1345, 1168 cm−1;
1H‐NMR: δ = 3.10 (s, 6H, CH3), 4.59 (s, 2H, SO2NH), 8.22–8.65
(m, 8H, Ar‐H); 13C‐NMR: δ = 31.69, 123.85, 129.75, 131.59,
138.88, 142.83, 168.53.
[2] Kier, L. B.; Roche, E. B. J Pharm Sci 1967, 56, 149.
[3] Goeres, E.; Faehndrich, A. Acta Biol Med Ger 1968, 20, 641.
[4] Shih, M. H.; Ke, F. Y. Bioorg Med Chem 2004, 12, 4633.
[5] Satyanarayana, K.; Rao, M. N. J Pharm Sci 1995, 84, 263.
[6] Dunkley, C. S.; Thoman, C. J. Bioorg Med Chem Lett 2003,
13, 2899.
[7] Satyanarayana, K.; Rao, M. N. Eur J Med Chem 1995, 30, 641.
[8] Kavali, J. R.; Badami, B. V. IL Farmaco 2000, 55, 406.
[9] (a) Moustafa, M. A.; Gineinah, M. M.; Nasr, M. N.; Waleed, A.
H. B. Arch Pharm 2004, 337, 427; (b) Moustafa, M. A.; Nasr, M. N.;
Gineinah, M. M.; Bayoumi, W. A. Arch Pharm 2004, 337, 164.
[10] Jogul, J. J.; Badami, B. V. J Serb Chem Soc 2006, 71, 851.
[11] (a) Supuran, C. T.; Casini, A.; Scozzafava, A. Med Res Rev
2003, 23, 535; (b) Moustafa, O. S.; Ahmad, R. A. Phosphorus Sulfur
Silicon Relat Elem 2003, 178, 475.
[12] Popoff, I. C.; Singhal, G. H.; Engle, A. R. J Med Chem 1971, 14, 550.
[13] Stewart, F. H. C. Chem Rev 1964, 64, 129.
[14] Daeniker, H. U.; Druey, J. Helv Chim Acta 1957, 40, 918.
[15] Thoman, C. J.; Voaden, D. J. Org Synth 1965, 45, 96.
[16] Bauer, A. W.; Kirby, W. M.; Sherris, J. C.; Turk, M. Am J Clin
Pathol 1966, 45, 493.
3,3′‐(Sulfonyldi‐1,4‐phenylene)bis[4‐(anilinosulfonyl)]sydnone
(7d). IR (KBr): 3260, 1730, 1350, 1161 cm−1; 1H‐NMR: δ = 7.12–8.50
(m, 18H, Ar‐H), 9.35 (s, 2H, SO2NH); 13C‐NMR: δ = 121.31, 123.76,
124.79, 129.85, 130.97, 133.40, 137.45, 138.21, 142.78, 168.66.
3,3′‐(Sulfonyldi‐1,4‐phenylene)bis(4‐{[(3‐chlorophenyl)
amino]sulfonyl}sydnone (7e). IR (KBr): 3260, 1730, 1335, 1162,
1
1055 cm−1; H‐NMR: δ = 7.00–8.30 (m, 16H, Ar‐H), 9.12 (s,
2H, -SO2NH); 13C‐NMR: δ = 120.09, 121.43, 123.57, 125.64,
128.52, 131.74, 133.87, 135.75, 138.47, 138.83, 168.13, 142.75.
3,3′‐(Sulfonyldi‐1,4‐phenylene)bis(4‐{[(2‐fluorophenyl)amino]
sulfonyl}sydnone (7f). IR (KBr): 3263, 1730, 1350, 1230, 1161 cm−1;
1H‐NMR: δ = 6.94–8.60 (m, 16H, Ar‐H), 8.96 (s, 2H, -SO2NH);
13C‐NMR: δ = 115.78, 123.13, 123.81, 124.01, 126.13, 126.97,
129.66, 133.19, 138.72, 142.71, 159.74, 167.89.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet