Synthesis and antimicrobial activity of some new cyanopyridines, isoxazoles, pyrazoles, and pyrimidines bearing sulfonamide moiety

Article abstract of DOI:10.1080/10426500307933

Reaction of p-aminoacetophenone 1 with p-substituted benzenesulfonyl chloride 2a,b in pyridine afforded p-acetyl derivatives 3a,b, which was then condensed with araldehydes to yield the corresponding chalcones 4a-f. On condensation of latter chalcones wit

Full text of DOI:10.1080/10426500307933

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Phosphorus, Sulfur, and Silicon and the Related
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Synthesis and Antimicrobial Activity of Some New
Cyanopyridines, Isoxazoles, Pyrazoles, and Pyrimidines
Bearing Sulfonamide Moiety
Osama S. Moustafa a & Ragaa A. Ahmad a
a Assiut University, Assiut, Egypt
Published online: 27 Oct 2010.
To cite this article: Osama S. Moustafa & Ragaa A. Ahmad (2003): Synthesis and Antimicrobial Activity of Some New
Cyanopyridines, Isoxazoles, Pyrazoles, and Pyrimidines Bearing Sulfonamide Moiety, Phosphorus, Sulfur, and Silicon and the
Related Elements, 178:3, 475-484
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Phosphorus, Sulfur and Silicon, 2003, Vol. 178:475–484
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DOI: 10.1080/10426500390170606
SYNTHESIS AND ANTIMICROBIAL ACTIVITY
OF SOME NEW CYANOPYRIDINES, ISOXAZOLES,
PYRAZOLES, AND PYRIMIDINES BEARING
SULFONAMIDE MOIETY
Osama S. Moustafa and Ragaa A. Ahmad
Assiut University, Assiut, Egypt
(Received April 10, 2002; accepted July 22, 2002)
Reaction of p-aminoacetophenone 1 with p-substituted benzenesulfonyl
chloride 2a,b in pyridine afforded p-acetyl derivatives 3a,b, which
was then condensed with araldehydes to yield the corresponding chal-
cones 4a–f. On condensation of latter chalcones with malononitrile
afford cyanopyridines 5a–f, the reaction of chalcones 4a–f with hy-
roxylamine hydrochloride furnished isoxazoles 6a–f, while condensa-
tion of chalcones with hyrazine hydrate afforded pyrazoline derivatives
7, 8. Urea or thiourea was reacted with chalcone 4b to yield pyrim-
idine derivatives 9, 10. The reaction of sulphonylchlorides 2a,b with
P-aminobenzophenone yield p-[(benzensulphonyl)amido]benzophenone
11a,b, which was then condensed with hydrazine hydrate to give the
corresponding hydazone derivatives 12a,b.
Keywords: Antimicrobial activity; cyanopyridines; isoxazoles; pyra-
zoles and pyrimidines; sulfonamide; synthesis
INTRODUCTION
Among the wide variety of heterocycles that have been explored for
3
developing pharmaceutically important molecules, cyanopyridines,1
isoxazoles4–6 have played an important role in the medicinal chem-
istry. Bezenesulfonamide derivatives also were reported as elastase
inhibitors,7 carbonic anhydrase, clostridium histolyticum collogenase
inhibitors,8,9 and herbicides and plant growth regulators.10 They show
affinities for ETA and ETB receptors in the low nonmolar range and
high functional antagonistic potency in vitro,11 which also exhibits
dual action to inhibit the thromboxane receptor and thromboxane
Address correspondence to Osama S. Moustafa, Chemistry Department, Faculty of
Science, Assiut University, Assiut, 71516, Egypt. E-mail: oshmous@acc.aun.edu.eg
475

476
O. S. Moustafa and R. A. Ahmad
synthase for cardiovascular and renal diseases.12 Antiproliferative,
antiviral, and antifungal activities have been similarly evaluated.13
In this respect, and also in continuation of our earlier work on syn-
thesis of different heterocyclic systems that containing highly biolog-
ical activity,14–18 these assests prompted us use benzensulfonamide
derivative to prepare a new cyanopyridines, isoxazoles, pyrazoles,
and pyrimidones with potential biological activity in our search
for novel heterocyclic compounds of pharmacological interest. Al-
most of the synthesized compounds were tested against bacteria and
fungi.
RESULTS AND DISCUSSION
As shown in Scheme 1 condensation of p-aminoacetophenone 1 with
benzensulfonyl chloride 2a or with p-tolunsulfonyl chloride 2b in pyri-
dine at 0 C yield [benzen (or tolune)-sulfonamido]acetophenone 3a and
3b respectively.21 The key intermediate chalcones 4a–f required for
the synthesis of heterocyclic systems in this article were obtained by
condensation of p-acetyl derivative 3a–f with virous aromatic aldehy-
des. Ring closure of chalcones 4a–f through reactions with malononi-
trile in the presence of pyridine gave cyanopyridine derivatives 5a–f
(Scheme 1).
SCHEME 1
Chalcones 4a–f on reaction with hydroxylamine hydrochloride in the
presence of sodium acetate in acetic acid furnished isoxazole deriva-
tives 6a–f (Scheme 2). Condensation of chalcones 4c,f with hydrazine

Synthesis and Antimicrobial Activity
477
SCHEME 2
SCHEME 3
hydrate (98%) in ethanol afforded the pyrazoline derivatives 7, 8
(Scheme 3). The reaction of 4b with urea in presence of ethano-
lic hydrogen chloride gave the pyrimidone derivative 9. Also, re-
action of 4b with thiourea in presence of ethanolic sodium hy-
droxide afforded the corresponding pyrimidine-2-thione derivative 10
(Scheme 4).
SCHEME 4

478
O. S. Moustafa and R. A. Ahmad
Reaction of p-aminobenzophenone with benzensulfonyl chlo-
ride 2a at 0 C19 or with p-tolunesulfonyl chloride 2b furnished
benzensulfonamido-N-p-pheylbenzoyl derivatives 11a,b Hydrazonlysis
of keto compounds 11a,b with hydrazine hydrate afforded the corre-
sponding hydrazone derivatives 12a,b (Scheme 5).
SCHEME 5
ANTIMICROBIAL ACTIVITY
The newly synthesized compounds were screened for their antibacterial
activity aganist different three species of bacteria. Gram positive. Bacil-
lus subtillus, Micrococcus luteus; Gram negative, Serration rhodenil;
and three species of fungi, Aspergillus fumigatus, Penicllum chrysogen,
and Fusarium equiseti using the filter paper technique20,21 measuring
the zone of inhibition in mm at 25 g concentration. The screening re-
sults are summarized in Table I and indicate that, among of tested com-
pounds, there is good growth inhibition aganist Gram positive bacteria,
however only two compounds (3a and 4f) showed good growth inhibition
against Gram negative bacteria. Concerning the antifungal activaties
only two compounds 3e and 11a were active aganist fungi, V. B. Patel
et al.22 reported that the activity of the similar compounds (cyanopyri-
dine sulphonamide derivatives) was compared with the known standerd
drugs, viz. ampicillin, chloramphenicol, norfloxacin, and griseofulvin.22
EXPERIMENTAL
Melting points were determined on a Gallen-Kamp melting point appa-
ratus and are uncorrected. IR spectra were recorded on a Pye-Unicam

Synthesis and Antimicrobial Activity
479
TABLE I Antimicrobial Activities of the Synthesized Compounds [Zone
of Inhibition in mm]
Antibacterial activity
Antifungal activity
Bacillus
subtillus
us
luteus
Serration
rhodenil
Aspergillus
fumigatus
Penicllum
chrysogen
Fusarium
equiseti
Comp. no.
3a
3b
4e
4f
5e
5f
6c
6e
6f
7
—
—
7
7
11
9
—
—
—
—
—
—
—
—
14
—
—
—
16
—
—
19
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
13
—
—
—
—
7
7
—
—
8
11a
11b
12a
—
—
—
1
SP3-100 spectrophotometer using KBr wafer technique. HNMR spec-
tra were measured on a Varian 390-90 MHz NMR spectrometer in a
suitable deutreated solvent, using TMS as internal standard. Elemen-
tal analyses were performed on a Perkin-Elmer 240 C microanalyzer
and all compounds gave results in acceptable range. Melting points,
yields, and spectroscopic data are listed in Tables II and III.
Synthesis of p-(Benzensulfonamido)acetophenone
Derivatives (3a,b)
Method A
To a mixture of p-aminoacetophenone 1 (0.01 mmol) in pyridine
(0.02 mmol), benzene or tolune sulphonylchloride (0.01 mmol) was
added portion-wise with constant stirring. The mixture was refluxed
for 3 h in (20 ml) ethanol; the contents were poured onto crushed ice
(60 g) and conc. HCl (5 ml) was added. The product seperated was fil-
tered and crystallized from ethanol, yield 67%, m.p. 262 C.
Method B
To a solution of p-aminoacetophenone 1 (0.01 mmol in pyridine
10 ml), benzene or tolouene sulphonylchloride (0.01 mmol) was added
portion-wise with constant stirring. The mixture was stirred for 30 min
at 0 C; the contents were poured onto crushed ice (60 g) and conc. HCl
(5 ml) was added. The separated product was filtered and crystallized
from ethanol.

480
O. S. Moustafa and R. A. Ahmad
TABLE II Physical Data of Compounds 4a–12b
No. M.P. C (Yield%) Formula mol. wt. No. M.P. C (Yield%) Formula mol. wt.
4a
4b
4c
4d
4e
4f
175
(83)
190
(70)
175
(80)
165
(75)
173
(77)
182
(68)
162
(72)
176
(70)
151
(65)
173
(70)
157
(65)
145
(62)
148
(68)
C21H17NO3S
363
6b
6c
6d
6e
6f
7
161
(71)
135
(77)
125
(69)
110
(70)
132
(71)
135
(77)
125
(68)
110
(70)
132
(66)
108
(75)
255
(70)
185
(75)
C21H15N3O5S
421
C22H18N2O4S
406
C22H18N2O3S
390
C22H17N3O5S
435
C23H20N2O4S
420
C22H21N3O3S
407
C23H23N3O3S
421
C22H18N4O5S
450
C23H18N4O4S2
418
C20H17NO3S
351
C19H17N3O2S
351
C20H19N3O2S
365
C
21H16N2O5S
408
C22H18NO4S
384
C22H19NO3S
377
C22H18N2O5S
422
C
23H21NO4S
407
5a
5b
5c
5d
5e
5f
C
24H18N4O2S
426
8
C24H17N5O4S
471
9
C
25H20N4O3S
456
10
C
25H20N4O2S
440
11b
12a
12b
C25H19N5O4S
485
C26H22N4O3S
470
6a
C
21H16N2O3S
376
Condensation of Acetyl Compound 3
with Aromatic Aldehydes
Synthesis of Chalcones (4a–f )
A mixture of acetyl compound 3 (0.01 mmol) and aromatic aldehydes
(0.01 mmol) in ethanol (20 ml), and NaOH (40%, 5 ml) was stirred for
5 h. The contents were poured onto crushed ice, isolated by acidifaction
(HCl, 5 ml), and crystallized from ethanol.
Reactions of Chalcones 4a–c with Malononitrile
Synthesis of Cyanopyridines (5a–f )
A mixture of chalcone 4a–f (0.1 mmol), malononitrile (0.1 mmol), and
ammonium acetate (0.8 mmol) was refluxed in ethanol (30 ml) for 6 h
in a water-bath. The cooled contents were then poured onto crushed ice
with constant stirring; the resulting solid was washed with water and
the residue was crystallized from proper solvent.

Synthesis and Antimicrobial Activity
481
TABLE III Spectroscopic Data of Compounds 3–12
Comp.
no.
IR ( cm 1)/1HNMR (ppm)
3a
3200 (NH), 1670 (C O), 1620 (C N), 1160–1350 (S O); (CDCl3): 2.4 (s, 3H,
CH3), 7.2–8.0 (m, 9H, Ar-H), 8.8 (s, 1H, NH)
3b
4a
4b
4c
4d
4e
4f
3230 (NH), 1660 (C O), 1165–1350 (str. S O); (CDCl3): 2.3 (s, 3H, CH3),
2.45 (s, 3H, CH3), 7.4–8.2 (m, 8H, Ar-H), 8.95 (s, 1H, NH)
3250 (NH), 2980 (CH-alph.), 1680 (C O), 1160 (S O); (DMSO-d6): 7.4–8.00
(m, 16H, Ar-H and CH CH), 8.9 (s, 1H, NH)
3230 (NH), 2980 (CH-alph.), 1670 (C O), 1165–1350 (str. S O); (CF3COOD):
7.4–8.2 (m, 15H, Ar-H and CH CH), 8.95 (s, 1H, NH)
3200 (NH), 2980 (CH-alph.), 1655 (C O), 1165–1350 (str. S O); (DMSO-d6):
2.3 (s, 3H, CH3), 7.5–8.4 (m, 15H, Ar-H and CH CH), 8.95 (s, 1H, NH)
3400 (NH), 2950 (CH-alph.), 1650 (C O), 1170–1350 (str. S O); (DMSO-d6):
2.3 (s, 3H, CH3), 7.3–8.2 (m, 15h, Ar-H and CH CH), 8.75 (s, 1H, NH)
3200 (NH), 2850 (CH-alph.), 1680 (C O), 1170–1350 (str. S O); (DMSO-d6):
2.4 (s, 3H, CH3), 7.4–8.0 (m, 14H, Ar-H and CH CH), 8.6 (s, 1H, NH)
3200 (NH), 2900 (CH-alph.), 1660 (C O), 1160–1350 (str. S O); (DMSO-d6):
2.5 (s, 3H, CH3), 7.2–7.9 (m, 14H, Ar-H and CH CH), 9.1 (s, 1H, NH)
3320, 3180 (NH, NH2), 2220 (CN), 1160–1350 (S O); (CF3COOD): 7.3–8.1
(m, 15H, Ar-H and CH, pyr.), 9.86 (s, 1H, NH)
3300, 3200 (NH, NH2), 2220 (CN) 1160–1350 (S O); (DMSO-d6): 2.46 (s, 2H,
NH2), 7.5–8.4 (m, 14H, Ar-H and CH, pyr.), 9.6 (s, 1H, NH)
3200–3420 (NH, NH2), 2220 (CN), 1150–1350 (str. S O); (CF3COOD): 2.4
(s, 3H, CH3), 7.5–8.4 (m, 14H, Ar-H and CH, pyr.), 9.80 (s, 1H, NH)
3300, 3400 (NH, NH2), 2210 (CN), 1620 (C N), 1160–1350 (str. S O);
(CF3COOD): 2.3 (s, 3H, CH3), 7.3–8.2 (m, 14H, Ar-H and CH, pyr.)
3300, 3200 (NH, NH2), 2210 (CN), 1610 (C N), 1170–1350 (str. S O);
(DMSO-d6): 2.35 (s, 3H, CH3), 2.8 (s, 2H, NH2), 7.2–8.1 (m, 13H, Ar-H),
9.6 (s, 1H, NH)
5a
5b
5c
5d
5e
5f
3200, 3350 (NH, NH2), 2220 (CN), 1620 (C N), 1160–1350 (str. S O);
(DMSO-d6): 2.1 (s, 3H, CH3), 2.35 (s, 3H, OCH3), 2.75 (s, 2H, NH2),
7.6–8.2 (m, 13H, Ar-H and CH, pyr.), 9.88 (s, 1H, NH)
6a
6b
6c
6d
6e
6f
3250 (NH), 1620 (C N), 1160–1350 (str. S O); (CF3COOD): 7.5–8.3 (m, 14H,
Ar-H), 8.8 (s, 1H, CH)
3240 (NH), 2950, 1600 (C N), 1165–1350 (str. S O); (DMSO-d6): 7.2–8.1
(m, 13H, Ar-H), 8.9 (s, 1H, CH), 9.7 (s, 1H, NH)
3250 (NH), 1590 (C N), 1165–1350 (str. S O); (DMSO-d6): 2.33 (s, 3H, CH3),
7.4–8.0 (m, 13H, Ar-H), 8.8 (s, 1H, CH), 9.5 (s, 1H, NH)
3280 (NH), 1620 (C N), 1165–1350 (str. S O); (DMSO-d6): 2.4 (s, 3H, CH3),
7.2–8.1 (m, 13H, Ar-H), 8.87 (s, 1H, CH), 9.5 (s, 1H, NH)
3220 (NH), 1600 (C N); (DMSO-d6): 2.3 (s, 3H, CH3), 7.2–8.1 (m, 12H, Ar-H),
8.9 (s, 1H, CH), 9.55 (s, 1H, NH)
3200 (NH), 1610 (C N); (DMSO-d6): 2.45 (s, 3H, CH3), 7.2–8.1 (m, 12H,
Ar-H), 8.92 (s, 1H, CH), 9.72 (s, 1H, NH)
7
3300–3100 (NH), 1610 (C N), 1160–1350 (str. S O); (DMSO-d6): 2.45 (s, 3H,
CH3), 4.35 (s, 2H, CH2), 7.2–8.1 (m, 13H, Ar-H), 8.92, 9.7 (2s, 2H, 2NH)
(Continued on next page)

482
O. S. Moustafa and R. A. Ahmad
TABLE III Spectroscopic Data of Compounds 3–12 (Continued)
Comp.
no.
IR ( cm 1)/1HNMR (ppm)
8
3280–3120 (NH), 1620 (C N), 1160–1350 (str. S O); (DMSO-d6): 2.1, 2.45
(2s, 6H, 2CH3), 4.2 (s, 2H, CH2), 7.2–8.1 (m, 12H, Ar-H), 8.90, 9.75
(2s, 2H, 2NH)
9
3200–3100 (NH), 1670 (C O), 1630 (C N), 116–1350 (str. S O); (DMSO-d6):
4.25 (s, 2H, CH2), 7.2–8.1 (m, 13H, Ar-H), 8.87, 9.57 (2s, 2H, 2NH)
3300–3100 (NH), 1610 (C N), 1160–1350 (str. S O)
10
11b
3250 (NH), 1680 (CO), 1610 (C N), 1165–1360 (str. S O); (CDCl3): 2.3 (s, 3H,
CH3), 7.2–8.1 (m, 13H, Ar-H), 9.5 (s, 2H, NH)
12a
12b
3300–3100 (NH, NH2), 1610 (C N), 116–1350 (str. S O); (CF3COOD): 7.3–8.2
(m, 14H, Ar-H)
3500–3200 (NH, NH2), 1610 (C N), 1150–1360 (str. S O); (CF3COOD): 2.3
(s, 3H, CH3), 7.2–8.3 (m, 13H, Ar-H)
Reactions of Chalcones (4a–c) with Hyroxylamine
Hydrochloride
Synthesis of Isoxazoles (6a–f )
Anhydroyus sodium acetate dissolved in a minimum amount of hot
acetic acid was added to the solution of hyroxylamine hydrochloride
in ethanol (20 ml). This solution was added to a solution of chalcones
4a–f in ethanol (20 ml). The mixture was refluxed for 6 h, concentrated,
and neutralized with NaOH. The isolated product was then filtered and
crystallized from ethanol.
Synthesis of Pyrazolines (7, 8)
A mixture of 2b (0.005 mmol), hyrazine hydrate (98%, 0.005 mmol), and
ethanol (25 ml) was refluxed for 8 h then cooled, filtered, and crystallized
from ethanol as yellowish crystals.
Synthesis of 4-[(Benzensulfonyl)anilino]-6-p-nitrophenyl-
2-oxo-1,2,5,6-tetrahydropyrimidine (9)
To (0.1 gm, 0.015 mmol) of urea in (20 ml) ethanol. (5 ml) of conc.
HCl was added to the formed solution of 2b (0.001 mmol). The mix-
ture was heated at reflux temperature for 8 h then concentrated to 1/3
its volume and cooled. The mixture was neutralized with cold NH4OH
and the precipitated material was crystallized from ethanol as yellow
crystals.

Synthesis and Antimicrobial Activity
483
Synthesis of 4-[(Benzensulfonyl)anilino]-6- p-
nitrophenyl-2-thioxo-1,2,5,6-tetrahydropyrimidine (10)
A mixture of 2b (0.1 mmol), thiourea (0.1 mmol), and NaOH (0.1 gm,
in ethanol 30 ml) was refluxed for 5 h, then concentrated, cooled,
and filtered. The precipitate was crystallized from abs. ethanol as red
crystals.
p-[(Benzenesulfonyl)amino]benzophenone (11a)
The title compound was prepared as literature,19 m.p. 106–107 C.
p-[(Tolunesulfonyl)amino]benzophenone (11b)
The title compound was synthesized following a procedure analogous
to that for compound 11a.
Synthesis of Hydrazones (12a,b)
A solution of ketone compound 8 (0.01 mmol) and hydrazine hydrate
(0.01 mmol) in ethanol (30 ml) was heated under reflux for 1 h. The
reaction mixture was cooled, the solid separated, and filtered and crys-
talized from ethanol as yellowish crystals.
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