Synthesis and antimicrobial activities evaluation of some new thiadiazinone and thiadiazepinone derivatives bearing sulfonamide moiety

Article abstract of DOI:10.1080/10426507.2017.1417292

A new series of novel functionalized 1,3,4-thiadiazin-5-ones and 1,3,4-thiadi-azepin-5-ones bearing sulfonamide moieties were synthesized via 1,3-dipolar cyclocondensation reaction of nitrilimines with α-mercaptoesters and mercaptosuccinic acid respectively. The structures of the prepared compounds were confirmed by spectral methods (IR, ¹H-NMR, ¹³C-NMR and MS spectroscopy) and elemental analysis. The newly synthesized compounds were screened for their in vitro antimicrobial activity. Some of titled compounds exhibited significant antimicrobial activity on several strains of microbes.

Full text of DOI:10.1080/10426507.2017.1417292

Phosphorus, Sulfur, and Silicon and the Related Elements
ISSN: 1042-6507 (Print) 1563-5325 (Online) Journal homepage: http://www.tandfonline.com/loi/gpss20
Synthesis and antimicrobial activities evaluation
of some new thiadiazinone and thiadiazepinone
derivatives bearing sulfonamide moiety
Hany M. M Dalloul, Khaled A El-Nwairy, Ali Z Shorafa & Ahmed S. Abu
Samaha
To cite this article: Hany M. M Dalloul, Khaled A El-Nwairy, Ali Z Shorafa & Ahmed S. Abu
Samaha (2017): Synthesis and antimicrobial activities evaluation of some new thiadiazinone and
thiadiazepinone derivatives bearing sulfonamide moiety, Phosphorus, Sulfur, and Silicon and the
Related Elements, DOI: 10.1080/10426507.2017.1417292
To link to this article: https://doi.org/10.1080/10426507.2017.1417292
Accepted author version posted online: 15
Dec 2017.
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Date: 16 December 2017, At: 12:48

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Synthesis and Antimicrobial Activities Evaluation of Some
New Thiadiazinone and Thiadiazepinone Derivatives Bearing
Sulfonamide Moiety
Hany M. M. Dalloul,a* Khaled A. El-Nwairy,b Ali Z. Shorafa,b Ahmed S. Abu
Samahac
a Department of Chemistry, Faculty of Applied Science, Alaqsa University of Gaza,
P.O.Box 4051, Gaza 76888, PNA. E-mail: hmdalloul60@yahoo.com
b Ministry of Education & Higher Education, Beirut street, Southern remal, Gaza, PNA.
c Department of Biology, Faculty of Applied Science, Alaqsa University of Gaza,
P.O.Box 4051, Gaza 76888, PNA.
ABSTRACT: A new series of novel functionalized 1,3,4-thiadiazin-5-ones and 1,3,4-
thiadi-azepin-5-ones bearing sulfonamide moieties were synthesized via 1,3-dipolar
cyclocondensation reaction of nitrilimines with α-mercaptoesters and mercaptosuccinic
acid respectively. The structures of the prepared compounds were confirmed by
1
spectral methods (IR, H-NMR, 13C-NMR and MS spectroscopy) and elemental
analysis. The newly synthesized compounds were screened for their in vitro
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antimicrobial activity. Some of titled compounds exhibited significant antimicrobial
activity on several strains of microbes.
Key words: Nitrilimines, Sulfa drugs, α-Mercaptoesters, Mercaptosuccinic acid, 1,3,4-
Thiadiazinone, 1,3,4-Thiadiazepinone.
1. INTRODUCTION
Sulfonamides represent an important class of medicinally effective molecules and are
known to possess various types of biological activities such as antibacterial [1-3], antiviral [4-7],
anti-carbonic anhydrase [8,9], high-ceiling diuretic [10], hypoglycemic [11,12], antithyroid [11],
anti-inflammatory [13], and antiglaucoma [10,11]. It is also known that aromatic or
heteroaromatic sulfonamides may act as antitumor agents through perturbation of cell cycle in
the G1 phase, distribution of microtubule assembly or angiogenesis inhibition [14-17].
Moreover, numerous sulfonamides were found to act as antitumor agents through carbonic
anhydrase (CA) inhibition [17-26].
It is well known that the nitrogen and sulfur containing heterocyclic compounds play an
important role in medicinal chemistry and pharmaceutical communities as these molecules have
potent biological activities [27]. 1,3,4-Thiadiazines are therapeutically important class of
heterocyclic compounds and are known to exhibit various pharmacological and medicinal
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applications [27]. 1,3,4-Thiadiazinone derivatives have attracted a great deal of interest due to a
variety of interesting biological activities. They are known as spasmolytic [30] and antibacterial
agents [31], important matrix metalloproteinase inhibitors [32,33], and they also display
cardiotonic, hypertensive [34,35], and other biological activities [36-38]. Thiadiazepines are
reported for their potent antimicrobial activity [39], antifungal activity [40] and inhibition of
metalloproteinase [41]. The literature survey revealed that some fused thiadiazepines exhibit
antidepressant [42], central nervous depressant [43], bactericidal [44,45], fungicidal [44,45], and
anticancer activity [46]. Recently, 1,4,5-dibenzo[b,f]thiadiazepine was reported to show good
neuroprotective properties against neurodegenerative diseases without anticholinergic effects
[47].
Taking into account all of the previous commentaries of the biological activities of
sulfonamides and in continuation of our study on the synthesis of biologically active
heterocycles [48,49], efforts have been made to synthesize a series of new 1,3,4-thiadiazin-5-one
and 1,3,4-thiadiazepin-5-one derivatives
incorporating sulfonamide moiety via
cyclocondensation reaction of nitrilimines containing moiety of sulfonamide with α-
mercaptoesters and mercaptosuccinic acid in anticipation of expected interesting biological
activities.
2. RESULTS AND DISCUSSION
2.1 Chemistry
Hydrazonoyl halides (nitrilimines precursors) have been widely used for the synthesis of
heterocyclic compounds. In recent years, cyclocondensations using nitrilimines have received
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considerable attention because they have been shown to be an efficient synthetic tool for the
preparation of various thia-aza heterocycles. The reactive nitrilimines are found to react with 2-
sulfanyl alkanoic acids or ethyl sulfanylacetate yielding acyclic adducts (4-arylhydrazono-5-oxo-
3-thiahexanoic acid or ethyl 6-aryl-4-aroyl-3,5,6-thiadiaza-4-hexenoate) which underwent
cyclization to 1,3,4-thiadiazinone rings in the presence of dicyclohexylcarbodiimide (DCC) or
lithium hydride(LiH), or methanolic sodium methoxide (NaOMe) [50]. In the present study, the
nitrilimines 2a-c having sulfonamide moieties were generated in situ from the respective
hydrazonoyl chlorides 1a-c, are found to react with ethyl mercaptoacetate for 3-4 d at room
temperature affording acyclic electrophilic addition products (3,5,6-thiadiaza-4-hexenoates) 3a-c
(Scheme 1). Cyclization to the corresponding 1,3,4-thiadiazin-5-ones 4a-c did not observed. The
3,5,6-thiadiaza-4-hexenoates 3a-c were cyclized intramolecularly to the corresponding 2,4-
disubstituted 1,3,4-thiadiazin-5-ones 4a-c by heating them with methanolic sodium methoxide
(NaOMe) or lithium hydride (LiH) (Scheme 1).
Similarly, the mercaptosuccinic acid reacts with reactive nitrilimines 2a-c for 4-6 d at room
temperature yielding the acyclic electrophilic addition products 5a-c (Scheme 2). Acyclic
adducts 5a-c underwent cyclization upon loosing water molecule, to the corresponding (4-
Heterylsulfamoylphenyl-2-phenylaminocarbonyl-5-oxo-5,6-dihydro-4H-1,3,4-thiadiazin-6-yl)-
acetic acid 6a-c and 1,3,4-thiadiazepine-5-ones 7a-c, in the presence of
dicyclohexylcarbodiimide
(DCC) in refluxing tetrahydrofuran (THF) (Scheme 2). The antimicrobial activities of the
synthesized compounds 4a-c, 6a-c and 7a-c were investigated.
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2.2 Spectroscopical data for compounds 3-7a-c
The assignment of structures 3-7a-c is based on their analytical and spectroscopic data. Physical
properties, molecular ion peaks and elemental analysis are presented in the Experimental
Section. The characteristic data of compounds 3-7a-c are given in detail in the Experimental
Section. All compounds gave satisfactory combustion analysis for the proposed structures which
were confirmed on the basis of their spectroscopic data. For compounds 3a-c, the electron impact
(EI) mass spectra displayed the correct molecular ions (M+.) in accordance with the suggested
structures. Their IR spectra showed three NH absorption bands at the region 3360-3200 cm−1.
The carbonyl absorption of the ester and amide groups appeared in the regions 1720-1710 cm−1
and 1655-1650 cm-1, respectively. The C–S stretching band appeared in the region 1230-1220
1
cm−1 and SO2 of sulfonamide group bands appeared around 1150 and 1060 cm-1. The H NMR
spectra of compounds 3a-c showed signals of the ethyl protons at δ = 1.28–1.13 ppm (t, 3H,
CH3) and 4.25-4.01 ppm (q, 2H, OCH2), indicating clearly that the ethyl group of the ester was
not lost, and that the compounds have acyclic structure. Also the N–NH proton appeared as a
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singlet at δ = 10.65-10.46 ppm. The C NMR spectra illustrate that compounds 3a-c have the
assigned acyclic structures. The carbonyl carbon of the ester group appeared at about δ = 170
ppm, and the signals of the CH2 and CH3 carbon atoms of the ethoxy group appeared at about δ =
61and 14 ppm, respectively. The methylene carbon of S–CH2 appeared at about δ = 34-33 ppm,
and the signal at δ ≈ 141 ppm is attributed to the C=N carbon atom. Structural elucidation of the
obtained thiadiazinones 4a-c was achieved as follows: their mass spectra displayed the correct
molecular ion peaks [M+] in accordance with the suggested structures and showed the loss of an
ethoxy group from the acyclic adducts 3a-c via ethanol elimination. Their IR spectra support the
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formation of the thiadiazinone ring by the absence of N-NH (around 3340 cm-1) and C=O
(around 1710 cm-1) vibration bands of the ester, and the appearance of a new absorption band for
a lactam (C=O of the thiadiazinone ring) in the region 1680-1670 cm−1. The 1H NMR spectra of
compounds 4a-c showed all the signals of the proposed structures, indicating the disappearance
1
of ethyl (CH2CH3) and N-NH protons. For example, H NMR spectrum of 4a in DMSO-d6
showed singlet at δ 3.90 assignable to CH2 of the thiadiazinone ring. The doublets at δ 6.63 (J =
4.5 Hz) and δ 8.76 (J = 9.1 Hz) are assignable to thiazole ring protons. The resonance singlets at
δ 10.12 and δ 11.61 are assignable to PhNH and SO2NH protons respectively. The remaining
aromatic protons showed multiplet in between δ 7.77-7.13 ppm. Finally, the 13C NMR data
illustrated that compounds 4a-c have the assigned cyclic structure by the absence of signals for
ester group carbons (170, 61, 14 ppm) and the presence of the signal at δ ≈ 161 ppm which is
typical for a lactam group. Furthermore, the signal of the methylene carbon (δ ≈ 34 ppm) of the
thioester moiety in the acyclic adducts 3a-c is shifted up field to δ ≈ 26 ppm in compounds 4a-c,
whereas the signal of the C=N carbon is recorded at δ ≈ 143 ppm. For compounds 5a-c, their IR
spectra are characterized by the 3NH bands in the region 3370-3220 cm-1, a broad hydroxyl
bands in the region 3200-2520 cm-1 indicating the carboxyl group, a strong and broad carbonyl
of the carboxyl groups band in the region 1730-1720 cm-1, a C=N band at 1630-1610 cm-1, and a
C-S stretching band appeared in the region 1240-1220 cm-1. The 1H NMR spectra of compounds
5a-c showed characteristic signals of the aliphatic and aromatic protons, especially the triplet at
3.60-3.70 ppm for the proton at C-3, and a doublet at 4.50-4.60 ppm for the protons at C-2. Also
the N-NH proton appeared as singlet at 10.51-10.54 ppm.
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Structural elucidation of the obtained 1,3,4-thiadiazin-5-ones 6a-c and 1,3,4-thiadiazepin-
5-ones 7a-c were achieved by their analytical and spectral data. Their mass spectra displayed the
correct molecular ion peaks [M+] in accordance with the suggested structures. The IR spectra of
those compounds 6a-c and 7a-c support the formation of the cyclic structures by the absence of
NH band and the appearance of a new absorption band for a lactam (C=O of the ring) in the
1
region 1670-1680 cm-1. Their H NMR spectra exhibited all the signals of the proposed
1
structures, indicating the disappearance of the signal of the proton of NNH. For example, H
NMR spectrum of 6b in DMSO-d6 showed doublet at δ 3.68 and triplet at δ 4.55 assignable to
CH2 and CH protons respectively. The triplet at δ 6.87 (J = 7.5 Hz) and doublet at δ 8.84 (J =
8.8 Hz) are assignable to pyrimidine ring protons. The resonance singlets at δ 9.93 and δ 11.61
are assignable to PhNH and SO2NH protons respectively. The aromatic protons showed
multiplet in the range of δ 7.89-7.11, and COOH proton resonated as singlet at δ 12.45 ppm.
Also for 7c the doublet at δ 3.48 (J = 6.9 Hz) and triplet at δ 4.61 (J = 6.9 Hz) are assignable to
CH2 and CH of thiadiazepinone ring protons respectively. The singlet at δ 2.35 was attributed to
CH3 of oxazole and the singlet at δ 6.21 was assignable to the oxazole ring proton. In addition,
singlets at δ 9.88 and δ 11.90 are assignable to PhNH and SO2NH protons respectively. The
multiplet between δ 7.84-7.07 is assigned to the aromatic protons and COOH proton resonated as
a singlet at δ 12.51 ppm.
Finally, also the 13C NMR data illustrated that compounds 6a-c and 7a-c have the assigned cyclic
structure by the presence of the signal at 159-160 ppm which is typical for a lactam group.
whereas the signal of the C=N carbon is recorded at 143-144 ppm.
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2.3 Antimicrobial activity.
The synthesized compounds 4a-c, 6a-c and 7a-c were screened in vitro for their
antimicrobial activity against a variety of bacterial strains such as Enterococci, Escherichia coli,
Staphylococcus aureus, Klebsiella spp, Proteus spp, and fungi such as Aspergillus niger,
Candida albicans, employing the nutrient agar disc diffusion method [51] at 1-100 mg/mL
concentration in dimethyl sulfoxide (DMSO) which used as solvent control, by measuring the
average diameter of the inhibition zone in mm. All the experiments were carried out in triplicate.
The results showed that all the tested compounds exhibited a good degree of activity against
different strains of bacteria and fungi compared with well-known antibacterial and antifungal
substances such as tetracycline and fluconazole respectively. The results are given in Table S 1
(Supplemental Materials). According to NCCLS (2004) [52], zones of inhibition for tetracycline
and fluconazole < 14 mm were considered resistant, between 15 and 18 mm were considered
weakly sensitive and > 19 mm were considered sensitive. The results confirm that, the
antimicrobial activity is strongly dependent on the nature of the substituents on triazinone and
thiadiazinone nucleus. The presence of sulfonamide moieties showed a better spectrum of
activity than the reference drug (Table S 1).
3. EXPERIMENTAL SECTION
3.1 Instruments and reagents
Melting points were determined using an electro thermal melting temperature apparatus
and are uncorrected. The IR spectra were measured as KBr pellets using a Satellite 3000 Mid
infrared spectrometer. 1H NMR and 13C NMR spectra were recorded on a Bruker AM 300 MHz
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spectrometer at r. t. in DMSO-d6 solution u sing tetramethylsilane (TMS) as internal reference.
Chemical shifts are expressed in δ (ppm) downfield from TMS and coupling constants are in
Hertz (Hz). Electron impact (EI) mass spectra were run on a Shimadzu GCMS-QP1000 EX
spectrometer at 70 eV. Elemental analysis were carried out at micro analytical laboratory, Cairo
University, Cairo, Egypt. Ethyl mercapto acetate, mercaptosuccinic acid, triethylamine (TEA),
tetrahydrofuran (THF), dicyclohexylcarbodiimide (DCC) and 1,4-dioxane were purchased from
Avocado Research Chemicals, England, and used without further purification. Hydrazonoyl
chlorides 1a-c employed in this study, were prepared via direct coupling of the appropriate sulfa
drug diazonium chloride with α-chloroacetoacetanilide in sodium acetate/ethanol solution
following standard procedures [53].
3.2 General procedure for Synthesis of 3,5,6-thiadiaza-4-hexenoates 3a-c.
To a stirred solution of the appropriate hydrazonoyl halide 1 (10 mmol) and ethyl
mercaptoacetate (15 mmol) in tetrahydrofuran (THF) (50 mL), triethylamine (3 mmol) in THF
(10 mL) was dropwise added at room temperature Stirring was continued for 48-72 h, then the
solvent was removed under vacuum, and the residual solid was washed with water (100 mL).
The solid products were collected and recrystallized from an appropriate solvent to afford the
desired compounds. The following compounds were prepared by this method.
Ethyl
4-phenylaminocarbonyl-6-[4-(thiazol-2-yl-sulfamoyl)phenyl]-3,5,6-thiadiaza-4-
hexenoate (3a). M.p. 213-215 ◦C (ethanol). Yield 72 %. IR: ν = 3365, 3346, 3270 (NH), 1718
(ester C=O), 1650 (amide C=O), 1597 (C=N), 1225 (C–S), 1150 (S=O) cm−1. 1H NMR (DMSO-
d6): δ = 12.70 (s, 1H, SO2NH), 10.65 (s, 1H, NH), 9.96 (s, 1H, PhNH), 8.74 (d, 1H, J = 9.1,
thiazole ring), 7.93-7.04 (m, 9H, Ar-H), 6.64 (d, 1H, J = 4.5, thiazole ring), 4.25-4.12 (q, 2H, J
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= 7.1 Hz, OCH2), 3.95 (s, 2H, SCH2), 1.28-1.15 (t, 3H, J = 7.1 Hz, CH3) ppm. C NMR
(DMSO-d6): δ = 170.1 (ester C=O), 159.4 (amide C=O), 141.7 (C=N), 167.9, 142.2, 139.6,
136.5, 135.4, 129.6, 128.6, 127.4, 125.1, 119.1, 116.5 (Ar-C and thiazole-C), 61.3 (OCH2), 33.2
(SCH2), 13.9 (CH3) ppm. MS: m/z = 519 [M+.]. Anal. Calcd. for C21H21N5O5S3 (519.62): C,
48.54; H, 4.07; N, 13.48; Found C 48.31; H, 3.98; N, 13.60.
Ethyl 4-phenylaminocarbonyl-6-[4-(pyrimidin-2-yl-sulfamoyl)phenyl]-3,5,6-thiadiaza-4-
hexenoate (3b). M.p. 236-238 ◦C (ethanol). Yield 75 %. IR: ν =3358, 3348, 3270 (NH), 1715
(ester C=O), 1655 (amide C=O), 1595 (C=N), 1230 (C–S), 1139 (S=O) cm−1. 1H NMR (DMSO-
d6): δ = 12.65 (s, 1H, SO2NH), 10.64 (s, 1H, N-NH), 9.93 (s, 1H, PhNH), 8.84 (d, 2H, J = 8.8
Hz, pyrimidine ring), 8.32-7.04 (m, 9H, Ar-H), 6.86 (t, 1H, J = 7.5 Hz, pyrimidine ring), 4.23-
4.12 (q, 2H, J = 7.1 Hz, OCH2), 3.96 (s, 2H, SCH2), 1.27-1.16 (t, 3H, J = 7.1 Hz, CH3) ppm.
13C NMR (DMSO-d6): δ = 170.8 (ester C=O), 159.9 (amide C=O), 141.2 (C=N), 168.2, 156.6,
145.7, 142.2, 140.9, 129.6, 129.2, 125.3, 122.4, 113.8, 110.4 (Ar-C and pyrimidine-C), 61.8
(OCH2), 34.2 (SCH2), 14.1 (CH3) ppm. MS: m/z = 514 [M+.]. Anal. Calcd. for C22H22N6O5S2
(514.59): C, 51.35; H, 4.31; N, 16.33; Found C, 51.58; H, 4.45; N, 16.22.
Ethyl 4-phenylaminocarbonyl-6-[4-(5-methyloxazol-3-yl-sulfamoyl)phenyl]-3,5,6-thiadi-
aza-4-hexen-oate (3c.) M.p. 218-220 ◦C (ethanol). Yield 73 %. IR: ν = 3372, 3343, 3270 (N–H),
1
1712 (ester C=O), 1650 (amide C=O), 1598 (C=N), 1226 (C–S), 1138 (S=O) cm−1. H NMR
(DMSO-d6): δ = 12.62 (s, 1H, SO2NH), 10.46 (s, 1H, N-NH), 9.95 (s, 1H, PhNH), 7.78-7.06 (m,
9H, Ar-H), 6.24 (s, 1H, oxazole ring), 4.13-4.01 (q, 2H, J = 7.1 Hz, OCH2), 3.89 (s, 2H, SCH2),
13
2.38 (s, 3H, CH3 on oxazole ring), 1.25-1.13 (t, 3H, J = 7.1 Hz, CH3) ppm. C NMR (DMSO-
d6): δ = 170.4 (ester C=O), 159.4 (amide C=O), 141.5 (C=N), 167.4, 155.6, 141.6, 136.2, 129.7,
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128.5, 127.5, 125.4, 125.1, 115.4, 95.2 (Ar-C and oxazole-C), 61.3 (OCH2), 33.5 (SCH2), 13.8
(CH3), 12.4 (CH3 oxazole) ppm. MS: m/z = 517 [M+.]. Anal. Calcd. for C22H23N5O6S2 (517.59):
C, 51.05; H, 4.48; N, 13.53; Found C, 50.82; H, 4.60; N, 13.65.
3.3 Cyclization of compounds 3a-c to 1,3,4-thiadiazin-5-ones 4a-c
Method A: Compounds 3a-c (5 mmol) were added to a methanolic solution of sodium
methoxide - prepared from sodium metal (0.12 g, 5 mmol) and methanol (20 mL) - under stirring
at r. t. The resulting solution was refluxed for 2-3 h. After cooling the solvent was removed
under reduced pressure, and the residue was washed with water. The solid was collected and
recrystallized from ethanol to give the desired 1,3,4-thiadiazinones 4a-c.
Method B: To a stirred solution of compounds 3a-c (5 mmol) in dry THF (30 mL) was
carefully added lithium hydride (0.08 g, 10 mmol) at r. t. The resulting reaction mixture was
refluxed for 30 min. After cooling, excess lithium hydride was destroyed with some drops of
glacial acetic acid. The solvent was evaporated under reduced pressure and the product extracted
three times with chloroform. The combined organic extracts were dried over anhydrous
magnesium sulfate, and the solvent was removed under reduced pressure. The resulting solid
product was collected and recrystallized from ethanol to give compounds 4a-c that were identical
with the ones prepared by method A.
2-phenylaminocarbonyl-4-[4-(thizol-2-yl-sulfamoyl)phenyl]-6H-1,3,4-thiadiazin-5-one
(4a). M. p. 251-253 ◦C (ethanol). Yield 70 %. IR: ν = 3365, 3273 (NH), 1678 (lactam C=O),
1650 (amide C=O), 1610 (C=N), 1149 (S=O), 684 (C-S) cm−1. 1H NMR (DMSO-d6): δ = 11.61
(s, 1H, SO2NH), 10.12 (s, 1H, PhN–H), 8.76 (d, 1H, J = 9.1, thiazole ring), 7.77-7.13 (m, 10H,
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Ar-H), 6.63 (d, 1H, J = 4.5, thiazole ring), 3.90 (s, 2H, CH2) ppm. C NMR (DMSO-d6): δ =
161.5 (lactam C=O), 158.5 (amide C=O), 143.3 (C=N), 166.7, 142.9, 140.6, 136.5, 135.3, 129.3,
128.7, 127.5, 125.4, 119.8, 116.5 (Ar-C and thiazole-C), 26.2 (CH2) ppm. MS: m/z = 473 [M]+.
Anal. Calcd. for C19H15N5O4S3 (473.55): C, 48.19; H, 3.19; N, 14.79; Found C, 48.41; H, 3.30;
N, 14.67.
2-phenylaminocarbonyl-4-[4-(pyrimidin-2-yl-sulfamoyl)phenyl]-6H-1,3,4-thiadiazin-5-
one (4b). M. p. 241-243 ◦C (ethanol). Yield 76 %. IR: ν = 3375, 3273 (NH), 1680 (lactam C=O),
1640 (amide C=O), 1615 (C=N), 1170 (S=O), 683 (C-S) cm−1. 1H NMR (DMSO-d6): δ = 11.60
(s, 1H, SO2NH), 10.14 (s, 1H, PhNH), 8.86 (d, 2H, J = 8.8 Hz, pyrimidine ring), 7.77-7.18 (m,
9H, Ar-H), 6.89 (t, 1H, J = 7.5 Hz, pyrimidine ring), 3.91 (s, 2H, CH2) ppm. 13C NMR (DMSO-
d6): δ = 162.2 (lactam C=O), 159.5 (amide C=O), 143.6 (C=N), 167.9, 156.5, 145.7, 142.7,
140.9, 129.6, 129.2, 125.3, 122.4, 116.2, 110.4 (Ar-C and pyrimidine-C), 26.6 (CH2) ppm. MS:
m/z = 468 [M]+. Anal. Calcd. for C20H16N6O4S2 (468.52): C, 51.27; H, 3.44; N, 17.94; Found C,
51.46; H, 3.35; N, 18.05.
2-phenylaminocarbonyl-4-[4-(5-methyloxazol-3-yl-sulfamoyl)phenyl]-6H-1,3,4-thiadia-
zin-5-one (4c). M. p. 232-234 ◦C (ethanol). Yield 75 %. IR: ν =3382, 3272 (NH), 1675 (lactam
C=O), 1645 (amide C=O), 1612 (C=N), 1153 (S=O), 682 (C-S) cm−1. 1H NMR (DMSO-d6): δ =
11.58 (s, 1H, SO2NH), 10.13 (s, 1H, PhNH), 7.78-7.14 (m, 9H, Ar-H), 6.34 (s, 1H, oxazole ring),
3.92 (s, 2H, CH2), 2.35 (s, 3H, CH3) ppm. 13C NMR (DMSO-d6): δ = 160.8 (lactam C=O), 158.6
(amide C=O), 143.4 (C=N), 166.9, 155.6, 141.0, 140.6, 136.5, 129.1, 128.7, 127.2, 125.2, 115.6,
96.0 (Ar-C and oxazole-C), 26.3 (CH2), 12.4 (CH3 oxazole). ppm. MS: m/z = 471 [M]+. Anal.
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Calcd. for C20H17N5O5S2 (471.52): C, 50.95; H, 3.63; N, 14.85; Found C, 51.15; H, 3.52; N,
14.97.
3.4 Synthesis of compounds 5a-c (general procedure)
Reaction of nitrilimines with mercaptosuccinic acid: To a mixture of the appropriate
hydrazonoyl halide 1a-c (0.01 mol) and mercaptosuccinic acid (7.50 g, 0.05 mol) in dry
tetrahydrofuran or 1,4-dioxane (100 mL), triethylamine (5 mL, 0.05 mol) was added at room
temperature and the reaction mixture was monitored by TLC. The stirring continued until the
starting substrates were completely consumed (4-6 d). The triethylammonium chloride salt was
filtered off, the solvent was removed under reduced pressure and the residue was partitioned
between ethyl acetate and water. The aqueous layer was extracted with ethyl acetate, and the
combined organic layers were extracted with saturated NaHCO3 solution, washed twice with brine
and dried over MgSO4. The solvent was evaporated in vacuo and the residue was treated with
ethanol, whereby 5a-c could be isolated by slow evaporation, or immediately cyclized to 6,7.
The prepared compounds 5a-c together with their physical and spectral data are given in
Supplemental Materials.
3.5 Synthesis of compounds 6 and 7 (general procedure)
Cyclization of compounds 5: To a stirred solution of compounds 5-a-c in THF (30 mL)
was added 1 equivalent DCC in THF (10 mL) at room temperature. The stirring continued until
the starting substrates were completely consumed (2-3 h). The precipitate (dicyclohexyl urea)
was filtered off, and the filtrate was evaporated under reduced pressure. The residue (viscous or
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crude solid) was dissolved in hot ethanol, and by slow cooling and evaporation of the solvent the
desired cyclic compounds were obtained as a mixture which chromatographed on preparative
TLC plates, using Merck silica gel 60 HF254 as the adsorbent, and CHCl3/EtOAc (5:1). The
characteristic data of the title compounds 6a-c and 7a-c are given in Supplemental Materials.
3.6 Antimicrobial activity screening.
Antimicrobial activity screening of the synthesized compounds was determined by the agar
dilution technique as recommended by the Clinical and Laboratory Standard Institute (CLSI)
[54]. The tested compounds were dissolved in dimethyl sulfoxide (DMSO). An inoculum of
about 1.5 x 108 colony forming unit per spot was applied to the surfaces of Mueller–Hinton agar
plates containing graded concentrations of the respective compound; plates were incubated at 37
oC for 18 h. All organisms used in this study were standard strains were obtained from the
Microbiology laboratory (Al-Aqsa University) and included bacterial strain such as Enterococci,
Escherichia coli, Staphylococcus aureus, Klebsiella spp, Proteus spp, and fungi strain such as
Aspergillus niger, Candida albicans. The MIC of Tetracycline and fluconazole was determined
concurrently as reference for antibacterial and antifungal activities, respectively (Table S 1).
Control DMSO was carried out with each experiment.
4. CONCLUSIONS
New series of functionalized 1,3,4-thiadiazinones 4a-c, 6a-c and 1,3,4-thiadiazepinones
7a-c containing benzenesulfonamide moiety were synthesized using hydrazonoyl halides as a
precursor of nitrilimines and evaluated for their in vitro antibacterial, and antifungal activities.
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The results confirm that the antimicrobial activity is strongly dependent on the nature of the
substituents on thiadiazinone and thiadiazepinone nucleus. The pyrimidinyl, thiazolyl and
methoxzolyl derivatives generally led to dramatic improvements in activity against both bacteria
and fungi. In short, the present study can lead medicinal chemists to design and synthesize
similar compounds with enhanced biological potency in future.
ACKNOWLEDGEMENTS
The authors are great thankful to the Qatar Charity for the financial support of this
research through Ibhath grant (GCC-07-06).
REFERENCES
[1] Gadad, A. K.; Mahajanshetti, C. S.; Nimbalkar, S.; Raichurkar, A. Eur. J. Med. Chem.
2000, 35, 853-857.
[2]
[3]
[4]
Misra, V. S.; Saxena, V. K.; Srivastava, R. J. Ind. Chem. Soc. 1982, 59, 781-782.
Zani, F.; Vicini, P. Arch. Pharm. 1998, 331, 219-223.
Scozzafava, A.; Owa, T.; Mastrolorenzo, A.; Supuran, C. T. Curr. Med. Chem., 2003, 10,
925–953.
[5]
Stranix, B. N.; Lavallee, J. G.; Sevigny, G. Bioorg. Med. Chem. Lett., 2006, 16, 3459–
3462.
15
ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
[6]
Beale, J. M. Jr. Anti-Infective Agents, in Wilson and Gisvold’s Text Book of Organic
Medicinal and Pharmaceutical Chemistry (Eds. J. H. Block and J. M. Beale, Jr.), 11th ed.,
Lippincott William and Wilkins, Philadelphia 2004, pp. 217–281.
Dogruer, D.; Urlu, S.; Onkol, T.; Ozcellik, B.; Sahin, M. F. Turk. J. Chem., 2010, 34, 57-
65.
[7]
[8]
[9]
Brzozowski, Z.; S1awiinski, J.; Saczewski, F.; Innocenti, A.; Supuran, C.T. Eur. J. Med.
Chem. 2010, 45, 2396-2404.
Renzi, G.; Scozzafava, A.; Supuran, C.T. Bioorg. Med. Chem. Lett. 2000, 10, 673-676.
[10] Maren, T. H. Physiol. Rev. 1967, 47, 595-781.
[11] Maren, T. H. Ann. Rev. Pharmacol. Toxicol. 1976, 16, 309-327.
[12] Drew, J. Science 2000, 287, 1960-1964.
[13] Li, J. J.; Anderson, D.; Burton, E.; Cogburn, J.; Collins, Garland, D.; Gregory, S.; Huang,
H.; Isakson, P.; Koboldt, C.; Logusch, E.; Norton, M.; Perkins, W.; Reinhard, E.; Seibert,
K.; Veenhuizem, A.; Zang, Y.; Reitz, D. B. Med. Chem. 1995, 38, 4570-4578.
[14] Saczewski, F.; Innocenti, A.; S1awinski, J.; Kornicka, A.; Brzozowski, Z.; Pomarnacka,
E.; Scozzafava, A.; Temperini, C.; Supuran, C. T. Bioorg. Med. Chem. 2008, 16, 3933-
3940.
[15] Garaj, V.; Puccetti, L.; Fasolis, G.; Winum, J. Y.; Montero, J .L.; Scozzafava, A.; Vullo,
D.; Innocenti, A.; Supuran, C.T. Bioorg. Med. Chem. Lett. 2005, 15, 3102-3108.
[16]
Saczewski, F.; S1awinski, J.; Kornicka, A.; Brzozowski, Z.; Pomarnacka, E.; Innocenti,
A.; Scozzafava, A.; Supuran, C. T. Bioorg. Med. Chem. Lett. 2006, 16, 4846-4851.
[17] Supuran, C.T.; Scozzafava, A.; Casini, A. Med. Res. Rev. 2003, 23, 146-189.
16
ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
[18] Supuran, C. T. Carbonic anhydrases: catalytic and inhibition mechanisms, distribution
and physiological roles, in: Carbonic Anhydrase. Its Inhibitors and Activators. CRC
Press, Boca Raton, 2004, pp. 1-23.
[19] Kivela, A.J.; Kivela, J.; Saarnio, J.; Parkkila, S. J. World Gastroenterol. 2005, 11, 155-
163.
[20] Supuran, C. T.; Scozzafava, A. Bioorg. Med. Chem. 2007, 15, 4336-4350.
[21] Talley, J. J.; Brown, D. L.; Carter, J. S.; Graneto, M. C.; Koboldt, C. M.; Masferrer, J. L.;
Perkins, W. E.; Rogers, R. S.; Shaffer, A. F. J. Med. Chem. 2000, 43, 775-777.
[22] Thun, M. J.; Henley, S. J.; Patrono, C. J. Natl. Cancer Inst. 2002, 94, 252-266.
[23] Wykoff, C. C.; Beasley, J.; Watson, H.; Turner, K.; Pastorek, J.; Sibtain, A.; Wilson, D.;
Turley, H.; Talks, K. L.; Maxwell, H. P.; Pugh, W. C.; Ratcliffe, J. P.; Harris, L. A.
Cancer Res. 2000, 60, 7075-7083.
[24]
Parkkila, S.; Rajaniemi, H.; Parkkila, A.; Kivelä, J.; Waheed, A.; Pastorekova, S.; Sly,
W.; Pastorek, J. Proc. Natl. Acad. Sci. USA 2000, 97, 2220-2224.
[25] Svastova, E.; Hulikova, A.; Rafajova, M.; Zatovicova, M.; Gibadulinova, A.; Casini, A.;
Cecchi, A.; Scozzafava, A.; Supuran, C. T.; Pastorek, J.; Pastorekova, S. FEBS Lett.
2004, 577, 439-445.
[26] Cecchi, A.; Hulikova, A.; Pastorek, J.; Pastorekova, S.; Scozzafava, A.; Winum, J. Y.;
Montero, J. L.; Supuran, C. T. J. Med. Chem. 2005, 48 4834-4841.
[27] Argyropoulou, I.; Geronikaki, A.; Vicini, P.; Zani, F. Arkivoc, 2009 (vi), 89-102.
[28] Demirbas, N.; Demirbas, A.; Karaoglu, S.; Celik, E. Arkivoc 2005, (i), 75-91.
17
ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
[29] Zircle, C.; Kaiser, C. In Medicinal Chemistry, Ed. Burger, A.; Wiley-Interscience, New
York 1970, p. 1410.
[30] Shakya, A. K.; Mishra, P.; Patnaik, G. K.; Shukla, R.; Srimal, R. C. Arch. Pharm. Res.,
1998, 21, 753-758.
[31] Pawar, M. J.; Burungale, A. B.; Karale, B. K. ARKIVOC, 2009, xiii, 97-107.
[32] Schroder, J.; Henke, A.; Wenzel, H.; Brandstetter, H.; Stammler, H. G.; Stammler, A.;
Pfeiffer, W. D.; Tschesche, H. J. Med. Chem., 2001, 44, 3231-3243.
[33] Tschesche, H.; Schroder, J. EP Pat. Appl. 1191024.
[34] Sugawara, H.; Endoh, M. Jpn. J. Pharmacol., 1999, 80, 55-65.
[35]
Himmel, H. M.; Amos, G. J.; Wettwer, E.; Ravens, U. J. Card. Pharm.,1999, 33, 301-
308.
[36] Dogan, H. N.; Duran, A.; Rollas, S.; Sener, G.; Uysal, M. K.; Gulen, D. Bioorg. Med.
Chem., 2002, 10, 2893-2898.
[37]
Carvalho, S. A.; Da-Silva, E.; Santa-Rita, R. M.; De-Castro, S.; Fraga, C. A. Bioorg.
Med. Chem. Lett., 2004, 14, 5967-5970.
[38]
Swamy, S.; Priya, B.; Prabhuswamy, B.; Doreswamy, B.; Prasad, J.; Rangappa, K. S.
Eur. J. Med. Chem., 2006, 41, 531-538.
[39] Kalluraya, B.; Gururaja, R. E.; Ganesha, R. Indian J. Chem. 2003, 42, 211-214.
[40] Dandia, A.; Singh, R.; Khaturia, S. Bioorg. Med. Chem., 2006, 14, 1303-1308.
[41] Duan, j.; Chen, L.; Chemey, R.; Decicco, C.; Voss, M. PCT Int. Appl. WO, 1999, 41246.
[42] Albrecht, W. L.; Sweet, F. W. US Pat (1976) 3,954,983; Chem. Abstr. 85 (1976) 78172g.
[43] Albrecht, W. L.; Jones, W. US Pat, (1976) 3,954,981; Chem. Abstr. 85 (1976) 177501v.
18
ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
[44] Molina, P.; Alajarin, M.; Perez, M.; Foces, M.; Hernandez Cano, F.; Claramunt, R. M.;
Elguero, J. J. Chem. Soc. Perkin Trans I, 1987, 1853-1860.
[45] Reddy, V.; Reddy, K. Chem. Pharm. Bull., 2010, 58, 1081-1084.
[46] Kalluraya, B. Ph D Thesis, Bangalore University, India, 1987.
[47] Gonzalez-Munoz, G.; Arce, M.; Lopez, B.; Perez, C.; Villarroya, M.; Lopez, M.; Garcia,
A.; Conde, S.; Rodriguez-Franco, M. Eur. J. Med. Chem., 2010, 45, 6152-6158.
[48] Dalloul, H. M. Can. Chem. Trans., 2015, 3, 108-117; J. Chem., 2015, 1-7; Open J. Org.
Chem., 2015, 3, 12-17.
[49] Dalloul, H. M.; El-nwairy, K. A.; Shorafa, A. Z.Abu; Samaha, A. S. Inter. J. Adv. Res.
Chem. Sci., 2016, 3, 1-9.
[50] Thaher, B. A.; Otto, H. H. Monatsh. Chem., 2002, 133, 1011-1116; Dalloul, H. M.;
Mohamed, E. A.; El-Shorafa, A. Z. Naturforsch., 2009, 63, 585-590.
[51] Irobi, O. N.; Moo-Young, M.; Anderson, W. A. Inter. J. Pharm., 1996, 34, 87-90; Grayer,
R. J.; Harborne, J. B. Phytochemistry, 1994, 37, 19-42.
[52] National Committee on Clinical Laboratory Standards (NCCLS), Richard A. Van Enk,
Ph.D. Bronson Methodist Hospital Kalamazoo, Michigan, 2004.
[53]
Nishiwaki, T.; Siato, T. J. Chem. Soc. (C) 1971, 2648-2652; Frohberg, P.; Drutkowski,
G.; Wagner, C. Eur. J. Org. Chem. 2002, 1654-1663.
[54] Clinical Laboratory Standards Institute, “Methods for dilution antimicrobial susceptibility
tests for bacteria grow aerobically”, Approved Standard M7-A4, Clinical and Laboratory
Standards Institute, Wayne, Pa, USA, 2005.
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Ar
O
Ar
NH
COOEt
O
R
N
N
NEt3
0 oC
Ar
N
O
R
N
S
THF, r.t
3-4 d
N
H
R
-
+
2
+
Cl(Br)
1
HS
3a-c
COOEt
R = PhNH-
NaOMe or
LiH, Reflux
Ar =
SO2NH-X
Ar
N
O
N
N
N
S
N
O
O
a; X =
c; X =
b; X =
N
R
S
4a-c
Scheme 1. Synthetic pathway for the preparation of compounds 3a-c and 4a-c.
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Ar
O
Ar
NH
COOY
O
R
N
N
NEt3
0 oC
Ar
N
O
R
N
THF, r.t
4-6 d
N
H
R
-
+
Cl(Br)
2
S
+
1
COOH
COOH
HS
HOOC
5a-c
R = PhNH-
DCC/THF
Reflux
Ar =
SO2NH-X
Ar
Ar
N
N
N
O
N
O
R
N
S
a; X =
O
R
S
N
O
+
S
b; X =
c; X =
COOH
N
N
COOH
6a-c
7a-c
O
Scheme 2. Synthetic pathway for the preparation of compounds 5-7a-c.
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