Synthesis, anticancer and radiosensitizing evaluation of some novel sulfonamide derivatives

European Journal of Medicinal Chemistry 92 (2015) 682e692

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European Journal of Medicinal Chemistry journal homepage: http://www.elsevier.com/locate/ejmech

Original article

Synthesis, anticancer and radiosensitizing evaluation of some novel sulfonamide derivatives Mostafa M. Ghorab a, c, *, Fatma A. Ragab b, Helmy I. Heiba a, Marwa G. El-Gazzar a, Sally S. Zahran a a b c

Department of Drug Radiation Research, National Center for Radiation Research and Technology, Nasr City, Cairo, Egypt Department of Pharmaceutical and Medicinal Chemistry, Faculty of Pharmacy, Cairo University, Egypt Department of Pharmacognosy, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia

a r t i c l e i n f o

a b s t r a c t

Article history: Received 5 November 2014 Received in revised form 2 January 2015 Accepted 19 January 2015 Available online 20 January 2015

In this study, novel series of sulfonamide derivatives were synthesized starting from 2-cyanoacetyl) hydrazono)ethyl)phenyl)benzenesulfonamide 4a and 2-cyanoacetyl)hydrazono)ethyl)phenyl)-4methylbenzenesulfonamide 4b. Different biologically active moieties as pyrazol, thiophene, pyridine and pyrimidines were introduced in order to investigate their in-vitro anticancer activity, in addition to a novel series of sulfonamide chalcones were synthesized from the reported 4-acetyl-N-(P-tolyl) benzenesulfonamide 3b. The newly synthesized sulfonamide derivatives were characterized by FT-IR, 1H NMR, 13 C NMR, mass spectroscopy and elemental analyses and were tested for their in-vitro anticancer activity against human tumor liver cell line (HEPG-2). The most potent compounds in this study were compounds 4a, 4b, 5a, 6a, 6b, 8, 9, 11, 13, 18 and 19 which showed higher activity than doxorubicin with IC50 ranging from 11.0 to 31.8 mM. Additionally, eight compounds among the most potent were evaluated for their ability to enhance the cell killing effect of g-radiation. © 2015 Elsevier Masson SAS. All rights reserved.

Keywords: Sulfonamide Anticancer Radiosensitizers

1. Introduction The hepatocellular carcinoma (HCC) is the most frequent histological type of primary liver carcinoma and is one of the cancer types of highest incidence worldwide [1]. The majority of patients diagnosed with HCC have low recovery rates, and conventional and modified therapies currently available are rarely beneficial [2]. The human liver cancer cell line HepG2, established in 1979, is the best characterized and most frequently used cell line to predict overall hepatotoxicity [3]. On the other hand, sulfonamides possess many types of biological activities [4,5]. Also, from the Literature survey it was found that aryl/heteroaryl sulfonamides may act as antitumor agents through several mechanisms [6]. Previously we studied about synthesis and biological activity of some sulfonamide containing different biologically active moieties and we observed many compounds have promising anticancer activity [7e20]. In addition, many hetrocyclic compounds incorporating pyridine, thiophene or benzothiophene moieties showed potential anticancer activities

* Corresponding author. Department of Pharmacognosy, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia. E-mail address: [email protected] (M.M. Ghorab). http://dx.doi.org/10.1016/j.ejmech.2015.01.036 0223-5234/© 2015 Elsevier Masson SAS. All rights reserved.

[21e25]. Furthermore, particular interest has been focused on the anticancer activity of chalcones which represent an important group of the polyphenolic family [26]. This family possesses an interesting spectrum of biological activities, including antimicriobial [27,28], anti-inflammatory [29], immunosuppressive [30] and anticancer activity [31,32]. Compounds of this family have been shown to interfere with each step of carcinogenesis, including initiation, promotion and progression [33]. Moreover, numerous chalcones appear to show activity against cancer cells, suggesting that these molecules or their derivatives may be considered as potential anticancer drugs [34]. In the design of new drugs, the development of hybrid molecules through the combination of different pharmacophores may lead to compounds with interesting biological profiles. In recent years, combination chemotherapy with agents possessing different mechanisms of action is one of the methods, which are, being adopted to treat cancer [35,36]. Following this approach and as a part of an ongoing effort to find alternate chemotherapeutic agents for hepatocellular carcinoma [11,12,37,38], we herein, report the design and synthesis of novel sulfonamide derivatives bearing a biologically active pyridine, thiophene, benzothiophene and chalcone moieties for evaluation as anticancer on liver human tumor cell lines (HEPG2) and as

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radiosensitizing agents.

2. Results and discussion 2.1. Chemistry The synthetic strategies utilized for the synthesis of the target compounds are outlined in (Schemes 1e3) which could assemble entirely the desired sulfonamide derivatives (4a,b-26) from the strategic starting materials N-(4-acetyl-N-(P-substituted) phenyl benzenesulfonamide (3a,b) [39,40]. Hence, to develop a more widely applicable approach for the synthesis of the target compounds we chose to evaluate two synthetic strategies based on substitution of the acetyl group, the first pathway is the reaction of the nitrogen nucleophile 2-cyanoacetohydrazide with compounds 3a,b to yield (E)-N-(4-(1-(2-(2-cyanoacetyl) hydrazono) ethyl)-N(P- substituted) phenyl benzenesulfonamide 4a,b in good yield (Scheme 1). The structural assignments to synthesized compounds were based on their physico-chemical characteristics and spectroscopic (IR, 1H NMR, 13C NMR, and mass spectral data) investigations. IR spectrum of compound 4a revealed characteristic strong intensity bands at 3340, 3219 and 2259 cm
1 for the introduced (2NH and C^N), respectively confirming the formation of cyanoacetyl hydrazono derivative. 1H NMR spectrum displayed up-field singlet at 3.3 ppm for the introduced CH2 group and downfield shifted singlet appearing at 10.9 ppm due to addition of NH group. 13C NMR exhibited new up-field signal at 27.3 ppm for CH2 and new signal at 125.7 ppm assigned to C^N. IR spectrum of compound 4b revealed characteristic strong intensity bands at 3438, 3245 and 2259 cm
1 for the introduced (2NH and C^N), respectively confirming the formation cyanoacetyl hydrazono derivative. 1H NMR spectrum displayed up-field singlet at 3.6 ppm for the introduced CH2 group and downfield shifted singlet appearing at 10.9 ppm, due to addition of NH group. 13C NMR exhibited new up-field signal at 38.6 ppm for CH2 and new signal at 126.6 ppm ascribed to C^N. A subsequent ring-closure approach effort for the synthesis of the

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target compounds 5e13 involves reaction of 4a, b with malononitrile in dioxane to give (Z)-4-(1-((4,6-diamino-3-cyano-2oxopyridin-1(2H)-yl)imino)ethyl)-N-p-substituted-phenyl-benzenesulfonamide (5a,b) (Scheme 1). IR spectrum of compound 5a revealed characteristic strong intensity bands at 3338 and 3210 cm
1 for the introduced two NH2 groups. 1H NMR spectrum displayed up-field singlet at 4.5 ppm assigned for the CH group and downfield shifted singlet appearing at 8.5 ppm, due to addition of NH2 group. 13C NMR exhibited new up-field signal at 83.1 ppm for CH pyridine, 148.4 ppm for (NeCeNH2) and 177.9 ppm for (CeNH2). IR spectrum of compound 5b revealed characteristic strong bands at 3389 and 3315 cm
1 for the two of NH2 groups. 1H NMR spectrum displayed up-field singlet at 4.1 ppm for the CH group and downfield shifted singlet appearing at 10.7 ppm, due to addition of NH2 group. 13C NMR exhibited new up-field signal at 83.1 ppm for CH pyridine, 143.6 ppm for (NeCeNH2) and 177.9 ppm for (CeNH2). Alternatively, malononitrile was reacted with compounds 4a, b in the presence of elemental sulfur and in absolute ethanol containing 3 drops of triethyl amine to yield the corresponding thiophene derivatives 6a, b (Scheme 1) this reaction goes in parallel to the reported Gewald's thiophene synthesis [41] and their spectroscopic data were consistent to their chemical structures. The corresponding N-(4-((Z)-1-(2-((E)-2-cyano-3-(dimethylamino) acryloyl) hydrazono) ethyl) phenyl)-4-methylbenzenesulfonamide 7 was obtained through the addition of DMF-DMA on 4b in xylene (Scheme 2). IR spectrum revealed bands at 2929, 2830 cm
1 for CH_aliphatic. 1H NMR spectrum displayed up-field singlet at 3.3 ppm for the addition of two group of CH3 and downfield shifted singlet appearing at 7.5 ppm due to introduced CH group. 13C NMR exhibited new up-field signal at 40.3 ppm for introduced two methyl group, 98.8 ppm for CeCN and down-field signal at 156 ppm for addition of CH group. Compound (Z)-2-cyano-3-(2-(1(4-(4-methylphenylsulfonamido) phenyl) ethylidene) hydrazinyl)3-oxopropanedithioic acid 8 was obtained via the reaction of CS2 with 4b in DMF containing KOH (Scheme 2), its IR spectrum revealed band at 1300 cm
1 for C]S group. 1H NMR spectrum

Scheme 1. Synthetic pathways for compounds 3a,b-6a,b.

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Scheme 2. Synthetic pathways for compounds 7e13.

displayed up-field singlet at 1.5 ppm for SH group and singlet at 3.5 ppm for the addition of CH group. 13C NMR exhibited new upfield signal at 61.9 ppm for CeC]N and down-field signal at 229.7 ppm for addition of C]S group. The reaction of compound 4b with cyclohexanone and elemental sulfur yielded the corresponding (Z)-N-(4-(1-(2-(3-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-2-carbonyl) hydrazono) ethyl) phenyl)-4-methyl benzenesulfonamide 9 the reaction proceeded according to similar reported reactions [42] (Scheme 2). The dicyanopyridinone derivatives 11 and 13 were obtained through treatment of compound 4b with aromatic benzylidine malononitriles 10 and 12 in dioxane in the presence of piperidine as a basic catalyst (Scheme 2). Their IR spectra confirmed the assigned structures by the presence of significant band for NH2 and an additional band for CN at their specified regions. 1H NMR spectra displayed disappearence of singlet at 3.6 ppm of CH2 group which was involved in the cyclization process and a new signal assigned for NH2 group appeared at 10.4 ppm which was exchangeable with D2O. 13C NMR for compounds 11 and 13 exhibited new up-field signal at 71.7, 76.5 ppm respectively for CeC]N and signals at 116.18 and 115.8 for CN group. The second pathway adopted for the synthesis of compounds 14e19 depends on the synthesis of novel sulfonamide derivatives bearing chalcone moieties which are considered an important class of anticancer agents [43]. The chalcones 14e19 were prepared by the ClaiseneSchmidt condensation between acetophenone derivative 3b and aromatic aldehydes in the presence of potassium hydroxide in ethanol [44] (Scheme 3). IR spectra of compounds 14e19 showed bands of C]O group at ranges of 1647e1680 cm
1, respectively. 1H NMR spectra of compounds 14e19 displayed

down-field doublet at 7.5 ppm, respectively assigned for CHCO group, and shows doublet of CHCH group at 8.06 ppm. 1H NMR spectrum of compound 15 show up-field singlet at 2.0 ppm of CH3 group. 13C NMR of compounds 14e19 exhibited new signals at the range of 121.3 ppm, for CHCO group together with signals at the range of 145.1 ppm for CH]CH group. Our interest in this area was to design and synthesize sulfonamide chalcones for structureeactivity relationship (SAR) studies in anticancer activities thus, the treatment of chalcone 18 with hydroxylamine hydrochloride in absolute ethanol containing KOH afforded the oxime derivative 20 [45,46] (Scheme 3). IR spectrum revealed broad band at 3451 cm
1 of OH group. 1H NMR spectrum displayed new up-field singlet at 2.3 ppm of OH group. 13C NMR exhibited new down-field-signal at 164.8 ppm due to addition of new C]N group. Compound 18 upon reacting with different hydrazine derivatives in basic conditions adopted reaction mechanism involving formation of intermediate (non-isolable) hydrazones and subsequent addition of NH on the carbonecarbon double bond of the propenone moiety. Similar formation of pyrazole derivative in literature showed hydrazine's attack preferentially on the carbonyl group of a,b-unsaturated ketones, rather than the double bond confirms the formation of compounds 21e24 [45,46] (Scheme 3). The formation of pyrazole was confirmed through the spectroscopic data by the disappearance of carbonyl group and the aliphatic bands in their IR spectra and the appearance of pyrazole protons in the range of 7.1e7.8 in their 1H NMR spectra. 13C NMR of compounds 21e24 exhibited new signal of CH-pyrazol at 99.7, 106.7, 103.5 and 104.5 ppm, respectively, signal of C]CeN pyrazol at 147.1, 144.5, 144.8 and 144.3 ppm, respectively and new signal of C]N at 147.7, 153.4, 152.3 and 152.3 ppm, respectively. Compounds 23, 24 showed new

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Scheme 3. Synthetic pathways for compounds 14e26.

signals for C]S at 176.8 and 174.9 ppm, respectively. Owing to the significant features of dihydropyrimidine derivatives a number of protocols for their synthesis have been developed, herein, reaction of compound 18 with urea and thiourea in ethanol in presence of KOH gave 25 and 26 following reported method [45,46]. IR of compound 25 showed band of C]O at 1669 cm
1. While, IR of compound 26 showed band C]S at 1300 cm
1. 1H NMR spectrum of compounds 25 and 26 showed singlet for CH at 6.0, 6.7 ppm respectively, while singlet of NH appeared at 8.5, 13.7 ppm respectively. 13C NMR of compounds 25 and 26 exhibited new signal at 106.6, 104.3 ppm of CH group respectively. 13C NMR of compound 25 showed signal at 156.3 ppm of C]O group, while spectrum of compound 26 show signal at 180.4 of C]S. Further, the mass spectra of all the synthesized compounds are in conformity with the assigned structures.

2.2. In-vitro anticancer evaluation against human tumor liver cancer (HEPG2) From the results in Table 1, it was found that compounds 4a, 4b, 5a, 6a, 6b, 8, 9, 11, 13, 18 and 19 were the most potent compounds in the study with IC50 ranges 11.0e31.8 mM and exhibited higher cytotoxic activities when compared with control and the reference drug doxorubicin (IC50 ¼ 36.3 mM). Compounds 3a, 3b, 5b, 7, 16 and 26 showed equipotent activities than that of the reference drug, ranging from 35.3 to 39.3 mM. A closure look into the structure activity relationship indicates that the acetophenone derivatives 3a, b showed equipotent activities as the reference drug (IC50 ¼ 35.3 and 35.8 mM) which was improved to be 28.0 and 26.0 mM in compound 4a, b due to addition of cyanoacetohydrazone moiety. The addition of pyridinone moiety

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Table 1 In-vitro anticancer screening of the synthesized compounds against HEPG2. Comp. No.

Control(DMSO)

Concentration (mM) 5

IC50 (mM) 12.5

25

50

Surviving fraction (mean ± SE)a 3a 3b 4a 4b 5a 5b 6a 6b 7 8 9 11 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Doxorubicin a

1.438 1.532 1.373 1.430 1.423 1.514 1.513 1.409 1.738 1.337 1.398 1.543 1.267 2.403 2.160 2.518 2.395 1.662 2.362 2.493 2.365 2.039 2.165 1.248 2.234 1.535

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

0.026 0.039 0.051 0.026 0.026 0.039 0.039 0.025 0.065 0.049 0.052 0.057 0.047 0.089 0.080 0.093 0.088 0.061 0.087 0.092 0.087 0.075 0.079 0.046 0.082 0.056

0.891 1.048 0.881 0.837 0.748 0.937 0.869 0.571 1.141 0.344 0.868 0.984 0.951 2.385 1.931 1.461 2.16 0.476 0.584 1.723 1.772 2.085 1.907 1.766 1.619 1.066 0.721

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

0.085 0.073 0.054 0.027 0.049 0.017 0.078 0.034 0.109 0.001 0.024 0.058 0.036 0.105 0.270 0.167 0.189 0.085 0.033 0.209 0.027 0.081 0.054 0.199 0.164 0.026 0.020

0.719 0.726 0.778 0.530 0.556 0.761 0.456 0.383 0.877 0.229 0.528 0.696 0.635 2.032 1.616 0.497 1.478 0.348 0.505 1.769 1.197 1.841 1.759 1.189 0.950 0.805 0.546

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

0.028 0.068 0.056 0.058 0.009 0.003 0.052 0.026 0.045 0.016 0.026 0.042 0.047 0.103 0.149 0.068 0.027 0.043 0.054 0.231 0.244 0.129 0.058 0.012 0.057 0.015 0.020

0.464 0.547 0.361 0.349 0.312 0.577 0.239 0.390 0.546 0.291 0.331 0.363 0.331 1.017 0.781 0.383 0.591 0.392 0.430 1.351 0.522 0.923 1.078 0.507 0.732 0.486 0.461

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

0.067 0.247 0.023 0.042 0.044 0.051 0.035 0.017 0.033 0.049 0.052 0.042 0.047 0.125 0.019 0.069 0.082 0.072 0.037 0.267 0.012 0.124 0.189 0.100 0.081 0.034 0.010

0.417 0.367 0.242 0.293 0.321 0.385 0.274 0.323 0.378 0.414 0.277 0.375 0.408 0.529 0.489 0.551 0.402 0.495 0.445 0.632 0.508 0.536 0.500 0.530 0.481 0.398 0.494

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

0.030 0.116 0.025 0.026 0.023 0.030 0.047 0.029 0.059 0.055 0.012 0.044 0.042 0.019 0.037 0.079 0.021 0.054 0.008 0.076 0.039 0.114 0.061 0.066 0.078 0.016 0.030

35.3 35.8 28.0 26.0 25.5 37.0 23.3 21.8 37.8 11.0 25.5 31.8 31.5 NA 49.8 39.3 43.3 26.0 30.3 NA 44.8 NA NA 45.3 46.3 36.5 36.3

Each value is the mean of three values ± standard Error; NA: no activity.

was proved to be successful in case of compound 5a which showed an increase in the activity (IC50 ¼ 25.5 mM). Oppositely, the activity of compound 5b decreased to be 37.0 mM. The efficiency of introducing thiophene ring was proved in compounds 6a, b whose activities were interestingly improved (IC50 ¼ 23.3 and 21.8 mM) in comformity with the well-documented anticancer activity of thiophene derivatives [47]. On the other hand introduction of dimethyl amino group through the reaction of 4b with DMF-DMA yielded compound 7 which showed relatively low activity (IC50 ¼ 37.8 mM). While, the addition of bifunctional CS2 afforded compound 8 which is the most potent candidate in this screening (IC50 ¼ 11.0 mM). Similarly, introduction of tetrahydrobenzo thiophene moiety resulted in high activity compound 9 (IC50 ¼ 25.5 mM). Concerning the dicyanopyridinone derivatives 11 and 13 they both showed lower activities (IC50 ¼ 31.8 and 31.5 mM) compared to the corresponding starting material 4b (IC50 ¼ 26.0 mM) but still they are more potent than doxorubicin. The synthesis of chalcone derivatives 14e19 indicated that the most potent among the six new compounds was the p-nitrophenyl derivative 18 (IC50 ¼ 26.0 mM) and this finding encouraged us to synthesize more derivatives by introducing oxime, pyrazole and pyrimidine moieties in compounds 20e26, respectively, aiming to obtain more potent anticancer agents but, unfortunately, the resulting compounds were with low activities except for compound 26 (IC50 ¼ 36.5 mM) and these results proved the importance of a,bunsaturated ketone system in chalcones as anticancer pharmacophore without any substitution [48,49].

2.3. Radiosensitizing evaluation The ability of the most active compounds 5a, 6a, 6b, 8, 9, 13, 18 and 19 to enhance the cell killing effect of ɤ-irradiation was studied. From the results obtained in Table 2, compound 5a showed an

in vitro anticancer activity with IC50 value of 25.5 mM, when the cells were subjected to different concentrations of the compound alone. While when the cells were subjected to the same concentrations of compound 5a, and irradiated with a single dose of ɤradiation at a dose level of 8 Gy, the IC50 value was synergistically decreased to 11.5 mM. Similarly, compound 6a showed IC50 value of 23.3 mM when used alone. The IC50 value was decreased to 18.3 mM, when the cells were treated with compound 6a in combination with ɤ-radiation. Also, compound 6b showed IC50 value of 21.8 mM when tested alone. The IC50 value was decreased to 5.8 mM, when the cells were treated with compound 6b in combination with ɤradiation. Similar findings for compounds 8, 9, 13, 18 and 19 which showed IC50 values of 11.0, 25.5, 31.5, 26.0 and 30.3 mM, respectively, while, their IC50 values decreased synergistically with radiation to become 5.0, 20.0, 23.5, 20.5 and 26.8 mM. The results proved the ability of the synthesized compounds to sensitize cancer cells to the lethal effects of ionizing radiation in order to decrease the dose of the drug and decrease its toxicity. The change in IC50 (mM) for compounds 5a, 6a, 6b, 8, 9, 13, 18 and 19 against HEPG2 before and after radiation is illustrated in Fig. 1.

3. Conclusion In summary, we had synthesized a novel series of sulfonamide derivatives. Most of the prepared compounds revealed potential anticancer activity against human liver cancer cell line. Compounds 4a, 4b, 5a, 6a, 6b, 8, 9, 11, 13, 18 and 19 were found to be more potent than doxorubicin. From the structureeactivity relationships, we may conclude that the introduction of carbon disulphide is associated with enhanced anticancer activity and gave the most potent compound in this study (IC50 ¼ 11.0 mM). Combination of sulfonamide with chalcone moiety in compound 18 increased the activity (IC50 ¼ 26.0 mM), but further substitution on a, b-

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Table 2 In-vitro anticancer screening of compounds 5a, 6a, 6b, 8, 9, 13, 18 and 19 against human liver cancer cell line (HEPG2) after exposure to ɤ-radiation. Comp. No.

Control (radiation)

Concentration (mM) 5

IC50 (mM) 12.5

25

50

Surviving fraction (mean ± SE)a 5a 6a 6b 8 9 13 18 19

1.116 1.011 1.232 1.123 0.917 1.032 1.215 1.187

± ± ± ± ± ± ± ±

0.041 0.037 0.045 0.040 0.033 0.037 0.044 0.042

0.395 0.526 0.291 0.245 0.521 0.439 0.558 0.591

± ± ± ± ± ± ± ±

0.095 0.015 0.037 0.019 0.031 0.056 0.040 0.051

0.194 0.386 0.227 0.206 0.524 0.603 0.451 0.471

± ± ± ± ± ± ± ±

0.194 0.090 0.010 0.007 0.017 0.262 0.122 0.025

0.299 0.253 0.105 0.189 0.329 0.345 0.368 0.394

± ± ± ± ± ± ± ±

0.021 0.004 0.019 0.043 0.024 0.049 0.039 0.079

0.340 0.322 0.174 0.158 0.229 0.352 0.249 0.408

± ± ± ± ± ± ± ±

0.043 0.016 0.006 0.008 0.010 0.027 0.143 0.033

11.5 18.3 5.80 5.00 20.0 23.5 20.5 26.8

Each value is the mean of three values ± Standard Error; Significant difference from control group at P < 0.001.

Fig. 1. Change in IC50 (mM) for compounds 5a, 6a, 6b, 8, 9, 13, 18 and 19 against HEPG2 before and after radiation.

unsaturated ketone system led to less active compounds. This study may provide valuable information for further of more potent anticancer agents. Moreover, the most active compounds showed interesting radiosensitizing activity when evaluated for their invitro anticancer activity in combination with g-irradiation.

4. Experimental 4.1. Chemistry Melting points were uncorrected and were taken in an open capillary tube on a Stuart melting point apparatus (Stuart Scientific, Redhill, UK). The IR spectra of the compounds were recorded on ABB Bomem FT-IR spectrometer MB 104 with KBr pellets. 1H NMR and 13C NMR spectra were recorded using a Bruker 300 NMR spectrometer operating at 400.13 and 100.77 MHz, respectively. Microanalyses were obtained with Elemental analyses system GmbH VarioEL V300 element analyzers which were found within the limit of 0.4% of theoretical values for all the synthesized compounds. The purity of the compounds was checked by thin layer chromatography (TLC) on pre-coated silica gel plates (Kiesel gel 0.25 mm, 60 G F 254, Merck)). The developing solvent system was chloroform/methanol (10:3) and the spot were visualized in UV chamber. IR, 1H NMR, 13C NMR and elemental analysis were consistent with the assigned structures and performed at the Microanalytical Laboratories of the Faculty of Science, Cairo University.

4.1.1. (E)-N-(4-(1-(2-(2-cyanoacetyl)hydrazono)ethyl)phenyl) benzenesulfonamide (4a) A mixture of 2ecyanoacetohydrazide (2.76 g, 0.01 mol) and 4acetyl-N-phenyl benzenesulfonamide 3a [31] (1 g, 0.01 mol) in dioxane (10 mL), was refluxed for 3 h, then left to cool. The solid product formed upon pouring onto ice/water was collected by filtration and recrystallized from ethanol to give 4a. Yield, 69%; m.p. 120e122  C. IR (KBr, cm
1): 3340, 3219 (2NH), 3058 (CH arom.), 2925, 2830 (CH aliph.), 2259 (C^N), 1667 (C]O), 1596 (C]N), 1347, 1162 (SO2). H1NMR (DMSO-d6): 2.1 [s, 3H, CH3], 3.3 [s, 2H, CH2], 6.6e7.2 [m, 5H, AreH], 8.0 [s, 1H, SO2NH exchangeable with D2O], 7.8, 7.7 [2d, 4H, AreH AB system, J ¼ 6.8 Hz], 10.9 [s, 1H, NH exchangeable with D2O]. C13NMR (DMSO-d6): 26.3, 27.3 (CH2), 117.9, 122.4, 125.7 (C^N), 126.6, 129.5 (2C), 129.7, 139.2, 142.1 (2C), 196.3 (C]O). MS m/z (%): 356 (Mþ) (1.4), 52.2 (100). Anal. Calcd. For C17H16N4O3S (356): C, 57.29; H, 4.52; N, 15.72. Found: C, 57.53; H, 4.32; N, 4.32. 4.1.2. (E)-N-(4-(1-(2-(2-cyanoacetyl)hydrazono)ethyl)phenyl)-4methylbenzenesulfonamide (4b) A mixture of 2ecyanoacetohydrazide (2 g, 0.007 mol) and in, 4acetyl-N-(P- tolyl)benzenesulfonamide 3b [32] (0.74 g, 0.007 mol) in dioxane (10 mL) was refluxed for 3 h, then left to cool. The solid product formed upon pouring onto ice/water was collected by filtration and recrystallized from ethanol to give 4b. Yield, 72.2%; m.p. 200e202  C. IR (KBr, cm
1): 3438, 3245 (2NH), 3058 (CH arom.), 2927, 2830 (CH aliph.), 2259 (C^N), 1680 (C]O), 1593 (C] N), 1349, 1156 (SO2). H1NMR (DMSO-d6): 2.1 [s, 3H, CH3], 2.5 [s, 3H, CH3 tolyl], 3.6 [s, 2H, CH2], 7.2, 7.3 [2d, 4H, AreH AB system, J ¼ 6.8 Hz], 8.0 [s, 1H, SO2NH exchangeable with D2O], 7.7, 7.8 [2d, 4H, AreH AB system, J ¼ 7.1 Hz], 10.9 [s,1H,NH exchangeable with D2O]. C13NMR (DMSO-d6): 20.8 (CH3 tolyl), 26.2, 38.6 (CH2), 117.8, 126.6 (C^N), 127.1, 129.7, 129.8, 131.8, 136.4, 142.3, 143.5 (2C), 196.3 (C] O). MS m/z (%): 370 (Mþ) (1.02), 90 (100). Anal. Calcd. For C18H18N4O3S (370): C, 58.36; H, 4.90; N, 15.12. Found: C, 58.70; H, 4.60; N, 15.40. 4.1.3. (Z)-4-(1-((4,6-diamino-3-cyano-2-oxopyridin-1(2H)-yl) imino)ethyl)-N-phenyl-benzenesulfonamide (5a) Equimolecular amounts of compound 4a (0.5 g, 0.0013 mol) and malononitrile (0.06 g, 0.0013 mol) in dioxane (10 mL) containing triethylamine (5dps) was heated under reflux for 6 h, then left to cool. The solid product formed upon pouring onto ice/water was collected by filtration and recrystallized from 1,4-dioxane to give 5a. Yield, 63.8%; m.p. 196e198  C. IR (KBr, cm
1): 3338, 3210, 3199 (NH2, NH), 3058 (CH arom.), 2925, 2864 (CH aliph.), 2273 (C^N), 1692 (C]O), 1510 (C]N), 1329, 1162 (SO2). H1NMR (DMSO-d6): 2.1 [s, 3H, CH3], 4.5 [s, 1H, CH-pyridine], 6.6e7.0 [m, 5H, AreH], 8.0 [s, 1H, SO2NH exchangeable with D2O],

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7.7, 7.8 [2d, 4H, AreH AB system, J ¼ 7.1 Hz], 8.5 [s, 4H, 2 NH2 exchangeable with D2O]. C13NMR (DMSO-d6): 13.5 (CH3), 69.9 (CeCN), 83.1 (CH-pyridine), 115.8 (C^N), 119.0, 122.4, 127.3, 127.3, 129.2, 129.5, 138.6, 142.0, 148.4 (NeCeNH2), 160.0 (C]O), 165.6, 177.9 (CeNH2). MS m/z (%): 423 (M þ 1) (3.49), 90.70 (100). Anal. Calcd. For C20H18N6O3S (422): C, 56.86; H, 4.29; N, 19.89. Found: C, 56.6; H, 4.41; N, 19.5. 4.1.4. (E)-N-(4-(1-((4,6-diamino-3-cyano-2-oxopyridin-1(2H)-yl) imino)ethyl)phenyl)-4-methylbenzenesulfonamide (5b) Equimolecular amounts of compound 4b (0.5 g, 0.0013 mol) and malononitrile (0.06 g, 0.0013 mol) in dioxane (10 mL) containing triethylamine (5dps) was heated under reflux for 6 h, then left to cool. The soild product formed upon pouring onto ice/water was collected by filtration and recrystallized from dioxane to give 5b. Yield, 44.16%; m.p. 146e148  C. IR (KBr, cm
1): 3389, 3315, 3219 (NH2, NH), 3058 (CH arom.), 2930, 2830 (CH aliph.), 2196 (C^N), 1661 (C]O), 1590 (C]N), 1349, 1156 (SO2). H1NMR (DMSO-d6): 2.1 [s, 3H, CH3], 2.5 [s, 3H, CH3 tolyl], 4.1 [s, 1H, CH pyridine], 7.2, 7.3 [2d, 4H, AreH AB system, J ¼ 6.8 Hz], 7.7, 7.8 [2d, 4H, AreH AB system, J ¼ 7.2 Hz ], 8.0 [s, 1H, SO2NH exchangeable with D2O], 10.7 [s, 4H,2 NH2 exchangeable with D2O]. C13NMR (DMSO-d6): 20.8, 26.2, 66.2 (CeC^N), 83.1 (C-pyridine), 117.8, 118.8 (C^N), 127.1, 129.6, 129.8, 131.8, 136.4, 142.2, 143.5, 143.6 (NeCeNH2), 143.6, 177.9 (CeNH2), 196.3 (C]O). MS m/z (%): 431 (M
5) (0.12), 104 (100). Anal. Calcd. For C21H20N6O3S (436): C, 57.79; H, 4.62; N, 19.25. Found: C, 58; H, 58; N, 19.52. 4.1.5. (E)-N-(4-(1-(2-(3,5-diamino-4-cyanothiophene-2-carbonyl) hydrazono)ethyl)phenyl)-benzenesulfonamide (6a) To a solution of compound 4a (0.35 g, 0.0013 mol)in absolute ethanol (10 mL) containing triethylamine (5dps) malononitrile (0.06 g, 0.0013 mol) together with elemental sulfur (0.032 g, 0.001 mol) were added. The reaction mixture was heated under reflux for 2 h, then left to cool and poured onto ice/water and the solid obtained was recrystallized from dioxane to give 6a. Yield, 82.2%; m.p. 167e169  C. IR (KBr, cm
1): 3390, 3250, 3194 (NH2, NH), 3058 (CH arom.), 2928, 2830 (CH aliph.), 2210 (C^N), 1692 (C]O), 1595 (C]N), 1328, 1152 (SO2). H1NMR (DMSO-d6): 2.16 [s, 3H, CH3], 6.6e7.2 [m, 5H, AreH], 6.2, 6.9 [s, 4H, 2NH2 exchangeable with D2O], 7.0 [s, 1H, NH exchangeable with D2O], 8.0 [s, 1H, SO2NH exchangeable with D2O], 7.7, 7.8 [2d, 4H, AreH AB system, J ¼ 7.2 Hz]. C13NMR (DMSO-d6): 13.5, 81.1 (CeCN), 117.9 (C^N), 119, 122.4, 127.19, 129.2, 129.3, 129.7, 132.9 (COC), 139.2 (CeS), 142.1, 150.0, 157.8 (CeNH2), 160.8 (SeCeNH2), 169.3 (C]O). MS m/z (%): 454 (Mþ) (0.25), 90 (100). Anal. Calcd. For C20H18N6O3S2 (454): C, 52.85; H, 3.99; N, 18.49. Found: C, 52.64; H, 4.33; N, 18.58. 4.1.6. (E)-N-(4-(1-(2-(3,5-diamino-4-cyanothiophene-2-carbonyl) hydrazono)ethyl)phenyl)-4-methylbenzenesulfonamide (6b) To a solution of compound 4b (0.37 g, 0,0013 mol) in absolute ethanol (10 ml) containing triethylamine (5dps) malononitrile (0.06 g, 0.0013 mol) together with elemental sulfur (0.032 g, 0.0013 mol) were added. The reaction mixture was heated under reflux for 2 h, then left to cool and poured onto ice/water and the solid obtained was recrystallized from dioxane to give 6b. Yield, 83.3%; m.p. 150e152  C. IR (KBr, cm
1): 3391, 3311, 3219 (NH2, NH), 3058 (CH arom.), 2928, 2830 (CH aliph.), 2202 (C^N), 1664 (C]O), 1596 (C]N), 1349, 1156 (SO2). H1NMR (DMSO-d6): 2.16 [s, 3H, CH3], 2.5 [s, 3H, CH3 tolyl], 7.2, 7.3[ 2d, 4H, AreH AB system, J ¼ 6.8 Hz], 7.7, 7.8 [2d, 4H, AreH AB system, J ¼ 7.1 Hz], 8.0 [s, 1H, SO2NH exchangeable with D2O], 10.5 [s, 2H, NH2 exchangeable with D2O], 10.7 [s, 2H, NH2 exchangeable with D2O], 10.9 [s, H, NH exchangeable with D2O]. C13NMR (DMSO-d6): 20.8, 26.2, 76.5 (CeC^N), 116 (C^N), 117.8, 127.5, 129.6, 129.7, 131.8, 132.9 (CeS), 136.4, 142.26,

143.3, 143.6, 152.0 (CeNH2), 165.5 (SeCeNH2), 196.3 (C]O). MS m/z (%): 466 (M
2) (0.23), 90 (100). Anal. Calcd. For C21H20N6O3S2 (468): C, 53.83; H, 4.30; N, 17.94. Found: C, 53.75; H, 4.52; N, 17.74. 4.1.7. N-(4-((Z)-1-(2-((E)-2-cyano-3-(dimethylamino)acryloyl) hydrazono)ethyl)phenyl)-4-methylbenzenesulfonamide (7) A mixture of 4b (0.3 g, 0.0008 mol) and dimethylformamidedimethylacetal (DMF-DMA) (0.09 g (0.11 ml), 0.0008 mol), in dry xylene (15 ml) was refluxed for 3 h and filtered, then the filtrate was cooled in refrigerator then filtered. The obtained soild was recrystallized from ethanol to give 7. Yield, 26.4%; m.p. 185e187  C. IR (KBr, cm
1): 3240 (NH), 3200 (CH arom.), 2929, 2830 (CH aliph.), 2288 (C^N), 1666 (C]O), 1588 (C]N), 1338, 1156 (SO2). H1NMR (DMSO-d6): 2.1 [s, 6H, CH3], 2.5 [s, 3H, CH3 tolyl], 3.3 [s, 6H, Ndimethyl], 7.2, 7.3 [2d, 4H, AreH AB system, J ¼ 6.9 Hz], 7.5 [s, 1H, C]CH], 7.7, 7.8 [2d, 4H, AreH AB system, J ¼ 7.2 Hz], 8.0 [s, 1H, SO2NH exchangeable with D2O], 10.7 [s, 1H, NH exchangeable with D2O]. C13NMR (DMSO- d6): 20.8, 26.2, 40.3 (N(CH3)2), 98.8 (CeCN), 117.8, 118.8 (C^N), 127.4, 129.7, 129.8, 131.8, 136.4, 142.3, 143.5, 143.6, 156.0 (CH), 196.3 (C]O). MS m/z (%): 420 (M
5) (0.05), 92.45 (100). Anal. Calcd. For C21H23N5O3S (425): C, 59.28; H, 5.45; N, 16.46. Found: C, 59.08; H, 5.65; N, 16.26. 4.1.8. (Z)-2-Cyano-3-(2-(1-(4-(4-methylphenylsulfonamido) phenyl)ethylidene)hydrazinyl)-3-oxopropanedithioic acid (8) Carbon disulfide (0.0061 g, 0.0008 mol) was added gradually to a cold solution of the acetohydrazide derivative 4b (0.3 g, 0.0008 mol) in N,N-dimethylformamide (5 mL) containing finely grounded potassium hydroxide (1.0 g) and the reaction mixture was left at room temperature for an additional 24 h with stirring. The reaction mixture was then triturated with cold water and neutralized with 1N HCl. The resulting precipitated soild was collected by filtration, washed with water, dried and recrystalized from dioxane to give 8. Yield, 98.31%; m.P. 146e148  C. IR (KBr, cm
1): 3380, 3213 (2 NH), 3058 (CH arom.), 2926, 2830 (CH aliph.), 2288 (C^N), 1664 (C]O), 1590 (C]N), 1338, 1156 (SO2), 1300 (C] S). H1NMR (DMSO-d6): 1.5 [s, 1H, SH exchangeable with D2O ], 2.1 [s, 3H, CH3], 2.5 [s, 3H, CH3 tolyl], 3.5 [s, 1H, CH], 7.0 [s, 1H, NH exchangeable with D2O], 7.2, 7.3 [2d, 4H, AreH AB system, J ¼ 6.8 Hz], 7.7, 7.8 [2d, 4H, AreH AB system, J ¼ 7.3 Hz], 8.0 [S, 1H, SO2NH exchangeable with D2O]. C13NMR (DMSO-d6): 20.8, 26.27, 61.9 (CeC^N), 115.3 (C^N), 117.8, 127.1, 129.6, 129.8, 131.8, 136.4, 140.7, 142.2, 143.6, 171 (C]O), 229.7 (C]S). MS m/z (%): 444 (M
2) (3.08), 63.5 (100). Anal. Calcd. For C19H18N4O3S3 (446): C, 51.10; H, 4.06; N, 12.55. Found: C, 51.0; H, 4.31; N, 12.33. 4.1.9. (Z)-N-(4-(1-(2-(3-amino-4,5,6,7-tetrahydrobenzo[b] thiophene-2-carbonyl)hydrazono)-ethyl)phenyl)-4methylbenzenesulfonamide (9) To a solution mixture of compound 4b (0.5 g, 0,0013 mol), absolute ethanol (10 mL), triethylamine (5dps) and cyclohexanone (0.13 g, 0.0013 mol), elemental sulfur (0.032 g, 0.0013 mol) was added. The reaction mixture was heated under reflux for 2 h, then left to cool and poured onto ice/water. The solid obtained was recrystallized from dioxane to give 9. Yield, 56.45%; m.p. 110e112  C. IR (KBr, cm
1): 3390, 3319, 3222 (NH2, NH), 3058 (CH arom.), 2930, 2830 (CH aliph.), 1660 (C]O), 1580 (C]N), 1349, 1156 (SO2). H1NMR (DMSO-d6): 1.7, 2.7 [m, 8H,CH2 cyclohexane], 2.2 [s, 3H, CH3], 2.5 [s, 3H, CH3 tolyl], 7.2, 7.3 [2d, 4H, AreH AB system, J ¼ 6.9 Hz], 7.7, 7.8[2d, 4H, AreH AB system, J ¼ 7.7 Hz], 8.0 [s, 1H, SO2NH exchangeable with D2O], 10.4 [s, 2H, NH2 exchangeable with D2O], 10.8 [s, 1H, NH exchangeable with D2O]. C13NMR (DMSO-d6): 20.8, 23.4 (C-hexane), 24.9 (C-hexane), 26.7, 117.8, 127.1, 129.6, 129.8, 131.8, 134.5, 135.2 (O]CeCeS), 136.4, 137.1 (CeNH2), 142.2, 143.5, 143.6, 147.4 (CeS), 169.3 (C]O). MS m/z (%): 482 (Mþ) (1.34),

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185.20 (100). Anal. Calcd. For C24H26N4O3S2 (482): C, 59.73; H, 5.43; N, 11.61; Found: C, 59.55; H, 5.63; N, 11.58. 4.1.10. (Z)-N-(4-(1-((6-amino-3,5-dicyano-4-(4-methoxyphenyl)2-oxopyridin-1(2H)-yl)imino)-ethyl)phenyl)-4methylbenzenesulfonamide (11) Equimolecular mixture of 4b (0.5 g, 0.0013 mol) and 2-(4methoxybenzylidene) malononitrile 10 (0.18 g, 0.0013 mol) in dioxane (5 ml) containing piperidine (0.5 ml), was heated under reflux for 4 h, then left to cool and poured onto ice/water containing few drops of HCl and the formed solid product was recrystallized from 1,4-dioxane to give 11. Yield, 67.6%; m.p. 116e118  C. IR (KBr, cm
1): 3390, 3301, 3214 (NH2, NH), 3058 (CH arom.), 2925, 2830 (CH aliph.), 2208 (2C^N), 1678 (C]O), 1580 (C]N), 1349, 1156 (SO2). H1 NMR (DMSO-d6): 2.1 [s, 3H, CH3], 2.5 [s, 3H, CH3 tolyl], 3.8 [s, 3H, OCH3], 7.1, 7.2 [2d, 4H, AreH AB system, J ¼ 6.8 Hz], 7.3, 7.4 [2d, 4H, AreH AB system, J ¼ 7.4 Hz], 7.6, 7.9 [2d, 4H, AreH AB system, J ¼ 8.1 Hz], 8.0 [ s, 1H, SO2NH exchangeable with D2O], 10.9 [s, 2H, NH2 exchangeable with D2O]. C13NMR (DMSO-d6): 20.8, 26.2, 55.6 (OCH3), 71.7 (CeCN), 113.1(C-phenyl), 116.1, 116.1 (C^N), 118.1, 127.1, 129.1, 129.1, 130.1 (C-phenyl), 132.1, 136.1, 138.1 (C-phenyl), 142.2, 143.1, 148.1 (CeOCH3), 159.5 (CeNH2), 165.1 (C]O), 169.4. MS m/z (%): 551 (M
1) (0.89), 50.55 (100). Anal. Calcd. For C29H24N6O4S (552): C, 63.03; H, 4.38; N, 15.21; Found: C, 63.33; H, 4.55; N, 15.41. 4.1.11. (Z)-N-(4-(1-((6-amino-3,5-dicyano-4-(4-nitrophenyl)-2oxopyridin-1(2H)-yl)imino)-ethyl)phenyl)-4methylbenzenesulfonamide (13) Equimolecular mixture of 4b (0.5 g, 0.0013 mol) and 2-(4nitrobenzylidene) malononitrile 12 (0.199 g, 0.0013 mol) in dioxane (5 ml) containing piperidine (0.5 ml), was heated under reflux for 4 h, then left to cool and poured onto ice/water containing few drops of HCL and the formed solid product was recrystallized from dioxane to give 13. Yield, 45.20%; m.p. 143e145  C. IR (KBr, cm
1): 3394, 3344, 3216 (NH2, NH), 3058 (CH arom.), 2925, 2830 (CH aliph.), 2208 (2C^N), 1660 (C]O), 1580 (C]N), 1349, 1156 (SO2). H1 NMR (DMSO-d6): 2.1 [s, 3H, CH3], 2.5 [s, 3H, CH3 tolyl], 7.1, 7.2 [2d, 4H, AreH AB system, J ¼ 6.6 Hz], 7.3, 7.4 [2d, 4H, AreH AB system, J ¼ 6.9 Hz], 7.6, 7.9 [2d, 4H, AreH AB system, J ¼ 7.1 Hz], 8.5 [s, 1H, SO2NH exchangeable with D2O], 10.4 [s, 2H, NH2 exchangeable with D2O ]. C13NMR (DMSO-d6): 20.8, 26.2, 76.5 (CeC^N), 115.8 (C^N), 117.8, 123.8 (C- phenyl), 127.6, 129.6, 129.8, 130.1 (Cphenyl), 131.4, 136.4, 138.6 (C- phenyl), 142.62, 143.59, 143.6, 147.1 (CeNO2), 159.5 (CeNH2), 160 (C]O), 169.4. MS m/z (%): 565 (M
2) (o.54), 75 (100). Anal. Calcd. For C28H21N7O5S (567): C, 59.25; H, 3.73; N, 17.27; Found C, 59.55; H, 3.43; N, 17.52. 4.1.12. General procedure for preparation of compounds (14e19) To stirring solution of 3b [40] (0.3 g, 0.001038 mol) in ethanol (15 mL) containing KOH (1.2 g), aromatic benzaldheydes, namely 4methyl, 4- fluoro, 4-chloro, 4-nitro, and 4- bromobenzaldehyde (0.001 mol) were added, the reaction mixture was stirred at room temperature for 24 h. The precipitated solid was obtained by filtration and the products were recrystallized from dioxane to give 14e19, respectively. 4.1.12.1. (E)-N-(4-cinnamoylphenyl)-4-methylbenzenesulfonamide (14). Yield, 97.36%; m.p. >300  C. IR (KBr, cm
1): 3268 (NH), 3055 (CH arom.), 2921, 2851 (CH aliph.), 1669 (C]O), 1399, 1127 (SO2). H1NMR (DMSO-d6): 2.08 [s, 3H, CH3tolyl], 7.1, 7.3[2d, 4H, AreH AB system, J ¼ 6.3 Hz], 7.5 [d, 1H, CHCO, J ¼ 7.9 Hz], 7.5e7.8 [m, 5H, AreH], 8.0 [s, 1H, SO2NH exchangeable with D2O], 8.06 [d, 1H, HC] CH, J ¼ 12 Hz] 8.0, 8.3 [2d, 4H, AreH AB system, J ¼ 7.2 Hz]. C13NMR

689

(DMSO-d6): 20.8, 116.8, 121.3 (CHCO), 127.9, 128.0, 128.3, 128.5, 128.6, 129.3, 132.0, 135.2, 136.7, 137.6, 143.5, 145.1 (HC]CH), 185.6 (C]O). MS m/z (%): 377(Mþ) (0.28), 92.55(100). Anal. Calcd. For C22H19NO3S (377): C, 70.00; H, 5.07; N, 3.71. Found: C, 70.2; H, 5.27; N, 3.51. 4 .1.12 . 2 . ( E ) - N - ( 4 - ( 3 - ( p - t o l y l ) a c r y l o y l ) p h e n y l ) - 4 methylbenzenesulfonamide (15). Yield, 63.49%; m.p. 225e227  C. IR (KBr, cm
1): 3318 (NH), 3032 (CH arom.), 2920, 2857 (CH aliph.), 1680 (C]O), 1308, 1110 (SO2). H1NMR (DMSO-d6): 2.0 [s, 6H, CH3 tolyl, p-CH3], 7.1, 7.3 [2d, 4H, AreH AB system, J ¼ 6.3 Hz], 7.5 [d, 1H, CHCO, J ¼ 8.1 Hz], 7.9, 8.0 [ 2d, 4H, AreH AB system, J ¼ 7.1 Hz], 8.0 [s, 1H, SO2NH], 8.06 [d,1H, HC]CH, J ¼ 6.9 Hz], 8.2, 8.3 [2d,4H, AreH AB system, J ¼ 7.1 Hz]. C13NMR (DMSO-d6): 20.8 (2CH3), 118.9, 121.3 (CHCO), 127.9, 128.1, 128.2, 128.3, 129.3, 132.0, 132.2, 136.7, 137.6 (2Ce CH3), 143.5, 145.1 (HC]CH), 185.2 (C]O). MS m/z (%): 390 (M
1) (0.26), 120.40 (100). Anal. Calcd. For C23H21NO3S (391): C, 70.56; H, 5.41; N, 3.58. Found: C, 70.36; H, 5.31; N, 3.88. 4.1.12 .3. (E)-N- (4-(3-( 4- flu orop henyl) a cr yl oyl ) p henyl ) -4 methylbenzenesulfonamide (16). Yield, 97.6%; m.p. 208e210  C. IR (KBr, cm
1): 3377 (NH), 3199 (CH arom.), 2924, 2850 (CH aliph.), 1652 (C]O), 1305, 1125 (SO2). H1NMR (DMSO-d6): 2.0 [s, 3H, CH3tolyl], 7.1, 7.3 [2d, 4H, AreH AB system, J ¼ 6.3 Hz], 7.5 [d, 1H, CHCO, J ¼ 6.9 Hz], 7.9, 8.0 [2d,4H, AreH AB system, J ¼ 6.9 Hz ], 8.0 [s, 1H, SO2NH exchangeable with D2O], 8.06 [d,1H, HC]CH, 12 Hz], 8.2, 8.3 [2d,4H, AreH AB system, J ¼ 7.1 Hz]. C13NMR (DMSO-d6): 20.8 (CH3), 117.94, 118.9, 121.3 (CHCO), 126.7, 127.9, 129.3, 129.4, 129.9, 132.0, 136.4, 137.6, 143.6, 145.1 (HC]CH), 162.1 (CeF), 185.23 (C]O). MS m/z (%): 395 (Mþ) (3.09), 65.50 (100). Anal. Calcd. For C22H18FNO3S (395): C, 66.82; H, 4.59; N, 3.54. Found: C, 66.52; H, 4.89; N, 3.34. 4.1.12.4. (E) -N -(4-(3-(4-chlorophenyl)acryloyl)p henyl)-4methylbenzenesulfonamide (17). Yield, 98.20%; m.p. >300  C. IR (KBr, cm
1): 3364 (NH), 3038 (CH arom.), 2930, 2838 (CH aliph.), 1660 (C]O), 1315, 1134 (SO2), 750 (CeCl). H1NMR (DMSO-d6): 2.0 [s, 3H, CH3 tolyl], 7.1, 7.3 [2d, 4H, AreH AB system, J ¼ 6.3 Hz], 7.5 [d, 1H, CHCO, J ¼ 7.5 Hz], 7.9, 8.0 [2d, 4H, AreH AB system, J ¼ 7.1 Hz], 8.0 [s, 1H, SO2NH exchangeable with D2O], 8.06 [d, 1H, HC]CH, J ¼ 7.5 Hz], 8.2, 8.3 [2d, 4H, AreH AB system, J ¼ 7.1 Hz]. C13NMR (DMSO-d6): 20.8 (CH3), 118.9, 121.3 (CHCO), 127.9, 128.3, 128.7, 129.0, 129.3, 132.0, 133.3, 133.5 (CeCl), 136.7, 137.6, 143.5, 145.1 (HC]CH), 185.4 (C]O). MS m/z (%): 411 (Mþ) (0.44), 92.45 (100). Anal. Calcd. For C22H18ClNO3S (411): C, 64.15; H, 4.40; N, 3.40. Found: C, 64.35; H, 4.20; N, 3.70. 4 .1.12 . 5 . ( E ) - N - ( 4 - ( 3 - ( 4 - n i t r o p h e n yl ) a c r yl o yl ) p h e n yl ) - 4 methylbenzenesulfonamide (18). Yield, 46.13%; m.p. 245e247  C. IR (KBr, cm
1): 3361 (NH), 3091 (CH arom.), 2933, 2848 (CH aliph.), 1652 (C]O), 1320, 1125 (SO2). H1NMR (DMSO-d6): 2.0 [s, 3H, CH3 tolyl], 7.1, 7.3 [2d, 4H, AreH AB system, J ¼ 6.3 Hz], 7.8 [d, 1H, CHCO, J ¼ 7.8 Hz], 7.9, 8.0 [2d, 4H, AreH AB system, J ¼ 7.8 Hz], 8.0 [s, 1H, SO2NH exchangeable with D2O], 8.06 [d, 1H, HC]CH, J ¼ 7.5 Hz], 8.2, 8.3 [2d,4H, AreH AB system, J ¼ 7.8 Hz]. C13NMR (DMSO-d6): 20.8 (CH3), 119.2, 119.5 (CHCO), 123.5, 126.17, 128.3, 129.1, 129.5, 130.19, 136.7, 138.0, 139.0, 141.9, 143.8 (HC]CH), 147.5 (CeNO2), 185.2 (C]O). MS m/z (%): 422 (Mþ) (1.01), 58.60 (100). Anal. Calcd. For C22H18N2O5S (422): C, 62.55; H, 4.29; N, 6.63. Found: C, 62.45; H, 4.49; N, 6.83. 4.1.12.6. (E)-N-(4-(3-(4-bromophenyl)acryloyl)phenyl)-4methylbenzenesulfonamide (19). Yield, 85.52%; m.p. 107e109  C. IR (KBr, cm
1): 3360 (NH), 3095 (CH arom.), 2937, 2840 (CH aliph.), 1647 (C]O), 1350, 1134 (SO2). H1NMR (DMSO-d6): 2.0 [s, 3H, CH3

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tolyl], 7.1,7.3 [2d, 4H, AreH AB system, J ¼ 6.3 Hz], 7.5 [d, 1H, CHCO, J ¼ 7.1 Hz], 7.9, 8.0 [2d, 4H, AreH AB system, J ¼ 6.4 Hz], 8.0 [s, 1H, SO2NH exchangeable with D2O], 8.06 [d, 1H, HC]CH, J ¼ 7.5 Hz], 8.2, 8.3 [2d, 4H, AreH AB system, J ¼ 6.4 Hz]. C13NMR (DMSO-d6): 20.8 (CH3), 119.2, 119.5 (CHCO), 122.9 (CeBr), 126.1, 128.3, 128.5, 129.77, 130.8, 131.6, 134.5, 136.7, 139.0, 141.9, 143.8 (HC]CH), 185.6 (C]O). MS m/z (%): 455 (Mþ) (0.19), 51.10 (100). Anal. Calcd. For C22H18BrNO3S (455): C, 57.90; H, 3.98; N, 3.07. Found: C, 57.60; H, 4.10; N, 3.27. 4.1.13. N-(4-((1Z, 2E)-1-(hydroxyimino)-3-(4-nitrophenyl)allyl) phenyl)-4-methyl-benzene-sulfonamide (20) A mixture of compound 18 (0.3 g, 0.00073 mol), hydroxylamine (0.05 g, 0.00073 mol) and 1.2 g KOH in ethanol (15 ml) was refluxed for 10 h, then cold and poured onto ice/water and neutralized with dilute hydrochloric acid. The precipitated was filtered and recrystallized from ethanol to give 20. Yield, 63.76%; m.p. > 300  C. IR (KBr, cm
1): 3451 (OH), 3265 (NH), 3015 (CH arom.), 2926, 2829 (CH aliph.), 1350, 1115 (SO2). H1NMR (DMSO-d6): 2.0 [s, 3H, CH3 tolyl], 2.3 [s, 1H, OH exchangeable with D2O], 6.6 [d, 1H, CH]CH, J ¼ 6.4 Hz], 6.63 [d, 1H, CHeC6H4, J ¼ 6.9 Hz], 7.0, 7.1 [2d, 4H, AreH AB system, J ¼ 7.1 Hz], 7.3, 7.5 [2d, 4H, AreH AB system, J ¼ 6.0 Hz], 8.0, 8.2 [2d, 4H, AreH AB system, J ¼ 6.0 Hz], 8.5 [s, 1H, SO2NH exchangeable with D2O]. C13NMR (DMSO-d6): 20.8, 122.3, 123.8, 127.9, 128.0, 128.6, 129.5, 129.8, 131.2, 134.0, 135.5, 142.3, 142.5, 142.6, 147.1, 164.8 (C]N). MS m/z (%): 437 (Mþ) (20.23), 58.5 (100). Anal. Calcd. For C22H19N3O5S (437): C, 60.40; H, 4.38; N, 9.61. Found: C, 60.21; H, 4.54; N, 9.43. 4.1.14. N-(4-(5-(4-nitrophenyl)-1H-pyrazol-3-yl)phenyl)-4methylbenzenesulfonamide (21) A mixture of compound 18 (0.3 g, 0.000738 mol), hydrazine hydrate (0.036 g (0.034 ml), 0.000738 mol) and 1.2 g KOH in ethanol (15 mL) and 5 drops TEA was refluxed for 15 h, then left to cool and poured onto ice/water and neutralized with dilute hydrochloric acid. The precipitated was filtered and recrystallized from ethanol to give 21. Yield, 62.5%; m.p. > 300  C. IR (KBr, cm
1): 3343, 3249 (2NH), 3199 (CH arom.), 2918, 2830 (CH aliph.), 1336, 1120 (SO2). H1NMR (DMSO-d6): 2.0 [s, 3H, CH3 tolyl], 7.1, 7.3[2d, 4H, AreH AB system, J ¼ 6.0 Hz], 7.2 [s, 1H, CH-pyrazol], 7.6, 8.0 [2d, 4H, AreH AB system, J ¼ 6.0 Hz], 8.0 [s, 1H, SO2NH exchangeable with D2O], 8.2, 8.3 [2d, 4H, AreH AB system, J ¼ 6.0 Hz], 10.3 [s, 1H, NH exchangeable with D2O]. C13NMR (DMSO-d6): 20.8, 99.7 (CH pyrazol), 124.4, 126.2, 127.8, 128.3, 128.8, 129.3, 134.2, 136.2, 137.6, 139.1, 139.7, 147.1 (C]CeN), 147.7 (C]N pyrazol), 147.9. MS m/z (%): 434 (Mþ) (19.82), 58.4 (100). Anal. Calcd. For C22H18N4O4S (434): C, 60.82; H, 4.18; N, 12.90. Found: C, 61.01; H, 4.32; N, 12.74. 4.1.15. N-(4-(5-(4-nitrophenyl)-1-phenyl-1H-pyrazol-3-yl)phenyl)4-methylbenzenesulfonamide (22) A mixture of compound 18 (0.3 g, 0.000738 mol), phenyl hydrazine (0.078 g, ml, 0.000738 mol) and 1.2 g KOH in ethanol (15 mL) and 5 drops TEA was refluxed for 15 h, then left to cool and poured onto ice/water and neutralized with dilute hydrochloric acid. The precipitated was filtered and recrystallized from ethanol to give 22. Yield, 53.7%; m.p. >300  C. IR (KBr, cm
1): 3354 (NH), 3198 (CH arom.), 2939, 2829 (CH aliph.), 1340, 1120 (SO2). H1NMR (DMSO-d6): 2.0 [s, 3H, CH3 tolyl], 7.1, 7.3 [2d, 4H, AreH AB system, J ¼ 6.0 Hz], 7.2 [s, 1H, CH-pyrazol], 7.5, 7.6 [m, 5H, AreH], 7.6, 8.0 [2d, 4H, AreH AB system, J ¼ 6.0 Hz], 8.0 [s, 1H, SO2NH exchangeable with D2O], 8.2, 8.3 [2d, 4H, AreH AB system, J ¼ 6.0 Hz]. C13NMR (DMSO-d6): 20.0, 106.7 (CH-pyrazol), 123.7 (CH phenyl), 124.4, 126.2, 126.4 (CH phenyl), 126.5, 127.8, 128.7, 129.3 (CH phenyl), 129.5, 131.2, 134.2, 137.5, 139.1, 139.7, 139.9 (CH phenyl), 144.5 (C]CeN), 147.9, 153.4 (C]N pyrazol). MS m/z (%):

512 (M þ 2) (2.43), 438.70 (100). Anal. Calcd. For C28H22N4O4S (510): C, 65.87; H, 4.34; N, 10.97. Found: C, 65.64; H, 4.55; N, 11.30.

4.1.16. N-(4-(5-(4-nitrophenyl)-1-carbothioamide-1H-pyrazole-3yl)phenyl)-4-methyl-benzenesulfonamide (23) A mixture of compound 18 (0.3 g, 0.000738 mol), thiosemicarbazide (0.067 g, 0.000738 mol) and 1.2 g KOH in ethanol (15 mL) and 5 drops TEA was refluxed for 15 h, then left to cool and poured onto ice/water and neutralized with dilute hydrochloric acid. The precipitated was filtered and recrystallized from ethanol to give 23. Yield, 54.3%; m.p. >300  C. IR (KBr, cm
1): 3390, 3342, 3286 (NH2, NH), 3184 (CH arom.), 2935, 2830 (CH aliph.), 1310 (C] S), 1305, 1120 (SO2). H1NMR(DMSO-d6): 2.0 [s, 3H, CH3 tolyl], 2.08 [s, 2H, NH2 exchangeable with D2O], 7.1, 7.3 [2d, 4H, AreH AB system, J ¼ 6.0 Hz], 7.2 [s, 1H, CH-pyrazol], 7.6, 8.0 [2d, 4H, AreH AB system, J ¼ 6.0 Hz], 8.2, 8.3 [2d, 4H, AreH AB system, J ¼ 6.0 Hz ], 8.0 [s, 1H, SO2NH exchangeable with D2O]. C13NMR (DMSO-d6): 20.8, 103.5 (CH-pyrazole), 123.5, 125.9, 127.8, 128.2, 128.3, 129.3, 133.8, 136.2, 137.6, 139.7, 140.0, 144.8 (C]CeN), 147.9, 152.3 (C]N), 176.8 (C]S). MS m/z (%): 493(Mþ) (9.67), 260.05 (100). Anal. Calcd. For C23H19N5O4S2 (493): C, 55.97; H, 3.88; N, 14.19. Found: C, 55.74; H, 4.10; N, 14.34.

4.1.17. N-(4-(-5-(4-nitrophenyl)-1-hydrazinecarbonothioyl-1Hpyrazol-3-yl)phenyl)-4-methylbenzenesulfonamide (24) A mixture of compound 18 (0.5 g, 0.00123 mol), thiocarbohydrazide (0.13 g, 0.00123 mol) and 1.2 g KOH in ethanol (15 mL) and 5 drops TEA was refluxed for 15 h, then left to cool and poured onto ice/water and neutralized with dilute hydrochloric acid. The precipitated was filtered and recrystallized from ethanol to give 24. Yield, 56%; m.p. 163e165  C. IR (KBr, cm
1): 3398, 3305, 3213 (NH2, 2NH), 3060 (CH arom.), 2928, 2830 (CH aliph.), 1320 (C]S), 1305, 1150 (SO2). H1NMR (DMSO-d6): 2.0 [s, 3H, CH3 tolyl], 3.89 [s, 3H, NH2, NH exchangeable with D2O], 7.1, 7.3 [2d, 4H, AreH AB system, J ¼ 6.0 Hz], 7.6, 7.7 [2d, 4H, AreH AB system, J ¼ 6.0 Hz], 7.8 [s, 1H, CH-pyrazol], 7.8, 7.83 [2d, 4H, AreH AB system, J ¼ 6.0 Hz], 8.0 [s, 1H, SO2NH exchangeable with D2O]. C13NMR (DMSO-d6): 20.8, 104.5 (CH-pyrazol), 119.4, 125.0, 126.4, 127.8, 127.9, 129.6, 131.4, 134.5, 136.2, 139.2, 139.7, 144.3 (C]CeN), 147.6, 152.3 (C]N), 174.9 (C]S). MS m/z (%): 508(Mþ) (19.24), 58.26 (100). Anal. Calcd. For C23H20N6O4S2 (508): C, 54.32; H, 3.96; N, 16.52. Found: C, 54.53; H, 4.20; N, 16.32.

4.1.18. N-(4-(6-(4-nitrophenyl)-2-oxo-1,2-dihydropyrimidin-4-yl) phenyl)-4-methyl-benzenesulfonamide (25) A mixture of compound 18 (0.3 g, 0.000738 mol), urea (0.044 g, 0.000738 mol) and 1.2 g KOH in ethanol (15 ml) and 5 drops TEA was refluxed for 9 h, then left to cool and poured onto ice/water and neutralized with dilute hydrochloric acid. The precipitated was filtered and recrystallized from ethanol to give 25. Yield, 54.5%; m.p. 167e169  C. IR (KBr, cm
1): 3382, 3217 (2NH), 3015 (CH arom.), 2919, 2825 (CH aliph.), 1669 (C]O), 1310, 1150 (SO2). H1NMR (DMSO-d6): 2.0 [s, 3H, CH3 tolyl], 6.0 [s, 1H, CHpyrimidine], 6.9, 7.0 [2d, 4H, AreH AB system, J ¼ 6.8 Hz], 8.0 [s, 1H, SO2NH exchangeable with D2O], 8.0, 8.1[2d, 4H, AreH AB system, J ¼ 6.3 Hz], 8.2, 8.3[2d, 4H, AreH AB system, J ¼ 7.2 Hz], 8.5 [s, 1H, NH exchangeable with D2O]. C13NMR (DMSO-d6): 20.8, 106.6 (CH-pyrimidine), 113.5, 117.9, 121.7, 126.7, 128.3, 129.3, 133.9, 136.4, 136.7, 137.6, 137.8, 147.1 (CeNO2), 156.3 (C]O), 163.3 (C]CeNH), 164.6 (C]N). MS m/z (%): 461 (M
1) (0.57), 91.05 (100). Anal. Calcd. For C23H18N4O5S (462): C, 59.73; H, 3.92; N, 12.11. Found: C, 59.55; H, 3.74; N, 12.34.

M.M. Ghorab et al. / European Journal of Medicinal Chemistry 92 (2015) 682e692

4.1.19. N-(4-(6-(4-nitrophenyl)-2-thioxo-1,2-dihydropyrimidin-4yl)phenyl)-4-metyhyl-benzenesulfonamide (26) A mixture of compound 18 (0.3 g, 0.000738 mol), thiourea (0.056 g, 0.000738 mol) and 1.2 g KOH in ethanol (15 ml) and 5 drops TEA was refluxed for 15 h, then left to cool and poured onto ice/water and neutralized with dilute hydrochloric acid. The precipitated was filtered and recrystallized from ethanol to give 26. Yield, 31.25%; m.p. 180e182  C. IR (KBr, cm
1): 3383, 3217 (2NH), 3128 (CH arom.), 2919, 2830 (CH aliph.), 1300 (C]S), 1320, 1115 (SO2). H1NMR (DMSO-d6): 2.0 [s, 3H, CH3 tolyl], 6.7 [s, 1H, CHpyrimidine], 6.9, 7.0 [2d, 4H, AreH AB system, J ¼ 7.5 Hz], 8.0 [s, 1H, SO2NH exchangeable with D2O], 8.0, 8.1 [2d, 4H, AreH AB system, J ¼ 7.5 Hz], 8.2, 8.3 [2d, 4H, AreH AB system, J ¼ 7.3 Hz], 13.7 [s, 1H, NH exchangeable with D2O]. C13NMR (DMSO-d6): 20.8, 104.3 (CH-pyrimidine), 117.9, 123.3, 126.5, 126.7, 129.5, 129.8, 131.8, 134.8, 136.3, 136.3, 142.2, 143.6, 165.3 (C]N pyrimidine), 176.4 (C] CeNH), 180.4 (C]S). MS m/z (%): 479 (M þ 1) (7.34), 60.75 (100). Anal. Calcd. For C23H18N4O4S2 (478): C, 57.73; H, 3.79; N, 11.71. Found: C, 57.53; H, 3.94; N, 11.54. 4.2. In-vitro anticancer evaluation against human tumor liver cancer (HEPG2) The in-vitro anticancer activity was measured for twenty six new compounds on liver human tumor cell line (HEPG2) using the Sulfo-Rhodamine-B stain (SRB) assay. The in-vitro anticancer screening was done by the pharmacology unit at the National Cancer Institute, Cairo University. The sulfo-rhodamine B (SRB) assay which was developed in 1990 [50], remains one of the most widely used methods for invitro cytotoxic screening. The assay relies on the ability of SRB to bind to protein components of cells that have been fixed to tissueculture plates by trichloroacetic acid (TCA). SRB is a bright-pink aminoxanthene dye with two sulfonic groups that bind to basic amino-acid residues under mild acidic conditions, and dissociate under basic conditions. The amount of dye extracted from stained cells is directly proportional to the cell mass [51]. Cells were plated in 96-multiwell plate (104 cells/well) for 24 h before treatment with the compounds to allow attachment of cell to the wall of the plate. Test compounds were dissolved in dimethylsulfoxide (DMSO) and diluted with saline to the appropriate volume. Different concentrations of the compounds under test (5, 12.5, 25 and 50 mM) were added to the cell monolayer. Triplicate wells were prepared for each individual dose. Monolayer cells were incubated with the compounds for 48 h at 37  C and in atmosphere of 5% CO2. After 48 h, cells were fixed, washed and stained for 30 min with 0.4% (wt/ vol) SRB dissolved in 1% acetic acid. Unbounded dye was removed by four washes with 1% acetic acid, and attached stain was recovered with TriseEDTA buffer. Color intensity was measured in an enzyme linked immunosorbent assay (ELISA) reader (Microplate reader; Sunostik; SPR-960B; China). The relation between surviving fraction and drug concentration is plotted to get the survival curve of each tumor cell line after the specified time. The concentration required for 50% inhibition of cell viability (IC50) was calculated and compared with the reference drug doxorubicin and the results are given in Table 1. Doxorubicin (CAS, 25316e40-9), the reference drug used in this study is a drug used in cancer chemotherapy. It is an anthracycline antibiotic, it works by intercalating DNA and inhibition of macromolecular biosynthesis. This inhibits the progression of the enzyme topoisomerase II, which relaxes supercoils in DNA for transcription. Doxorubicin stabilizes the topoisomerase II complex after it has broken the DNA chain for replication, preventing the DNA double helix from being resealed and thereby stopping the process of replication. It is commonly used in the treatment of a wide range of

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cancers as in acute leukemia's Hodgkin's disease, and other lymphomas and cancers of the breast, adrenal cortex, endometrium, lung, ovary, and other sites [52]. 4.3. Radisensitizing evaluation Irradiation was performed in the National Center for Radiation Research and Technology, Atomic Energy Authority, using Gamma cell-40 (137Cs) source. The most active compounds 5a, 6a, 6b, 8, 9, 13, 18 and 19 were selected to be reevaluated for their in-vitro cytotoxic activity in combination with g-irradiation. Cells were plated in 96-multiwell plate (104cells/well) for 24 h before g-irradiation with a single dose of 8 Gy. Cells were incubated for 48 h at 37  C in atmosphere of 5% CO2. After 48 h, cells were fixed, washed and stained with 0.4% (wt/vol) SRB dissolved in 1% acetic acid, for 30 min. Excess unbound dye was removed by four washes with 1% acetic acid and attached stain was recovered with TriseEDTA buffer. Color intensity was measured in an ELISA reader (Microplate reader; Sunostik; SPR-960B; China) at a wave length of 570 nm. In another multiwell plate, cells were incubated with the previously mentioned selected compounds; compounds 5a, 6a, 6b, 8, 9, 13, 18, and 19 in molar concentrations of 5, 12.5, 25, 50 mM. After 2 h, cells were subjected to a single dose of g-radiation at a dose level of 8 Gy with a dose rate of 0.758 rad/sec for 17.73 min, and then the cytotoxicity was measured 48 h, after irradiation. The surviving fractions were measured using the above mentioned procedures by ELISA reader. The surviving fractions were expressed as mean values ± standard error. The results were analyzed using 1-way ANOVA test and given in Table 2. Appendix A. Supplementary data Supplementary data related to this article can be found at http:// dx.doi.org/10.1016/j.ejmech.2015.01.036. References [1] S.P. Dourakis, New developments in systemic therapy for hepatocellular carcinoma, Curr. Canc. Ther. Rev. 4 (2008) 219e226. [2] L.C. Chiang, L.T. Ng, I.C. Lin, P.L. Kuo, C.C. Lin, Anti-proliferative effect of apigenin and its apoptotic induction in human Hep G2 cells, Cancer Lett. 37 (2006) 207e214. [3] J. Niklas, F. Noor, E. Heinzle, Effects of drugs in subtoxic concentrations on the metabolic fluxes in human hepatoma cell line Hep G2, Toxicol. Appl. Pharmacol. 240 (2009) 327e336. [4] J. Drews, Drug discovery: a historical perspective, Science 287 (2000) 1960e1964. [5] C.T. Supuran, A. Casini, A. Mastrolorenzo, A. Scozzafava, COX-2 selective inhibitors, carbonic anhydrase inhibition and anticancer properties of sulfonamides belonging to this class of pharmacological agents, Mini-Rev. Med. Chem. 4 (2004) 625e632. [6] F. Abbate, A. Casini, T. Owa, A. Scozzafava, C.T. Supuran, Carbonic anhydrase inhibitors: E7070, a sulfonamide anticancer agent, potently inhibits cytosolic isozymes I and II, and transmembrane, tumor-associated isozyme IX, Bioorg. Med. Chem. Lett. 14 (2004) 217e223. [7] M.M. Ghorab, M.S. Alsaid, M. Ceruso, Y.M. Nissan, C.T. Supuran, Carbonic anhydrase inhibitors: synthesis, molecular docking, cytotoxic and inhibition of the human carbonic anhydrase isoforms I, II, IX, XII with novel benzenesulfonamides incorporating pyrrole, pyrrolopyrimidine and fused pyrrolopyrimidine moieties, Bioorg. Med. Chem. 14 (2014) 3684e3695. [8] M.M. Ghorab, M.G. El-Gazzar, M.S. Alsaid, Synthesis and anti-breast cancer evaluation of novel N-(guanidinyl) benzenesulfonamides, Int. J. Mol. Sci. 4 (2014) 5582e5595. [9] M.S. Bashandy, M.S. Alsaid, R.K. Arafa, M.M. Ghorab, Design, synthesis and molecular docking of novel N,N-dimethylbenzenesulfonamide derivatives as potential antiproliferative agents, J. Enzym Inhib. Med. Chem. 5 (2014) 619e627. [10] M.M. Ghorab, M. Ceruso, M.S. Alsaid, Y.M. Nissan, R.K. Arafa, C.T. Supuran, Novel sulfonamides bearing pyrrole and pyrrolopyrimidine moieties as carbonic anhydrase inhibitors: synthesis, cytotoxic activity and molecular modeling, Eur. J. Med. Chem. 87 (2014) 186e196. [11] M.M. Ghorab, F.A. Ragab, H.I. Heiba, M.G. El-Gazzar, M.G. El-Gazzar, Synthesis, in-vitro anticancer screening and radiosensitizing evaluation of some new N-

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