CHAPTER 5 Synthesis characterization and pharmacological activity of Nimesulide based sulphonamides

Transcription

1 264 Chapter - 5 CHAPTER 5 Synthesis characterization and pharmacological activity of Nimesulide based sulphonamides

2 265 Chapter Synthesis, Characterization and pharmacological activity of Nimesulide based sulphonamides 5.1 Introduction Sulfonamides play a versatile role in many medicinal chemistry analogue programs, these are a very important class of compounds in the pharmaceutical industry, being widely used anticancer, anti- inflammatory and antiviral agents. rganic sulfur compounds are widespread in numerous natural products and widely used as various artificial chemicals. Not only the medicinal importance the sulfonamides like Naphtholic naphthalene sulfonate containing sulfonamide group and its derivatives can be used to synthesize universal dyes, acid dyes, and cationic dyes. There is an urgent need for processes involved in structural modifications of lead compounds that enhance pharmacological activity, improve pharmacokinetic properties, or reduce unwanted side effects in the field of drug discovery. Epidemiological and animal model studies have suggested that nonsteroidal anti-inflammatory drugs (NSAIDs) can act as chemopreventive agents. A growing body of experimental and epidemiological evidence suggests that the use of NSAIDs (non-steroidal anti-inflammatory drugs) may decrease the incidence of mammary cancer, tumor burden, and tumor volume.

3 266 Chapter - 5 Celecoxib, a CX-2 (cyclooxygenase 2) selective inhibitor, shows strong chemopreventive activity against mammary carcinoma in rats in some studies. 1 In addition to CX inhibition, these small molecules could target other molecular pathways. The CX-2 inhibitor nimesulide is able to suppress the development of 2-amino-1-methyl-6-phenylimidazo [4,5- b]pyridine (PhIP)-induced mammary gland carcinogenesis in rats. Researchers proved that nimesulide also suppresses aromatase activity and expression in several breast cancer cell lines In brief, CX- 2 inhibitors benefit breast cancer patients in several ways. Firstly, they decrease PGE2 production which subsequently promotes tumor invasiveness, angiogenesis, and progression. Secondly, they inhibit some kinases which are related with tumor growth. Thirdly, they decrease aromatase activity which is the key enzyme for the biosynthesis of estrogen. The cyclooxygenase-2 (CX-2) inhibitor nimesulide shows anticancer effects in several cancer cell lines via CX-2-dependent and -

4 267 Chapter - 5 independent mechanisms. The molecular structure of nimesulide was used as a starting scaffold to design novel sulfonanilide analogs and examine the structural features that contribute to this anticancer effect. 2 ther research demonstrated that nimesulide also suppressed aromatase activity and expression in several breast cancer cell lines. Nimesulide derivatives which do not have CX-2 inhibitory activity were more active than nimesulide to target aromatase. Further study reveals that several nimesulide analogs were able to selectively inhibit Her2 overexpressing breast cancer cell proliferation, which suggests that they are potentially able to overcome AI resistant breast cancer cell growth. Because of the unique character of nimesulide derivatives, we propose that the modification of the structure might change the drug from a CX-2 inhibitor to an anti-cancer agent. Garcinol (camboginol) from the fruit rind of Guttiferae species shows anti-carcinogenic and anti-inflammatory properties.

5 268 Chapter - 5 Garcinol potently interferes with 5-lipoxygenase and microsomal prostaglandin (PG) E2synthase enzymes that play pivotal roles in inflammation and tumorigenesis. In cell-free assays, garcinol inhibited the activity of purified 5- lipoxygenase and blocked the mpges-1-mediated conversion of PGH2 to PGE2 with IC50 values of 0.1 and 0.3 μm respectively. Garcinol suppressed 5-lipoxygenase product formation also in intact human neutrophils and reduced PGE2 formation in interleukin-1β-stimulated A549 human lung carcinoma cells as well as in human whole blood stimulated by lipopolysaccharide. In contrast, neither Ca 2+ -ionophore (A23187)-induced arachidonic acid release in neutrophils nor CX-2 activity in A549 cells or whole blood measured as formation of 6-keto PGF1α, or isolated human recombinant CX-2 were significantly affected by garcinol ( 30 μm). Together the high potency of garcinol to selectively suppress PGE2 synthesis and 5-lipoxygenase product formation provides a molecular basis for the anti-inflammatory and anti-carcinogenic effects of garcinol and rationalizes its therapeutic use (Figure 5.1).

6 269 Chapter - 5 Figure 5.1 Mechanism of anti-inflammatory and anti-carcenogenic activity of gercinol Arachidonic Acid CX-1 CX-2 5-Lipoxygenase PGI 2 Synthase PGH 2 Gercinol LTA 4 mpges-1 6-Keto PGF 1 PGI 2 PGE 2 Leukotrienes Nimesulide, a preferential CX-2 inhibitor is a non-carboxylic acid nonsteroidal anti-inflammatory drug (NSAID) that has been in patient s use for the treatment of pain for more than 20 years. 1 Derivatives of nimesulide have shown antiviral, anticancer 2 and CX-2 inhibiting 3 properties. We anticipated that combination of structural features of these NSAIDs nimesulide (2) with substituted sulfonyl chlorides in a single molecule would provide novel agents possessing potent pharmacological activities. Herein we report the synthesis, structure analysis and in vitro pharmacological evaluation of a series of hybrid molecules based on sulfonamides.

7 270 Chapter - 5 Figure 5.2 Design of novel molecules based on nimesulide and sulfonyl Chlorides ArS 2 Cl N 2 NHS 2 Ar 2 A Pharmacologically active derivatives of Nimesulide Renard and his team reported 4 the synthesis and the pharmacological evaluation of pyridine analogues of nimesulide, a CX-2 preferential inhibitor. The cyclooxygenases inhibitory activities were evaluated in vitro using a human whole blood mode. According to the in vitro results, a selection of compounds exhibiting moderate to high CX- 2/CX-1 selectivity ratio were further evaluated in vivo in a moderate of λ carrageenan-induced pleurisy in rats. Some of the selected compounds (3) displayed similar or improved anti-inflammatory properties when compared to nimesulide and celecoxib. R S NH X N R = CH 3, CF 3 X =, S, NH 3

8 271 Chapter - 5 Kavitha and his team have described a simple and rapid synthesis 5 of novel cyclic substituted imides (4) from nimesulide. The aromatic amine prepared from nimesulide was reacted with a variety of cyclic anhydrides in the presence of sodium acetate to afford the desired products. Some of the compounds synthesized showed anti-inflammatory activity when tested in rats. N 4 Pyridinic analogues 6 of nimesulide were given by Julemont and his team. Compound 4, N-(3-phenoxy-4-pyridinyl)trifluoromethane sulfonamide, showed in vitro a strong inhibitory activity on the two cyclooxygenase enzymes, being more active but less CX-2 selective than nimesulide. Physicochemical studies and structural analyses indicated that the anionic sulfonamide species seemed to be the active form of methanesulfonamides, which optimally interacted with CX enzymes active sites.

9 272 Chapter - 5 NHS 2 CF 3 N 5 A series of CX-2 selective inhibitor nimesulide derivatives were synthesized. 7 Their anti-cell proliferation activities were evaluated with a long term estrogen deprived MCF-7aro (LTEDaro) breast cancer cell line, which is the biological model of aromatase inhibitor resistance for hormone dependent breast cancer. Compared to nimesulide which inhibited LTEDaro cell proliferation with an IC50 at μM, several new compounds showed IC50 close to 1.0 μm. The results suggest that A position as 2, 5 dimethyl or dichloro benzyl is the best fit. R 2 H N N S R1 6 Julemont and his team has synthesized the pyridinic analogues of nimesulide 8 based on their major ionic state at the physiological ph of 7.4 the alkane sulfonamides 7 and the anionic trifluoromethane sulfonamides 8 compounds. Pharmacological evaluation in vitro showed

10 273 Chapter - 5 that pyridinium compounds are generally more selective toward CX-2 when compared to their pyridinic analogues. Compound (8) displayed a better CX-2 selectivity when compared to nimesulide. Compound () showed a similar in vivo profile as nimesulide when tested in the rat aw odema. CH 3 2 S NH Cl 2 S CF 3 NH H N N N 7 8 Synthesis of a series of compounds 9 structurally related to the anti-inflammatory agent nimesulide has been accomplished via Pdcatalyzed C C bond forming reactions. Thus 4-iodo derivative, prepared from nimesulide, participated in Sonogashira (9), Heck (10) and Suzuki (11) coupling reactions to afford the corresponding alkynyl, alkenyl and aryl substituted products. Some of the compounds synthesized were tested for anti-inflammatory activities in vivo. NHCCH 3 NHCCH 3 NHCCH 3 R R = C(CH 3 ) 2 H, CH 2 (CH 2 ) 4 CH 3 C(CH 3 ) 3 R' R' = C 2 CH 3 C 2 C 2 H 5 C 2 nbu C 2 H 5 CN R'' R'' = CH 3 CH 2 H F

11 274 Chapter Present work We report the synthesis of benzene sulfonamides as hybrid molecules derived from nimesulide by straight forward sulfonylation of the key intermediate nimesulide based N-(4-Amino-2-phenoxy-phenyl)- methane sulfonamide with an appropriate and commercially available sulfonyl chlorides. Thus reduction of 2 with Sn/HCl 10 followed by the treatment of 12 with sulfonyl chlorides 13 in the presence of chloroform gave the compound 14a-d (Scheme 1). Scheme 1 Sn/HCl ArS 2 Cl (13) N 2 NH 2 HN S 2 Ar a-d

12 275 Chapter - 5 Table 5.1 Comparison of Time and Yield of products 14a-d Sl. No. ArS2Cl (13) Product (14) Time & Yield (%) 1. Cl S 13a CH 3 HN S CH 3 9 h / 48 14a 2. Cl S NHCCH 3 HN S 8 h / 51 13b 14b NHCCH 3 3. Cl S 13c Cl HN S Cl 14 h / 31 14c 4. Cl S H 3 C 13d CH 3 HN S H 3 C CH 3 14 h / 32 14d

13 276 Chapter - 5 All the compounds were characterized by spectral analysis IR, MASS, and 1 HNMR. Structure of the compound was characterized by X- ray analysis and was found to be in the form of a monomer. Figure 5.3 RTEP view of compound N-[4-(4-methanesulfonylamino-3- phenoxy phenylsulfamoyl)-phenyl]-acetamide (14b)

14 277 Chapter Conclusion In conclusion, reduction of nimesulide (2) followed by treating the N-(4-Amino-2-phenoxy-phenyl)-methane sulfonamide (12) with different sulfonyl chlorides (13a-d) provided novel benzene sulfonamide derivatives. But unfortunately we were able to synthesize very few compounds 14a-d, because of various drawbacks such as long reaction time, tedious manipulations in the isolation of the pure products, and very less yield. Many trials were made by changing the solvent, reaction conditions, and the reagent, but we were not successful in preparing these sulfonamides in good yield. 5.4 Experimental section General procedure for the preparation of benzene sulfonamides N-(4-amino-2-phenoxy phenyl)methanesulfonamide (12, 1 g, 3.56 mmol) was dissolved in dry chloroform and triethylamine (0.6 ml) was added to it. The solution was cooled to 0ºC and benzene sulfonyl chloride (13, 3.56 mmol) was added drop wise with stirring. The reaction mixture was then stirred at room temperature for the time given in Table 5.1, poured into water (20 ml) and extracted with chloroform (3 25 ml). rganic layers were collected, combined, washed with 10% HCl (10 ml) followed by water (2 10 ml), dried over anhydrous Na2S4 and concentrated.

15 278 Chapter - 5 The residue was purified by re-crystallization from chloroform ethyl acetate mixture. Preparation of N-(4-methanesulfonylamino-3-phenoxy-phenyl)-4- methyl-benzenesulfonamide (14a): HN S CH 3 This compound was prepared according to the general procedure using N-(4-amino-2-phenoxy phenyl)methanesulfonamide (12, 1 g, mol), benzene sulfonyl chloride (13a, 0.52 g, mol), triethylamine (1.0 ml, mol) and solvent (15 ml) as described in general procedure to give 48% of the product as white solid; mp 142 ºC; IR (KBr cm -1 ): 3331, 3230, 1659, 1590; MS (ES): m/z 433 (M+, 100%); 1 H NMR (200 MHz, DMS-d6) δ 10. 2(s, 1H), 9.2 (s, 1H), (m, 12H), 2.9 (s, 3H), 2.3 (s, 3H); Molecular formula: C20H20N25S2.

16 279 Chapter - 5 Synthesis of N-[4-(4-methanesulfonylamino-3-phenoxy phenylsulfamoyl)-phenyl]-acetamide (14b): HN S NHCCH 3 This compound was prepared according to the general procedure using N-(4-amino-2-phenoxy phenyl)methanesulfonamide (12, 1 g, mol), 4-Acetylamino-benzene sulfonyl chloride (13b, g, mol), triethylamine (1.0 ml, mol) and solvent (15 ml) as described in general procedure to give 51% of the product as white solid; mp 186 ºC; IR (KBr cm -1 ): 3231, 3315, 1658, 1604; MS (ES): m/z 476 (M+, 100%); 1 HNMR (200 MHz, DMS-d6): δ 9.87 (s, 1H), 9.77 (s, 1H), 8.17 (s, 1H), (m, 12H), 2.16 (s, 3H), 2.89 (s, 3H), 9.77 (s, 1H), Molecular formula: C21H21N36S2. Synthesis of 4-Chloro-N-(4-methanesulfonylamino-3-phenoxyphenyl)-benzenesulfonamide (14c): HN S Cl

17 280 Chapter - 5 This compound was prepared according to the general procedure using N-(4-amino-2-phenoxy phenyl)methanesulfonamide (12, 1 g, mol), 4-chloro-benzene sulfonyl chloride (13c, 0.62 g, mol), triethylamine (1.0 ml, mol) and solvent (15 ml) as described in general procedure to give 31% of the product as off white solid; mp: C; IR (KBr cm -1 ): 3386, 3318, 1692, 1590, 1090; MS (ES) m/z: 453 (M +, 100%), 1 HNMR (400 MHz, DMS-d6): δ 9.71 (bs, 1H, NH, D2 exchangeable), 7.78 (m, 6H, ArH), 7.55 (d, 1H, J=12Hz), 7.44 (t, 2H, J=12Hz), 7.23 (t, 1H, J=12Hz), 6.97 (d, 2H, J=12Hz), 6.12 (bs, 1H, NH, D2 exchangeable), 2.01 (s, 3H); Molecular formula: C19H17ClN25S2. Synthesis of N-(4-methanesulfonylamino-3-phenoxy-phenyl)-2,4- dimethyl-benzenesulfonamide (14d): HN S H 3 C CH 3 This compound was prepared according to the general procedure using N-(4-amino-2-phenoxy phenyl)methanesulfonamide (12, 1 g, mol), 3,5-Dimethyl-benzene sulfonyl chloride (13d, 0.61 g, mol), triethylamine (1.0 ml, mol) and solvent (15 ml) as described in general procedure to give 32% of the product as white solid; mp: 164-

18 281 Chapter C; IR (KBr cm -1 ): 3378, 3326, 1653, 1590; MS (ES) m/z: 447 (M +, 100%), 1 HNMR (400 MHz, DMS-d6): δ (bs, 1H, NH, D2 exchangeable), 9.21 (bs, 1H, NH, D2 exchangeable), 8.19 (s, 1H), 7.42 (m, 3H), (M, 3H), (m, 2H), 6.54 (s, 1H), 6.52 (m, 1H), 2.91 (s, 3H), 2.45 (s, 6H); Molecular formula: C21H22N25S2.

19 282 Chapter References 1. L. J. Roberts, J. D. Morrow, J. G. Hardman, L. E. eds. Limbird. 2001, 687. McGraw-Hill, New York. 2. S. Karakuş, S. G. Küçükgüzel, I. Küçükgüzel, E. D. Clercq, C. Pannecouque, G Andrei, R. Snoeck, F. Şahin,. F. Bayrak, Eur. J. Med. Chem. 2009, 44, C. Michaux, C. Charlier, F. Julémont, Leval, X. de Leval, JM. Dogné, B. Pirotte, F. Durant, Eur. J. Med. Chem. 2005, 40, R. Jean-Francois, A. Deniz, G. Nancy, B. Pirotte, X. de Levalt. J. Med. Chem. 2009, 52, K.Kavitha, V. R. Reddy, K. MukkantI, S. Pal. J. Braz. Chem. Soc. 2010, 21, 6, F. Julemont, X. de Leval, C. Michaux, J. Damas, C. Charlier, F. Durant, B. Pirotte, J. M. Dogne. J. Med. Chem. 2002, 45, Bin Su, Shiuan Chen. Bioorg. Med. Chem. Lett. 2009, 19(23): F. Julemont, X. de Leval, C. Michaux, R. Jean-Francüois, W. Jean- Yves, M. Jean-Louis, J. Damas, D. Jean-Michel, B. Pirotte. J. Med. Chem. 2004, 47,

20 283 Chapter D. Shylaprasad, C. Vijay kumar, K. Mukkanti, S. Pal. Appl. rganometal. Chem. 2010, 24, S. Pericherla, J. Mareddy, R.D. P. Geetha, P. V. Gollapudi, S. Pal, J. Braz. Chem Soc. 2007, 18, 384.

21 284 Chapter Some important spectra of the compounds Figure HNMR spectrum of N-(4-methanesulfonylamino-3-phenoxy- phenyl)-4-methyl-benzenesulfonamide (14a) HN S CH 3 Figure CNMR spectrum of N-(4-methanesulfonylamino-3-phenoxy- phenyl)-4-methyl-benzenesulfonamide (14a) HN S CH 3

22 285 Chapter - 5 Figure 5.6 Mass spectrum of N-(4-methanesulfonylamino-3-phenoxy-phenyl)- 4-methyl-benzenesulfonamide (14a) HN S CH 3 Figure 5.7 IR spectrum of N-(4-methanesulfonylamino-3-phenoxy-phenyl)-4- methyl-benzenesulfonamide (14a) HN S CH 3

23 286 Chapter - 5 Figure HNMR spectrum of N-[4-(4-methanesulfonylamino-3-phenoxy phenylsulfamoyl) -phenyl]-acetamide (14b) HN S NHCCH 3