CHEMMEDCHEM FULL PAPERS DOI: 10.1002/cmdc.201402320
From Antidiabetic to Antifungal: Discovery of Highly Potent Triazole–Thiazolidinedione Hybrids as Novel Antifungal Agents Shanchao Wu, Yongqiang Zhang, Xiaomeng He, Xiaoying Che, Shengzheng Wang, Yang Liu, Yan Jiang, Na Liu, Guoqiang Dong, Jianzhong Yao, Zhenyuan Miao, Yan Wang, Wannian Zhang,* and Chunquan Sheng*[a] In an attempt to discover a new generation of triazole antifungal agents, a series of triazole–thiazolidinedione hybrids were designed and synthesized by molecular hybridization of the antifungal agent fluconazole and rosiglitazone (an antidiabetic). Most of the target compounds showed good to excellent inhibitory activity against a variety of clinically important fungal pathogens. In particular, compounds (Z)-5-(2,4-dichlorobenzylidene)-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione) (15 c), (Z)-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(furan3-ylmethylene)thiazolidine-2,4-dione (15 j), and (Z)-3-(2-(2,4-di-
fluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(furan3-ylmethylene)thiazolidine-2,4-dione (15 r) were highly active against Candida albicans, with MIC80 values in the range of 0.03–0.15 mm. Moreover, compounds 15 j and 15 r were found to be effective against four fluconazole-resistant clinical isolates; these two compounds are particularly promising antifungal leads for further optimization. Molecular docking studies revealed that the hydrogen bonding interactions between thiazolidinedione and CYP51 from C. albicans are important for antifungal activity. This study also demonstrates the effectiveness of molecular hybridization in antifungal drug discovery.
Introduction The worldwide incidence of invasive fungal infections (IFIs) has been increasing over the past few decades.[1] Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus are the most common fungal pathogens in humans which are associated with high mortality (20–90 %) among immunocompromised populations.[2] In particular, Candida species are currently the most common fungal pathogens for humans and are the fourth leading cause of nosocomial bloodstream infections in the United States.[3] Clinically available drugs for IFIs are represented principally by four classes of compounds: polyenes (e.g., amphotericin B), triazoles (e.g., fluconazole and voriconazole, Figure 1), echinocandins (e.g., caspofungin, micafungin, and anidulafungin), and fluorinated pyrimidines (e.g., 5-fluorocytosine).[4] Among them, triazole antifungal agents have emerged as the first-line drugs for the treatment and prophylaxis of many kinds of IFIs.[5] Despite the clinical success of triazole antifungals, they still suffer from several limitations. First, broad use of triazoles has led to severe drug resistance, which has significantly decreased their clinical efficacy.[6] Second, the antifungal spectrum and therapeutic window for triazoles are [a] S. Wu,+ Y. Zhang,+ X. He,+ Dr. X. Che, Dr. S. Wang, Y. Liu, Y. Jiang, N. Liu, Dr. G. Dong, Prof. J. Yao, Prof. Z. Miao, Prof. Y. Wang, Prof. W. Zhang, Prof. C. Sheng School of Pharmacy, Second Military Medical University 325 Guohe Road, Shanghai 200433 (China) E-mail: [email protected] [email protected]
relatively narrow. Third, triazoles generally have drug-related side effects such as hepatic and renal toxicity. Therefore, it highly desirable to develop a new generation of triazole antifungal agents with improved pharmacological, pharmacokinetic, and safety profiles. New antifungal triazoles are emerging rapidly,[7] and two candidates (isavuconazole and albaconazole, Figure 1) are under late-stage clinical trials.[8] Triazole antifungals are inhibitors of lanosterol 14a-demethylase (CYP51). CYP51 catalyzes the synthesis of ergosterol from lanosterol in the fungal cell membrane. Inhibition of CYP51 causes depletion of ergosterol, accumulation of methylsterols within the cell membrane, and finally results in the inhibition of fungal cell growth or leads to cell death.[9] Despite the importance of CYP51 in antifungal drug discovery, crystal structures of CYP51s from pathogenic fungi have yet to be reported. Previously, we constructed three-dimensional models of CYP51 from Candida albicans (CACYP51), Cryptococcus neoformans (CNCYP51), and Aspergillus fumigatus (AFCYP51) by homology modeling,[10] and investigated the binding modes of triazole antifungal agents by molecular docking and molecular dynamics simulations.[10a, 11] Guided by the results from molecular modeling, a number of new triazoles were rationally designed and synthesized by our research group.[11b, 12] Among them, iodiconazole was developed as a tropical antifungal agent, and its phase III clinical trial is finished.[13] Inspired by these results, a series of triazole–thiazolidinedione hybrids were rationally designed and synthesized, as reported herein.
[+] These authors contributed equally to this work.
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Figure 1. Structures of triazole antifungal agents.
Most of the target compounds showed good to excellent broad-spectrum antifungal activity. Chemistry Synthesis of the target compounds is outlined in Scheme 1. Compound 11 was synthesized by our previously reported procedure (Scheme 1).[11b] It was then dissolved in dichloromethane, and the solution was neutralized with a saturated solution of sodium carbonate to afford the oxirane intermediate 12. A ring-opening reaction was performed between rosiglitazone and oxirane 12 in the presence of tetra-n-butylammonium bromide (TBABr) and DMSO to furnish the target compound 13 a. In the presence of piperidine, thiazolidinedione was allowed to react with various aldehydes in ethanol at reflux to give thiazolidinedione intermediates 14 a–v. Similar ring-opening reactions were performed between thiazolidinediones (16 and 14 a–v) and oxirane 12 to afford the target compounds 13 b and 15 a–v. All target compounds were obtained as racemates.
four inhibitor binding regions: a tertiary alcohol binding pocket (S1), a triazole binding pocket (S2), a difluorophenyl binding pocket (S3), and a C3 side chain binding pocket (S4).[10b, 11b] Most of the medicinal chemistry efforts for triazole optimization were focused on variation of the C3 side chains, with triazole, difluorophenyl, and tertiary alcohol being maintained as essential pharmacophores.[14] The C3 side chain binding pocket is located in a hydrophobic hydrogen bonding site (facing FG loop), which can bind diverse chemotypes.[15] As shown in Figure 1, various side chains with different lengths can be accommodated by the S4 pocket, which plays an important role in antifungal activity and pharmacokinetic profiles. Thus, we envisioned that a drug-like side chain can be designed from drugs already on the market. To validate this hypothesis, we reviewed FDA-approved drugs, particularly those with properties suitable for fitting into the CYP51 S4 pocket. As a proof-of-concept study, rosiglitazone (an antidiabetic drug) was chosen for the molecular design. Thus, fluconazole–rosiglitazone hybrid molecule 13 a was designed (Figure 2) and docked into the active site of CACYP51 using a well-validated docking protocol.[16] As shown in Figure 3 A, the binding modes of triazole, tertiary alcohol, and di-
Results and Discussion Design rationale of triazole– thiazolidinedione hybrids Computational analysis of the CACYP51 active site revealed
Figure 2. Design rationale of triazole–thiazolidinedione hybrids.
2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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www.chemmedchem.org pound 13 a indicated that the rosiglitazone-containing side chain binds CACYP51 by a nonlinear conformation (Figure 3 A), which differs from triazole antifungal agents with a long side chain (e.g., itraconazole and posaconazole).[10a] To clarify the essential structural element in the rosiglitazone side chain, only the thiazolidinedione group was retained to afford compound 13 b, which can be regarded as a bioisostere of fluconazole. Interestingly, simplification of the side chain led to a significant improvement in antifungal activity. The MIC80 value of compound 13 b against C. albicans is 0.17 mm, which is fourfold more potent than fluconazole and 64fold more potent than lead compound 13 a. The binding mode of compound 13 b was further clarified by molecular docking. As depicted in Figure 3 B, the carbonyl group of thiazolidinedione forms a hydrogen bond with Tyr118 of CACYP51, which may explain the increase in antifungal activity. The results also indicated that the terminal portion of rosiglitazone is unfavorable for inhibitor binding. SARs of triazole–thiazolidinedione hybrids Considering the hydrophobic nature of the S4 pocket, various aromatic groups were introduced onto the thiazolidinedione ring to further improve antifungal activity. First, compounds 15 a–h were synthesized and assayed. Gratifyingly, most of the compounds showed excellent antifungal activity (Table 1). With respective MIC80 values against C. albicans of 0.03 and 0.029 mm, compounds 15 c and 15 g were found to be significantly more active than 13 b. In particular, compound 15 c is also highly active against C. neoformans (MIC80 = 0.12 mm) and C. tropicalis (MIC80 = 0.0078 mm). Structure–activity relationship (SAR) analysis revealed that the introduction of a phenylethylene group on the thiazolidinedione ring (compound 15 b) has relatively little impact on antifungal activity. In contrast, substitutions on the phenylethylene group are quite important for antifungal activity. For example, 2,4-dichloro (15 c) and 4-bromo (15 g) substitutions are favorable for anti-
Scheme 1. Reagents and conditions: a) ClCH2COCl, AlCl3, CH2Cl2, 40 8C, 3 h, 50 %; b) triazole, K2CO3, CH2Cl2, RT, 24 h, 70.0 %; c) (CH3)3SOI, NaOH, toluene, 60 8C, 3 h, 62.3 %; d) CH2Cl2, Na2CO3, RT, 10 min, 73.2 %; e) DMSO, TBABr, 80 8C, 3 h, 55–63 %; f) EtOH, piperidine, reflux, 5 h, 36.4–89.3 %.
fluorophenyl are similar to that of fluconazole. The rosiglitazone-containing side chain is located in the S4 pocket and forms hydrophobic interactions with the surrounding residues (e.g., Phe126 and Tyr118). Subsequently, compound 13 a was synthesized and subjected to antifungal assays. Fortunately, it showed broad-spectrum antifungal activity against C. albicans and C. neoformans, with respective MIC80 values of 6.72 and 13.45 mm. Lead optimization of triazole–thiazolidinedione hybrids Encouraged by the results, further structural optimization of compound 13 a was performed. The docking model of com 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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www.chemmedchem.org Table 1. In vitro antifungal activity of the target compounds. Compound 13 a 13 b 15 a 15 b 15 c 15 d 15 e 15 f 15 g 15 h fluconazole
Figure 3. Docking conformations of compounds A) 13 a and B) 13 b in the active site of CACYP51. The hydrogen bond is represented as a dashed line.
MIC80 [mm][a] C. tro.
C. alb.
C. neo.
6.72 0.17 1.92 0.14 0.030 0.13 0.13 8.76 0.029 2.25 0.82
13.45 11.29 30.69 36.16 0.12 8.50 8.02 > 100 7.67 9.02 52.24
– 0.71 > 100 0.56 0.0078 8.50 0.50 > 100 1.92 9.02 0.20
A. fum. > 100 > 100 > 100 > 100 > 100 > 100 > 100 > 100 > 100 > 100 > 100
[a] Data are the mean of n = 3 experiments; C. alb.: Candida albicans, C. neo.: Cryptococcus neoformans, C. tro.: Candida tropicalis, A. fum.: Aspergillus fumigatus.
fungal activity, whereas 2-bromo (15 a) and 2-methyl Table 2. In vitro antifungal activity and spectrum of the target compounds. (15 f) groups had negative effects. In an attempt to obtain more SAR information and Compound MIC80 [mm][a] investigate the antifungal spectrum, compounds C. alb. C. par. C. neo. C. gla. A. fum. T. rub. M. gyp. 15 i–v, with more phenylethylene substitutions (e.g., 15i 1.06 4.23 4.23 2.17 > 100 4.23 8.47 alkyl groups) or phenyl/heterocycle replacements 15j 0.15 1.16 4.62 0.29 > 100 4.62 9.25 were designed and synthesized. In general, these de15k 0.57 1.13 72.16 4.51 > 100 2.25 36.08 15l 1.09 0.54 4.34 0.54 > 100 2.17 8.69 rivatives also showed good to excellent broad-spec15m 4.19 16.76 67.10 4.19 > 100 16.76 > 100 trum antifungal activity (Table 2). Besides the fungal 15n 1.01 2.21 8.10 0.51 > 100 2.21 8.10 pathogens listed in Table 1, the compounds were 15o 0.53 4.28 68.46 0.27 > 100 68.46 68.46 also active against other Candida spp. (C. glabrata 15p 4.51 36.08 > 100 1.13 > 100 36.08 18.04 15q 1.04 8.36 8.36 1.04 > 100 4.18 2.09 and C. parapsilosis) and dermatophytes (T. rubrum 15r 0.15 1.16 2.31 0.29 > 100 4.62 1.16 and M. gypseum). Among the various substitutions 15s 0.56 2.24 4.49 2.24 > 100 8.98 4.49 on phenylethylene, the 4-methoxy (15 i), 4-fluoro 15t 0.31 2.46 1.23 0.31 > 100 39.37 19.68 (15 l), 4-chloro (15 m), 4-cyano (15 o), and 2,4-difluoro 15u 2.06 8.24 8.24 4.12 > 100 2.06 8.24 15v 1.11 2.23 8.92 0.56 > 100 2.23 8.92 (15 q) derivatives were found to be more potent. For fluconazole 0.81 3.26 6.53 3.26 > 100 3.26 26.12 the heterocyclic derivatives, 2-furyl analogue 15 j and 3-furyl analogue 15 r showed the best activity. The [a] Data are the mean of n = 3 experiments; C. alb.: Candida albicans, C. par.: Candida parapsilosis, C. neo.: Cryptococcus neoformans, C. gla.: Candida glabrata, A. fum.: AsperMIC80 values of compounds 15 j and 15 r against gillus fumigatus, T. rub.: Trichophyton rubrum, M. gyp.: Microsporum gypseum. C. albicans were both 0.15 mm. Moreover, they also showed excellent activity against C. glabrata (MIC80 = 0.29 mm). 3-Pyridinyl derivative 15 k was more potent than 2-pyridinyl derivative 15 h and 4-pyridinyl derivative 15 p. Moreover, 2-quinolinyl (15 n), 2-pyrrolyl that are effective against resistant fungal strains. Herein, com(15 s), and 2-thienyl (15 v) derivatives were less active than the pounds 15 j and 15 r were assayed for inhibitory activity corresponding furyl derivatives. Molecular docking studies reagainst four clinical isolates of C. albicans (Table 3), which are vealed that a hydrogen bond between thiazolidinedione and resistant to fluconazole (MIC > 3343.45 mm). Interestingly, the Tyr118 was retained for compounds 15 c and 15 j (Figure 4). two compounds were proven to be effective against these fluThe substituted phenyl or furan formed hydrophobic interacconazole-resistant isolates, highlighting their promise as canditions with Leu121, Phe380, Met508, and Val509 among others. dates for further optimization. The substitutions on the phenyl ring (e.g., dichloro substitution of compound 15 c) contributed additional hydrophobic interactions with Met508 and Val509, and thus had different effects Conclusions on antifungal activity. From a clinical perspective, a serious problem for triazole anIn summary, molecular hybridization of fluconazole and rosiglitifungal agents is the emergence of resistant fungal strains, tazone was used to design a series of triazole–thiazolidinewhich significantly decrease the therapeutic efficacy. Therefore, dione derivatives. Among them, compounds 15 c, 15 g, 15 j, it is highly desirable to develop new triazole antifungal agents and 15 r showed excellent activity against C. albicans, with 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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www.chemmedchem.org Synthesis of (Z)-5-(2,4-dichlorobenzylidene)thiazolidine-2,4dione (14 c): A mixture of thiazolidinedione (200 mg, 1.71 mmol, 1 equiv), 2,4-dichlorobenzaldehyde (448.3 mg, 2.56 mmol, 1.5 equiv), piperidine (217.9 mg, 2.50 mmol, 1.5 equiv) and EtOH (20 mL) was stirred at reflux for 5 h. The reaction mixture was poured into ice water, and a yellow solid precipitated. After filtration, product 14 c (280 mg) was obtained, which could be used directly in the subsequent step without further purification. The synthetic procedures for compounds 14 a–v were similar to those used for the synthesis of compound 14 c.
Figure 4. Stereoview of the docking conformation of compound 15 c (A) and j (B) in the active site of CACYP51. The hydrogen bond is represented as a dashed line.
Table 3. Inhibitory activities of compounds 15 j and 15 r against fluconazole-resistant clinical isolates of C. albicans (all MIC values in mm). Clinical isolate 100 103 805 0710922
15 j MIC80
MIC50
74.00 4.62 148.01 9.25 18.50 0.58 > 148.01 > 148.01
15 r MIC80 MIC50 37.00 2.31 74.00 18.50 74.00 0.58 74.00 1.16
Fluconazole MIC80 MIC50 > 3343.45 > 3343.45 > 3343.45 > 3343.45
> 3343.45 > 3343.45 > 3343.45 > 3343.45
MIC80 values in the range of 0.029–0.15 mm. Moreover, compounds 15 j and 15 r were also found to be effective against fluconazole-resistant clinical isolates. Molecular docking studies revealed that the target compounds interact with CACYP51 mainly through hydrogen bonding and hydrophobic interactions. Taken together, the results of this study have provided some promising lead compounds for the development of a new generation of triazole antifungal agents and have proven the effectiveness of molecular hybridization in antifungal drug discovery.
Experimental Section General synthesis procedures: All reagents and solvents were reagent grade. 1H and 13C NMR spectra were recorded on Bruker 500 or 600 spectrometers, with TMS as the internal standard and CDCl3 or [D6]DMSO as the solvent. Chemical shifts (d) and coupling constants (J) are given in ppm and Hz, respectively. ESI mass spectrometric data were collected on an API-3000 LC–MS spectrometer. TLC analysis was carried out on silica gel plates G F254 (Qindao Haiyang Chemical, China). Silica gel column chromatography was performed with Silica gel 60G (Qindao Haiyang Chemical, China). 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Synthesis of (Z)-5-(2,4-dichlorobenzylidene)-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine2,4-dione (15 c): A mixture compound 14 c (278.4 mg, 1.02 mmol, 1.0 equiv), oxirane intermediate 12 (484.6 mg, 2.04 mmol, 2.0 equiv), TBABr (19.3 mg, 0.10 mmol, 0.1 equiv), and DMSO (10 mL) was stirred at 80 8C for 3 h, then diluted with EtOAc (50 mL). The organic layer was washed with H2O (3 20 mL), dried over anhydrous Na2SO4, and filtered. The solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane/EtOAc 3:1!1:1, v/v) to give 15 c as a yellow solid (0.48 g, 55 % yield, two steps). 1H NMR (600 MHz, [D6]DMSO): d = 8.35 (s, 1 H), 7.88 (s, 1 H), 7.79 (s, 1 H), 7.72 (s, 1 H), 7.44 (s, 1 H), 7.04–7.40 (m, 6 H), 5.75 (s, 1 H), 4.90 (d, J = 14.7 Hz, 1 H), 4.85 (d, J = 14.7 Hz, 1 H), 3.8 ppm (m, 2 H); 13C NMR (75 MHz, CDCl3, TMS): d = 160.44, 152.00, 144.87, 135.77, 135.61, 133.79, 130.68, 130.44, 129.91, 129.43, 129.37, 129.30, 129.24, 126.85, 122.31, 112.61, 112.56, 112.28, 105.66, 105.30, 104.96, 84.37, 84.30, 57.01, 30.60, 30.49 ppm; MS (ESI) m/z: 543.37 [(M + MeOH)H]. The synthetic procedures for compounds 15 a–v were similar to those used for compound 15 c. 3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(4-(2-(methyl(pyridin-2-yl)amino)ethoxy)benzyl)thiazolidine-2,4-dione (13 a): Yellow oil (0.33 g, 55.3 %); 1H NMR (500 MHz, CDCl3, TMS): d = 8.15 (d, J = 4.1 Hz, 1 H), 8.00 (s, 1 H), 7.80 (s, 1 H), 7.46 (m, 2 H), 7.10 (d, J = 8.4 Hz, 2 H), 6.82 (m, 4 H), 6.54 (m, 2 H), 4.74 (t, J = 13.1 Hz, 1 H), 4.39 (m, 2 H), 4.13 (m, 3 H), 3.96 (m, 3 H), 3.36 (m, 1 H), 3.14 (d, J = 4.4 Hz, 3 H), 2.94 ppm (m, 1 H); 13C NMR (500 MHz, CDCl3, TMS): d = 174.64, 174.48, 171.81, 158.41, 158.27, 151.73, 147.84, 144.49, 137.27, 130.44, 130.32, 129.89, 127.30, 127.20, 114.72, 111.75, 111.57, 105.70, 104.24, 66.28, 55.37, 51.82, 51.62, 49.42, 47.75, 37.97, 37.79, 37.55 ppm; HRMS (ESI) calcd (%) for C29H28F2N2O4 [M + H]: 595.1939, found: 595.1947. 3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione (13 b): Pale yellow oil (0.23 g, 63.0 %); 1 H NMR (500 MHz, CDCl3, TMS): d = 8.13 (s, 1 H), 7.85 (s, 1 H), 6.77– 7.55 (m, 3 H), 5.30 (s, 1 H), 4.71 (dd, 2 H, J1 = 10.8 Hz, J2 = 14.1 Hz), 4.02 (s, 2 H), 3.50 (d, 1 H, J = 14.4 Hz), 2.94 ppm (d, 1 H, J = 14.4 Hz); 13 C NMR (500 MHz, CDCl3, TMS): d = 164.64, 164.48, 161.32, 161.16, 160.29, 160.14, 157.03, 156.88, 151.52, 144.43, 130.22, 130.15, 130.10, 130.02, 124.49, 124.44, 124.32, 124.26, 111.80, 111.76, 111.53, 111.48, 104.56, 104.22, 104.20, 103.86, 75.51, 75.44, 61.95, 56.45, 56.38, 41.46, 41.40, 35.12, 29.67, 14.06 ppm; MS (ESI) m/z: 355.30 [M + H]. (Z)-5-(2-Bromobenzylidene)-3-(2-(2,4-difluorophenyl)-2-hydroxy3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione (15 a): Yellow oil (0.30 g, 57.2 %); 1H NMR (500 MHz, CDCl3, TMS): d = 8.18 (s, 1 H), 8.15 (s, 1 H), 7.86 (s, 1 H), 6.80–7.70 (m, 7 H), 5.03 (s, 1 H), 4.86 (d, 1 H, J = 14.2 Hz), 4.64 (d, 1 H, J = 14.3 Hz), 4.40 (d, 1 H, J = 14.4 Hz), 4.14 ppm (d, 1 H, J = 14.3 Hz); 13C NMR (125 MHz, CDCl3, TMS): d = 168.2, 166.68, 165.90, 164.28, 164.18, 162.28, 160.05, 159.95, 158.09, 157.99, 151.47, 144.70, 144.24, 138.00, 134.00,
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CHEMMEDCHEM FULL PAPERS 133.17, 132.67, 131.84, 130.68, 129.98, 129.94, 129.90, 129.86, 129.03, 127.96, 126.90, 126.45, 123.44, 112.00, 111.98, 111.84, 104.57, 104.36, 104.15, 75.93, 75.89, 71.94, 62.66, 55.72, 55.66, 47.93, 29.69 ppm; MS (ESI) m/z: 522.31 [M + H]. (Z)-5-Benzylidene-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione (15 b): White solid (0.25 g, 56.1 %); 1H NMR (500 MHz, CDCl3, TMS): d = 8.05 (s, 1 H,), 7.89 (s, 1 H), 7.83 (s, 1 H), 6.79–7.54 (m, 8 H), 5.30 (s, 1 H), 4.85 (d, 1 H, J = 14.3 Hz), 4.64 (d, 1 H, J = 14.3 Hz), 4.39 (d, 1 H, J = 14.4 Hz), 4.18 ppm (d, 1 H, J = 14.4 Hz); MS (ESI) m/z: 443.41 [M + H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(2,4-dimethylbenzylidene)thiazolidine-2,4-dione (15 d): White solid (0.27 g, 56.3 %); 1H NMR (500 MHz, CDCl3, TMS): d = 8.31 (s, 1 H), 8.04 (s, 1 H), 7.89 (s, 1 H), 6.88–7.34 (m, 6 H), 5.20 (s, 1 H), 4.80 (d, 1 H, J = 14.7 Hz), 4.68 (d, 1 H, J = 14.7 Hz), 3.62 (d, 1 H, J = 14.2 Hz), 3.19 (d, 1 H, J = 14.3 Hz), 2.29 (s, 3 H), 2.21 ppm (s, 3 H); MS (ESI) m/z: 471.48 [M + H]. (Z)-5-(4-(tert-Butyl)benzylidene)-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione (15 e): Pale yellow solid (0.28 g, 55.3 %); 1H NMR (500 MHz, CDCl3, TMS): d = 8.11 (s, 1 H), 8.01 (s, 1 H), 7.94 (s, 1 H), 6.21–7.39 (m, 7 H), 5.48 (s, 1 H), 4.33 (dd, 1 H, J1 = 9.0 Hz, J2 = 14.0 Hz), 3.48 (d, 1 H, J = 10.2 Hz), 3.23 (d, 1 H, J = 10.2 Hz), 1.30 ppm (s, 9 H); MS (ESI) m/z: 499.52 [M + H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(2-methylbenzylidene)thiazolidine-2,4-dione (15 f): White solid (0.27 g, 57.1 %); 1H NMR (500 MHz, CDCl3, TMS): d = 8.42 (s, 1 H), 7.99 (s, 1 H), 7.93 (s, 1 H), 6.89–7.34 (m, 7 H), 4.82 (d, 1 H, J = 14.6 Hz), 4.71 (d, 1 H, J = 14.6 Hz), 3.63 (d, 1 H, J = 14.4 Hz), 3.21 (d, 1 H, J = 14.3 Hz), 2.22 ppm (s, 3 H); MS (ESI) m/z: 457.45 [M + H]. (Z)-5-(4-Bromobenzylidene)-3-(2-(2,4-difluorophenyl)-2-hydroxy3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione (15 g): Brown oil (0.31 g, 58.4 %); 1H NMR (500 MHz, CDCl3, TMS): d = 8.72 (s, 1 H), 8.11 (s, 1 H), 8.02 (s, 1 H), 6.88–7.53 (m, 7 H), 4.88 (d, 1 H, J = 14.6 Hz), 4.78 (d, 1 H, J = 13.7 Hz), 3.72 (d, 1 H, J = 13.8 Hz), 3.34 ppm (d, 1 H, J = 15.0 Hz); MS (ESI) m/z: 521.32 [M + H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(pyridin-2-ylmethylene)thiazolidine-2,4-dione (15 h): Pale brown solid (0.26 g, 56.7 %); 1H NMR (500 MHz, CDCl3, TMS): d = 8.25 (s, 1 H), 8.14 (s, 1 H), 7.88 (s, 1 H), 6.88–8.06 (m, 6 H), 5.30 (s, 1 H), 4.81 (d, 1 H, J = 14.7 Hz), 4.68 (d, 1 H, J = 14.7 Hz), 3.88 (d, 1 H, J = 14.2 Hz), 3.32 ppm (d, 1 H, J = 14.2 Hz); MS (ESI) m/z: 434.41 [M + H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(4-methoxybenzylidene)thiazolidine-2,4-dione (15 i): Yellow oil (0.29 g, 59.3 %); 1H NMR (600 MHz, CDCl3, TMS): d = 8.20 (s, 1 H), 7.85 (s, 1 H), 7.84 (s, 1 H), 7.51 (m, 1 H), 7.45 (d, J = 8.8 Hz, 2 H), 7.00 (d, J = 8.8 Hz, 2 H), 6.82 (m, 2 H), 5.16 (br s, 1 H), 4.86 (d, J = 14.3 Hz, 1 H), 4.66 (d, J = 14.3 Hz, 1 H), 4.41 (d, J = 14.3 Hz, 1 H), 4.15 (d, J = 14.3 Hz, 1 H), 3.88 ppm (s, 3 H); 13C NMR (500 MHz, CDCl3, TMS): d = 168.68, 167.53, 161.87, 135.21, 132.49, 131.13, 129.94, 125.49, 116.99, 114.89, 111.91, 104.64, 104.30, 103.93, 55.53, 47.94 ppm; MS (ESI) m/z: 473.57 [M + H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(furan-3-ylmethylene)thiazolidine-2,4-dione (15 j): White solid (0.24 g, 55.2 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.28 (s, 1 H), 8.07 (d, J = 1.6 Hz, 1 H), 7.70 (s, 1 H), 7.69 (s, 1 H), 7.26 (m, 1 H), 7.18 (m, 1 H), 7.13 (d, J = 3.5 Hz, 1 H), 6.87 (t, J =
2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemmedchem.org 8.0 Hz, 1 H), 6.76 (dd, J = 1.8, 3.5 Hz, 1 H), 6.05 (s, 1 H), 4.82 (d, J = 14.7 Hz, 1 H), 4.59 (d, J = 14.7 Hz, 1 H), 4.10 ppm (s, 2 H); 13C NMR (75 MHz, CDCl3, TMS): d = 169.54, 167.07, 151.72, 149.51, 130.06, 120.73, 118.69, 117.84, 113.36, 111.68, 55.59, 29.69 ppm; MS (ESI) m/z: 433.36 [M + H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(pyridin-3-ylmethylene)thiazolidine-2,4-dione (15 k): White solid (0.27 g, 59.2 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.85 (d, J = 2.37 Hz, 1 H), 8.64 (dd, J = 1.5, 4.8 Hz, 1 H), 8.28 (s, 1 H), 7.98 (dt, J = 2.0, 8.2 Hz, 1 H), 7.92 (s, 1 H), 7.69 (s, 1 H), 7.57 (dd, J = 4.8, 8.0 Hz), 1 H), 7.27 (dd, J = 8.9, 15.9 Hz, 1 H), 7.19 (m, 1 H), 6.89 (t, J = 8.05 Hz, 1 H), 6.10 (s, 1 H), 4.82 (d, J = 14.4 Hz, 1 H), 4.61 (d, J = 14.4 Hz, 1 H), 4.15 (d, J = 14.3 Hz, 1 H), 4.12 ppm (d, J = 14.3 Hz, 1 H); 13C NMR (75 MHz, CDCl3, TMS): d = 167.57, 166.56, 151.91, 151.59, 151.10, 144.53, 136.11, 131.11, 130.03, 129.96, 129.90, 129.83, 129.02, 123.95, 122.93, 122.52, 122.34, 112.03, 111.80, 111.75, 104.67, 104.32, 103.96, 60.38, 55.51, 55.42, 47.96, 47.91, 21.03, 14.18 ppm; MS (ESI) m/z: 444.30 [M + H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(4-fluorobenzylidene)thiazolidine-2,4-dione (15 l): White solid (0.27 g, 58.6 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.28 (s, 1 H), 7.90 (s, 1 H), 7.70 (dd, J = 5.7, 8.8 Hz, 1 H), 7.69 (s, 1 H), 7.40 (t, J = 8.8 Hz, 2 H), 7.27 (dd, J = 8.9, 15.9 Hz, 1 H), 7.18 (m, 1 H), 6.88 (t, J = 8.05 Hz, 1 H), 6.08 (s, 1 H), 4.82 (d, J = 14.6 Hz, 1 H), 4.61 (d, J = 14.6 Hz, 1 H), 4.14 (d, J = 14.1 Hz, 1 H), 4.11 ppm (d, J = 14.1 Hz, 1 H); 13C NMR (75 MHz, CDCl3, TMS): d = 168.19, 167.09, 165.58, 162.20, 151.85, 144.56, 133.84, 132.50, 132.29, 130.05, 129.97, 129.92, 129.85, 129.22, 129.18, 122.58, 122.41, 122.36, 119.97, 116.54, 112.02, 111.97, 116.54, 112.02, 111.97, 116.54, 112.02, 111.97, 111.74, 111.70, 104.65, 104.29, 103.94, 55.58, 55.49, 47.93, 47.88 ppm; MS (ESI) m/z: 461.40 [M + H]. (Z)-5-(4-Chlorobenzylidene)-3-(2-(2,4-difluorophenyl)-2-hydroxy3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione (15 m): Brown solid (0.29 g, 60.2 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.37 (s, 1 H), 7.89 (s, 1 H), 7.71 (s, 1 H), 7.58 (d, J = 8.7 Hz, 2 H), 7.49 (d, J = 8.7 Hz, 2 H), 7.33 (m, 1 H), 7.16 (m, 1 H), 7.06 (td, J = 2.4, 8.4 Hz, 1 H), 4.91 (d, J = 14.9 Hz, 1 H), 4.86 (d, J = 14.9 Hz, 1 H), 3.88 (d, J = 14.4 Hz, 1 H), 3.73 ppm (d, J = 14.4 Hz, 1 H); 13C NMR (75 MHz, CDCl3, TMS): d = 160.75, 151.95, 144.84, 137.29, 135.63, 132.47, 131.70, 129.43, 129.37, 129.30, 129.24, 128.86, 120.57, 120.47, 120.41, 119.28, 112.58, 112.30, 112.25, 105.62, 105.28, 104.92, 84.28, 84.22, 57.04, 30.55, 30.45, 29.67 ppm; MS (ESI) m/z: 477.45 [M + H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(quinolin-2-ylmethylene)thiazolidine-2,4-dione (15 n): Gray solid (0.31 g, 62.2 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.49 (d, J = 8.4 Hz, 1 H), 8.29 (s, 1 H), 8.13 (d, J = 8.1 Hz, 1 H), 8.06 (s, 1 H), 8.03 (d, J = 7.9 Hz, 1 H), 7.97 (d, J = 8.4 Hz, 1 H), 7.85 (m, 1 H), 7.69 (s, 1 H), 7.68 (m, 1 H), 6.87–7.30 (m, 3 H), 6.08 (s, 1 H), 4.85 (d, J = 14.4 Hz, 1 H), 4.63 (d, J = 14.4 Hz, 1 H), 3.31 ppm (s, 2 H); 13C NMR (75 MHz, CDCl3, TMS): d = 173.31, 167.36, 151.74, 151.16, 147.71, 144.62, 137.13, 130.60, 130.08, 130.01, 129.88, 129.64, 129.14, 128.05, 127.65, 127.36, 127.16, 123.80, 122.61, 122.48, 111.96, 111.92, 111.68, 111.64, 104.65, 104.29, 103.95, 55.72, 55.63, 47.43, 47.39, 29.69 ppm; MS (ESI) m/z: 494.42 [M + H]. (Z)-4-((3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1yl)propyl)-2,4-dioxothiazolidin-5-ylidene)methyl)benzonitrile (15 o): Pale yellow solid (0.26 g, 55.7 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.25 (s, 1 H), 7.97 (d, J = 8.4 Hz, 2 H), 7.92 (s, 1 H), 7.77 (d, J = 8.4 Hz, 2 H), 7.67 (s, 1 H), 7.24 (dd, J = 8.8, 15.8 Hz, 1 H), 7.17 (m, 1 H), 6.87 (td, J = 2.4, 8.4 Hz, 1 H), 6.08 (s, 1 H), 4.79 (d, J = 14.4 Hz, 1 H), 4.59 (d, J = 14.4 Hz, 1 H), 4.13 (d, J = 14.1 Hz, 1 H),
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4.09 ppm (d, J = 14.1 Hz, 1 H); 13C NMR (125 MHz, CDCl3, TMS): d = 167.37, 166.47, 164.28, 164.18, 162.28, 162.18, 160.00, 159.90, 158.04, 157.94, 151.89, 144.52, 137.10, 132.88, 132.13, 130.38, 129.99, 129.95, 129.91, 129.87, 124.35, 122.45, 122.42, 122.35, 122.32, 117.90, 113.86, 112.05, 112.03, 111.89, 111.86, 104.55, 104.34, 104.13, 75.98, 75.94, 55.48, 55.42, 47.96, 47.93, 29.69 ppm; MS (ESI) m/z: 468.43 [M + H].
1.07 (m, 2 H), 0.88 ppm (m, 2 H); 13C NMR (125 MHz, CDCl3, TMS): d = 163.88, 161.13, 159.43, 159.34, 157.44, 157.34, 155.28, 155.18, 153.32, 147.31, 147.22, 147.19, 146.94, 146.77, 146.71, 140.69, 139.94, 139.80, 139.49, 125.25, 125.21, 125.18, 125.13, 117.88, 117.85, 117.78, 117.75, 115.91, 107.09, 017.06, 016.92, 106.90, 99.72, 99.52, 99.51, 99.30, 71.23, 71.19, 51.37, 50.90, 50.85, 43.03, 43.05, 24.93 ppm; MS (ESI) m/z: 407.39 [M + H].
(Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(pyridin-4-ylmethylene)thiazolidine-2,4-dione (15 p): Yellow solid (0.26 g, 58.5 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.72 (m, 2 H), 8.26 (s, 1 H), 7.84 (s, 1 H), 7.68 (s, 1 H), 7.54 (m, 2 H), 6.85–7.28 (m, 3 H), 6.12 (s, 1 H), 4.79 (d, J = 13.8 Hz, 1 H), 4.59 (d, J = 13.8 Hz, 1 H), 4.11 ppm (s, 2 H); 13C NMR (125 MHz, DMSO, TMS): d = 172.18, 170.77, 168.33, 166.37, 166.27, 165.76, 163.69, 155.90, 155.76, 150.16, 150.01, 145.22, 134.89, 131.57, 129.08, 128.95, 128.60, 128.53, 116.02, 115.87, 109.16, 79.50, 79.46, 60.01, 53.28 ppm; MS (ESI) m/z: 444.52 [M + H].
(Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(4-(dimethylamino)benzylidene)thiazolidine-2,4-dione (15 u): Red solid (0.27 g, 55.0 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.28 (s, 1 H), 7.74 (s, 1 H), 7.68 (s, 1 H), 7.45 (d, J = 9.03 Hz, 2 H), 7.27 (m, 1 H), 7.17 (m, 1 H), 6.88 (td, J = 2.2, 8.6 Hz, 1 H), 6.82 (d, J = 9.03 Hz, 2 H), 6.03 (s, 1 H), 4.82 (d, J = 14.7 Hz, 1 H), 4.59 (d, J = 14.7 Hz, 1 H), 4.12 (d, J = 14.0 Hz, 1 H), 4.09 (d, J = 14.0 Hz, 1 H), 3.02 ppm (s, 6 H); 13C NMR (125 MHz, CDCl3, TMS): d = 169.12, 167.98, 164.16, 164.07, 162.17, 162.07, 160.11, 160.01, 158.14, 158.05, 151.95, 151.58, 144.62, 136.40, 132.87, 130.08, 130.03, 130.00, 129.96, 122.77, 122.74, 122.66, 122.63, 120.24, 112.49, 111.96, 111.77, 111.75, 111.61, 111.58, 104.47, 104.26, 104.05, 76.00, 75.96, 55.80, 55.75, 45.00, 47.97, 40.00, 30.21, 30.05, 29.69, 29.35 ppm; MS (ESI) m/z: 486.64 [M + H].
(Z)-5-(2,4-Difluorobenzylidene)-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione (15 q): White solid (0.28 g, 56.7 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.26 (s, 1 H), 7.84 (s, 1 H), 7.68 (s, 1 H), 6.85–7.58 (m, 6 H), 6.12 (s, 1 H), 4.79 (d, J = 14.2 Hz, 1 H), 4.58 (d, J = 14.2 Hz, 1 H), 4.13 (d, J = 14.6 Hz, 1 H), 4.07 ppm (d, J = 14.6 Hz, 1 H); 13C NMR (75 MHz, CDCl3, TMS): d = 168.13, 166.84, 164.92, 164.76, 163.16, 161.59, 161.43, 160.68, 160.52, 159.77, 157.41, 157.25, 151.82, 144.54, 132.87, 132.76, 130.05, 129.98, 129.92, 129.85, 128.94, 127.17, 127.08, 124.82, 124.77, 122.57, 122.52, 122.39, 122.34, 121.38, 121.22, 116.49, 116.20, 112.03, 111.99, 111.75, 111.71, 104.65, 104.31, 103.95, 55.57, 55.48, 47.94, 47.89 ppm; MS (ESI) m/z: 479.57 [M+H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(furan-3-ylmethylene)thiazolidine-2,4-dione (15 r): Pale brown solid (0.24 g, 55.0 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.27–8.28 (m, 2 H), 7.89–7.90 (m, 1 H), 7.77 (s, 1 H), 7.69 (s, 1 H), 7.16–7.28 (m, 2 H), 6.90 (td, J = 2.8, 11.2 Hz, 1 H), 6.77–6.78 (m, 1 H), 6.07 (s, 1 H), 4.81 (d, J = 14.3 Hz, 1 H), 4.60 (d, J = 14.3 Hz, 1 H), 4.11 (d, J = 14.1 Hz, 1 H), 4.08 ppm (d, J = 14.1 Hz, 1 H); 13C NMR (75 MHz, CDCl3, TMS): d = 167.86, 166.88, 164.90, 164.74, 161.58, 161.42, 160.70, 157.42, 157.27, 151.79, 146.68, 145.15, 144.55, 130.05, 129.97, 129.92, 129.85, 125.80, 122.59, 122.54, 122.41, 120.89, 119.58, 111.99, 111.94, 111.71, 111.67, 108.98, 104.64, 104.30, 103.94, 55.61, 55.52, 47.95, 47.91, 29.68 ppm; MS (ESI) m/z: 433.60 [M + H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-((1-methyl-1H-pyrrol-2-yl)methylene)thiazolidine-2,4dione (15 s): Yellow solid (0.29 g, 64.6 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.27(s, 1 H), 7.69 (s, 1 H), 7.68 (s, 1 H), 6.84–7.35 (m, 4 H), 6.51 (dd, J = 1.2, 4.0 Hz, 1 H), 6.29 (dd, J = 2.6, 4.0 Hz, 1 H), 6.05 (s, 1 H), 4.81 (d, J = 14.5 Hz, 1 H), 4.57 (d, J = 14.5 Hz, 1 H), 4.09 (s, 2 H), 3.76 ppm (s, 3 H); 13C NMR (125 MHz, CDCl3, TMS): d = 168.70, 167.57, 164.19, 164.09, 162.20, 162.10, 160.09, 159.98, 158.12, 158.03, 144.64, 130.05, 130.01, 129.98, 129.93, 129.25, 127.91, 122.69, 122.66, 122.59, 122.56, 122.05, 116.63, 113.09, 111.83, 111.81, 116.67, 111.64, 111.31, 104.50, 104.29, 104.08, 76.00, 75.96, 55.76, 55.71, 48.00, 47.98, 34.35, 29.69 ppm; MS (ESI) m/z: 446.54 [M + H]. (Z)-5-(Cyclopropylmethylene)-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione (15 t): Yellow solid (0.29 g, 64.6 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.25 (s, 1 H), 7.65 (s, 1 H), 7.11–7.25 (m, 2 H), 6.85 (td, J = 2.6, 8.5 Hz, 1 H), 6.55 (d. J = 11.1 Hz, 1 H), 5.98 (s, 1 H), 4.77 (d, J = 14.7 Hz, 1 H), 4.53 (d, J = 14.7 Hz, 1 H), 4.03 (s, 2 H), 1.40 (m, 1 H),
2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
(Z)-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(thiophen-2-ylmethylene)thiazolidine-2,4-dione (15 v): Yellow solid (0.26 g, 57.2 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d 8.28 (s, 1 H), 8.15 (s, 1 H), 8.03 (d, J = 5.0 Hz, 1 H), 7.71 (d, J = 3.7 Hz, 1 H), 7.69 (s, 1 H), 7.30 (dd, J = 3.7, 5.0 Hz, 1 H), 7.17–7.28 (m, 2 H), 6.89 (td, J = 2.2, 8.6 Hz, 1 H), 6.08 (s, 1 H), 4.81 (d, J = 14.7 Hz, 1 H), 4.60 (d, J = 14.7 Hz, 1 H), 4.13 (d, J = 13.7 Hz, 1 H), 4.10 ppm (d, J = 13.7 Hz, 1 H); 13C NMR (125 MHz, CDCl3, TMS): d = 167.02, 164.56, 164.46, 162.55, 160.81, 159.72, 151.92, 140.72, 139.99, 138.01, 137.94, 136.17, 135.85, 133.75, 132.89, 131.84, 131.58, 130.29, 129.49, 129.45, 129.41, 129.37, 127.72, 127.00, 120.22, 114.79, 114.51, 112.48, 112.34, 112.31, 111.54, 111.38, 105.45, 105.24, 105.03, 104.27, 104.06, 103.85, 84.35, 84.31, 74.80, 57.05, 56.67, 5310, 43.50, 43.46, 30.81, 30.75 ppm; MS (ESI) m/z: 449.53 [M + H]. In vitro antifungal activity assay: In vitro antifungal activity was measured according to the protocols from the National Committee for Clinical Laboratory Standards (NCCLS). The serial dilution method in 96-well microtest plates was used to determine the minimum inhibitory concentration (MIC) of the target compounds. Tested fungal strains were obtained from the ATCC or clinical isolates. Briefly, the MIC value is defined as the lowest concentration of test compound that results in a culture with turbidity less than or equal to 80 % inhibition relative to growth of the control. Tested compounds were dissolved in DMSO and serially diluted in growth medium. The yeasts were incubated at 35 8C, and the mold and dermatophytes at 28 8C. Growth MIC was determined at 24 h for Candida species, at 72 h for Cryptococcus neoformans, and at seven days for Aspergillus fumigatus.
Acknowledgements This work was supported in part by the National Natural Science Foundation of China (grant 81222044), the Key Project of Science and Technology of Shanghai (grant 13431900301), and the 863 Hi-Tech Program of China (grant 2014AA020525). Keywords: antifungal agents · Candida albicans · molecular hybridization · thiazolidinedione · triazoles
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CHEMMEDCHEM FULL PAPERS [1] D. A. Enoch, H. A. Ludlam, N. M. Brown, J. Med. Microbiol. 2006, 55, 809 – 818. [2] a) C. C. Lai, C. K. Tan, Y. T. Huang, P. L. Shao, P. R. Hsueh, J. Infect. Chemother. 2008, 14, 77 – 85; b) B. J. Park, K. A. Wannemuehler, B. J. Marston, N. Govender, P. G. Pappas, T. M. Chiller, AIDS 2009, 23, 525 – 530. [3] H. Wisplinghoff, T. Bischoff, S. M. Tallent, H. Seifert, R. P. Wenzel, M. B. Edmond, Clin. Infect. Dis. 2004, 39, 309 – 317. [4] a) F. C. Odds, Rev. Iberoam. Micol. 2005, 22, 229 – 237; b) F. C. Odds, A. J. Brown, N. A. Gow, Trends Microbiol. 2003, 11, 272 – 279. [5] C. Lass-Flçrl, Drugs 2011, 71, 2405 – 2419. [6] M. A. Pfaller, Am. J. Med. 2012, 125, S3 – 13. [7] a) R. Guillon, F. Pagniez, C. Rambaud, C. Picot, M. Duflos, C. Loge, P. Le Pape, ChemMedChem 2011, 6, 1806 – 1815; b) R. Guillon, F. Pagniez, F. Giraud, D. Crepin, C. Picot, M. Le Borgne, F. Morio, M. Duflos, C. Loge, P. Le Pape, ChemMedChem 2011, 6, 816 – 825; c) R. Guillon, C. Loge, F. Pagniez, V. Ferchaud-Roucher, M. Duflos, C. Picot, P. Le Pape, J. Enzyme Inhib. Med. Chem. 2011, 26, 261 – 269; d) R. Guillon, F. Giraud, C. Loge, M. Le Borgne, C. Picot, F. Pagniez, P. Le Pape, Bioorg. Med. Chem. Lett. 2009, 19, 5833 – 5836; e) F. Giraud, R. Guillon, C. Loge, F. Pagniez, C. Picot, M. Le Borgne, P. Le Pape, Bioorg. Med. Chem. Lett. 2009, 19, 301 – 304; f) R. Guillon, F. Pagniez, C. Picot, D. Hedou, A. Tonnerre, E. Chosson, M. Duflos, T. Besson, C. Loge, P. Le Pape, ACS Med. Chem. Lett. 2013, 4, 288 – 292; g) S. Yu, X. Chai, Y. Wang, Y. Cao, J. Zhang, Q. Wu, D. Zhang, Y. Jiang, T. Yan, Q. Sun, Drug Des. Dev. Ther. 2014, 8, 383 – 390; h) X. Cao, Z. Sun, Y. Cao, R. Wang, T. Cai, W. Chu, W. Hu, Y. Yang, J. Med. Chem. 2014, 57, 3687 – 3706. [8] O. Trel, Expert Rev. Anti-Infect. Ther. 2011, 9, 325 – 338. [9] G. I. Lepesheva, M. R. Waterman, Biochim. Biophys. Acta Proteins Proteomics 2011, 1814, 88 – 93. [10] a) C. Sheng, Z. Miao, H. Ji, J. Yao, W. Wang, X. Che, G. Dong, J. Lu, W. Guo, W. Zhang, Antimicrob. Agents Chemother. 2009, 53, 3487 – 3495; b) C. Sheng, W. Wang, X. Che, G. Dong, S. Wang, H. Ji, Z. Miao, J. Yao, W. Zhang, ChemMedChem 2010, 5, 390 – 397; c) C. Sheng, W. Zhang, M. Zhang, Y. Song, H. Ji, J. Zhu, J. Yao, J. Yu, S. Yang, Y. Zhou, J. Lu, J. Biomol. Struct. Dyn. 2004, 22, 91 – 99.
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From Antidiabetic to Antifungal: Discovery of Highly Potent Triazole–Thiazolidinedione Hybrids as Novel Antifungal Agents Shanchao Wu, Yongqiang Zhang, Xiaomeng He, Xiaoying Che, Shengzheng Wang, Yang Liu, Yan Jiang, Na Liu, Guoqiang Dong, Jianzhong Yao, Zhenyuan Miao, Yan Wang, Wannian Zhang,* and Chunquan Sheng*[a] In an attempt to discover a new generation of triazole antifungal agents, a series of triazole–thiazolidinedione hybrids were designed and synthesized by molecular hybridization of the antifungal agent fluconazole and rosiglitazone (an antidiabetic). Most of the target compounds showed good to excellent inhibitory activity against a variety of clinically important fungal pathogens. In particular, compounds (Z)-5-(2,4-dichlorobenzylidene)-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione) (15 c), (Z)-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(furan3-ylmethylene)thiazolidine-2,4-dione (15 j), and (Z)-3-(2-(2,4-di-
fluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(furan3-ylmethylene)thiazolidine-2,4-dione (15 r) were highly active against Candida albicans, with MIC80 values in the range of 0.03–0.15 mm. Moreover, compounds 15 j and 15 r were found to be effective against four fluconazole-resistant clinical isolates; these two compounds are particularly promising antifungal leads for further optimization. Molecular docking studies revealed that the hydrogen bonding interactions between thiazolidinedione and CYP51 from C. albicans are important for antifungal activity. This study also demonstrates the effectiveness of molecular hybridization in antifungal drug discovery.
Introduction The worldwide incidence of invasive fungal infections (IFIs) has been increasing over the past few decades.[1] Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus are the most common fungal pathogens in humans which are associated with high mortality (20–90 %) among immunocompromised populations.[2] In particular, Candida species are currently the most common fungal pathogens for humans and are the fourth leading cause of nosocomial bloodstream infections in the United States.[3] Clinically available drugs for IFIs are represented principally by four classes of compounds: polyenes (e.g., amphotericin B), triazoles (e.g., fluconazole and voriconazole, Figure 1), echinocandins (e.g., caspofungin, micafungin, and anidulafungin), and fluorinated pyrimidines (e.g., 5-fluorocytosine).[4] Among them, triazole antifungal agents have emerged as the first-line drugs for the treatment and prophylaxis of many kinds of IFIs.[5] Despite the clinical success of triazole antifungals, they still suffer from several limitations. First, broad use of triazoles has led to severe drug resistance, which has significantly decreased their clinical efficacy.[6] Second, the antifungal spectrum and therapeutic window for triazoles are [a] S. Wu,+ Y. Zhang,+ X. He,+ Dr. X. Che, Dr. S. Wang, Y. Liu, Y. Jiang, N. Liu, Dr. G. Dong, Prof. J. Yao, Prof. Z. Miao, Prof. Y. Wang, Prof. W. Zhang, Prof. C. Sheng School of Pharmacy, Second Military Medical University 325 Guohe Road, Shanghai 200433 (China) E-mail: [email protected] [email protected]
relatively narrow. Third, triazoles generally have drug-related side effects such as hepatic and renal toxicity. Therefore, it highly desirable to develop a new generation of triazole antifungal agents with improved pharmacological, pharmacokinetic, and safety profiles. New antifungal triazoles are emerging rapidly,[7] and two candidates (isavuconazole and albaconazole, Figure 1) are under late-stage clinical trials.[8] Triazole antifungals are inhibitors of lanosterol 14a-demethylase (CYP51). CYP51 catalyzes the synthesis of ergosterol from lanosterol in the fungal cell membrane. Inhibition of CYP51 causes depletion of ergosterol, accumulation of methylsterols within the cell membrane, and finally results in the inhibition of fungal cell growth or leads to cell death.[9] Despite the importance of CYP51 in antifungal drug discovery, crystal structures of CYP51s from pathogenic fungi have yet to be reported. Previously, we constructed three-dimensional models of CYP51 from Candida albicans (CACYP51), Cryptococcus neoformans (CNCYP51), and Aspergillus fumigatus (AFCYP51) by homology modeling,[10] and investigated the binding modes of triazole antifungal agents by molecular docking and molecular dynamics simulations.[10a, 11] Guided by the results from molecular modeling, a number of new triazoles were rationally designed and synthesized by our research group.[11b, 12] Among them, iodiconazole was developed as a tropical antifungal agent, and its phase III clinical trial is finished.[13] Inspired by these results, a series of triazole–thiazolidinedione hybrids were rationally designed and synthesized, as reported herein.
[+] These authors contributed equally to this work.
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Figure 1. Structures of triazole antifungal agents.
Most of the target compounds showed good to excellent broad-spectrum antifungal activity. Chemistry Synthesis of the target compounds is outlined in Scheme 1. Compound 11 was synthesized by our previously reported procedure (Scheme 1).[11b] It was then dissolved in dichloromethane, and the solution was neutralized with a saturated solution of sodium carbonate to afford the oxirane intermediate 12. A ring-opening reaction was performed between rosiglitazone and oxirane 12 in the presence of tetra-n-butylammonium bromide (TBABr) and DMSO to furnish the target compound 13 a. In the presence of piperidine, thiazolidinedione was allowed to react with various aldehydes in ethanol at reflux to give thiazolidinedione intermediates 14 a–v. Similar ring-opening reactions were performed between thiazolidinediones (16 and 14 a–v) and oxirane 12 to afford the target compounds 13 b and 15 a–v. All target compounds were obtained as racemates.
four inhibitor binding regions: a tertiary alcohol binding pocket (S1), a triazole binding pocket (S2), a difluorophenyl binding pocket (S3), and a C3 side chain binding pocket (S4).[10b, 11b] Most of the medicinal chemistry efforts for triazole optimization were focused on variation of the C3 side chains, with triazole, difluorophenyl, and tertiary alcohol being maintained as essential pharmacophores.[14] The C3 side chain binding pocket is located in a hydrophobic hydrogen bonding site (facing FG loop), which can bind diverse chemotypes.[15] As shown in Figure 1, various side chains with different lengths can be accommodated by the S4 pocket, which plays an important role in antifungal activity and pharmacokinetic profiles. Thus, we envisioned that a drug-like side chain can be designed from drugs already on the market. To validate this hypothesis, we reviewed FDA-approved drugs, particularly those with properties suitable for fitting into the CYP51 S4 pocket. As a proof-of-concept study, rosiglitazone (an antidiabetic drug) was chosen for the molecular design. Thus, fluconazole–rosiglitazone hybrid molecule 13 a was designed (Figure 2) and docked into the active site of CACYP51 using a well-validated docking protocol.[16] As shown in Figure 3 A, the binding modes of triazole, tertiary alcohol, and di-
Results and Discussion Design rationale of triazole– thiazolidinedione hybrids Computational analysis of the CACYP51 active site revealed
Figure 2. Design rationale of triazole–thiazolidinedione hybrids.
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www.chemmedchem.org pound 13 a indicated that the rosiglitazone-containing side chain binds CACYP51 by a nonlinear conformation (Figure 3 A), which differs from triazole antifungal agents with a long side chain (e.g., itraconazole and posaconazole).[10a] To clarify the essential structural element in the rosiglitazone side chain, only the thiazolidinedione group was retained to afford compound 13 b, which can be regarded as a bioisostere of fluconazole. Interestingly, simplification of the side chain led to a significant improvement in antifungal activity. The MIC80 value of compound 13 b against C. albicans is 0.17 mm, which is fourfold more potent than fluconazole and 64fold more potent than lead compound 13 a. The binding mode of compound 13 b was further clarified by molecular docking. As depicted in Figure 3 B, the carbonyl group of thiazolidinedione forms a hydrogen bond with Tyr118 of CACYP51, which may explain the increase in antifungal activity. The results also indicated that the terminal portion of rosiglitazone is unfavorable for inhibitor binding. SARs of triazole–thiazolidinedione hybrids Considering the hydrophobic nature of the S4 pocket, various aromatic groups were introduced onto the thiazolidinedione ring to further improve antifungal activity. First, compounds 15 a–h were synthesized and assayed. Gratifyingly, most of the compounds showed excellent antifungal activity (Table 1). With respective MIC80 values against C. albicans of 0.03 and 0.029 mm, compounds 15 c and 15 g were found to be significantly more active than 13 b. In particular, compound 15 c is also highly active against C. neoformans (MIC80 = 0.12 mm) and C. tropicalis (MIC80 = 0.0078 mm). Structure–activity relationship (SAR) analysis revealed that the introduction of a phenylethylene group on the thiazolidinedione ring (compound 15 b) has relatively little impact on antifungal activity. In contrast, substitutions on the phenylethylene group are quite important for antifungal activity. For example, 2,4-dichloro (15 c) and 4-bromo (15 g) substitutions are favorable for anti-
Scheme 1. Reagents and conditions: a) ClCH2COCl, AlCl3, CH2Cl2, 40 8C, 3 h, 50 %; b) triazole, K2CO3, CH2Cl2, RT, 24 h, 70.0 %; c) (CH3)3SOI, NaOH, toluene, 60 8C, 3 h, 62.3 %; d) CH2Cl2, Na2CO3, RT, 10 min, 73.2 %; e) DMSO, TBABr, 80 8C, 3 h, 55–63 %; f) EtOH, piperidine, reflux, 5 h, 36.4–89.3 %.
fluorophenyl are similar to that of fluconazole. The rosiglitazone-containing side chain is located in the S4 pocket and forms hydrophobic interactions with the surrounding residues (e.g., Phe126 and Tyr118). Subsequently, compound 13 a was synthesized and subjected to antifungal assays. Fortunately, it showed broad-spectrum antifungal activity against C. albicans and C. neoformans, with respective MIC80 values of 6.72 and 13.45 mm. Lead optimization of triazole–thiazolidinedione hybrids Encouraged by the results, further structural optimization of compound 13 a was performed. The docking model of com 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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www.chemmedchem.org Table 1. In vitro antifungal activity of the target compounds. Compound 13 a 13 b 15 a 15 b 15 c 15 d 15 e 15 f 15 g 15 h fluconazole
Figure 3. Docking conformations of compounds A) 13 a and B) 13 b in the active site of CACYP51. The hydrogen bond is represented as a dashed line.
MIC80 [mm][a] C. tro.
C. alb.
C. neo.
6.72 0.17 1.92 0.14 0.030 0.13 0.13 8.76 0.029 2.25 0.82
13.45 11.29 30.69 36.16 0.12 8.50 8.02 > 100 7.67 9.02 52.24
– 0.71 > 100 0.56 0.0078 8.50 0.50 > 100 1.92 9.02 0.20
A. fum. > 100 > 100 > 100 > 100 > 100 > 100 > 100 > 100 > 100 > 100 > 100
[a] Data are the mean of n = 3 experiments; C. alb.: Candida albicans, C. neo.: Cryptococcus neoformans, C. tro.: Candida tropicalis, A. fum.: Aspergillus fumigatus.
fungal activity, whereas 2-bromo (15 a) and 2-methyl Table 2. In vitro antifungal activity and spectrum of the target compounds. (15 f) groups had negative effects. In an attempt to obtain more SAR information and Compound MIC80 [mm][a] investigate the antifungal spectrum, compounds C. alb. C. par. C. neo. C. gla. A. fum. T. rub. M. gyp. 15 i–v, with more phenylethylene substitutions (e.g., 15i 1.06 4.23 4.23 2.17 > 100 4.23 8.47 alkyl groups) or phenyl/heterocycle replacements 15j 0.15 1.16 4.62 0.29 > 100 4.62 9.25 were designed and synthesized. In general, these de15k 0.57 1.13 72.16 4.51 > 100 2.25 36.08 15l 1.09 0.54 4.34 0.54 > 100 2.17 8.69 rivatives also showed good to excellent broad-spec15m 4.19 16.76 67.10 4.19 > 100 16.76 > 100 trum antifungal activity (Table 2). Besides the fungal 15n 1.01 2.21 8.10 0.51 > 100 2.21 8.10 pathogens listed in Table 1, the compounds were 15o 0.53 4.28 68.46 0.27 > 100 68.46 68.46 also active against other Candida spp. (C. glabrata 15p 4.51 36.08 > 100 1.13 > 100 36.08 18.04 15q 1.04 8.36 8.36 1.04 > 100 4.18 2.09 and C. parapsilosis) and dermatophytes (T. rubrum 15r 0.15 1.16 2.31 0.29 > 100 4.62 1.16 and M. gypseum). Among the various substitutions 15s 0.56 2.24 4.49 2.24 > 100 8.98 4.49 on phenylethylene, the 4-methoxy (15 i), 4-fluoro 15t 0.31 2.46 1.23 0.31 > 100 39.37 19.68 (15 l), 4-chloro (15 m), 4-cyano (15 o), and 2,4-difluoro 15u 2.06 8.24 8.24 4.12 > 100 2.06 8.24 15v 1.11 2.23 8.92 0.56 > 100 2.23 8.92 (15 q) derivatives were found to be more potent. For fluconazole 0.81 3.26 6.53 3.26 > 100 3.26 26.12 the heterocyclic derivatives, 2-furyl analogue 15 j and 3-furyl analogue 15 r showed the best activity. The [a] Data are the mean of n = 3 experiments; C. alb.: Candida albicans, C. par.: Candida parapsilosis, C. neo.: Cryptococcus neoformans, C. gla.: Candida glabrata, A. fum.: AsperMIC80 values of compounds 15 j and 15 r against gillus fumigatus, T. rub.: Trichophyton rubrum, M. gyp.: Microsporum gypseum. C. albicans were both 0.15 mm. Moreover, they also showed excellent activity against C. glabrata (MIC80 = 0.29 mm). 3-Pyridinyl derivative 15 k was more potent than 2-pyridinyl derivative 15 h and 4-pyridinyl derivative 15 p. Moreover, 2-quinolinyl (15 n), 2-pyrrolyl that are effective against resistant fungal strains. Herein, com(15 s), and 2-thienyl (15 v) derivatives were less active than the pounds 15 j and 15 r were assayed for inhibitory activity corresponding furyl derivatives. Molecular docking studies reagainst four clinical isolates of C. albicans (Table 3), which are vealed that a hydrogen bond between thiazolidinedione and resistant to fluconazole (MIC > 3343.45 mm). Interestingly, the Tyr118 was retained for compounds 15 c and 15 j (Figure 4). two compounds were proven to be effective against these fluThe substituted phenyl or furan formed hydrophobic interacconazole-resistant isolates, highlighting their promise as canditions with Leu121, Phe380, Met508, and Val509 among others. dates for further optimization. The substitutions on the phenyl ring (e.g., dichloro substitution of compound 15 c) contributed additional hydrophobic interactions with Met508 and Val509, and thus had different effects Conclusions on antifungal activity. From a clinical perspective, a serious problem for triazole anIn summary, molecular hybridization of fluconazole and rosiglitifungal agents is the emergence of resistant fungal strains, tazone was used to design a series of triazole–thiazolidinewhich significantly decrease the therapeutic efficacy. Therefore, dione derivatives. Among them, compounds 15 c, 15 g, 15 j, it is highly desirable to develop new triazole antifungal agents and 15 r showed excellent activity against C. albicans, with 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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www.chemmedchem.org Synthesis of (Z)-5-(2,4-dichlorobenzylidene)thiazolidine-2,4dione (14 c): A mixture of thiazolidinedione (200 mg, 1.71 mmol, 1 equiv), 2,4-dichlorobenzaldehyde (448.3 mg, 2.56 mmol, 1.5 equiv), piperidine (217.9 mg, 2.50 mmol, 1.5 equiv) and EtOH (20 mL) was stirred at reflux for 5 h. The reaction mixture was poured into ice water, and a yellow solid precipitated. After filtration, product 14 c (280 mg) was obtained, which could be used directly in the subsequent step without further purification. The synthetic procedures for compounds 14 a–v were similar to those used for the synthesis of compound 14 c.
Figure 4. Stereoview of the docking conformation of compound 15 c (A) and j (B) in the active site of CACYP51. The hydrogen bond is represented as a dashed line.
Table 3. Inhibitory activities of compounds 15 j and 15 r against fluconazole-resistant clinical isolates of C. albicans (all MIC values in mm). Clinical isolate 100 103 805 0710922
15 j MIC80
MIC50
74.00 4.62 148.01 9.25 18.50 0.58 > 148.01 > 148.01
15 r MIC80 MIC50 37.00 2.31 74.00 18.50 74.00 0.58 74.00 1.16
Fluconazole MIC80 MIC50 > 3343.45 > 3343.45 > 3343.45 > 3343.45
> 3343.45 > 3343.45 > 3343.45 > 3343.45
MIC80 values in the range of 0.029–0.15 mm. Moreover, compounds 15 j and 15 r were also found to be effective against fluconazole-resistant clinical isolates. Molecular docking studies revealed that the target compounds interact with CACYP51 mainly through hydrogen bonding and hydrophobic interactions. Taken together, the results of this study have provided some promising lead compounds for the development of a new generation of triazole antifungal agents and have proven the effectiveness of molecular hybridization in antifungal drug discovery.
Experimental Section General synthesis procedures: All reagents and solvents were reagent grade. 1H and 13C NMR spectra were recorded on Bruker 500 or 600 spectrometers, with TMS as the internal standard and CDCl3 or [D6]DMSO as the solvent. Chemical shifts (d) and coupling constants (J) are given in ppm and Hz, respectively. ESI mass spectrometric data were collected on an API-3000 LC–MS spectrometer. TLC analysis was carried out on silica gel plates G F254 (Qindao Haiyang Chemical, China). Silica gel column chromatography was performed with Silica gel 60G (Qindao Haiyang Chemical, China). 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Synthesis of (Z)-5-(2,4-dichlorobenzylidene)-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine2,4-dione (15 c): A mixture compound 14 c (278.4 mg, 1.02 mmol, 1.0 equiv), oxirane intermediate 12 (484.6 mg, 2.04 mmol, 2.0 equiv), TBABr (19.3 mg, 0.10 mmol, 0.1 equiv), and DMSO (10 mL) was stirred at 80 8C for 3 h, then diluted with EtOAc (50 mL). The organic layer was washed with H2O (3 20 mL), dried over anhydrous Na2SO4, and filtered. The solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane/EtOAc 3:1!1:1, v/v) to give 15 c as a yellow solid (0.48 g, 55 % yield, two steps). 1H NMR (600 MHz, [D6]DMSO): d = 8.35 (s, 1 H), 7.88 (s, 1 H), 7.79 (s, 1 H), 7.72 (s, 1 H), 7.44 (s, 1 H), 7.04–7.40 (m, 6 H), 5.75 (s, 1 H), 4.90 (d, J = 14.7 Hz, 1 H), 4.85 (d, J = 14.7 Hz, 1 H), 3.8 ppm (m, 2 H); 13C NMR (75 MHz, CDCl3, TMS): d = 160.44, 152.00, 144.87, 135.77, 135.61, 133.79, 130.68, 130.44, 129.91, 129.43, 129.37, 129.30, 129.24, 126.85, 122.31, 112.61, 112.56, 112.28, 105.66, 105.30, 104.96, 84.37, 84.30, 57.01, 30.60, 30.49 ppm; MS (ESI) m/z: 543.37 [(M + MeOH)H]. The synthetic procedures for compounds 15 a–v were similar to those used for compound 15 c. 3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(4-(2-(methyl(pyridin-2-yl)amino)ethoxy)benzyl)thiazolidine-2,4-dione (13 a): Yellow oil (0.33 g, 55.3 %); 1H NMR (500 MHz, CDCl3, TMS): d = 8.15 (d, J = 4.1 Hz, 1 H), 8.00 (s, 1 H), 7.80 (s, 1 H), 7.46 (m, 2 H), 7.10 (d, J = 8.4 Hz, 2 H), 6.82 (m, 4 H), 6.54 (m, 2 H), 4.74 (t, J = 13.1 Hz, 1 H), 4.39 (m, 2 H), 4.13 (m, 3 H), 3.96 (m, 3 H), 3.36 (m, 1 H), 3.14 (d, J = 4.4 Hz, 3 H), 2.94 ppm (m, 1 H); 13C NMR (500 MHz, CDCl3, TMS): d = 174.64, 174.48, 171.81, 158.41, 158.27, 151.73, 147.84, 144.49, 137.27, 130.44, 130.32, 129.89, 127.30, 127.20, 114.72, 111.75, 111.57, 105.70, 104.24, 66.28, 55.37, 51.82, 51.62, 49.42, 47.75, 37.97, 37.79, 37.55 ppm; HRMS (ESI) calcd (%) for C29H28F2N2O4 [M + H]: 595.1939, found: 595.1947. 3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione (13 b): Pale yellow oil (0.23 g, 63.0 %); 1 H NMR (500 MHz, CDCl3, TMS): d = 8.13 (s, 1 H), 7.85 (s, 1 H), 6.77– 7.55 (m, 3 H), 5.30 (s, 1 H), 4.71 (dd, 2 H, J1 = 10.8 Hz, J2 = 14.1 Hz), 4.02 (s, 2 H), 3.50 (d, 1 H, J = 14.4 Hz), 2.94 ppm (d, 1 H, J = 14.4 Hz); 13 C NMR (500 MHz, CDCl3, TMS): d = 164.64, 164.48, 161.32, 161.16, 160.29, 160.14, 157.03, 156.88, 151.52, 144.43, 130.22, 130.15, 130.10, 130.02, 124.49, 124.44, 124.32, 124.26, 111.80, 111.76, 111.53, 111.48, 104.56, 104.22, 104.20, 103.86, 75.51, 75.44, 61.95, 56.45, 56.38, 41.46, 41.40, 35.12, 29.67, 14.06 ppm; MS (ESI) m/z: 355.30 [M + H]. (Z)-5-(2-Bromobenzylidene)-3-(2-(2,4-difluorophenyl)-2-hydroxy3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione (15 a): Yellow oil (0.30 g, 57.2 %); 1H NMR (500 MHz, CDCl3, TMS): d = 8.18 (s, 1 H), 8.15 (s, 1 H), 7.86 (s, 1 H), 6.80–7.70 (m, 7 H), 5.03 (s, 1 H), 4.86 (d, 1 H, J = 14.2 Hz), 4.64 (d, 1 H, J = 14.3 Hz), 4.40 (d, 1 H, J = 14.4 Hz), 4.14 ppm (d, 1 H, J = 14.3 Hz); 13C NMR (125 MHz, CDCl3, TMS): d = 168.2, 166.68, 165.90, 164.28, 164.18, 162.28, 160.05, 159.95, 158.09, 157.99, 151.47, 144.70, 144.24, 138.00, 134.00,
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CHEMMEDCHEM FULL PAPERS 133.17, 132.67, 131.84, 130.68, 129.98, 129.94, 129.90, 129.86, 129.03, 127.96, 126.90, 126.45, 123.44, 112.00, 111.98, 111.84, 104.57, 104.36, 104.15, 75.93, 75.89, 71.94, 62.66, 55.72, 55.66, 47.93, 29.69 ppm; MS (ESI) m/z: 522.31 [M + H]. (Z)-5-Benzylidene-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione (15 b): White solid (0.25 g, 56.1 %); 1H NMR (500 MHz, CDCl3, TMS): d = 8.05 (s, 1 H,), 7.89 (s, 1 H), 7.83 (s, 1 H), 6.79–7.54 (m, 8 H), 5.30 (s, 1 H), 4.85 (d, 1 H, J = 14.3 Hz), 4.64 (d, 1 H, J = 14.3 Hz), 4.39 (d, 1 H, J = 14.4 Hz), 4.18 ppm (d, 1 H, J = 14.4 Hz); MS (ESI) m/z: 443.41 [M + H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(2,4-dimethylbenzylidene)thiazolidine-2,4-dione (15 d): White solid (0.27 g, 56.3 %); 1H NMR (500 MHz, CDCl3, TMS): d = 8.31 (s, 1 H), 8.04 (s, 1 H), 7.89 (s, 1 H), 6.88–7.34 (m, 6 H), 5.20 (s, 1 H), 4.80 (d, 1 H, J = 14.7 Hz), 4.68 (d, 1 H, J = 14.7 Hz), 3.62 (d, 1 H, J = 14.2 Hz), 3.19 (d, 1 H, J = 14.3 Hz), 2.29 (s, 3 H), 2.21 ppm (s, 3 H); MS (ESI) m/z: 471.48 [M + H]. (Z)-5-(4-(tert-Butyl)benzylidene)-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione (15 e): Pale yellow solid (0.28 g, 55.3 %); 1H NMR (500 MHz, CDCl3, TMS): d = 8.11 (s, 1 H), 8.01 (s, 1 H), 7.94 (s, 1 H), 6.21–7.39 (m, 7 H), 5.48 (s, 1 H), 4.33 (dd, 1 H, J1 = 9.0 Hz, J2 = 14.0 Hz), 3.48 (d, 1 H, J = 10.2 Hz), 3.23 (d, 1 H, J = 10.2 Hz), 1.30 ppm (s, 9 H); MS (ESI) m/z: 499.52 [M + H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(2-methylbenzylidene)thiazolidine-2,4-dione (15 f): White solid (0.27 g, 57.1 %); 1H NMR (500 MHz, CDCl3, TMS): d = 8.42 (s, 1 H), 7.99 (s, 1 H), 7.93 (s, 1 H), 6.89–7.34 (m, 7 H), 4.82 (d, 1 H, J = 14.6 Hz), 4.71 (d, 1 H, J = 14.6 Hz), 3.63 (d, 1 H, J = 14.4 Hz), 3.21 (d, 1 H, J = 14.3 Hz), 2.22 ppm (s, 3 H); MS (ESI) m/z: 457.45 [M + H]. (Z)-5-(4-Bromobenzylidene)-3-(2-(2,4-difluorophenyl)-2-hydroxy3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione (15 g): Brown oil (0.31 g, 58.4 %); 1H NMR (500 MHz, CDCl3, TMS): d = 8.72 (s, 1 H), 8.11 (s, 1 H), 8.02 (s, 1 H), 6.88–7.53 (m, 7 H), 4.88 (d, 1 H, J = 14.6 Hz), 4.78 (d, 1 H, J = 13.7 Hz), 3.72 (d, 1 H, J = 13.8 Hz), 3.34 ppm (d, 1 H, J = 15.0 Hz); MS (ESI) m/z: 521.32 [M + H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(pyridin-2-ylmethylene)thiazolidine-2,4-dione (15 h): Pale brown solid (0.26 g, 56.7 %); 1H NMR (500 MHz, CDCl3, TMS): d = 8.25 (s, 1 H), 8.14 (s, 1 H), 7.88 (s, 1 H), 6.88–8.06 (m, 6 H), 5.30 (s, 1 H), 4.81 (d, 1 H, J = 14.7 Hz), 4.68 (d, 1 H, J = 14.7 Hz), 3.88 (d, 1 H, J = 14.2 Hz), 3.32 ppm (d, 1 H, J = 14.2 Hz); MS (ESI) m/z: 434.41 [M + H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(4-methoxybenzylidene)thiazolidine-2,4-dione (15 i): Yellow oil (0.29 g, 59.3 %); 1H NMR (600 MHz, CDCl3, TMS): d = 8.20 (s, 1 H), 7.85 (s, 1 H), 7.84 (s, 1 H), 7.51 (m, 1 H), 7.45 (d, J = 8.8 Hz, 2 H), 7.00 (d, J = 8.8 Hz, 2 H), 6.82 (m, 2 H), 5.16 (br s, 1 H), 4.86 (d, J = 14.3 Hz, 1 H), 4.66 (d, J = 14.3 Hz, 1 H), 4.41 (d, J = 14.3 Hz, 1 H), 4.15 (d, J = 14.3 Hz, 1 H), 3.88 ppm (s, 3 H); 13C NMR (500 MHz, CDCl3, TMS): d = 168.68, 167.53, 161.87, 135.21, 132.49, 131.13, 129.94, 125.49, 116.99, 114.89, 111.91, 104.64, 104.30, 103.93, 55.53, 47.94 ppm; MS (ESI) m/z: 473.57 [M + H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(furan-3-ylmethylene)thiazolidine-2,4-dione (15 j): White solid (0.24 g, 55.2 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.28 (s, 1 H), 8.07 (d, J = 1.6 Hz, 1 H), 7.70 (s, 1 H), 7.69 (s, 1 H), 7.26 (m, 1 H), 7.18 (m, 1 H), 7.13 (d, J = 3.5 Hz, 1 H), 6.87 (t, J =
2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemmedchem.org 8.0 Hz, 1 H), 6.76 (dd, J = 1.8, 3.5 Hz, 1 H), 6.05 (s, 1 H), 4.82 (d, J = 14.7 Hz, 1 H), 4.59 (d, J = 14.7 Hz, 1 H), 4.10 ppm (s, 2 H); 13C NMR (75 MHz, CDCl3, TMS): d = 169.54, 167.07, 151.72, 149.51, 130.06, 120.73, 118.69, 117.84, 113.36, 111.68, 55.59, 29.69 ppm; MS (ESI) m/z: 433.36 [M + H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(pyridin-3-ylmethylene)thiazolidine-2,4-dione (15 k): White solid (0.27 g, 59.2 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.85 (d, J = 2.37 Hz, 1 H), 8.64 (dd, J = 1.5, 4.8 Hz, 1 H), 8.28 (s, 1 H), 7.98 (dt, J = 2.0, 8.2 Hz, 1 H), 7.92 (s, 1 H), 7.69 (s, 1 H), 7.57 (dd, J = 4.8, 8.0 Hz), 1 H), 7.27 (dd, J = 8.9, 15.9 Hz, 1 H), 7.19 (m, 1 H), 6.89 (t, J = 8.05 Hz, 1 H), 6.10 (s, 1 H), 4.82 (d, J = 14.4 Hz, 1 H), 4.61 (d, J = 14.4 Hz, 1 H), 4.15 (d, J = 14.3 Hz, 1 H), 4.12 ppm (d, J = 14.3 Hz, 1 H); 13C NMR (75 MHz, CDCl3, TMS): d = 167.57, 166.56, 151.91, 151.59, 151.10, 144.53, 136.11, 131.11, 130.03, 129.96, 129.90, 129.83, 129.02, 123.95, 122.93, 122.52, 122.34, 112.03, 111.80, 111.75, 104.67, 104.32, 103.96, 60.38, 55.51, 55.42, 47.96, 47.91, 21.03, 14.18 ppm; MS (ESI) m/z: 444.30 [M + H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(4-fluorobenzylidene)thiazolidine-2,4-dione (15 l): White solid (0.27 g, 58.6 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.28 (s, 1 H), 7.90 (s, 1 H), 7.70 (dd, J = 5.7, 8.8 Hz, 1 H), 7.69 (s, 1 H), 7.40 (t, J = 8.8 Hz, 2 H), 7.27 (dd, J = 8.9, 15.9 Hz, 1 H), 7.18 (m, 1 H), 6.88 (t, J = 8.05 Hz, 1 H), 6.08 (s, 1 H), 4.82 (d, J = 14.6 Hz, 1 H), 4.61 (d, J = 14.6 Hz, 1 H), 4.14 (d, J = 14.1 Hz, 1 H), 4.11 ppm (d, J = 14.1 Hz, 1 H); 13C NMR (75 MHz, CDCl3, TMS): d = 168.19, 167.09, 165.58, 162.20, 151.85, 144.56, 133.84, 132.50, 132.29, 130.05, 129.97, 129.92, 129.85, 129.22, 129.18, 122.58, 122.41, 122.36, 119.97, 116.54, 112.02, 111.97, 116.54, 112.02, 111.97, 116.54, 112.02, 111.97, 111.74, 111.70, 104.65, 104.29, 103.94, 55.58, 55.49, 47.93, 47.88 ppm; MS (ESI) m/z: 461.40 [M + H]. (Z)-5-(4-Chlorobenzylidene)-3-(2-(2,4-difluorophenyl)-2-hydroxy3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione (15 m): Brown solid (0.29 g, 60.2 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.37 (s, 1 H), 7.89 (s, 1 H), 7.71 (s, 1 H), 7.58 (d, J = 8.7 Hz, 2 H), 7.49 (d, J = 8.7 Hz, 2 H), 7.33 (m, 1 H), 7.16 (m, 1 H), 7.06 (td, J = 2.4, 8.4 Hz, 1 H), 4.91 (d, J = 14.9 Hz, 1 H), 4.86 (d, J = 14.9 Hz, 1 H), 3.88 (d, J = 14.4 Hz, 1 H), 3.73 ppm (d, J = 14.4 Hz, 1 H); 13C NMR (75 MHz, CDCl3, TMS): d = 160.75, 151.95, 144.84, 137.29, 135.63, 132.47, 131.70, 129.43, 129.37, 129.30, 129.24, 128.86, 120.57, 120.47, 120.41, 119.28, 112.58, 112.30, 112.25, 105.62, 105.28, 104.92, 84.28, 84.22, 57.04, 30.55, 30.45, 29.67 ppm; MS (ESI) m/z: 477.45 [M + H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(quinolin-2-ylmethylene)thiazolidine-2,4-dione (15 n): Gray solid (0.31 g, 62.2 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.49 (d, J = 8.4 Hz, 1 H), 8.29 (s, 1 H), 8.13 (d, J = 8.1 Hz, 1 H), 8.06 (s, 1 H), 8.03 (d, J = 7.9 Hz, 1 H), 7.97 (d, J = 8.4 Hz, 1 H), 7.85 (m, 1 H), 7.69 (s, 1 H), 7.68 (m, 1 H), 6.87–7.30 (m, 3 H), 6.08 (s, 1 H), 4.85 (d, J = 14.4 Hz, 1 H), 4.63 (d, J = 14.4 Hz, 1 H), 3.31 ppm (s, 2 H); 13C NMR (75 MHz, CDCl3, TMS): d = 173.31, 167.36, 151.74, 151.16, 147.71, 144.62, 137.13, 130.60, 130.08, 130.01, 129.88, 129.64, 129.14, 128.05, 127.65, 127.36, 127.16, 123.80, 122.61, 122.48, 111.96, 111.92, 111.68, 111.64, 104.65, 104.29, 103.95, 55.72, 55.63, 47.43, 47.39, 29.69 ppm; MS (ESI) m/z: 494.42 [M + H]. (Z)-4-((3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1yl)propyl)-2,4-dioxothiazolidin-5-ylidene)methyl)benzonitrile (15 o): Pale yellow solid (0.26 g, 55.7 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.25 (s, 1 H), 7.97 (d, J = 8.4 Hz, 2 H), 7.92 (s, 1 H), 7.77 (d, J = 8.4 Hz, 2 H), 7.67 (s, 1 H), 7.24 (dd, J = 8.8, 15.8 Hz, 1 H), 7.17 (m, 1 H), 6.87 (td, J = 2.4, 8.4 Hz, 1 H), 6.08 (s, 1 H), 4.79 (d, J = 14.4 Hz, 1 H), 4.59 (d, J = 14.4 Hz, 1 H), 4.13 (d, J = 14.1 Hz, 1 H),
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4.09 ppm (d, J = 14.1 Hz, 1 H); 13C NMR (125 MHz, CDCl3, TMS): d = 167.37, 166.47, 164.28, 164.18, 162.28, 162.18, 160.00, 159.90, 158.04, 157.94, 151.89, 144.52, 137.10, 132.88, 132.13, 130.38, 129.99, 129.95, 129.91, 129.87, 124.35, 122.45, 122.42, 122.35, 122.32, 117.90, 113.86, 112.05, 112.03, 111.89, 111.86, 104.55, 104.34, 104.13, 75.98, 75.94, 55.48, 55.42, 47.96, 47.93, 29.69 ppm; MS (ESI) m/z: 468.43 [M + H].
1.07 (m, 2 H), 0.88 ppm (m, 2 H); 13C NMR (125 MHz, CDCl3, TMS): d = 163.88, 161.13, 159.43, 159.34, 157.44, 157.34, 155.28, 155.18, 153.32, 147.31, 147.22, 147.19, 146.94, 146.77, 146.71, 140.69, 139.94, 139.80, 139.49, 125.25, 125.21, 125.18, 125.13, 117.88, 117.85, 117.78, 117.75, 115.91, 107.09, 017.06, 016.92, 106.90, 99.72, 99.52, 99.51, 99.30, 71.23, 71.19, 51.37, 50.90, 50.85, 43.03, 43.05, 24.93 ppm; MS (ESI) m/z: 407.39 [M + H].
(Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(pyridin-4-ylmethylene)thiazolidine-2,4-dione (15 p): Yellow solid (0.26 g, 58.5 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.72 (m, 2 H), 8.26 (s, 1 H), 7.84 (s, 1 H), 7.68 (s, 1 H), 7.54 (m, 2 H), 6.85–7.28 (m, 3 H), 6.12 (s, 1 H), 4.79 (d, J = 13.8 Hz, 1 H), 4.59 (d, J = 13.8 Hz, 1 H), 4.11 ppm (s, 2 H); 13C NMR (125 MHz, DMSO, TMS): d = 172.18, 170.77, 168.33, 166.37, 166.27, 165.76, 163.69, 155.90, 155.76, 150.16, 150.01, 145.22, 134.89, 131.57, 129.08, 128.95, 128.60, 128.53, 116.02, 115.87, 109.16, 79.50, 79.46, 60.01, 53.28 ppm; MS (ESI) m/z: 444.52 [M + H].
(Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(4-(dimethylamino)benzylidene)thiazolidine-2,4-dione (15 u): Red solid (0.27 g, 55.0 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.28 (s, 1 H), 7.74 (s, 1 H), 7.68 (s, 1 H), 7.45 (d, J = 9.03 Hz, 2 H), 7.27 (m, 1 H), 7.17 (m, 1 H), 6.88 (td, J = 2.2, 8.6 Hz, 1 H), 6.82 (d, J = 9.03 Hz, 2 H), 6.03 (s, 1 H), 4.82 (d, J = 14.7 Hz, 1 H), 4.59 (d, J = 14.7 Hz, 1 H), 4.12 (d, J = 14.0 Hz, 1 H), 4.09 (d, J = 14.0 Hz, 1 H), 3.02 ppm (s, 6 H); 13C NMR (125 MHz, CDCl3, TMS): d = 169.12, 167.98, 164.16, 164.07, 162.17, 162.07, 160.11, 160.01, 158.14, 158.05, 151.95, 151.58, 144.62, 136.40, 132.87, 130.08, 130.03, 130.00, 129.96, 122.77, 122.74, 122.66, 122.63, 120.24, 112.49, 111.96, 111.77, 111.75, 111.61, 111.58, 104.47, 104.26, 104.05, 76.00, 75.96, 55.80, 55.75, 45.00, 47.97, 40.00, 30.21, 30.05, 29.69, 29.35 ppm; MS (ESI) m/z: 486.64 [M + H].
(Z)-5-(2,4-Difluorobenzylidene)-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione (15 q): White solid (0.28 g, 56.7 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.26 (s, 1 H), 7.84 (s, 1 H), 7.68 (s, 1 H), 6.85–7.58 (m, 6 H), 6.12 (s, 1 H), 4.79 (d, J = 14.2 Hz, 1 H), 4.58 (d, J = 14.2 Hz, 1 H), 4.13 (d, J = 14.6 Hz, 1 H), 4.07 ppm (d, J = 14.6 Hz, 1 H); 13C NMR (75 MHz, CDCl3, TMS): d = 168.13, 166.84, 164.92, 164.76, 163.16, 161.59, 161.43, 160.68, 160.52, 159.77, 157.41, 157.25, 151.82, 144.54, 132.87, 132.76, 130.05, 129.98, 129.92, 129.85, 128.94, 127.17, 127.08, 124.82, 124.77, 122.57, 122.52, 122.39, 122.34, 121.38, 121.22, 116.49, 116.20, 112.03, 111.99, 111.75, 111.71, 104.65, 104.31, 103.95, 55.57, 55.48, 47.94, 47.89 ppm; MS (ESI) m/z: 479.57 [M+H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(furan-3-ylmethylene)thiazolidine-2,4-dione (15 r): Pale brown solid (0.24 g, 55.0 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.27–8.28 (m, 2 H), 7.89–7.90 (m, 1 H), 7.77 (s, 1 H), 7.69 (s, 1 H), 7.16–7.28 (m, 2 H), 6.90 (td, J = 2.8, 11.2 Hz, 1 H), 6.77–6.78 (m, 1 H), 6.07 (s, 1 H), 4.81 (d, J = 14.3 Hz, 1 H), 4.60 (d, J = 14.3 Hz, 1 H), 4.11 (d, J = 14.1 Hz, 1 H), 4.08 ppm (d, J = 14.1 Hz, 1 H); 13C NMR (75 MHz, CDCl3, TMS): d = 167.86, 166.88, 164.90, 164.74, 161.58, 161.42, 160.70, 157.42, 157.27, 151.79, 146.68, 145.15, 144.55, 130.05, 129.97, 129.92, 129.85, 125.80, 122.59, 122.54, 122.41, 120.89, 119.58, 111.99, 111.94, 111.71, 111.67, 108.98, 104.64, 104.30, 103.94, 55.61, 55.52, 47.95, 47.91, 29.68 ppm; MS (ESI) m/z: 433.60 [M + H]. (Z)-3-(2-(2,4-Difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-((1-methyl-1H-pyrrol-2-yl)methylene)thiazolidine-2,4dione (15 s): Yellow solid (0.29 g, 64.6 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.27(s, 1 H), 7.69 (s, 1 H), 7.68 (s, 1 H), 6.84–7.35 (m, 4 H), 6.51 (dd, J = 1.2, 4.0 Hz, 1 H), 6.29 (dd, J = 2.6, 4.0 Hz, 1 H), 6.05 (s, 1 H), 4.81 (d, J = 14.5 Hz, 1 H), 4.57 (d, J = 14.5 Hz, 1 H), 4.09 (s, 2 H), 3.76 ppm (s, 3 H); 13C NMR (125 MHz, CDCl3, TMS): d = 168.70, 167.57, 164.19, 164.09, 162.20, 162.10, 160.09, 159.98, 158.12, 158.03, 144.64, 130.05, 130.01, 129.98, 129.93, 129.25, 127.91, 122.69, 122.66, 122.59, 122.56, 122.05, 116.63, 113.09, 111.83, 111.81, 116.67, 111.64, 111.31, 104.50, 104.29, 104.08, 76.00, 75.96, 55.76, 55.71, 48.00, 47.98, 34.35, 29.69 ppm; MS (ESI) m/z: 446.54 [M + H]. (Z)-5-(Cyclopropylmethylene)-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)thiazolidine-2,4-dione (15 t): Yellow solid (0.29 g, 64.6 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d = 8.25 (s, 1 H), 7.65 (s, 1 H), 7.11–7.25 (m, 2 H), 6.85 (td, J = 2.6, 8.5 Hz, 1 H), 6.55 (d. J = 11.1 Hz, 1 H), 5.98 (s, 1 H), 4.77 (d, J = 14.7 Hz, 1 H), 4.53 (d, J = 14.7 Hz, 1 H), 4.03 (s, 2 H), 1.40 (m, 1 H),
2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
(Z)-3-(2-(2,4-difluorophenyl)-2-hydroxy-3-(1H-1,2,4-triazol-1-yl)propyl)-5-(thiophen-2-ylmethylene)thiazolidine-2,4-dione (15 v): Yellow solid (0.26 g, 57.2 %); 1H NMR (600 MHz, [D6]DMSO, TMS): d 8.28 (s, 1 H), 8.15 (s, 1 H), 8.03 (d, J = 5.0 Hz, 1 H), 7.71 (d, J = 3.7 Hz, 1 H), 7.69 (s, 1 H), 7.30 (dd, J = 3.7, 5.0 Hz, 1 H), 7.17–7.28 (m, 2 H), 6.89 (td, J = 2.2, 8.6 Hz, 1 H), 6.08 (s, 1 H), 4.81 (d, J = 14.7 Hz, 1 H), 4.60 (d, J = 14.7 Hz, 1 H), 4.13 (d, J = 13.7 Hz, 1 H), 4.10 ppm (d, J = 13.7 Hz, 1 H); 13C NMR (125 MHz, CDCl3, TMS): d = 167.02, 164.56, 164.46, 162.55, 160.81, 159.72, 151.92, 140.72, 139.99, 138.01, 137.94, 136.17, 135.85, 133.75, 132.89, 131.84, 131.58, 130.29, 129.49, 129.45, 129.41, 129.37, 127.72, 127.00, 120.22, 114.79, 114.51, 112.48, 112.34, 112.31, 111.54, 111.38, 105.45, 105.24, 105.03, 104.27, 104.06, 103.85, 84.35, 84.31, 74.80, 57.05, 56.67, 5310, 43.50, 43.46, 30.81, 30.75 ppm; MS (ESI) m/z: 449.53 [M + H]. In vitro antifungal activity assay: In vitro antifungal activity was measured according to the protocols from the National Committee for Clinical Laboratory Standards (NCCLS). The serial dilution method in 96-well microtest plates was used to determine the minimum inhibitory concentration (MIC) of the target compounds. Tested fungal strains were obtained from the ATCC or clinical isolates. Briefly, the MIC value is defined as the lowest concentration of test compound that results in a culture with turbidity less than or equal to 80 % inhibition relative to growth of the control. Tested compounds were dissolved in DMSO and serially diluted in growth medium. The yeasts were incubated at 35 8C, and the mold and dermatophytes at 28 8C. Growth MIC was determined at 24 h for Candida species, at 72 h for Cryptococcus neoformans, and at seven days for Aspergillus fumigatus.
Acknowledgements This work was supported in part by the National Natural Science Foundation of China (grant 81222044), the Key Project of Science and Technology of Shanghai (grant 13431900301), and the 863 Hi-Tech Program of China (grant 2014AA020525). Keywords: antifungal agents · Candida albicans · molecular hybridization · thiazolidinedione · triazoles
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CHEMMEDCHEM FULL PAPERS [1] D. A. Enoch, H. A. Ludlam, N. M. Brown, J. Med. Microbiol. 2006, 55, 809 – 818. [2] a) C. C. Lai, C. K. Tan, Y. T. Huang, P. L. Shao, P. R. Hsueh, J. Infect. Chemother. 2008, 14, 77 – 85; b) B. J. Park, K. A. Wannemuehler, B. J. Marston, N. Govender, P. G. Pappas, T. M. Chiller, AIDS 2009, 23, 525 – 530. [3] H. Wisplinghoff, T. Bischoff, S. M. Tallent, H. Seifert, R. P. Wenzel, M. B. Edmond, Clin. Infect. Dis. 2004, 39, 309 – 317. [4] a) F. C. Odds, Rev. Iberoam. Micol. 2005, 22, 229 – 237; b) F. C. Odds, A. J. Brown, N. A. Gow, Trends Microbiol. 2003, 11, 272 – 279. [5] C. Lass-Flçrl, Drugs 2011, 71, 2405 – 2419. [6] M. A. Pfaller, Am. J. Med. 2012, 125, S3 – 13. [7] a) R. Guillon, F. Pagniez, C. Rambaud, C. Picot, M. Duflos, C. Loge, P. Le Pape, ChemMedChem 2011, 6, 1806 – 1815; b) R. Guillon, F. Pagniez, F. Giraud, D. Crepin, C. Picot, M. Le Borgne, F. Morio, M. Duflos, C. Loge, P. Le Pape, ChemMedChem 2011, 6, 816 – 825; c) R. Guillon, C. Loge, F. Pagniez, V. Ferchaud-Roucher, M. Duflos, C. Picot, P. Le Pape, J. Enzyme Inhib. Med. Chem. 2011, 26, 261 – 269; d) R. Guillon, F. Giraud, C. Loge, M. Le Borgne, C. Picot, F. Pagniez, P. Le Pape, Bioorg. Med. Chem. Lett. 2009, 19, 5833 – 5836; e) F. Giraud, R. Guillon, C. Loge, F. Pagniez, C. Picot, M. Le Borgne, P. Le Pape, Bioorg. Med. Chem. Lett. 2009, 19, 301 – 304; f) R. Guillon, F. Pagniez, C. Picot, D. Hedou, A. Tonnerre, E. Chosson, M. Duflos, T. Besson, C. Loge, P. Le Pape, ACS Med. Chem. Lett. 2013, 4, 288 – 292; g) S. Yu, X. Chai, Y. Wang, Y. Cao, J. Zhang, Q. Wu, D. Zhang, Y. Jiang, T. Yan, Q. Sun, Drug Des. Dev. Ther. 2014, 8, 383 – 390; h) X. Cao, Z. Sun, Y. Cao, R. Wang, T. Cai, W. Chu, W. Hu, Y. Yang, J. Med. Chem. 2014, 57, 3687 – 3706. [8] O. Trel, Expert Rev. Anti-Infect. Ther. 2011, 9, 325 – 338. [9] G. I. Lepesheva, M. R. Waterman, Biochim. Biophys. Acta Proteins Proteomics 2011, 1814, 88 – 93. [10] a) C. Sheng, Z. Miao, H. Ji, J. Yao, W. Wang, X. Che, G. Dong, J. Lu, W. Guo, W. Zhang, Antimicrob. Agents Chemother. 2009, 53, 3487 – 3495; b) C. Sheng, W. Wang, X. Che, G. Dong, S. Wang, H. Ji, Z. Miao, J. Yao, W. Zhang, ChemMedChem 2010, 5, 390 – 397; c) C. Sheng, W. Zhang, M. Zhang, Y. Song, H. Ji, J. Zhu, J. Yao, J. Yu, S. Yang, Y. Zhou, J. Lu, J. Biomol. Struct. Dyn. 2004, 22, 91 – 99.
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