Targeting the energy coupling factor (ECF) transporters as novel antimicrobial target

Abstract

The present invention relates to novel inhibitors of the Energy Coupling Factor (ECF) Transporters. These compounds of general formula (Ia) or (Ib) are useful in the treatment of bacterial infections, especially caused by Streptococcus pneumoniae, Enterococcus faecium, Enterococcus faecalis.

Description

[0001] Targeting the Energy Coupling Factor (ECF) Transporters as novel antimicrobial target

[0002] The present invention relates to novel inhibitors of the Energy Coupling Factor (ECF) Transporters. These compounds are useful in the treatment of bacterial infections, especially caused by Streptococcus pneumoniae, Enterococcus faecium, or Enterococcus faecalis.

[0003] The energy-coupling factor (ECF) transporters are a family of transmembrane proteins involved in the uptake of vitamins into a wide range of bacteria. The term ECF transporter was coined in the 1970s to describe transporters that are used in Lactobacillus casei for the uptake of vitamins.1Later on, ECF transporters have been found to be particulary abundant in the Firmicutes phylum of Gram-positive bacteria, including human pathogenic species.2Importantly, they are not present in eukaryotes and are specific importers of essential micronutrients such as water-soluble vitamins (folate3, riboflavin4, cobalamin5, biotin6, niacin7, thiamine8, pantothenate9) and metal cations (Ni2+and Co2+)10into bacteria and archaea. Clinically relevant bacteria where the ECF tranporters genes are essential are: S. pneumoniae, Staphylococcus aureus, E. faecium, E. faecalis, Clostridium tetani, C. novyi and C. difficile ,11Therefore, ECF transporters can be considered as novel potential antimicrobial targets to tackle infection due to their central role in the metabolism of bacteria.

[0004] They belong to the adenosine 5’ -triphosphate (ATP)-binding cassette (ABC) transporters and consist of two ATP-hydrolyzing, nucleotide-binding domain named ECF-A and, two transmembrane proteins, termed ECF-T and the S-component.12’13The ECF-A and ECF-T together form the tricomponent ECF module.13Main scaffold of the entire complex is the integral membrane ECF-T having a coupling domain on the cytoplasmatic side and two long a-helices that are arranged in X shape. These a- helices interact tightly with the ATPases and move jointly when, upon nucleotide binding and release, the ATPases switch between the open and closed conformation. The S-components are integral membrane proteins (20-25 KDa) and bind the substrate to be transported. This organization is typical and a unique feature for the ECF transporters, as other ABC utilize a soluble substrate-binding protein to capture ligands.14

[0005] ECF transporters are classified into two groups, group-l and -II. The ECF module in group-l interacts exclusively with a single “dedicated” S-component, whereas the module in group-l I interacts with different ones. The present invention describes novel inhibitors of the ECF-type II, meaning that multiple S-components (specific for different substrate) can interact with the same ECF module,15opening up the possibility to simultaneously block the uptake of several vitamins at the same time with only one inhibitor.

[0006] The present invention provides compounds of formula (la) and (lb): wherein

[0007] Z1N or CH;

[0008] Z2is 0, S or NH;

[0009] Z3is N or CH;

[0010] Z4is N or CH;

[0011] Y is hydrogen; halogen; -C1-4 alkyl; -C1-4 haloalkyl; COOH; OH; CONH2; CONHR’; PO(OH)2; or PO(OR’)2; R’ is a C1-4 alkyl group;

[0012] X is a bond; a C1-4 alkylene group; a -S-C1-4 alkylene group; a -O-C1-4 alkylene group; a -NH-C1-4 alkylene group; an optionally substituted phenylene group; or an optionally substituted heteroarylene group containing 5 or 6 ring atoms that are independently selected from C, N, 0 and S;

[0013] R1is hydrogen, halogen, an alkyl group, a cycloalkyl group, an optionally substituted phenyl group; or an optionally substituted heteroaryl group containing 5 or 6 ring atoms that are independently selected from C, N, 0 and S; and

[0014] R2is hydrogen, halogen, an alkyl group, a cycloalkyl group, an optionally substituted phenyl group; or an optionally substituted heteroaryl group containing 5 or 6 ring atoms that are independently selected from C, N, 0 and S; or a salt thereof.

[0015] According to a preferred embodiment, the present invention provides compounds of formula (Ila) and (lib):

[0016] (Ha) (Hb). wherein Z1, Z2, Z3, Z4, R1, R2and X are as defined above or below, or a salt thereof.

[0017] According to a further preferred embodiment, the present invention provides compounds of formula (III): wherein R1, R2and X are as defined above or below, or a salt thereof.

[0018] According to a moreover preferred embodiment, the present invention provides compounds of formula (IV): wherein R1and R2are as defined above or below, or a salt thereof.

[0019] Preferably, X is a Ci-4 alkylene group; an optionally substituted phenylene group; or an optionally substituted heteroarylene group containing 5 or 6 ring atoms that are independently selected from C, N, 0 and S.

[0020] Further preferably, R1is an optionally substituted phenyl group; or an optionally substituted heteroaryl group containing 5 or 6 ring atoms that are independently selected from C, N, 0 and S.

[0021] Moreover preferably, R2is an optionally substituted phenyl group; or an optionally substituted heteroaryl group containing 5 or 6 ring atoms that are independently selected from C, N, 0 and S. Further preferably, X is selected from the following groups:

[0022] -CH2-CH2-; -CH2-CH2-CH2-;

[0023] Further preferably, X is a bond or selected from the following groups: -S-CH(CH3)-; - CH2CH2-; and -CH2-.

[0024] Further preferably, X is selected from the following groups:

[0025] Moreover preferably, X is the following group:

[0026] Further preferably, X is selected from the following groups: -CH2-CH2-; and -CH2-CH2- CH2-.

[0027] Moreover preferably, X is the following group: -CH2-CH2-.

[0028] Further preferably, R1is an optionally substituted phenyl group. Moreover preferably, R2is an optionally substituted phenyl group.

[0029] The term "optionally substituted" refers to a group which is unsubstituted or substituted by one or more (especially by one, or two; preferably by one) substituent(s).

[0030] If a group comprises more than one substituent, these substituents are independently selected, i.e. , they may be the same or different.

[0031] Preferably, the optional substituents are independently selected from halogen; -OH; - NH2; -CN; -C1-4 alkyl; -C1-4 haloalkyl; -O-C1-4 alkyl; -O-C1-4 haloalkyl; -SO2NH2; - SO2CH3; -O-CH2-CH2-; and -O-CH2-O-.

[0032] Further preferably, the optional substituents are independently selected from -F; -Cl; - Me; -OMe; -CF3; -OCF3; -SO2NH2; -SO2CH3; -OCH(CH3)2; and -CN.

[0033] According to a preferred embodiment, the following compounds are excluded from the scope of the present application:

[0034] According to a further preferred embodiment, the compounds disclosed in S. Farooq, Z. Ngaini, ChemistrySelect 2022, 7, e202103984 (doi.org / 10.1002 / slct.202103984) are excluded from the scope of the present application (especially compounds 4a to 4c disclosed in Table 1 thereof).

[0035] According to another embodiment, the use of these compounds as inhibitors of the Energy Coupling Factor (ECF) Transporters is encompassed by the present invention; especially the use of these compounds in the treatment of bacterial infections, especially caused by Streptococcus pneumoniae, Enterococcus faecium, or Enterococcus faecalis.

[0036] The most preferred compounds of the present invention are the compounds disclosed in the examples, or a salt thereof.

[0037] The present invention moreover provides a compound selected from the following compounds: and

[0038] The present invention further provides a compound of the following general formula: wherein R1is a substituted phenyl group; especially wherein R1is selected from the following groups:

[0039] It is further preferred to combine the preferred embodiments of the present invention in any desired manner (e.g., any embodiment for R1may be combined with any embodiment of R2).

[0040] The expression alkyl refers to a saturated, straight-chain or branched hydrocarbon group that contains from 1 to 20 carbon atoms, preferably from 1 to 15 carbon atoms, especially from 1 to 10 (e.g., 1 , 2, 3 or 4) carbon atoms, for example a methyl (Me, CH3), ethyl (Et), n-propyl (nPr), / so-propyl ( / Pr), n-butyl (nBu), / so-butyl ( / Bu), sec-butyl (sBu), fe / Y-butyl (fBu), n-pentyl, / so-pentyl, n-hexyl, 2,2-dimethylbutyl or n-octyl group. The expression haloalkyl refers to a saturated, straight-chain or branched hydrocarbon group as defined above, wherein one or more hydrogen atoms have been replaced by a halogen atom.

[0041] The expression C1-4 alkyl refers to a saturated, straight-chain or branched hydrocarbon group that contains from 1 to 4 carbon atoms; for example, a methyl (Me, CH3), ethyl (Et), n-propyl (nPr), / so-propyl ( / Pr), n-butyl (nBu), / so-butyl ( / Bu), sec-butyl (sBu), or tert-buty I (fBu) group.

[0042] The expression C1-4 haloalkyl refers to a saturated, straight-chain or branched hydrocarbon group that contains from 1 to 4 carbon atoms, wherein one or more hydrogen atoms have been replaced by a halogen atom (preferably F or Cl); for example, a 2,2,2-trichloroethyl or a trifluoromethyl (CF3) group.

[0043] The expression cycloalkyl refers to a saturated or partially unsaturated (for example, a cycloalkenyl group) cyclic group that contains one or more rings (preferably 1 or 2), and contains from 3 to 14 ring carbon atoms, preferably from 3 to 10 (especially 3, 4, 5, 6 or 7) ring carbon atoms. Specific examples of cycloalkyl groups are a cyclopropyl, cyclobutyl, cyclopentyl, spiro[4,5]decanyl, norbornyl, cyclohexyl, cyclopentenyl, cyclohexadienyl, decalinyl, bicyclo[4.3.0]nonyl, propellane (e.g., [1.1.1 ]propellane) tetraline, cyclopentylcyclohexyl, or cyclohex-2-enyl group. Preferably, the expression cycloalkyl refers to a saturated cyclic group that contains one ring and from 3 to 7 ring carbon atoms.

[0044] Examples for a heteroaryl group containing 5 or 6 ring atoms that are independently selected from C, N, 0 and S are pyridyl, imidazolyl, thiazolyl, isothiazolyl, 1 ,2,3- triazolyl, 1 ,2,4-triazolyl, oxadiazolyl, thiadiazolyl, pyrazinyl, pyrimidinyl, pyridazinyl, oxazolyl, tetrazolyl, and isoxazolyl groups.

[0045] The suffix "-ene" like e.g., in "phenylene" refers to the corresponding divalent group.

[0046] The term halogen refers to F, Cl, Br or I. Owing to their substitution, the compounds of the present invention may contain one or more centers of chirality. The present invention therefore includes both all pure enantiomers and all pure diastereomers and also mixtures thereof in any mixing ratio. The present invention moreover also includes all c / s / frans-isomers of the compounds of the present invention and also mixtures thereof. The present invention moreover includes all tautomeric forms of the compounds of the present invention.

[0047] The present invention further provides pharmaceutical compositions comprising one or more compounds described herein or a salt, solvate or hydrate thereof, optionally in combination with one or more carrier substances and / or one or more adjuvants. The pharmaceutical composition of the present invention may contain a further antibacterial compound.

[0048] The present invention furthermore provides compounds or pharmaceutical compositions as described herein for use in the treatment of bacterial infections, especially caused by Streptococcus pneumoniae, Enterococcus faecium, or Enterococcus faecalis.

[0049] The present invention further provides a compound as described herein or a pharmaceutical composition as defined herein for the preparation of a medicament for the treatment of bacterial infections, especially caused by Streptococcus pneumoniae, Enterococcus faecium, or Enterococcus faecalis.

[0050] The present invention furthermore provides a method for treating a subject suffering from or susceptible to a bacterial infection, especially caused by Streptococcus pneumoniae, Enterococcus faecium, or Enterococcus faecalis comprising administering to the subject an effective amount of a compound or of a pharmaceutical composition as described herein. According to a further embodiment, the present invention provides the use of the compounds as described herein as inhibitors of the Energy Coupling Factor (ECF) Transporters.

[0051] Examples of salts (especially of pharmacologically acceptable salts) of sufficiently basic compounds are salts of physiologically acceptable mineral acids like hydrochloric, hydrobromic, sulfuric and phosphoric acid; or salts of organic acids like methanesulfonic, p-toluenesulfonic, lactic, acetic, trifluoroacetic, citric, succinic, fumaric, maleic and salicylic acid. Further, a sufficiently acidic compound may form alkali or earth alkali metal salts, for example sodium, potassium, lithium, calcium or magnesium salts; ammonium salts; or organic base salts, for example methylamine, dimethylamine, trimethylamine, triethylamine, ethylenediamine, ethanolamine, choline hydroxide, meglumin, piperidine, morpholine, tris-(2-hydroxyethyl)amine, lysine or arginine salts; all of which are also further examples of salts of the compounds described herein.

[0052] The compounds described herein may be solvated, especially hydrated. The solvation / hydration may occur during the process of production or as a consequence of the hygroscopic nature of the initially water-free compounds. The solvates and / or hydrates may e.g. be present in solid or liquid form.

[0053] The therapeutic use of the compounds described herein, their salts, solvates and hydrates, respectively, as well as formulations and pharmaceutical compositions also lie within the scope of the present invention.

[0054] In general, the compounds and pharmaceutical compositions described herein will be administered by using the established and acceptable modes known in the art.

[0055] For oral administration, such therapeutically useful agents can be administered by one of the following routes: oral, e.g. as tablets, dragees, coated tablets, pills, semisolids, soft or hard capsules, for example soft and hard gelatine capsules, aqueous or oily solutions, emulsions, suspensions or syrups, parenteral including intravenous, intramuscular and subcutaneous injection, e.g. as an injectable solution or suspension, rectal as suppositories, by inhalation or insufflation, e.g. as a powder formulation, as microcrystals or as a spray (e.g., liquid aerosol), transdermal, for example via an transdermal drug delivery system (TDDS) such as a plaster containing the active ingredient or intranasal. For the production of such tablets, pills, semisolids, coated tablets, dragees and hard, e.g. gelatine, capsules the therapeutically useful product may be mixed with pharmaceutically inert, inorganic or organic excipients as are e.g. lactose, sucrose, glucose, gelatine, malt, silica gel, starch or derivatives thereof, talc, stearinic acid or their salts, dried skim milk, and the like. For the production of soft capsules, one may use excipients as are e.g., vegetable, petroleum, animal or synthetic oils, wax, fat, and polyols. For the production of liquid solutions, emulsions or suspensions or syrups one may use as excipients e.g., water, alcohols, aqueous saline, aqueous dextrose, polyols, glycerin, lipids, phospholipids, cyclodextrins, vegetable, petroleum, animal or synthetic oils. Especially preferred are lipids and more preferred are phospholipids (preferred of natural origin; especially preferred with a particle size between 300 to 350 nm) preferred in phosphate buffered saline (pH = 7 to 8, preferred 7.4). For suppositories one may use excipients as are e.g. vegetable, petroleum, animal or synthetic oils, wax, fat and polyols. For aerosol formulations, one may use compressed gases suitable for this purpose, e.g., oxygen, nitrogen and carbon dioxide. The pharmaceutically useful agents may also contain additives for conservation, stabilization, e.g., UV stabilizers, emulsifiers, sweetener, aromatizers, salts to change the osmotic pressure, buffers, coating additives and antioxidants.

[0056] In general, in the case of oral or parenteral administration to adult humans weighing approximately 80 kg, a daily dosage of about 1 mg to about 10,000 mg, preferably from about 5 mg to about 1 ,000 mg, should be appropriate, although the upper limit may be exceeded when indicated. The daily dosage can be administered as a single dose or in divided doses, or for parenteral administration, it may be given as continuous infusion or subcutaneous injection. EXAMPLES

[0057] 1. Chemistry

[0058] All compounds were synthesized via two previously reported synthetic routes (Schemes 1 and 2).16’17The first route starts from the respective 1 ,2-diphenylethan-1- one (I), either synthesized via a previously published method16or commercially obtained, which was then brominated in the presence of Br2 (II).

[0059] Scheme 1. Synthetic route towards (3-5, 7-9, 11-15). Reagents and conditions: (i) Br2, CHCI3, reflux, 2 h; (ii) 1. Et3N, MeCN, 45 °C, 6 h; 2. NH4OAc, reflux, 3 h, 11-34% yield (over two steps) (3-5, 7-9, 11 and 12); (iii) 1. Et3N, MeCN, 45 °C, 6 h; 2. NH4OAc, reflux, 3 h, 11-27% yield (over two steps) (13-15).

[0060] (1 , 6, 10, and 16-25) VII VI

[0061] Scheme 2. Synthetic route to (1 , 6, 10, and 16-25). Reagents and conditions, EtsN, acetone, room temperature, overnight; (ii), BF3 Et2O, acetamide, MeCN, 120 °C, overnight; (iii), N-bromosuccinimide, acetic acid, 80 °C, 2 h; (iv), 1. Respective boronic acid, CS2CO3, Pd(dppf)Cl2, 1 ,4-dioxane / water (9 / 1 ), 110 °C, 1 h, microwave; 2. LiOH (2 M), 1 ,4-dioxane / water (9:1 ), room temperature, overnight. 1-4 % yield (over all steps)

[0062] The resulting brominated intermediate was then mixed, without prior purification, with the respective carboxylic acid and the mixture was heated to 45 °C for 6 h and refluxed for 3 h to form the oxazole and afford the final product (Scheme 1 ). The second synthetic route commences from the respective 2-bromo-1 -phenylethan-1 -one (III), which was added to a basic solution containing the corresponding carboxylic acid IV, affording the related 2-oxo-2-phenylethyl acetate (V). Heating this intermediate to 120 °C in a solution containing BF3 Et2O and acetamide generated the oxazole VI, which was selectively brominated at the 5-position (VII) using N-bromosuccinimide (NBS). Lastly, a Suzuki reaction with phenylboronic acid and subsequent saponification of a potential ester ultimately provided the desired compound (Scheme 2).

[0063] 2. SAR

[0064] Compounds 1 and 3-12 (Table 1 ) were synthesized to evaluate the structure-activity relationship at R2. Analysis of compounds 1 and 3-6 revealed a preference for halogen atoms at this position of the phenyl ring. Comparable activities to 1 were obtained for fluoro- (3) and trifluoromethyl-substituted (4) derivatives, while derivatives bearing nonhalogenated moieties (5, 6) demonstrated decreased activity. Next, the influence of the position of the halogen on the phenyl ring (7-9) was investigated. It became clear that both para (1, 3) and meta (7) positions are favorable for retaining activity, whereas substitution in the ortho position led to a decrease in activity (8, 9). Further, disubstitution led to an increase in potency, with 12 (ECF-T %inhibition at 50 pM = 42.9 ± 12.3) demonstrating double the inhibition at 50 pM compared to the parent compound 1 (ECF-T %inhibition at 50 pM = 21.1 ± 0.7).

[0065] Table 1. In vitro activities for compounds (1, 3-12) in ECF-T whole-cell uptake assay aAssays were performed in replicate as independent experiments (n = 2); values are shown as mean ± SD.

[0066] In order to evaluate the structure-activity relationship at group X, 12 was used as starting point. At first, the linker length was increased by one carbon atom (13), which led to a decrease in activity. Since this decrease in activity might be due to the increased flexibility of the alkyl linker, it was replaced with a more rigid phenyl ring (14- 16) and the carboxylic acid was arranged in all possible orientations. Here the metasubstituted derivative demonstrated superior activity over the other orientations and the parent compound (12). To further capitalize on the increase in potency by this replacement, the phenyl was interchanged with a pyridine ring to increase the hydrophilicity. This exchange led to a slight decrease in activity (15, ECF-T ICso = 5.1 ± 2.6 pM; 17 ECF-T ICso = 8.2 ± 0.9 pM).

[0067] Table 2. In vitro activities for compounds (13-17) in ECF-T whole-cell uptake assay aAssays were performed in replicate as independent experiments (n > 2); va ues are shown as mean ± SD; n.d. = not determined. In order to evaluate the structure-activity relationship at R1, 15 was selected as starting point. When analyzing the following results, it has to be considered that inhibitory activities were measured at a lower inhibitor concentration than for previous regions. Despite the diversity, there seemed to be only some preference for slightly lipophilic groups in this region, with compounds (20-23) demonstrating comparable inhibitory activities. Additionally, disubstitution of the phenyl ring did not lead to an increase in activity in this case (24, 25).

[0068] Table 3. In vitro activities for compounds (18-25) in ECF-T whole-cell uptake assay aAssays were performed in replicate as independent experiments (n > 2); va ues are shown as mean ± SD; n.d. = not determined.

[0069] Compound 22 was used for further exploration of the biological potential of the compounds of the present invention.

[0070] 3. Biological Evaluation

[0071] 3. 1. Uptake assay into proteoliposome

[0072] To further validate ECF transporters as the target of the compounds of the present invention, a proteoliposome-based uptake assay was performed as demonstrated by Swier et aU8During this assay, purified folate-specific transporter ECF-FolT2 from L delbrueckii is reconstituted in proteoliposomes and the uptake of radiolabelled folate into the proteoliposomes is quantified at certain time intervals. As can be seen in Table

[0073] 4, there is a clear difference in uptake inhibition between 1 and 22. Whereas 1 demonstrates a relative inhibition of folate uptake of 44% at a concentration 150 pM, 22 reaches a relative inhibition of 95% at the same concentration. In summary, both 1 and 22 are capable of inhibiting the ECF-FolT2 in a proteoliposome-based uptake assay which further complements the results obtained from the whole-cell uptake assay.

[0074] Table 4. Relative inhibition of ECF-FolT2 in proteoliposome uptake assay aAssays were performed in replicate as independent experiments (n = 2); values are shown as mean ± SD.

[0075] 2.3.1. Antimicrobial profiling

[0076] Compound 22 was evaluated for its antibacterial activity against a panel of Grampositive pathogens of relevance. Enterococcus faecalis and E. faecium are among the most frequent causative agents of hospital-acquired infections, resulting in a wide range of infections, including infections of the urinary tract, bloodstream, and endocardium.19Streptococcus pneumoniae is the leading cause of pneumonia, especially in elderly and children under five years of age, and poses a great threat to public health in low- and middle-income countries. Furthermore, both E. faecium and S. pneumoniae are on the World Health Organization’s priority list for research and development of new antibiotics.20Compound 22 demonstrated a minimum inhibitory concentration (MIC) of 4 pM against E. faecalis and E. faecium. Interestingly, the compound exhibited enhanced potency against a vancomycin-resistant strain of E. faecium (MIC = 2 pM). Even more promising results were obtained for S. pneumoniae, with 1 demonstrating an MIC between 32 and 16 pM, while 22 achieved the same at a concentration between 0.5 and 1 pM. Additionally, 22 exhibited similar efficacy against a penicillin-resistant strain of S. pneumoniae, whereas 1 showed reduced potency against this strain. In summary, compound 22 demonstrates significant growth inhibition of relevant strains of Gram-positive bacteria and their resistant variants. Table 5. Whole-cell activity of 1 and 22 against relevant Gran-positive pathogens. aAssays were performed in replicate as independent experiments (n > 2); values are shown as mean ± SD;bVancomycin-resistant Enterococcus faecium strain;cPenicillin-resistant Streptococcus pneumonia strain; Enterococcus faecalis', Minimum inhibitory concentration (MIC).

[0077] 4. Experimental section

[0078] 4. 1. General information

[0079] Starting materials and solvents were purchased from commercial suppliers, and used without further purification. All chemical yields refer to purified compounds and were not optimized. Column chromatography was performed using the automated flash chromatography system CombiFlash®Rf (Teledyne Isco) equipped with RediSepRf silica columns. Preparative RP-HPLC was performed either using an UltiMate 3000 Semi-Preparative System (Thermo Fisher Scientific) equipped with nucleodur®C18 Gravity (250 mm x 16 mm, 5 pm) column or using a Pure C-850 Flash / Prep (Buchi) equipped with Nucleodur C18 HTec (250 mm x 40 mm, particle size 5 pm). Low- resolution mass spectrometry and purity control of final compounds was carried out using an Ultimate 3000-MSQ LCMS system (Thermo Fisher Scientific) consisting of a pump, an autosampler, an MWD detector and an ESI quadrupole mass spectrometer.1H and13C NMR spectra were recorded as indicated on a Broker Avance Neo 500 MHz (1H, 500 MHz;13C, 126 MHz) with prodigy cryoprobe system. Chemical shifts were recorded as 5 values in ppm units and referenced against the residual solvent peak (DMSO-c / 6, 6= 2.50, 39.52 and CDC -cH: 5=7.26, 77.16). Splitting patterns describe apparent multiplicities and are designated as s (singlet), br s (broad singlet), d (doublet), dd (doublet of doublet), t (triplet), q (quartet), m (multiplet). Coupling constants (J) are given in Hertz (Hz). High-resolution mass spectra were recorded on a ThermoFisher Scientific (TF, Dreieich, Germany) Q Exactive Focus system equipped with heated electrospray ionization (HESI)-II source.

[0080] 4.2. Chemistry

[0081] The synthesis and analysis of compounds (3 - 5, 7 - 9, 11 - 15) was reported in the literature.16’17

[0082] 4.2.1. General procedure 1 (GP-1) for the synthesis of 6 and 10

[0083] To a round-bottomed flask, 4-methoxy-4-oxobutanoic acid (1.5 equiv), trimethylamine (2.2 equiv) and acetone were added (100 mL). The solution was stirred at room temperature for 15 min, after which, the respective 2-bromo-1 -phenylethan-1 -one (1 equiv) was added, and the solution was stirred at room temperature overnight. Subsequently, the solvent was removed in vacuo, the residue dissolved in CH2CI2, washed with water (3x), dried over MgSCk, filtered, and the solvent was removed in vacuo. Next, the solid was added to a dry crimp tube, which was charged with acetamide (7 equiv), boron trifluoride diethyl etherate (1 .2 equiv) and dry ACN (15 mL). Next, the vial was capped, and the solution was stirred at 120 °C overnight. Afterwards, H2O (20 mL) was added, and the resulting solution was extracted with a mixture of CHCh / propanol (3:1 , 3x15 mL). The organic fractions were combined, dried over MgSCk, filtered, and the solvent removed in vacuo. The residue was partially purified using flash chromatography using DCM / MeOH as eluent in a gradient (100% to 95% CH2CI2). The combined fractions were dried, and the solid was added to a flask containing acetic acid (15 mL) and / V-bromosuccinimide (1.2 equiv). The resulting solution was stirred at 80 °C for 2 h. Next, water (20 mL) was added, and the mixture was filtered. The collected precipitate was washed with water (3x) and dried at room temperature overnight. The residue was then added to a microwave vial containing phenylboronic acid (1.2 equiv) and CsCOs (2.2 equiv) in a degassed solution of 1 ,4- dioxane and water (9 / 1 ). Next, [Pd(dppf)Cl2] (0.01 equiv) was added, and the resulting solution was stirred in the microwave at 110 °C for 45 min, after which, more phenylboronic acid (1.2 equiv) was added. The mixture was stirred at 110 °C in the microwave for 45 min. Subsequently, the solution was filtered; to the filtrate, an aqueous solution of LiOH was added (0.5 mL, 2 N), and the resulting solution was stirred at room temperature overnight. Next, the solution was neutralized by the addition of an aqueous solution of HCI (1 N). Water (20 mL) was added, and the resulting mixture was extracted with DCM (3x, 15 mL), dried over MgSCM, filtered, solvent removed in vacuo, and the residue was purified by preparative HPLC affording the title compound.

[0084] 4.2.2. General procedure 2 (GP-2) for the synthesis of 16 and 17

[0085] To a round-bottomed flask, the respective carboxylic acid (1 equiv), trimethylamine (2.2 equiv) and acetone were added (100 mL). The solution was stirred at room temperature for 15 min, after which, 2-bromo-1-(3,4-dichlorophenyl)ethan-1 -one (1.2 equiv) was added, and the solution was stirred at room temperature overnight. Subsequently, the solvent was removed in vacuo, the residue dissolved with CH2CI2, washed with water (3x) dried over MgSCk, filtered, and the solvent was removed in vacuo. Next, the solid was added to a dry crimp tube and acetamide (7 equiv), boron trifluoride diethyl etherate (1 .2 equiv) and dry ACN (15 mL) were added. Next, the vial was capped, and the solution was stirred at 120 °C overnight. H2O (20 mL) was added, and the resulting solution was extracted with a mixture of CHCh / propanol (3:1 , 3x15 mL). The organic fractions were combined, dried over MgSCM, filtered, and the solvent removed in vacuo. The combined fractions were dried, and the solid was added to a flask containing acetic acid (15 mL) and / V-bromosuccinimide (1.2 equiv). The resulting solution was stirred at 80 °C for 2 h, after which, water (20 mL) was added, and the mixture was filtered. The collected precipitate was washed with water (3x), and dried at room temperature overnight. The residue was then added to a microwave vial containing phenylboronic acid (1.2 equiv) and CsCOs (2.2 equiv) in a degassed solution of 1 ,4-dioxane and water (9:1 , 5 mL). Next, [Pd(dppf)Cl2] (0.01 equiv) was added, and the resulting solution was stirred in the microwave at 110 °C for 45 min, after which, more phenylboronic acid (1.2 equiv) was added. The mixture was stirred at 110 °C in the microwave for 45 min. Subsequently, the solution was filtered; to the filtrate, an aqueous solution of LiOH was added (0.5 mL, 2 N), and the resulting solution was stirred at room temperature overnight. Next, the solution was neutralized by the addition of an aqueous solution of HCI (1 N). Water (20 mL) was added, and the resulting mixture was extracted with DCM (3x, 15 mL), dried over MgSCk, filtered, the solvent removed in vacuo, and the residue was purified by preparative HPLC affording the title compound.

[0086] 4.2.3. General procedure 3 (GP-3) for the synthesis of 18 - 25

[0087] To a microwave vial containing II (1 equiv), CS2CO3 (2.2 equiv) and a degassed solution of 1 ,4-dioxane / water (9 / 1 , 5 mL), the respective boronic acid was added (1.2 equiv). Next, [Pd(dppf)Cl2] (0.01 equiv) was added, and the resulting solution was stirred in the microwave at 110 °C for 30 min, after which, more boronic acid (1 .2 equiv) was added, and the mixture was again stirred at 110 °C in the microwave for 45 min. Subsequently, the solution was filtered; to the filtrate, an aqueous solution of LiOH was added (0.5 mL, 2 N), and the resulting solution was stirred at room temperature overnight. Next, the solution was neutralized by the addition of an aqueous solution of HCI (1 N). Water (20 mL) was added, and the resulting mixture was extracted with CH2CI2 (3x15 mL), dried over MgSO4, filtered, and the solvent removed in vacuo. The residue was purified by preparative HPLC affording the title compound.

[0088] 4.2.4. 3-(4-(4-Chlorophenyl)-5-phenyloxazol-2-yl)propanoic acid (1)

[0089] A flask was charged with succinic acid (0.2 g, 1.7 mmol), trimethylamine (0.5 g, 5.1 mmol) and acetone (20 mL), and the resulting solution was stirred at room temperature for 30 min, after which, 2-bromo-4'-chloroacetophenone (0.4 g, 1.7 mmol) was added. The mixture was stirred at room temperature for 3 h, after which, water (20 mL) was added, and the solution was made slightly basic by the addition of an aqueous solution of NaOH (1 N, 2 mL). Next, CH2CI2 (20 mL) was added, and the resulting mixture was extracted (3x), the water fraction was acidified by the addition of an aqueous solution of HCI (1 N, 10 mL) and was extracted (3x) by a mixture of CHCh / propanol (3:1 , 3x15 mL). The resulting organic fractions were washed with saturated aqueous NaCI solution, dried over MgSCM, filtered, and solvent was removed in vacuo. The residue was then added to a crimp vail containing acetamide (0.5 g, 8.6 mmol) and boron trifluoride diethyl etherate (0.2 g, 1.7 mmol). The tube was capped and mixed under neat conditions overnight at 100 °C. Next, water was added, and the solution was made slightly basic by the addition of an aqueous solution of NaOH (1 N, 2 mL). Next CH2CI2 was added, and the resulting mixture was extracted (3x), the water fraction was acidified by the addition of an aqueous solution of HCI (1 N, 10 mL) and was extracted with a mixture of CHCh / propanol (3:1 , 3x15 mL). The resulting organic fractions were washed with saturated aqueous NaCI solution, dried over MgSCM, filtered, and the solvent was removed in vacuo. Next, chloroform (3 mL) and / V-bromosuccinimide (0.1 g, 0.6 mmol) were added, and the resulting mixture was stirred at reflux for 2 h after which, water was added. The resulting mixture was made slightly basic by the addition of an aqueous solution of NaOH (1 N, 2 mL). Next, EtOAcwas added, and the resulting mixture was extracted (3x), the water fraction was acidified by the addition of an aqueous solution of HCI (1 N, 10 mL) and was extracted (3x) by a mixture of CHCh / propanol (3:1 , 3x15 mL). The resulting organic fractions were washed with saturated aqueous NaCI solution, dried over MgSO4, filtered, and the solvent was removed in vacuo. The solid was added to a degassed solution of 1 ,4-dioxane / H2O (4:1 , 20 mL) containing Na2COs (0.1 g, 1.3 mmol) and phenylboronic acid (0.1 g, 0.4 mmol). Polymer-bound [Pd[(C6Hs)3P]4] (0.01 g) was added, and the reaction mixture was stirred overnight at 100 °C. Next, an aqueous solution of HCI (1 N, 25 mL) was added, and the resulting mixture was extracted (3x) with a mixture of CHCh / propanol (3:1 , 3x15 mL). The combined organic fractions were washed with saturated aqueous NaCI solution, dried over MgSCM, filtered, and dried in vacuo. The residue was purified using preparative RP-HPLC, affording 1 as a white solid (0.01 g, 2% yield).1H NMR (500 MHz, DMSO-c / 6) 5 = 12.35 (br s, 1 H), 7.88 (d, J = 8.5 Hz, 1 H), 7.56 (d, J = 8.5 Hz, 1 H), 7.58 - 7.54 (m, 1 H), 3.04 - 2.99 (m, 1 H), 2.76 - 2.72 (m, 1 H).13C NMR (126 MHz, DMSO-c / 6) 5 = 173.5, 163, 145.3, 133.5, 133, 131.2, 129.4, 129.3, 129.1 , 128.5, 126.9, 30.6, 23.3. HRMS (ESI+) calculated for C18H15CINO3 [M+H]+328.06622, found 328.07302. Purity by HPLC = 100%.

[0090] 4.2.4. 3-(5-(4-Cyanophenyl)-4-phenyloxazol-2-yl)propanoic acid. (6). According to GP-1 , using 4-(2-bromoacetyl)benzonitrile (0.4 g, 1.79 mmol) afforded after purification by preparative HPLC 6 as a white solid (0.01 g, 2% yield).1H NMR (500 MHz, CDC -cf) 5 = 7.77 (d, J = 8.2 Hz, 2H), 7.63 (d, J = 8.2 Hz, 2H), 7.57 - 7.52 (m, 2H), 7.44 - 7.39 (m, 3H), 3.25 - 3.16 (m, 2H), 3.03 - 2.93 (m, 2H).13C NMR (126 MHz, CDCb-cf) <5 = 176.5, 162.5, 147.6, 137, 133.5, 132.6, 129.7, 129.2, 128.4, 128.3,

[0091] 127.3, 119, 111.6, 30.8, 23.4. HRMS (ESI+) calculated for C19H15N2O3 [M+H]+319.10044, found 319.10768. Purity by HPLC = 100%.

[0092] 4.2.5. 3-(4-(3,5-Dichlorophenyl)-5-phenyloxazol-2-yl)propanoic acid (10).

[0093] According to GP-1 , using 2-bromo-1 -(3,5-dichlorophenyl)ethan-1-one (0.45 g, 1.68 mmol), affording after purification by preparative HPLC 10 as a white solid (0.01g, 2% yield).1H NMR (500 MHz, CDCb-cf) 5 = 7.56 (d, J = 1 .8 Hz, 1 H), 7.55 - 7.53 (m, 3H), 7.44 - 7.39 (m, 3H), 7.31 (t, J = 1 .8 Hz, 1 H), 3.24 - 3.16 (m, 2H), 3.02 - 2.95 (m, 2H).13C NMR (126 MHz, CDCb-cf) 5 = 176.9, 162.2, 147, 135.4, 132.7, 129.6, 129.2, 128.3, 127.1 , 126.2, 30.8, 23.4. HRMS (ESI+) calculated for C18H14CI2NO3 [M+H]+362.02725, found 362.01485. Purity by HPLC = 99%.

[0094] 4.2.6. 2-(4-(3,4-Dichlorophenyl)-5-phenyloxazol-2-yl)benzoic acid (16)

[0095] According to GP-2, using 2-(methoxycarbonyl)benzoic acid (0.4 g, 1.49 mmol), affording after purification by preparative HPLC 16 as a white solid (0.01 g, 2% yield).1H NMR (500 MHz, CDCb-cf) 5 = 8.48 (dd, J = 7.7, 1.0 Hz, 1 H), 8.23 (dd, J = 7.8, 1.1 Hz, 1 H), 7.80 (d, J = 1 .8 Hz, 1 H), 7.74 - 7.70 (m, 1 H), 7.69 - 7.63 (m, 3H), 7.62 - 7.62 (m, 1 H), 7.54 - 7.50 (m, 1 H), 7.49 - 7.45 (m, 4H).13C NMR (126 MHz, CDCb-cf) 5 =

[0096] 167.3, 159.6, 147.3, 134.5, 133.3, 133.1 , 132.4, 132.4-132.3 (m, 1 C), 131.5, 130.9,

[0097] 130.4, 130.3, 130.2, 129.4, 129.3, 129.2, 127.1 , 127, 126.8, 123.9. HRMS (ESI+) calculated for C22H14CI2NO3 [M+H]+410.02725, found 410.003459. Purity by HPLC: 100%.

[0098] 4.2.7. 4-(4-(3,4-Dichlorophenyl)-5-phenyloxazol-2-yl)picolinic acid (17)

[0099] According to GP-2, using 2-(methoxycarbonyl)isonicotinic acid (0.5 g, 2.76 mmol), affording after purification by preparative HPLC 17 as a yellowish solid (0.1 g, 1 % yield).1H NMR (500 MHz, CDCb-cf) 5 = 8.91 - 8.87 (m, 1 H), 8.79 (br d, J = 4.9 Hz, 1 H), 8.29 (br d, J = 4.4 Hz, 1 H), 7.90 (d, J = 1 .2 Hz, 1 H), 7.72 - 7.65 (m, 2H), 7.56 (dd, J = 8.3, 1.4 Hz, 1 H), 7.53 - 7.45 (m, 4H).13C NMR (126 MHz, CDC -cf) 5 = 163.7,

[0100] 156.8. 149, 136.6, 135.5, 133.1 , 132.8, 131.6, 130.7, 130.1 , 129.8, 129.2, 127.4, 127.2, 126.9, 123.9, 120.1. HRMS (ESI+) calculated for C21 H13CI2N2O3 [M+H]+411 .02250, found 411 .03005. Purity by HPLC: 100%.

[0101] 4.2.8. 3-(5-(4-Cyanophenyl)-4-(3,4-dichlorophenyl)oxazol-2-yl)benzoic acid (18).

[0102] According to GP-3, using (4-cyanophenyl)boronic acid (0.02g, 0.14 mmol), affording after purification by preparative HPLC 18 as a white solid (0.01 g, 15% yield).1H NMR (500 MHz, DMSO-c / 6) 5 = 8.65 - 8.62 (m, 1 H), 8.38 (d, J = 7.8 Hz, 1 H), 8.14 (d, J = 7.6 Hz, 1 H), 7.99 - 7.96 (m, 2H), 7.93 (d, J = 1.8 Hz, 1 H), 7.89 (d, J = 8.2 Hz, 2H), 7.78 - 7.71 (m, 2H), 7.63 (dd, J = 8.4, 1 .7 Hz, 1 H).13C NMR (126 MHz, DMSO-c / 6) 5 = 166.2, 159.5, 144.5, 135.8, 132.8, 131.6, 131.6, 131.5, 131.4, 131.3, 131 , 129.4, 127.7, 126.8, 126.6, 118.1 , 111.1 , 54.6. HRMS (ESI+) calculated for C23H13CI2N2O3 [M+H]+435.02250, found 435.02912. Purity by HPLC: 98%.

[0103] 4.2.9. 3-(4-(3,4-Dichlorophenyl)-5-(4-methoxyphenyl)oxazol-2-yl)benzoic acid (19).

[0104] According to GP-3, using (4-methoxyphenyl)boronic acid (0.03 g, 0.21 mmol), affording after purification by preparative HPLC 19 as a white solid (0.1 g, 27% yield).1H NMR (500 MHz, DMSO-c / 6) 5 = 8.59 (s, 1 H), 8.32 (d, J = 7.8 Hz, 1 H), 8.11 (d, J = 7.8 Hz, 1 H), 7.89 (d, J = 2.0 Hz, 1 H), 7.74 - 7.69 (m, 2H), 7.64 (d, J = 8.7 Hz, 2H), 7.63 - 7.60 (m, 1 H), 7.10 (d, J = 8.9 Hz, 2H), 3.83 (s, 3H).13C NMR (126 MHz, DMSO-c / 6) 5 = 167.3-166.9 (m, 1 C), 159, 147.4, 133, 132.1 , 131.9, 131.6, 131.2, 130.6, 130.3, 129.4, 127.7, 127.2, 127.1 , 120.2, 115.2. HRMS (ESI+) calculated for C23H16CI2NO4 [M+H]+440.03781 , found 440.04358. Purity by HPLC: 100%.

[0105] 4.2. 10. 3-(4-(3,4-Dichlorophenyl)-5-(4-(trifluoromethyl)phenyl)oxazol-2-yl)benzoic acid (20).

[0106] According to GP-3, using (4-(trifluoromethyl)phenyl)boronic acid (0.03g, 0.14 mmol), affording after purification by preparative HPLC 20 as a white solid (0.01 g, 8% yield).1H NMR (500 MHz, DMSO-c / 6) 5 = 8.63 (s, 1 H), 8.34 (br d, J = 7.6 Hz, 1 H), 8.13 (d, J = 7.8 Hz, 1 H), 7.94 - 7.90 (m, 3H), 7.90 - 7.86 (m, 2H), 7.76 (d, J = 8.4 Hz, 1 H), 7.73 - 7.69 (m, 1 H), 7.64 (dd, J = 8.4, 1.8 Hz, 1 H).13C NMR (126 MHz, DMSO-c / 6) 6 = 166.8, 160, 135.7, 132.2, 132, 131.9, 131.7, 131.6, 131.4, 129.8, 129.8, 128.1 , 127.5,

[0107] 127.1 , 126.4, 126.3, 55.1.19F NMR (470 MHz, DMSO-c / 6) 5 = -61 .3 (s). HRMS (ESI+) calculated for C23H13CI2F3NO3 [M+H]+478.01463, found 478.02262. Purity by HPLC: 98%.

[0108] 4.2.11. 3-(5-(4-Chlorophenyl)-4-(3,4-dichlorophenyl)oxazol-2-yl)benzoic acid (21 ).

[0109] According to GP-3, using (4-chlorophenyl)boronic acid (0.03 g, 0.21 mmol), affording after purification by preparative HPLC 21 as a white solid (0.01 g, 12% yield).1H NMR (500 MHz, DMSO-c / 6) 5 = 8.62 - 8.60 (m, 1 H), 8.35 - 8.32 (m, 1 H), 8.14 - 8.10 (m, 1 H), 7.91 - 7.89 (m, 1 H), 7.75 - 7.70 (m, 4H), 7.63 - 7.58 (m, 3H).13C NMR (126 MHz, DMSO-c / 6) 5 = 167.1 , 159.7, 146, 134.8, 134.7, 132.6, 132.2, 132.1 , 131.7, 131.7, 130.6, 130.2, 129.8, 129.8, 129.2, 128.1 , 127.2, 126.9, 126.8. HRMS (ESI+) calculated for C22H13CI3NO3 [M+H]+443.98828, found 443.99533. Purity by HPLC: 95%.

[0110] 4.2. 12. 3-(4-(3,4-Dichlorophenyl)-5-(3-(trifluoromethyl)phenyl)oxazol-2-yl)benzoic acid (22).

[0111] According to GP-3, using (3-(trifluoromethyl)phenyl)boronic acid (0.03 g, 0.14 mmol), affording after purification by preparative HPLC 22 as a white solid (0.02 g, 35% yield).1H NMR (500 MHz, DMSO-c / 6) 5 = 8.63 (s, 1 H), 8.39 (d, J = 7.8 Hz, 1 H), 8.13 (d, J = 7.8 Hz, 1 H), 8.04 (s, 1 H), 7.99 (d, J = 7.8 Hz, 1 H), 7.91 (d, J = 1 .8 Hz, 1 H), 7.86 (d, J = 7.9 Hz, 1 H), 7.78 - 7.71 (m, 3H), 7.63 (dd, J = 8.4, 1.8 Hz, 1 H).13C NMR (126 MHz, DMSO-c / 6) 5 = 166.2, 159.2, 144.7, 134.6, 131.6, 131.4, 131.4, 131 , 130.9, 130.5,

[0112] 130.1 , 130.1 , 129.5, 128.9, 128.2, 127.4, 126.6, 126.1 , 54.6.19F NMR (470 MHz, DMSO-c / 6) 5 = -61.39 (s). HRMS (ESI+) calculated for C23H13CI2F3NO3 [M+H]+478.01463, found 478.02030. Purity by HPLC: 100%.

[0113] 4.2. 13. 3-(4-(3,4-Dichlorophenyl)-5-(m-tolyl)oxazol-2-yl)benzoic acid (23).

[0114] According to GP-3, using m-tolylboronic acid (0.02 g, 0.14 mmol), affording after purification by preparative HPLC 23 as a white solid (0.02 g, 30% yield).1H NMR (500 MHz, DMSO-c / 6) 5 = 8.60 (s, 1 H), 8.34 (d, J = 7.8 Hz, 1 H), 8.12 (d, J = 7.8 Hz, 1 H), 7.90 (d, J = 2.0 Hz, 1 H), 7.74 - 7.70 (m, 2H), 7.63 (dd, J = 8.5, 1 .9 Hz, 1 H), 7.57 (s, 1 H), 7.48 - 7.45 (m, 1 H), 7.43 - 7.39 (m, 1 H), 7.34 - 7.31 (m, 1 H), 2.39 - 2.36 (m, 3H).13C NMR (126 MHz, DMS0-d6) 5 = 166.6, 158.9, 146.8, 138.7, 133.6, 132.4,

[0115] 131.5, 131.1 , 130.9, 130.5, 130.2, 129.8, 129.1 , 129, 127.5, 127.4, 127.4, 126.7,

[0116] 126.6, 124.3, 54.9, 20.9 HRMS (ESI+) calculated for C23H16CI2NO3 [M+H]+424.04290, found 424.04891 . Purity by HPLC: 99%.

[0117] 4.2. 14. 3-(4-(3,4-Dichlorophenyl)-5-(3,5-dichlorophenyl)oxazol-2-yl)benzoic acid (24). According to GP-3, using 3,5-dichlorophenyl)boronic acid (0.03 g, 0.14 mmol), affording after purification by preparative HPLC 24 as a white solid (0.01 g, 4% yield).1H NMR (500 MHz, DMSO-d6) 5 =13.40 (br s, 1 H), 8.64 (s, 1 H), 8.41 (br d, J = 7.6 Hz, 1 H), 8.14 (br d, J = 7.8 Hz, 1 H), 7.96 - 7.90 (m, 1 H), 7.80 - 7.69 (m, 5H), 7.69 - 7.58 (m, 1 H), 7.58 - 7.58 (m, 1 H).13C NMR (126 MHz, DMSO-d6) 5 = 167.1 , 160.2 - 160.1 (m, 1 C), 144.2, 136.1 , 135.4, 132.4, 132.2, 132.2, 132, 131.7, 131.3, 131 , 130.3, 130,

[0118] 129.4, 128.3, 127.5, 126.8, 125.8. HRMS (ESI+) calculated for C22H12CI4NO3 [M+H]+479.94635, found: 479.95290. Purity by HPLC: 100%.

[0119] 4.2. 15. 3-(4-(3, 4-Dichlorophenyl)-5-(4-methoxy-3-(trifluoromethyl)phenyl)oxazol-2- yl)benzoic acid (25).

[0120] According to GP-3, using (4-methoxy-3-(trifluoromethyl)phenyl)boronic acid (0.03 g, 0.14 mmol), affording after purification by preparative HPLC 25 as a white solid (0.03 g, 57% yield).1H NMR (500 MHz, DMSO-d6) 5 = 8.61 (s, 1 H), 8.35 (d, J = 7.8 Hz, 1 H), 8.12 (d, J = 7.8 Hz, 1 H), 7.96 - 7.88 (m, 3H), 7.74 - 7.69 (m, 2H), 7.61 (dd, J = 8.3, 1.9 Hz, 1 H), 7.43 (d, J = 8.7 Hz, 1 H), 3.97 (s, 3H)13C NMR (126 MHz, DMSO-d6) 5 = 166.8, 159.1 , 158, 145.6, 133.7, 133.3, 132.3, 132.1 , 131.8, 131.7, 131.3, 131.2,

[0121] 130.4, 130, 129.2, 127.6, 127.6, 126.9, 126.7, 125.8, 125.7, 119.8, 114, 56.7, 55.1.19F NMR (470 MHz, DMSO-d6) 5 = -61.25 (s). HRMS (ESI+) calculated for C24H15CI2F3NO4 [M+H]+508.02520, found 508.03169. Purity by HPLC: 98%.

[0122] 4.3. Biological assays

[0123] 4.3.1. ECF-FolT inhibition assay. This assay was performed based on the protocol reported by Bousis et al. with minor modifications.22

[0124] 4.3.2. Uptake assay into proteoliposome

[0125] This assay was performed based on the protocol reported by Swier et al. with minor modifications.18

[0126] 4.3.3. Screening against clinically relevant Gram-positive pathogens.

[0127] All microorganisms were obtained from the German Collection of Microorganisms and Cell Cultures (DSMZ) and were handled according to standard procedures. Bacteria were inoculated into tryptic soy broth (TSB) to obtain a final inoculum of 105 colonyforming units (CFU) / mL. The tested compounds were prepared as DMSO stocks (20 mM). Serial dilutions of derivatives in the growth medium (0.06 to 128 pM) were prepared in sterile 96-well plates, and the bacterial suspensions were added. Growth inhibition was assessed after static incubation at 37 °C for 24 h. S. pneumoniae was grown at 5% CO2. MIC values are defined as the lowest compound concentration where no visible growth is observed.

[0128] 5. Further compounds

[0129] The synthesis of compounds 26 to 35 can e.g. be carried out according to described procedures22.

[0130] Compounds 26-33 were synthesized according to the following scheme:

[0131] Compound 34 was synthesized according to the following scheme: in an ultrasound bath then 10% HCL for l h

[0132] Compound 35 can be synthesized according to the following schemes: 24h 20h

[0133] 2,5-Dimethylcelecoxib

[0134] CAS: 457639-26-8

[0135] Compound 36 (CAS: 1631083-05-0) was purchased from a commercially available library. This compound can be synthesized according to general reported procedures23-24.

[0136] References

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Claims

Claims1. A compound of formula (la) or (lb):(la) (lb) whereinZ1N or CH;Z2is 0, S or NH;Z3is N or CH;Z4is N or CH;Y is hydrogen; halogen; -C1-4 alkyl; -C1-4 haloalkyl; COOH; OH; CONH2; CONHR’; PO(OH)2; or PO(OR’)2;R’ is a C1-4 alkyl group;X is a bond; a C1-4 alkylene group; a -S-C1-4 alkylene group; a -O-C1-4 alkylene group; a -NH-C1-4 alkylene group; an optionally substituted phenylene group; or an optionally substituted heteroarylene group containing 5 or 6 ring atoms that are independently selected from C, N, 0 and S;R1is hydrogen, halogen, an alkyl group, a cycloalkyl group, an optionally substituted phenyl group; or an optionally substituted heteroaryl groupcontaining 5 or 6 ring atoms that are independently selected from C, N, 0 and S; andR2is hydrogen, halogen, an alkyl group, a cycloalkyl group, an optionally substituted phenyl group; or an optionally substituted heteroaryl group containing 5 or 6 ring atoms that are independently selected from C, N, 0 and S; or a salt thereof, for use in the treatment of a bacterial infection.

2. Use of a compound of formula (la) or (lb):(la) (lb) whereinZ1N or CH;Z2is 0, S or NH;Z3is N or CH;Z4is N or CH;Y is hydrogen; halogen; -Ci-4 alkyl; -Ci-4 haloalkyl; COOH; OH; CONH2;CONHR’; PO(OH)2; or PO(OR’)2;R’ is a C1-4 alkyl group;X is a bond; a C1-4 alkylene group; a -S-C1-4 alkylene group; a -O-C1-4 alkylene group; a -NH-C1-4 alkylene group; an optionally substituted phenylene group; or an optionally substituted heteroarylene group containing 5 or 6 ring atoms that are independently selected from C, N, 0 and S;R1is hydrogen, halogen, an alkyl group, a cycloalkyl group, an optionally substituted phenyl group; or an optionally substituted heteroaryl group containing 5 or 6 ring atoms that are independently selected from C, N, 0 and S; andR2is hydrogen, halogen, an alkyl group, a cycloalkyl group, an optionally substituted phenyl group; or an optionally substituted heteroaryl group containing 5 or 6 ring atoms that are independently selected from C, N, 0 and S; or a salt thereof, for the preparation of a medicament for the treatment of a bacterial infection.

3. A method for treating a subject suffering from or susceptible to a bacterial infection comprising administering to the subject an effective amount of a compound of formula (la) or (lb):(la) (lb)whereinZ1N or CH;Z2is 0, S or NH;Z3is N or CH;Z4is N or CH;Y is hydrogen; halogen; -C1-4 alkyl; -C1-4 haloalkyl; COOH; OH; CONH2; CONHR’; PO(OH)2; or PO(OR’)2;R’ is a C1-4 alkyl group;X is a bond; a C1-4 alkylene group; a -S-C1-4 alkylene group; a -O-C1-4 alkylene group; a -NH-C1-4 alkylene group; an optionally substituted phenylene group; or an optionally substituted heteroarylene group containing 5 or 6 ring atoms that are independently selected from C, N, 0 and S;R1is hydrogen, halogen, an alkyl group, a cycloalkyl group, an optionally substituted phenyl group; or an optionally substituted heteroaryl group containing 5 or 6 ring atoms that are independently selected from C, N, 0 and S; andR2is hydrogen, halogen, an alkyl group, a cycloalkyl group, an optionally substituted phenyl group; or an optionally substituted heteroaryl group containing 5 or 6 ring atoms that are independently selected from C, N, 0 and S; or a salt thereof.

4. The compound for use according to claim 1 or the use according to claim 2 or the method according to claim 3, wherein the compound is a compound of formula (Ila) or (lib), or a salt thereof:(Ha) (Hb).

5. The compound for use according to claim 1 or the use according to claim 2 or the method according to claim 3, wherein the compound is a compound of formula (III), or a salt thereof:(HI).

6. The compound for use according to any one of claims 1 , 4 or 5 or the use according to any one of claims 2, 4 or 5 or the method according to any one of claims 3, 4 or 5, whereinX is a C1-4 alkylene group; an optionally substituted phenylene group; or an optionally substituted heteroarylene group containing 5 or 6 ring atoms that are independently selected from C, N, 0 and S;R1is an optionally substituted phenyl group; or an optionally substituted heteroaryl group containing 5 or 6 ring atoms that are independently selected from C, N, 0 and S; andR2is an optionally substituted phenyl group; or an optionally substituted heteroaryl group containing 5 or 6 ring atoms that are independently selected from C, N, 0 and S.

7. The compound for use according to any one of claims 1 or 4 to 6 or the use according to any one of claims 2 or 4 to 6 or the method according to any one of claims 3 to 6, wherein X is selected from the following groups: -CH2-CH2-; - CH2-CH2-CH2-;8. The compound for use according to any one of claims 1 or 4 to 7 or the use according to any one of claims 2 or 4 to 7 or the method according to any one of claims 3 to 7, wherein X is selected from the following groups:

9. The compound for use according to any one of claims 1 or 4 to 8 or the use according to any one of claims 2 or 4 to 8 or the method according to any one of claims 3 to 8, wherein X is the following group:

10. The compound for use according to any one of claims 1 or 4 to 7 or the use according to any one of claims 2 or 4 to 7 or the method according to any one of claims 3 to 7, wherein X is a group of formula -CH2-CH2-.

11. The compound for use according to any one of claims 1 , 4 or 6 or the use according to any one of claims 2, 4 or 6 or the method according to any one of claims 3, 4 or 6, wherein the compound is a compound of formula (IV), or a salt thereof:(IV).

12. The compound for use according to any one of claims 1 or 4 to 11 or the use according to any one of claims 2 or 4 to 1 1 or the method according to any one of claims 3 to 11 , wherein R1is an optionally substituted phenyl group.

13. The compound for use according to any one of claims 1 or 4 to 12 or the use according to any one of claims 2 or 4 to 12 or the method according to any one of claims 3 to 12, wherein R2is an optionally substituted phenyl group.

14. The compound for use according to any one of claims 1 or 4 to 13 or the use according to any one of claims 2 or 4 to 13 or the method according to any one of claims 3 to 13, wherein R1and / or R2are unsubstituted or substituted by one or two (especially by one) substituent(s).

15. The compound for use according to any one of claims 1 or 4 to 14 or the use according to any one of claims 2 or 4 to 14 or the method according to any one of claims 3 to 14, wherein the optional substituents are independently selectedfrom halogen; -OH; -NH2; -CN; -C1-4 alkyl; -C1-4 haloalkyl; -O-C1-4 alkyl; -O-C1-4 haloalkyl; -SO2NH2; -SO2CH3; -O-CH2-CH2-; and -O-CH2-O-.

16. The compound for use according to any one of claims 1 or 4 to 15 or the use according to any one of claims 2 or 4 to 15 or the method according to any one of claims 3 to 15, wherein the optional substituents are independently selected from -F; -Cl; -Me; -OMe; -CF3; -OCF3; -SO2NH2; -SO2CH3; -OCH(CH3)2; and - CN.

17. The compound for use according to any one of claims 1 or 4 to 16 or the use according to any one of claims 2 or 4 to 16 or the method according to any one of claims 3 to 16, wherein the following compounds are excluded:

18. The compound for use according to any one of claims 1 or 4 to 17 or the use according to any one of claims 2 or 4 to 17 or the method according to any one of claims 3 to 17, wherein the bacterial infection is caused by Streptococcus pneumoniae, Enterococcus faecium, or Enterococcus faecalis.

19. The compound for use according to any one of claims 1 or 4 to 18 or the use according to any one of claims 2 or 4 to 18 or the method according to any oneof claims 3 to 18, wherein the bacterial infection is treated by inhibiting the Energy Coupling Factor (ECF) Transporters.

20. A compound of formula (V):wherein R1is a substituted phenyl group.

21. The compound according to claim 20 wherein R1is substituted by one or two (especially by one) substituent(s).

22. The compound according to claim 20 or 21 , wherein the substituents are independently selected from halogen; -OH; -NH2; -CN; -C1-4 alkyl; -C1-4 haloalkyl; -O-C1-4 alkyl; -O-C1-4 haloalkyl; -SO2NH2; -SO2CH3; -O-CH2-CH2-; and -O-CH2-O-.

23. The compound according to claim 20 or 21 , wherein the substituents are independently selected from -F; -Cl; -Me; -OMe; -CF3; -OCF3; -SO2NH2; - SO2CH3; -OCH(CH3)2; and -CN.

24. A compound selected from the following compounds:and the following compounds:

25. Pharmaceutical composition comprising a compound according to any one of claims 20 to 24 and optionally one or more carrier substances and / or one or more adjuvants.

26. Compound according to any one of claims 20 to 24 or pharmaceutical composition according to claim 25 for use in the treatment of a bacterial infection.

27. Compound according to any one of claims 20 to 24 or pharmaceutical composition according to claim 25 for use in the treatment of a bacterial infection caused by Streptococcus pneumoniae, Enterococcus faecium, or Enterococcus faecalis.

28. Use of a compound according to any one of claims 20 to 24 or of a pharmaceutical composition according to claim 25 for the preparation of a medicament for the treatment of a bacterial infection.

29. Use of a compound according to any one of claims 20 to 24 or of a pharmaceutical composition according to claim 25 for the preparation of a medicament for the treatment of a bacterial infection caused by Streptococcus pneumoniae, Enterococcus faecium, or Enterococcus faecalis.

30. A method for treating a subject suffering from or susceptible to a bacterial infection comprising administering to the subject an effective amount of a compound according to any one of claims 20 to 24 or of a pharmaceutical composition according to claim 25.

31. A method for treating a subject suffering from or susceptible to a bacterial infection caused by Streptococcus pneumoniae, Enterococcus faecium, or Enterococcus faecalis comprising administering to the subject an effective amount of a compound according to any one of claims 20 to 24 or of a pharmaceutical composition according to claim 25.

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