Maxime Bessières

Elżbieta Plebanek

Payel Chatterjee

Punya Shrivastava-Ranjan

Mike Flint

Christina F Spiropoulou

Dawid Warszycki

Andrzej J Bojarski

Vincent Roy
email: vincent.roy@univ-orleans.fr

Luigi A Agrofoglio
email: luigi.agrofoglio@univ-oleans.fr

Punya Shrivastava- Ranjan

Design, synthesis and biological evaluation of 2-substituted-6-[(4-substituted-1-piperidyl)methyl]-1Hbenzimidazoles as inhibitors of ebola virus infection

Keywords: Ebola virus, viral entry, Niemann-Pick C1, benzimidazole-piperidine derivatives, docking studies 25a

ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

The family Filoviridae includes five genera: Cuevavirus, Marburgvirus, Ebolavirus, Striavirus and Thamnovirus [START_REF] Kuhn | Virus nomenclature below the species level: a standardized nomenclature for natural variants of viruses assigned to the family Filoviridae[END_REF]2]. Since 1967, when Marburg virus was first isolated, numerous filovirus hemorrhagic fever (HF) outbreaks have occurred, often with high fatality rates. The most virulent Ebolavirus species is Zaire ebolavirus (EBOV) with mortality rate of up to 90%, [3]. Filoviruses cause HF, associated with immune suppression and a systemic inflammatory response in human and non-human primates.

Filoviruses are enveloped, non-segmented, negative-sense, singlestranded RNA viruses [4]. To begin the infection cycle, the virus must transport its genetic information through the membrane of a target cell. The envelope glycoprotein (GP) of filovirus mediates binding to cellular receptors and the subsequent fusion of the virus envelope with the host cell membrane [START_REF] Aleksandrowicz | Ebola virus enters host cells by macropinocytosis and clathrin-mediated endocytosis[END_REF][START_REF] Hofmann-Winkler | Host cell factors in filovirus entry: novel players, new insights[END_REF][START_REF] Takada | Filovirus tropism: cellular molecules for viral entry[END_REF][8]. Study of the host factors that promote or restrict Ebola replication is of great interest as it may thus lead to the development of novel therapeutics. It has been reported that filovirus GP interacts with multiple molecules for entry into host cells [4]; the entry mechanism is complex, involving not only cell-surface molecules but also intracellular proteins. Several cellsurface molecules are thought to participate in viral entry [4,[START_REF] Hofmann-Winkler | Host cell factors in filovirus entry: novel players, new insights[END_REF][START_REF] Hunt | Filovirus entry: A novelty in the viral fusion world[END_REF][START_REF] Bhattacharyya | Cellular factors implicated in filovirus entry[END_REF] including the cellular lectins DC-SIGN, DC-SIGNR, LSECtin, ASPGR-1 and hMGL [START_REF] Takada | Human macrophage C-type lectin specific for galactose and N-acetylgalactosamine promotes filovirus entry[END_REF][START_REF] Gramberg | LSECtin interacts with filovirus glycoproteins and the spike protein of SARS coronavirus[END_REF][START_REF] Marzi | DC-SIGN and DC-SIGNR interact with the glycoprotein of marburg virus and the S protein of severe acute respiratory syndrome coronavirus[END_REF]. The T-cell immunoglobulin and mucin domain-containing protein 1 (TIM-1) was also shown to be a factor with a role in virus entry [START_REF] Kondratowicz | T-cell immunoglobulin and mucin domain 1 (TIM-1) is a receptor for Zaire Ebolavirus and Lake Victoria Marburgvirus[END_REF]. Another known host cell factor is the Tyro3/Axl/Mer (TAM) family of tyrosine kinase receptors [START_REF] Aleksandrowicz | Ebola virus enters host cells by macropinocytosis and clathrin-mediated endocytosis[END_REF]. Other molecules involved in filovirus entry are α3 and β1 integrins [START_REF] Takada | Downregulation of β1 integrins by Ebola virus glycoprotein: implication for virus entry[END_REF] as well as cathepsins (L and B) [START_REF] Chandran | Endosomal proteolysis of the Ebola virus glycoprotein is necessary for infection[END_REF]. If promising results with antibody therapies have been reported, and very recently one has been approved for the treatment of EBOV infection [18] one important application for an anti-EBOV small molecule could be the treatment of persistently-infected patients, as antibodies may be unable to access the immunologically-privileged sites that harbor the virus. Thus, some representative antifilovirus small molecules, belonging to several chemical classes [START_REF] Edwards | Current status of small molecule drug development for Ebola virus and other filoviruses[END_REF][START_REF] Picazo | Small molecules inhibitors of Ebola virus infection[END_REF], are shown in Fig. 1; they target virus genome replication such as nucleosides BCX4430

and GS-5734 (remdesivir) (two non-obligate RNA chain terminator), or virus entry such as CID23631927 (a cathepsin L inhibitor), the benzimidazole FGI-103 (mechanism to be established), toremifene and terconazole (two Niemann-Pick C1dependent inhibitors).

In 2011, Côté et al. identified the benzylpiperazine adamantane diamide-derived (3.47) as inhibitor of Ebola virus entry [START_REF] Côté | Small molecule inhibitors reveal Niemann-Pick C1 is essential for Ebola virus infection[END_REF]. Compound 3.47, alongside a genetic screening study, was used to identify Niemann-Pick C1 protein (NPC1) as an essential receptor required for EBOV entry [START_REF] Côté | Small molecule inhibitors reveal Niemann-Pick C1 is essential for Ebola virus infection[END_REF][START_REF] Carette | Ebola virus entry requires the cholesterol transporter Niemann-Pick C1[END_REF]. Compound 3.47 is reported to blocked binding of EBOV-GP to NPC1; however, this inhibitor has unfavourable properties for in vivo application. In 2013, Shoemaker et al.

demonstrated the inhibition of EBOV entry by multiple cationic amphiphiles [START_REF] Shoemaker | Multiple cationic amphiphiles induce a Niemann-Pick C phenotype and inhibit Ebola virus entry and infection[END_REF]. The mechanism of this inhibition was NPC1-dependent, but different from that described for the compound 3.47.

More recently, Rong et al. reported some 4-(aminomethyl)benzamides (CBS1118) as potent entry inhibitors of Ebola virus [START_REF] Gaisina | Discovery and structural optimization of 4-(aminomethyl)benzamides as potent entry inhibitors of Ebola and Marburg virus infections[END_REF].

Toremifene, and other selective estrogen receptor modulators, were first identified as inhibitors of EBOV infection in screens of approved drugs, with toremifene conferring a statistically significant survival benefit in the mouse model of infection [START_REF] Johansen | FDA-approved selective estrogen receptor modulators inhibit Ebola virus infection[END_REF][START_REF] Johansen | A screen of approved drugs and molecular probes identifies therapeutics with anti-Ebola virus activity[END_REF][START_REF] Madrid | A systematic screen of FDA-approved drugs for inhibitors of biological threat agents[END_REF].

Crystallographic and biochemical studies have subsequently shown that toremifene's mechanism of action is through binding in a large cavity in the EBOV glycoprotein and destabilizing its structure [START_REF] Zhao | Toremifene interacts with and destabilizes the Ebola virus glycoprotein[END_REF][START_REF] Fels | A hyperstabilizing mutation in the base of the Ebola virus glycoprotein acts at multiple steps to abrogate viral entry[END_REF][START_REF] Bortz | A virion-based assay for glycoprotein thermostability reveals key determinants of filovirus entry and its inhibition[END_REF]. Thus, there are multiple steps and targets within the EBOV entry mechanism that might be subject to therapeutic intervention.

Figure 1. Some anti-ebola molecules and general structure of our new inhibitors Several of the virus entry inhibitors are sharing common moieties, such as benzimidazole, piperazine and piperidine. Based on this finding, we report herein the synthesis of hitherto unknown 2-substituted-6-[(4-substituted-1-piperidyl)methyl]-1Hbenzimidazoles (Fig. 1); those compounds are targeting NPC1 involved in Ebola virus entry. The main scaffold is formed by a benzimidazole moiety, which has been an important pharmacophore and privileged structure in medicinal chemistry [START_REF] Ates-Alagoz | Antimicrobial activities of 1H-benzimidazole-based molecules[END_REF],

linked to a piperidine ether and its isostere 4-methylpiperidine. Modifications are done at C2 position on the benzymidazole moiety with substituted phenyl group having (or not) a trifluoromethyl-and trifluoromethyl ether due to its peculiar properties (steric and electronic effects and enhanced lipophilicity) [START_REF] Besset | New entries toward the synthesis of OCF3-containing molecules[END_REF] (blue dashed rectangle). We investigate also the influence of [(phenoxy-methyl)phenyl group bearing a enzymatic stable phosphonate diester (green dashed rectangle) bounded at C4 of the piperidine moiety by either X = O (4-aryloxy-, serial A) or X = CH2 (4benzyl-, serial B). All compounds were evaluated for their ability to inhibit EBOV entry.

Results and discussion

Chemistry

Synthesis of 2-substitued-6-[(4-aryloxy-1-piperidyl)methyl]-1H-benzimidazoles (serial A)

The chosen strategy to the desired 2-substituted-6-[(4-substituted-1-piperidyl)methyl]-1H-benzimidazoles was to follow a convergent synthesis ending with the coupling of a (4-substituted)-1-piperidine fragment at C6 position of a 6-(chloromethyl)-1Hbenzimidazole fragment, under SN conditions. Thus, the synthesis of the (4substituted)-1-piperidine fragment started with either the α,α-dibromo-m-xylene (1a)

or the α,α-dibromo-p-xylene (1b), which were converted to their phosphonate analogs 2a (para position) and 2b (meta position), respectively, respectively, by SN of bromine with diethylphosphite. Beside, catechol (3) was monoprotected to 4.

Then, the nucleophilic substitution with 2a and 2b in the presence of a 4 afforded the compounds 5a and 5b, respectively, after 20 minutes at 80 °C under microwave irradiation. Removal of the pyrane protecting group by a treatment with pyridinium ptoluenesulfonate (PPTS) during 3 hours in ethanol afforded 6a and 6b, respectively, in excellent yields (Scheme 1). The protected piperidine-4-one [START_REF] Takada | Filovirus tropism: cellular molecules for viral entry[END_REF] was reduced to 8 and activated as tosyl leaving group analog 9. After a brief optimization of the solvent, the activation and the substrate, it appears that the nucleophilic substitution of tosylpiperidine 9 with 6a and 6b, respectively, runs in optimal conditions with dimethylacetamide (DMA) under microwave irradiation (Scheme 2) and gave the protected piperidines 10a and 10b, respectively, in good yields. After deprotection of the carbamate group with trifluoroacetic acid, the (4-aryloxy)-1-piperidines 11a (para-position) and 11b (metaposition) were isolated, respectively. Facing some difficulties to build these 2-substituted-6-[(4-benzyl-1-piperidyl)methyl]-1H-benzimidazoles through the similar above described approach, we considered an alternative approach based first on the synthesis of the 2-(4-piperidylmethyl)phenol ( 22), followed then on its selective functionalization of either the piperidine moiety or the phenol moiety, (Scheme 4). Thus, the 2-bromophenol 17 was protected to its tetrahydropyranyl ether 18. The transmetallation of 18 with n-BuLi followed by the nucleophilic addition on N-Boc-piperidine-4-carboxaldehyde afforded 19.

Unfortunately

Antiviral evaluation

The anti-EBOV activity and cytotoxicity of our molecules were assessed using an infectious recombinant reporter EBOV and by cell viability assay, respectively (Table 1), toremifene being used as positive control [START_REF] Johansen | FDA-approved selective estrogen receptor modulators inhibit Ebola virus infection[END_REF]. EBOV entry, we used HIV pseudotype particles bearing the EBOV GP. Both 25a and 26a inhibited the EBOV GP-mediated entry of these particles into Huh7 cells, with EC50 and CC50 values similar to those seen with infectious EBOV (Fig. 2A). The EBOV entry receptor is NPC1, which functions in the cellular trafficking of cholesterol.

We looked to see the effect of 25a and 26a on the subcellular localization of cholesterol in HeLa cells. Both of these compounds induced a dramatic accumulation of cholesterol to intracellular vacuoles, similar to that seen with U18666A, a known inhibitor of EBOV entry that acts through NPC1 (Fig. 2B). This effect was associated with minimal cytotoxicity in HeLa cells (Fig. 2C). Together, this data suggests that the mechanism by which 25a and 26a block EBOV infection is through the inhibition of viral entry at the level of NPC1.

Chemoinformatics

In order to explain these data, 25a and 26a were docked in the active site of induced fit optimized NPC1 crystallized structure (Fig. 3). The recently crystallized structure of NPC1 (PDB id: 5U73) [START_REF] Li | 3.3 Å Structure of Niemann-Pick C1 protein reveals insights into the function of the Cterminal luminal domain in cholesterol transport[END_REF] was used for the initial docking model generation in Schrӧdinger Suite (Protein Preparation Wizard Tool [START_REF] Sastry | Protein and ligand preparation: parameters, protocols, and influence on virtual screening enrichments[END_REF] and Glide [35] at default settings, except the size of the grid box set as 30x30x30 Å). Because the model showed highly unsatisfactory efficiency in retrospective virtual screening experiments, cluster-specific models were next obtained in an induced-fit docking approach. All 1637 compounds active against NPC1 fetched from the ChEMBL [START_REF] Gaulton | The ChEMBL database in 2017[END_REF] and the PDSP databases [START_REF] Besnard | Automated design of ligands to polypharmacological profiles[END_REF] (Ki or equivalent less than 1000 nM for ChEMBL ligands or marked as an active for PDSP compounds) were clustered with the Hierarchical Clustering tool in Canvas [38]. After manual refinements, compounds were split into 20 distinct chemical classes. Centroids from each cluster were used for the induced-fit docking procedure [START_REF] Sherman | Novel procedure for modeling ligand/receptor induced fit effects[END_REF] which generated one model per cluster.

Screening efficiency (tested as previously, with the application of all actives and 88k decoys generated with the application of DUD-E formalism [START_REF] Mysinger | Directory of useful decoys, enhanced (DUD-E): better ligands and decoys for better benchmarking[END_REF]) was significantly improved and the best performing model (AUC increased from 0.501 for the crystal structure to 0.722 for the best-optimized model) was used for the docking studies of compounds 25a and 26a . Analysis of the docking modes showed that several of the NPC1 amino acids that participate in binding to GP [START_REF] Wang | Identification of surface residues on Niemann-Pick C2 essential for hydrophobic handoff of cholesterol to NPC1 in lysosomes[END_REF][START_REF] Li | Clues to the mechanism of cholesterol transfer from the structure of NPC1 middle lumenal domain bound to NPC2[END_REF][START_REF] Wang | Ebola viral glycoprotein bound to its endosomal receptor Niemann-Pick C1[END_REF] are involved in the binding of compounds 25a and 26a. The benzimidazole moiety of both compounds formed a hydrogen bond with Q421 and pi-pi stacking interaction with Y423. Both compounds created additional pipi stacking interaction: compound 25a with F504 and compound 26a with F503.

Moreover, compound 26a was hydrogen-bonded with Y423.

The #stars parameter, of the QikProp ADME prediction program, can be used to help determine the drug-likeness of a particular compound. The #stars values of approved drugs are generally found in the acceptable range of 0-5. The most favorable value #star=0 was found for compound 26a. This value indicated 26a is an ideally drug-like molecule (Table 2). Investigated compounds showed few violations of Lipinski's rule of five (RuleOfFive) and Jorgensen's rule of three (RuleOfThree). However, these guidelines for defining drug-like properties and oral availability are not always entirely predictive for an optimal lead molecule. All compounds showed good predicted human oral absorption. Their low aqueous solubility (ClQPlogS) and high -predicted octanol/water partition coefficient (QPlogPo/w) indicated the hydrophobic properties.

The distribution of the compounds was simulated by calculation of binding affinities to human serum albumin (QPlogKhsa). The estimated values have been found in the acceptable range for almost all our compounds. To predict the drug cytotoxicity, the estimation of IC50 values for blockage of HERG K+ channel was used, and every compound was found to be in the acceptable range. All molecules showed excellent predicted Caco-2 cell (model for the gut-blood barier) permeability and great predicted MDCK cell (good mimic for the blood-brain barrier) permeability. Thus, these compounds are predicted to cross the blood/brain barrier (QPlogBB) and may potentially exhibit some activity in the central nervous system.

Conclusions

We have developed an efficient synthesis for the generation of functionalized 2substituted-6-[(4-substituted-1-piperidyl)methyl]-1H-benzimidazoles as entry inhibitors of Ebola virus. The exploration of our scaffolds was focused on the piperidine moiety as center core, and we also investigated the influence of various substitution at the benzimidazole moiety. Our compounds also exhibited a potent anti-EBOV activity, with four compounds with a submicromolar activity, and two of them 25a and 26a with an excellent selectivity index of, respectively, 10 and 20 (2 to 3 times more selective than the FDA-approved anti-cancer drug Toremifene). Data suggests that the mechanism by which 25a and 26a block EBOV infection is through the inhibition of viral entry at the level of NPC1. Finally, the ADME-Tox profile of our compounds showed an excellent in silico profile for almost all synthesized compounds, with good calculated permeability and solubility, low HERG toxicity, high permeability and good protein plasma interaction. Altogether, these compounds deserve to be further optimized and developed as potential antifiloviral drugs..

Experimental

Chemistry

Commercially available chemicals were of reagent grade and used as received. The reactions were monitored by thin layer chromatography (TLC) analysis using silica gel plates (Kieselgel 60F254, E. Merck). Column chromatography was performed on Silica Gel 60 M (0.040e0.063 mm, E. Merck). The 1 H and 13 C NMR spectra were recorded on a Varian InovaUnity 400 spectrometer (400 MHz) in (d4) methanol, CDCl3, shift values in parts per million relative to SiMe4 as internal reference. High

Resolution Mass spectra were performed on a Bruker maxis mass spectrometer by the "Fédération de Recherche"

General procedure 1 (for the synthesis of 2a and 2b):

The microwave vial was charged with α,α-dibromo-m/p-xylene (0.40 g, 1.5 mmol, 2 equiv), phosphite derivative (0.75 mmol, 1 equiv) and DMF (0.8 mL). The reaction mixture was heated at 150 °C for 2 minutes through microwave activation. Then, mixture was poured into water and product was extracted with EtOAc. Combined organic phases were washed with water and brine, then dried over MgSO4 and concentrated under vacuum. Purification by column chromatography on silica gel (PE/EtOAc or DCM/MeOH) gave the desired product.

Diethyl 4-(bromomethyl)benzylphosphonate (2a). The title compound was

prepared from α,α-dibromo-p-xylene (1a) (0.40 g, 1.5 mmol, 2 equiv) and triethyl phosphite (0.13 mL, 0.75 mmol, 1 equiv) following the general procedure 1.

Compound 2a (0.21 g, 88%) was obtained as a colorless oil. 1

Diethyl 3-(bromomethyl)benzylphosphonate (2b). The title compound was

prepared from α,α-dibromo-m-xylene (1b) (0.40 g, 1.5 mmol, 2 equiv) and triethyl phosphite (0.13 mL, 0.75 mmol, 1 equiv) following the general procedure 1.

Compound 2b (0.23 g, 94%) was obtained as a colorless oil. 1

2-(Oxan-2-yloxy)phenol (4).

Catechol 3 (2 g, 18.2 mmol, 1 equiv) and dihydropyran (1.66 mL, 18.2 mmol, 1 equiv) were added to a solution of pyridinium ptoluenesulfonate (46 mg, 0.182 mmol, 1 mmol%) in DCM (35 mL). The solution was then stirred at room temperature for 3 hours, and the solvent were removed under reduced pressure. The resulted mixture was then dissolved in EtOAc, washed twice with NaHCO3, once with brine, dried over MgSO4 and concentrated to afford pure compound 4 (3.30 g, 94%) as a yellowish oil, [START_REF] Moradgholi | Highly efficient synthesis of tetra benzo spiro bis-crown ether[END_REF]. CAS: 21645-25-0.

Diethyl ({4-[2-(oxan-2-yloxy)phenoxymethyl]phenyl}methyl)phosphonate (5a).

In a 10-20 mL microwave vial, compound 4 (1.12 g, 1 eq., 5.74 mmol) was dissolved in DMF (18 mL).

Diethyl ({3-[2-(oxan-2-yloxy)phenoxymethyl]phenyl}methyl)phosphonate (5b).

Compound 4 (665 mg, 1.1 eq., 3.43 mmol) was dissolved in DMF (10 mL) in a 10-20 mL microwave vial. To this solution were added potassium carbonate (868 mg., 2 eq., 6.28 mmol), compound 2b (1 g, 1eq., 3.14 mmol) and few crystals of sodium iodide (catalytic amount). The solution was then stirred 20 min. at 80 °C under microwave irradiation. After evaporation of all volatiles, the residue was purified by silica gel chromatography to afford desired product 5b as a colorless oil.

(974 mg, 72%).

Diethyl {[3-(2-hydroxyphenoxymethyl)phenyl]methyl}phosphonate (6b).

To a solution of phosphonate 5b (1.60 g, 1 eq., 3.6 mmol) in ethanol (37 mL) pyridium p-toluenesulfonate (45 mg, 5 mol%, 0.18 mmol) was added. The mixture was then stirred at 55 °C for 3 hours, followed by the evaporation of all volatiles. The residue was then purified by flash chromatography, eluting Petroleum Ether/EtOAc 65:35 to 1:1, to give unprotected compound 6b as a light brown oil. (1.28 g, quant.) atmosphere. This solution was cooled at 0 °C and sodium borohydride was subsequently added portionwise (950 mg, 1 eq., [START_REF] Johansen | FDA-approved selective estrogen receptor modulators inhibit Ebola virus infection[END_REF].1 mmol). The mixture was allowed to reach room temperature and stirred for 20h. The solution was carefully quenched at 0 °C with 2N sodium hydroxide (20 mL), followed by evaporation of all volatiles. The mixture was then dissolved in EtOAc (40 mL) and water (20 mL). The aqueous phase was extracted with EtOAc (3 x 40 mL), the organic phases were washed with H2O (20 mL), brine (20 mL), dried over MgSO4 and concentrated under reduced pressure. Purification by silica gel column chromatography (Petroleum Ether/EtOAc 8:2) afforded desired product 8 as a white solid. (4.8 g, 95%), [START_REF] Hirst | Pyrrolopyrimidines as therapeutic agents[END_REF]. CAS : 109384-19-2.

tert-Butyl 4-[(4-methylbenzenesulfonyl)oxy]piperidine-1-carboxylate (9).

To a solution of compound 8 (5 g, 1 eq., 24.8 mmol) in DCM (50 mL), triethylamine (13.9 mL, 4 eq., 99.4 mmol) and p-toluenesulfonyl chloride (9.47 g, 2 eq., 49.7 mmol)

were added. The mixture was stirred 20h at room temperature followed by the concentration of this solution under reduced pressure. The residue was then dissolved in DCM (20 mL) and water (20 mL), extracted with DCM (20 mL), washed with 1N HCl (40 mL), extracted twice with DCM (2 x 40 mL), dried over MgSO4 and evaporated. The crude was then purified by silica gel column chromatography (Petroleum ether/EtOAc 8:2) to afford desired product 9 as a white crystalline solid.

(8.7 g, 99%), [START_REF] Zhang | Aminoquinazoline derivatives and their salts and methods of use[END_REF]. CAS : 118811-07-7.

tert-Butyl-4-{[2-({4-[(diethoxyphosphoryl)methyl]phenyl}methoxy)phenyl]methyl }piperidine-1-carboxylate (10a).

In a 10-20 mL microwave vial, phosphonate compound 6a (512 mg, 1 eq., 1.46 mmol) was dissolved in dimethylacetamide (13 mL). To this solution, potassium carbonate (404 mg, 2 eq., 2.92 mmol) and compound 9 (778 mg, 1.5 eq., 2.19 mmol) were then added and this mixture was stirred at 140 °C during 30 min under microwave irradiation. The resulting residue was dissolved in EtOAc (20 mL) and water (25 mL), and the aqueous phase was extracted thrice with EtOAc (3 x 20 mL). The organic phases were then washed 5 times with water (5 x 25 mL), once with brine (25 mL) and dried over magnesium sulfate. The residue was concentrated under reduced pressure and purified by silica gel column chromatography, eluting DCM/MeOH 99:1, to afford the intermediate 10a as colorless oil which was directly engaged in the next step.

tert-Butyl-4-{[2-({3-[(diethoxyphosphoryl)methyl]phenyl}methoxy)

phenyl]-methyl}piperidine-1-carboxylate (10b). In a 2-5 mL microwave vial, phosphonate compound 6b (100 mg, 1 eq., 0.29 mmol) was dissolved in dimethylacetamide (DMA, 2.5 mL). To this solution potassium carbonate (81 mg, 2 eq., 0.57 mmol) and compound 9 (152 mg, 1.5 eq., 0.43 mmol) were afterwards added. This reaction mixture was stirred at 140 °C for 30 min under microwave irradiation. The resulting residue was dissolved in EtOAc (10 mL) and water (5 mL), and the aqueous phase was extracted thrice with EtOAc (3 x 10 mL). The organic phases were then washed 5 times with water (5 x 5 mL), once with brine (5 mL) and dried over magnesium sulfate. The crude was concentrated under reduced pressure and purified by silica gel column chromatography, eluting DCM/MeOH 99:1, to afford desired product 10b as colorless oil. (100 mg, 71%). 1

General procedure 4 (for reduction with AlLiH4):

To the mixture of LiAlH4 (0.03 g, 0.8 mmol, 2 equiv) in dry THF (1 mL), cooled at 0 °C, solution of methyl 2substitued-benzimidazole-5 carboxylate (1 equiv) in dry THF (1 mL) was slowly added. The ice bath was removed, and the reaction mixture was stirred for 2-4h.

After completion EtOAc and water were added. Then, aqueous phase was extracted with EtOAc (3x) and combined organic phases were dried over MgSO4 and concentrated to give desired product.

4.1.13.1. 5-Hydroxymethyl-2-phenyl-benzimidazole (14a). The title compound was prepared from 13a (0.10 g, 0.4 mmol, 1 equiv) following the general procedure 4.

Compound 14a (0.09 g, quantitative) was obtained as a white solid. 1

5-Hydroxymethyl-2-[3-(trifluoromethyl)phenyl]-benzimidazole (14c).

The title compound was prepared from 13c (0.31 g, 0.96 mmol, 1 equiv) following the general procedure 4. Compound 14c (0.27 g, 95%) was obtained as a white solid.

HRMS (ESI) m/z [M+H]

+ calcd for C15H12F3N2O 309.0890 found 309.0893.

5-Hydroxymethyl-2-[3-(trifluoromethoxy)phenyl]-benzimidazole (14e).

The title compound was prepared from 13e (1.61 g, 4.80 mmol, 1 equiv) following the general procedure 4. Compound 14e (1.41 g, 95%) was obtained as a white solid.

General procedure 5 (for coupling piperidine fragment with benzimidazole fragment) :

To a flask containing benzimidazole derivative (1 eq.),

SOCl2 (29 eq.) was added and the resulted mixture was stirred for 2h30 at 80 °C.

After cooling to room temperature, SOCl2 was evaporated and the obtained solid was diluted with ACN (4 mL) and cooled to 0 °C. Then, to this solution, piperidine derivative (1 eq.) and diisopropylethylamine (5.3 eq.) were added. The ice bath was removed and the reaction mixture was allowed to stir for 16-19h at room temperature.

After concentration, the crude product was purified by column chromatography (DCM/MeOH) to give the desired product.

Diethyl ({4-[2-({1-[(2-phenyl-1H-1,3-benzodiazol-6-yl)methyl]piperidin-4-yl}oxy)phenoxymethyl]-phenyl}methyl)phosphonate (15a). The title compound

was obtained following the general procedure 5 from benzimidazole 14a (31 mg, 1 eq., 0.138 mmol), SOCl2 (293 µL, 29 eq., 4.01 mmol) and then compound 11a (60 mg, 1 eq., 0.138 mmol), diisopropylethylamine (124 µL, 5.3 eq., 0.73 mmol) in ACN (2 mL). After purification by silica gel column chromatography, eluting DCM/MeOH 95:5, the clean compound 15a was obtained as an amorphous creamy solid. (

Diethyl {[4-(2-{[1-({2-[4-(trifluoromethoxy)phenyl]-1H-1,3-benzodiazol-

6-yl}methyl)piperidin-4-yl]oxy}phen-oxymethyl)phenyl]methyl}phosphonate (15d).

The title compound was obtained following the general procedure 5 from benzimidazole 14d (36 mg, 1 eq., 0.12 mmol), SOCl2 (244 µL, 29 eq., 3.35 mmol)

and then compound 11a (50 mg, 1 eq., 0.12 mmol), diisopropylethylamine (104 µL,

(15e).

The title compound was obtained following the general procedure 5 from benzimidazole 14e (36 mg, 1 eq., 0.12 mmol), SOCl2 (244 µL, 29 eq., 3.35 mmol)

and then compound 11a (50 mg, 1 eq., 0.12 mmol), diisopropylethylamine (104 µL, 5.3 eq., 0.61 mmol) in ACN (2 mL). After purification by silica gel column chromatography, eluting DCM/MeOH 95:5, the clean compound 15e was obtained as an amorphous creamy solid. (18 mg, 25%) eq., 0.099 mmol), SOCl2 (210 µL, 29 eq., 2.87 mmol) and then compound 11b (43 mg, 1 eq., 0.099 mmol), diisopropylethylamine (90 µL, 5.3 eq., 0.53 mmol) in ACN (3 mL). After purification by silica gel column chromatography, eluting DCM/MeOH 95:5, the clean compound 16a was obtained as an amorphous creamy solid. (24 mg, 38%) 2H, H 3 , H 5 pip), 1.45 (dq, J = 13.0, 10.9 Hz, 2H, H 3 , H 5 pip), 1.17 (t, J = 7.1 Hz, 6H, CH3). 13

Scheme 1 .

 1 Scheme 1. Synthesis of compounds 6a and 6b. Reagents and conditions: (a) diethylphosphite, DMF, 150 °C, MW, 2 min, 90% (b) DHP, PPTS, DCM, r.t., 3 h, 88-94% (c) NaI, K2CO3, DMF, MW, 80 °C, 20 min, 72% (d) PPTS, EtOH, 55 °C, 3 h, 99%.

Scheme 2 .

 2 Scheme 2. Synthesis of (4-aryloxy)-1-piperidines 11a and 11b. Reagents and conditions: (a) NaH, MeOH, rt, 20 h, 95% (b) TsCl, Et3N, DCM, r.t., 20 h, 98% (c) 6a and 6b, K2CO3, DMA, MW, 140 °C, 30 min, 72% (d) TFA in DCM 1:2, r.t., 1 h.

Scheme 4 .

 4 Scheme 4. Synthesis of compound 22. Reagents and conditions: (a) PPTS, DHP, DCM, r.t., 12 h, quant. (b) 1. n-BuLi, THF, -78 °C, 30 min., 2. 1-Boc-piperidine-4carboxaldehyde, THF, r.t., 3 h, 60-65%. c) TFA, Et3SiH, DCM, rt, 1 h, (21% from 19) and (65% from 21) (d) BnCl, K2CO3, DMF, 70 °C, 12 h, quant. (e) H2, Pd/C, EtOAc, rt, 24 h, 10 bars, quant.

7 a

 7 Effective concentration required to inhibit virus-expressed reporter fluorescence by 50%. b Cytotoxic concentration required to cause a loss of cell viability by 50% c Selectivity Index defined as CC50/EC50. As a result, all componds having our benzimidazole-piperidine scaffold were found to possess a good potency (EC50 µM range). The introduction of CF3-and CF3Ogroups (for increased lopophilicity) didn't improve the SI. Analogs bearing a piperidine-ether moiety (e.g. 2-substitued-6-[(4-aryloxy-1-piperidyl)methyl]-1Hbenzimidazoles -serial A) appear to be less active than the 2-substituted-6-[(4benzyl-1-piperidyl)methyl]-1H-benzimidazoles (Serial B). Compounds 16a (EC50 = 1.88 µM, SI = 7) and 26b (EC50 = 0.87 µM, SI = 5) displayed good inhibitory activity, and a SI comparable or nearly equipotent to toremifene (EC50 = 0.38 μM; CC50 = 2.50 µM and SI = 7). Among those molecules, compound 26a (EC50 = 0.93 µM, SI = 10) and 25a (EC50 = 0.64 µM, SI = 20) are of great interest, meanwhile compound 25a stood out as the most potent against EBOV. 25a and 26a are isomers of position and they both belong to serial B. To test if 25a and 26a inhibited

Figure 2 :

 2 Figure 2: Compounds block EBOV GP-mediated entry and alter the subcellular distribution of intracellular cholesterol, consistent with inhibition of NPC1 activity. (A & B) Compounds block the entry of HIV pseudotype particles bearing the EBOV GP. Data represent the mean ± standard deviation from 3 biological repeats. Blue circles, entry; green, viability for (A) compound 25a and (B) compound 26a. (C) Compounds alter the distribution of intracellular cholesterol, consistent with an inhibition of NPC1 activity. Immunofluorescence micrographs of HeLa cells treated with compounds 25a, 26a or their DMSO-vehicle, or U18666A or its water-vehicle, then stained with filipin to visualize intracellular cholesterol. Bars are equivalent to 100 µm. (D) Minimal cytotoxicity in HeLa cells treated with these compounds. Cellular viability, relative to the DMSO vehicle-control, as determined by CellTiter-Glo. Data represent the mean ± standard deviation from 3 biological repeats.

Figure 3 .

 3 Figure 3. The docking binding poses of compound 25a (orange) 26a (purple) and in the active site of NPC1 (PDB ID: 5U73). Residues within a distance of 4Å from compounds have been shown. Hydrogen bond and pi-pi stacking interactions between NPC1 and docked compounds are in red and blue, respectively. In the left bottom corner, whole NPC1 protein is shown, with the binding site highlighted in the red box.

  H NMR (400 MHz, CDCl3) δ 7.36 (d, J = 8.1 Hz, 2H), 7.32 -7.23 (m, 2H), 4.49 (s, 2H, Br-CH2), 4.09 -3.89 (m, 4H, O-CH2), 3.16 (d, J = 21.8 Hz, 2H, CH2-P), 1.26 (t, J = 7.1 Hz, 6H, CH3).

  H NMR (400 MHz, CDCl3) δ 7.38 -7.21 (m, 4H), 4.49 (s, 2H, Br-CH2), 4.12 -3.94 (m, 4H, O-CH2), 3.16 (d, J = 21.7 Hz, 2H, CH2-P), 1.26 (t, J = 7.1 Hz, 6H, CH3).

  )piperidin-4-yl]oxy}phen-oxymethyl)phenyl]methyl}phosphonate

4. 1 . 14 . 6 .

 1146 Diethyl ({3-[2-({1-[(2-phenyl-1H-1,3-benzodiazol-6-yl)methyl]piperidin-4-yl}oxy)phenoxymethyl]-phenyl}methyl)phosphonate (16a). The title compoundwas obtained following the general procedure 5 from benzimidazole 14a(22 mg, 1

  C NMR (101 MHz, MeOD) δ 157.91 (C quat -CH2), 139.20 (d, J = 3.2 Hz, C quat ), 133.95 (d, J = 9.3 Hz, C quat ), 131.97(C Ar ), 130.47 (d, J = 6.7 Hz, C Ar ), 129.82 (d, J = 6.6 Hz, C Ar ), 129.74 (d, J = 3.1 Hz, C Ar ), 129.02(C quat ), 128.72(C Ar ), 127.05 (d, J = 3.7 Hz, C Ar ), 121.76(C Ar ), 113.04(C Ar ), 70.61(CH2-O), 63.79 (d, J = 6.9 Hz, CH2-O-P), 45.11(C 2 , C 6 pip), 37.31 (CH2), 35.84 (C 4 pip), 33.54 (d, J = 138.0Hz, CH2-P), 29.73 (C 3 , C 5 pip), 16.62 (d, J = 6.1 Hz, CH3) 31 P NMR (162 MHz, MeOD) δ 27.01. HRMS-ESI (m/z) [M+H] + calcd for C24H35NO4P 432.2304, found 432.2299. 4.1.23.1. Diethyl ({4-[2-({1-[(2-phenyl-1H-1,3-benzodiazol-6-yl)methyl]piperidin-4-yl}methyl)phenoxy-methyl]phenyl}-methyl)phosphonate (25a

  Abbreviations usedBOCButyloxycarbonyl Bs Broad signal DCM Dichloromethane DHP 3,4-Dihydropyran DIPEA N,N-Diisoproylethylamine DMA Dimethylacetamide DMF N,N-Dimethylformamide DMSO Dimethylsulfoxyde EBOV Ebola virus FDA US food and drug administration HF Hemorrhagic fever GP Glycoprotein MW Microwaves NPC1 Niemann Pick C1 protein PPTS Pyridinium p-toluenesulfonate RNA Ribonucleic acid r.t. room temperature SN Nucleophilic substitution

Table 1 . Anti-EboV activity of benzimidazole analogues Number Compound EC50 a (µM) CC50 b (µM) SI c

 1

	15a

Table 2 .

 2 ADME profile of synthesized compounds

#stars QPlogPo/w QPlogKhsa QPlogHERG QPPCaco QPPMDCK Percent Human Oral Absorption Rule of Five Rule of Three Range or recommended values

		0-5	-2.0-6.5	-1.5-1.5	Below -5	<25 poor, >500 great	<25 poor, >500 great	<25 poor, >80% high	Max 4	Max 3
	3.47 [22]	3	4.54	0.54	-5.21	60.06	71.04	72.39	1
	15a	2	6.31	1.04	-8.16	608.80	321.19	87.82	2
	15b	4	7.61	1.40	-7.90	736.35	1285.39	96.89	2
	15c	7	7.83	1.44	-8.33	752.54	1879.53	100	2
	15d	8	7.93	1.55	-8.33	748.73	1490.82	100	2
	15e	3	7.67	1.37	-7.71	1397.40	3433.29	100	2
	16a	4	6.90	1.18	-8.72	1113.77	625.09	95.94	2
	16b	7	8.07	1.49	-8.34	1033.88	2646.59	100	2
	16c	4	7.64	1.29	-7.66	1455.18	3833.36	100	2
	16d	7	7.88	1.44	-8.64	1113.92	2744.82	100	2
	16e	6	7.86	1.44	-8.58	1111.66	2721.34	100	2
								21

  To this solution, potassium carbonate (1.58 g, 2 eq., 11.48 mmol), compound 2a (2.03 g, 1.1 eq., 6.32 mmol) and few crystals of sodium iodide

(catalytic amount) were added. The mixture was then stirred 20 min. at 80 °C under microwave irradiation. After evaporation of all volatiles, the residue was purified by silica gel chromatography to afford desired product 5a as a colorless oil. (1.42 g, 57%).

1

H NMR (400 MHz, CDCl3) δ 7.40 (d, J = 7.8 Hz, 2H, H Ar ), 7.30 (dd, J = 8.2, 2.5 Hz, 2H, H Ar ), 7.15 (m, 1H, H Ar ), 6.93 (m, 3H, H Ar ), 5.43 (s, 1H, H anomeric ), 5.09 (t, J = 2.1 Hz, 2H, CH2-O), 4.01 (m, 4H, CH2-O-Phosph), 3.60 (m, 1H, H 5 ), 3.15 (d, J = 21.6 Hz, 2H, CH2-P), 2.16 -1.79 (m, 3H, H 2/3/4/5 ), 1.74 -1.56 (m, 4H, H 2/3/4/5 ), 1.23 (t, J = 7.0 Hz, 6H, CH3). 13 C NMR (101 MHz, CDCl3) δ 149.45 (C quat ), 147.16 (C quat ), 136.13 (d, J = 3.6 Hz, C quat ), 131.11 (d, J = 9.3 Hz, C quat ), 129.83 (d, J = 6.8 Hz, C Ar ), 127.42 (d, J = 3.0 Hz, C Ar ), 122.58 (C Ar ), 121.84 (C Ar ), 118.56 (C Ar ), 115.58 (C Ar ), 97.61 (C Anomeric ), 71.06 (CH2-O), 62.12 (d, J = 6.8 Hz, CH2-O-P), 61.99 (C 5 ), 33.55 (d, J = 138.1 Hz, CH2-P), 30.39 (C 2/3/4 ), 25.30 (C 2/3/4 ), 18.72 (C 2/3/4 ), 16.36 (d, J = 5.9 Hz, CH3). 31 P NMR (162 MHz, CDCl3) δ 26.27. HRMS-ESI (m/z) [M+Na] + calcd for C23H31NaO6P 457.1756, found 457.1760.

.11. General procedure 2 (for BOC removal) :

  Hz, C Ar ), 128.74 (d, J = 2.5 Hz, C Ar ), 126.00 (d, J = 3.7 Hz, C Ar ), 122.57 (C Ar ), 121.79 (C Ar ), 118.59 (C Ar ), 115.52 (C Ar ), 79.11 (C quat Boc), 74.19 (C 4 Trifluoroacetic acid (100 eq.) wasadded dropwise to a mixture of Boc-compound (1 eq.) in DCM (2:1 DCM/TFA v/v).The reaction was stirred at room temperature for 2h and then volatiles were removed under reduced pressure. The crude product was extracted with EtOAc, washed with NaHCO3 until pH 7, dried over MgSO4, filtrated and concentrated under vacuum. Hz, C quat ), 129.78 (d, J = 6.6 Hz, C Ar ), 127.65 (d, J = 3.3 Hz, .7 mmol) was added to a solution of compound 10b (105 mg, 1 eq., 0.197 mmol) in DCM (3 mL). Pure compound 11b was obtained after flash column chromatography (DCM/MeOH 95:5), affording desired product as an orange solid. Hz, 2H, H 3 , H 5 pip), 1.96 (dd, J = 13.1,2.9 Hz, 2H, H 3 , H 5 pip), 1.22 (td, J = 7.1, 0.5 Hz, 6H, CH3).13 C NMR (101 MHz, CDCl3)δ 150.77 (C quat ), 146.38 (C quat ), 137.04 (d, J = 3.4 Hz, C quat ), 131.41 (d, J = 9.5 Hz, C quat ), 129.87 (d, J = 6.7 Hz, C Ar ), 128.91 (d, J = 6.0 Hz, C Ar ), 126.78 (d, J = 3.2 Hz, C Ar ), 124.51 (d, J = 5.0 Hz, C Compound 13a (0.97 g, 97%) was obtained as a white solid. 1 H NMR (250 MHz, CDCl3) δ 8.39 (s, 1H), 8.18 -8.10 (m, 2H), 8.00 (dd, J = 8.5, 1.5 Hz, 1H), 7.66 (d, J = 8.2 Hz, 1H), 7.53 -7.45 (m, 3H), 3.97 (s, 3H, CH3). 13 C NMR (101

	(58 mg, 68%). 1 H NMR (400 MHz, CDCl3) δ 7.50 (d, J = 2.3 Hz, 1H, H Ar ), 7.29 (m, 1H, H Ar ), 7.15 (m, 2H, H Ar ), 6.96 (m, 4H, H Ar ), 4.98 (s, 2H, CH2-O), 4.60 (s, 1H, H 4 MHz, CDCl3) δ 167.97, 130.99, 129.44, 129.38, 127.08, 125.02, 124.70, 52.42 (CH3). HRMS (ESI) m/z [M+H] + calcd for C15H13N2O2 253.0972 found 253.0974. 4.1Pure compounds were obtained after purification by flash column chromatography pip), 3.95 (2x ddq, J = 7.6, 6.6, 0.5 Hz, 4H, CH2-O-P), 3.32 (td, J = 12.9, 3.8 Hz, 2H, 4.1.12.2. 5-Methyl carboxylate-2-[4-(trifluoromethyl)phenyl]-benzimidazole
	with DCM/MeOH (95:5) as eluent. H 2 , H 6 pip), 3.12 (d, J = 21.8 Hz, 2H, CH2-P), 3.09 (m, 2H, H 2 , H 6 pip), 2.25 (tdd, J = (13b). The title compound was prepared from 4-trifluoromethyl-benzaldehyde (0.41
	CH2-O), 4.41 (m, 1H, H 4 pip), 3.87 (ddq, J = 6.9, 6.1, 0.4 Hz, 4H, CH2-O-P), 3.56 (m, 2H, H 2 , H 6 pip), 3.17 (d, J = 21.5 Hz, 2H, CH2-P),3.15 (m, 2HH 2 , H 6 pip),1.79 (s, 2H, H 3 , H 5 pip), 1.51 (s, 2H, H 3 , H 5 pip), 1.35 (s, 9H, CH3 Boc), 1.07 (dt, J = 6.9, 0.4 Hz, 6H, CH3). pip), 70.43(CH2-O), 61.83 (d, J = 6.5 Hz, CH2-O-P), 39.74 (C 2 , C 6 pip, under DMSO 4.1.11.1. Diethyl ({4-[2-(piperidin-4-yloxy)phenoxymethyl]phenyl}methyl) C Ar ), 123.08 (C Ar ), 121.41 (C Ar ), 118.82 (C Ar ), 114.95 (C Ar ) , 70.80 (C 4 pip), 70.52 (CH2-O), 62.35 (d, J = 7.0 Hz, CH2-O-P), 40.24(C 2 , C 6 pip), 31.86(d, J = 138.0 Hz, mL, 3.00 mmol, 1 equiv) following the general procedure 3. Compound 13b (0.90 g, 93%) was obtained as a white solid. 1 H NMR (400 MHz, DMSO) δ 13.51 (s, 1H, NH), 8.39 (d, J = 8.3 Hz, 2H), 8.35 -7.99 (m, 1H), 7.95 (d, J = 8.3 Hz, 2H), 7.92 -7.82 (m, 1H), 7.81 -7.59 (m, 1H), 3.88 (s, 3H, CH3). 13 C NMR (101 MHz, DMSO) δ 166.63, 133.31, 130.33, 127.43, 126.05, 126.01, 125.40, 122.69, 111.82, 52.05 (CH3). C16H12F3N2O2 321.0845 found 321.0848. IR (cm -1 ) 3296, 1688, 1618, 1443, 1319, 1289, 1239, 1225, 1163, 1114, 1100, 1064, 1019, 984, 850, 765, 749, 696, 653. Mp 260 °C. 12.8, 4.7, 2.2 Combined organic phases were dried over MgSO4 and concentrated. The crude 4.1
	peak),32.71 (d, J = 134.0 Hz, CH2-P), 31.00 (C 3 , C 5 pip), 28.53 (CH3 Boc), 16.64 (d, CH2-P), 27.06(C 3 , C 5 pip), 15.24(d, J = 6.1 Hz, CH3). 31 P NMR (162 MHz, CDCl3) δ product was purified by flash column chromatography (PE/EtOAc or DCM/MeOH) to
	J = 5.9 Hz, CH2-O-P). 31 P NMR (162 MHz, DMSO) δ 26.34. HRMS-ESI (m/z) 27.50. HRMS-ESI (m/z) [M+H] + calcd for C23H33NO5P 434.2097, found 434.2100. afford desired product.
	[M+H] + calcd for C28H41NO7P 534.2621, found 534.2615.

H NMR (400 MHz, DMSO) δ 7.29 (m, 3H, H Ar ), 7.19 (s, 1H, H Ar ), 7.01 (m, 2H, H Ar ), 6.85 (m, 2H, H Ar ), 5.03 (s, 2H, 13 C NMR (101 MHz, DMSO) δ 154.36 (C=O), 150.05 (C quat ), 147.18 (C quat ), 137.83 (d, J = 3.0 Hz, C quat ), 132.88 (d, J = 8.7 Hz, C quat ), 129.61 (d, J = 6.8 Hz, C Ar ), 129.07 (d, J = 6.8 phosphonate (11a). Following general procedure 2, trifluoroacetic acid (11.1 mL, 100 eq., 146 mmol) was added to a solution of intermediate 10a in DCM (20 mL). Pure compound 11a was obtained after flash column chromatography (DCM/MeOH 95:5), affording desired product as an orange solid. (588 mg, 67%). 1 H NMR (400 MHz, CDCl3) δ 7.45 (d, J = 8.0 Hz, 2H, H Ar ), 7.29 (d, J = 8.2, 2.5 Hz, 2H, H Ar ), 7.09 (m, 2H, H Ar ), 7.01 (t, J = 7.3 Hz, 1H, H Ar ), 6.94 (m, 1H, H Ar ), 5.10 (s, 2H, CH2-O), 4.57 (quint., J = 4.3 Hz, 1H, H 4 pip), 4.04 (2x ddq, J = 7.7, 6.7, 2.3 Hz, 4H, CH2-O-P), 3.38 (dt, J = 13.0, 7.0 Hz, 2H, H 2 , H 6 pip), 3.26 (d, J = 21.8 Hz, 2H, CH2-P), 3.09 (m, 2H, H 2 , H 6 pip), 3.13 (tdd, J = 12.8, 5.0 Hz, 2H, H 3 , H 5 pip), 2.03 (dt, J = 7.1,5.3 Hz, 2H, H 3 , H 5 pip), 1.26 (t, J = 7.0 Hz, 6H, CH3). 13 C NMR (101 MHz, CDCl3) δ 146.55 (C quat ), 135.15 (d, J = 3.8 4.1.11.2. Diethyl ({3-[2-(piperidin-4-ylmethyl)phenoxymethyl]phenyl}methyl) phosphonate (11b). Following general procedure 2, trifluoroacetic acid (1.5 mL, 100 eq., 19Ar ), 123.47(C Ar ), 121.87(C Ar ), 119.29(C Ar ), 114.14(C Ar ), 71.32(C 4 pip), 70.80 (CH2-O), 63.09 (d, J = 6.9 Hz, CH2-O-P), 39.44(C 2 , C 6 pip), 32.96 (d, J = 139.5 Hz, CH2-P), 26.66(C 3 , C 5 pip), 16.06 (d, J = 6.2 Hz, CH3). 31 P NMR (162 MHz, CDCl3) δ 26.57. HRMS-ESI (m/z) [M+H] + calcd for C23H33NO5P 434.2097, found 434.2094. 4.1.12. General procedure 3 (for benzimidazole ring construction): Solution of an aldehyde (12a-e, respectively), (1 equiv) in 40% NaHSO3 (4 mL) was stirred for 1h at room temperature, then solution of methyl 3,4-diaminobenzoate (0.65 g, 3.94 mmol, 1 equiv) in EtOH (2 mL) was added. Resulting mixture was stirred at 100 °C for 1-4h, then concentrated. Residue was dissolved in water and extracted with EtOAc. 4.1.12.1. 5-Methyl carboxylate-2-phenyl-benzimidazole (13a). The title compound was prepared from benzaldehyde 12a (0.4 mL, 3.94 mmol, 1 equiv) following the general procedure 3. 19 F NMR (376 MHz, DMSO) δ -61.30. HRMS (ESI) m/z [M+H] + calcd for

.12.3. 5-Methyl carboxylate-2-[3-(trifluoromethyl)phenyl]-benzimidazole (13c). The

	title compound was prepared from 3-trifluoromethyl-benzaldehyde (0.24 mL, 1.8 mmol, 1 equiv) following the general procedure 3. Compound 13c (0.44 g, 76%) was obtained as a white solid. 1 H NMR (400 MHz, DMSO) δ 13.45 (s, 1H, NH), 8.53 (s, 1H), 8.49 (d, J = 7.8 Hz, 1H), 8.22 (s, 1H), 7.92 -7.80 (m, 3H), 7.75 -7.68 (m, 1H), 3.88 (s, 3H, CH3). 13 C NMR (101 MHz, DMSO) δ 166.64, 152.21, 130.60, 130.55, 130.36, 130.03, 129.71, 126.85, 126.82, 125.35, 123.84, 123.66, 123.14, 1098, 1070, 991, 919, 803, 772, 751, 700, 688, 650, 612.Mp 190 °C. 4.1.12.4. 5-Methyl carboxylate-2-[4-(trifluoromethoxy)phenyl]-benzimidazole (13d). The title compound was prepared from 4-trifluoromethoxybenzaldehyde (0.75 mL, 5.3 mmol, 1 equiv) following the general procedure 3. Compound 13d (1.38 g, 78%) was obtained as a light yellow solid. 1 H NMR (400 MHz, DMSO) δ 8.31 (d, J = 8.7 Hz, 2H, H Ar ), 8.21 (s, 1H, H Ar ), 7.87 (dt, J = 8.4 Hz, 1H, H Ar ), 7.70 (d, J = 8.7 Hz, 1H, H Ar ), 7.59 3.88 (s, 3H, CH3). 13 C NMR (101 MHz, DMSO) δ 167.15(C=O), 152.98(C quat ), 150.12(C quat ), 129.31(C Ar ), 129.25(C Ar ), 126.73(C Ar ), 124.11(C Ar ), 123.96(C Ar ), 121.99(C Ar ), 121.77(C Ar ), 52.50 (CH3). 19 F NMR (376 MHz, DMSO) δ -56.64. HRMS (ESI) m/z [M+H] + calcd for C16H12F3N2O2 337.0839 found 337.0842. (C=O), 153.88 (C quat ), 152.66 (C quat ), 149.31 (C quat ), 132.26 (C Ar ), 131.81 (C quat ), 126.20 (C Ar ), 124.27 (C Ar ), 123.31 (C Ar ), 119.39 (C Ar ), 52.53 (CH3) 19 F NMR (376 MHz, DMSO) δ -56.71. HRMS (ESI) m/z [M+H] + calcd for C16H12F3N2O2 337.0839 123.10, 122.64, 52.05 (CH3). 1628, 1538, 1459, 1438, 1331, 1306, 1285, 1270, 1221, 1182, 1166, 1121, 1108, found 337.0841.

19

F NMR (376 MHz, DMSO) δ -61.

[START_REF] Besset | New entries toward the synthesis of OCF3-containing molecules[END_REF]

. HRMS (ESI) m/z

[M+H] + calcd for C16H12F3N2O2 321.0845 found 321.0848. IR (cm -1 ) 3296, 1694, 4.1.12.5. 5-Methyl carboxylate-2-[3-(trifluoromethoxy)phenyl]-benzimidazole (13e). The title compound was prepared from 3-trifluoromethoxybenzaldehyde (0.75 mL, 5.3 mmol, 1 equiv) following the general procedure 3. Compound 13e (1.61 g, 91%) was obtained as a light yellow solid. 1 H NMR (400 MHz, DMSO) δ 8.24 (d, J = 7.6 Hz, 2H, H Ar ), 8.16 (s, 1H, H Ar ), 7.88 (d, J = 8.4 Hz, 1H, H Ar ), 7.75 (m, 2H, H Ar ), 7.55 (d, J = 7.6 Hz, 1H, H Ar ), 3.89 (s, 3H, CH3). 13 C NMR (101 MHz, DMSO) δ 167.12

  C 2 , C 6 pip), 32.00 (d, J = 138.2 Hz, CH2-P), 29.14 (C 3 , C 5 pip), 15.23 (d, J = 6.0 Hz, CH3).31 P NMR (162 MHz, MeOD) δ 27.43 HRMS-ESI (m/z) [M+H] + calcd for C37H43N3O5P 640.2941, found 640.2935.

	4.1.14.3. Diethyl {[4-(2-{[1-({2-[3-(trifluoromethyl)phenyl]-1H-1,3-benzodiazol-6-
	yl}methyl)piperidin-4-yl]oxy}phen-oxymethyl)phenyl]methyl}phosphonate
	(15c). The title compound was obtained following the general procedure 5 from
	4.1.14.2. Diethyl {[4-(2-{[1-({2-[4-(trifluoromethyl)phenyl]-1H-1,3-benzodiazol-6-benzimidazole 14c (47 mg, 1 eq., 0.16 mmol), SOCl2 (340 µL, 29 eq., 4.68 mmol)
	yl}methyl)piperidin-4-yl]oxy}phenoxy-methyl)phenyl]methyl}phosphonate and then compound 11a (70 mg, 1 eq., 0.16 mmol), diisopropylethylamine (144 µL,
	(15b). The title compound was obtained following the general procedure 5 from 5.3 eq., 0.85 mmol) in ACN (4 mL). After purification by silica gel column
	benzimidazole 14b (0.16 mmol), SOCl2 (340 µL, 29 eq., 4.68 mmol) and then chromatography, eluting DCM/MeOH 95:5, the clean compound 15c was obtained as
	compound 11a (70 mg, 1 eq., 0.16 mmol), diisopropylethylamine (144 µL, 5.3 eq., an amorphous creamy solid. (24 mg, 21%) 1 H NMR (400 MHz, MeOD) δ 8.41 (bs,
	0.85 mmol) in ACN (4 mL). After purification by silica gel column chromatography, 1H, H Ar ), 8.33 (d, J = 8.0 Hz, 1H, H Ar ), 7.71 (m, 5H, H Ar ), 7.32 (m, 4H, H Ar ), 6.94 (m,
	eluting DCM/MeOH 95:5, the clean compound 15b was obtained as an amorphous 4H, H Ar ), 5.01 (s, 2H, CH2-O), 4.40 (s, 1H, H 4 pip), 3.96 (m, 4H, CH2-O-P), 3.82 (s,
	2H, CH2-N), 3.19 (d, J = 23.3 Hz, 2H, CH2-P), 2.97 (bs, 2H, H 2 , H 6 pip), 2.68 (bs, 2H, creamy solid. (28 mg, 32%) 1H, H 4 pip), 3.98 (m, 4H, CH2-O-P), 3.75 (s, 2H, CH2-N), 3.20 (d, J = 21.8 Hz, 2H, H 2 , H
	CH2-P), 2.89 (bs, 2H, H 2 , H 6 pip), 2.51 (bs, 2H, H 2 , H 6 pip), 1.89 (m, 4H, H 3 , H 5 pip),
	29 mg, 1.20 (t, J = 7.1 Hz, 6H, CH3). 13 C NMR (101 MHz, MeOD) δ 150.89 (C quat ), 150.05
	40%) 1 H NMR (400 MHz, MeOD) δ 8.12 (d, J = 7.0 Hz, 2H, H Ar ), 7.63 (m, 5H, H Ar ), (C quat ), 147.19 (C quat ), 136.29 (d, J = 3.0 Hz, C quat ), 131.36 (C quat ), 131.04 (C quat ),
	7.37 (m, 5H, H Ar ), 7.04 (m, 2H, H Ar ), 6.91 (dquint, J = 7.3, 1.9 Hz,2H, H Ar ), 5.06 (s, 130.94 (C quat ), 130.72 (C quat ), 130.63 (C quat ), 129.83 (C Ar ), 129.78 (C Ar ), 129.67 (d, J =
	2H, CH2-O), 4.48 (s, 1H, H 4 pip), 4.00 (ddq, J = 8.8, 7.0, 1.8 Hz, 4H, CH2-O-P), 3.93 6.6 Hz, C Ar ), 127.50 (d, J = 3.3 Hz, C Ar ), 126.38 (C Ar ), 125.36 (C Ar ), 125.14 (C Ar ),
	(s, 2H, CH2-N), 3.24 (d, J = 21.7 Hz, 2H, CH2-P), 3.06 (bs, 2H, H 2 , H 6 pip), 2.76 (bs, 123.08 (C Ar ), 122.66 (C Ar ), 122.19 (C Ar ), 121.45 (C Ar ), 118.29 (C Ar ), 115.33 (C Ar ),
	2H, H 2 , H 6 pip), 1.97 (m, 4H, H 3 , H 5 pip), 1.23 (t, J = 7.0 Hz, 6H, CH3). 13 C NMR (101 70.50 (CH2-O), 62.48 (CH2-N), 62.30 (d, J = 7.0 Hz, CH2-O-P), 49.37 (C 2 , C 6 pip),
	MHz, MeOD) δ 150.15 (C quat ), 147.01 (C quat ), 136.24 (d, J = 3.9 Hz, C quat ), 131.11 (d, 31.96 (d, J = 138.1 Hz, CH2-P), 29.70 (C 3 , C 5 pip), 15.25 (d, J = 5.9 Hz, CH3). 31 P
	J = 9.2 Hz, C quat ), 130.19 (C Ar ), 129.71 (d, J = 6.6 Hz, C Ar ), 129.42 (C Ar ), 128.79 (C Ar ), NMR (162 MHz, MeOD) δ 27.42. 19 F NMR (376 MHz, MeOD) δ -64.25. HRMS-ESI
	(m/z) [M+H] + calcd for C39H42F3N3O5P 708.2811, found 708.2812.

127.59 (d, J = 4.0 Hz, C Ar ), 126.48 (C Ar ), 122.46 (C Ar ), 121.46 (C Ar ), 118.52 (C Ar ), 115.23 (C Ar ), 70.49 (CH2-O), 62.30 (d, J = 6.9 Hz, CH2-O-P), 62.09 (CH2-N), 48.99

(1 H NMR (400 MHz, MeOD) δ 8.42 (bs, 1H, H Ar ), 8.33 (d, J = 8.0 Hz, 1H, H Ar ), 7.70 (m, 5H, H Ar ), 7.38 (d, J = 8.0 Hz, 2H, H Ar ), 7.28 (m, 3H, H Ar ), 6.98 (m, 2H, H Ar ), 6.88 (m, 2H, H Ar ), 5.01 (s, 2H, CH2-O), 4.37 (d, J = 7.4 Hz, 6 pip), 1.95 (m, 4H, H 3 , H 5 pip), 1.18 (t, J = 6.9 Hz, 6H, CH3). 13 C NMR (101 MHz, MeOD) δ 150.10 (C Ar ), 137.46 (d, J = 1.7 Hz, C Ar ), 136.93 (C Ar ), 136.27 (d, J = 3.7 Hz, C quat ), 129.87 (C Ar ), 129.82 (C Ar ), 129.68 (d, J = 6.7 Hz, C Ar ), 127.54 (d, J = 3.0 Hz, C Ar ), 123.85 (C Ar ), 122.34 (C Ar ), 121.45 (C Ar ), 118.42 (C Ar ), 115.29 (C Ar ), 70.51 (CH2-O), 62.30 (d, J = 6.8 Hz, CH2-O-P), 62.25 (CH2-N), 49.20 (C 2 , C 6 pip), 31.91 (d, J = 137.5 Hz, CH2-P), 29.34 (C 3 , C 5 pip), 15.21 (d, J = 5.9 Hz, CH3). 31 P NMR (162 MHz, MeOD) δ 27.44. 19 F NMR (376 MHz, MeOD) δ -64.33. HRMS-ESI (m/z) [M+H] + calcd for C39H42F3N3O5P 708.2811, found 708.2809.

  MeOH 95:5, the clean compound 15d was obtained as an amorphous creamy solid. (17 mg, 23%) 1 H NMR (400 MHz, MeOD) δ 8.17 (d, J = 9.0 Hz, 2H, H Ar ), 7.61 (m, 2H, H Ar ), 7.46 (d, J = 8.7 Hz, 2H, H Ar ), 7.39 (d, J = 7.8 Hz, Hz, C quat ), 131.00 (d, J = 9.2 Hz, C quat ), 129.68 (d, J = 6.7 Hz, C Ar ), 128.59 (C Ar ), 128.33 (C Ar ), 127.53 (d, J = 2.7 Hz, C Ar ), 125.04 (C Ar ), 122.29 (C Ar ), 121.74 (C Ar ), 121.45 (C Ar ), 121.18 (C Ar ), 118.37 (C Ar ), 115.30 (C Ar ), 70.50 (CH2-O), 62.30 (d, J =

	2H, H Ar ), 7.30 (m, 3H, H Ar ), 6.99 (m, 2H, H Ar ), 6.89 (m, 2H, H Ar ), 5.02 (s, 2H, CH2-O),
	4.40 (s, 1H, H 4 pip), 3.99 (dqd, J= 9.8, 7.0, 1.6 Hz, 4H, CH2-O-P), 3.80 (s, 2H, CH2-
	N), 3.21 (d, J = 21.9 Hz, 2H, CH2-P), 2.95 (bs, 2H, H 2 , H 6 pip), 2.58 (bs, 2H, H 2 , H 6
	pip), 1.92 (m, 4H, H 3 , H 5 pip), 1.21 (t, J = 7.1 Hz, 6H, CH3). 13 C NMR (101 MHz,
	MeOD) δ 151.27 (C quat ), 150.42 (C quat ), 150.08 (C quat ), 147.13 (C quat ), 136.27 (d, J =
	4.0

5.3 eq., 0.61 mmol) in ACN (2 mL). After purification by silica gel column chromatography, eluting DCM/6.9 Hz, CH2-O-P), 62.30 (CH2-N), 49.20 (C 2 , C 6 pip), 31.96 (d, J = 137.2 Hz, CH2-P), 29.49 (C 3 , C 5 pip), 15.24 (d,J = 6.0 Hz, CH3).

31

P NMR (162 MHz, MeOD) δ 27.43. 19 F NMR (376 MHz, MeOD) δ -59.34. HRMS-ESI (m/z) [M+H] + calcd for C39H42F3N3O6P 724.2760, found 724.2757.

  J = 8.0, 7.0, 1.6 Hz, 4H, CH2-O-P), 3.77 (s, 2H, CH2-N), 3.21 (d, J = 21.7Hz, 2H, CH2-P), 2.91 (s, 2H, H 2 , H 6 pip), 2.54 (s, 2H, H 2 , H 6 pip), 1.91 (s, 4H, H 3 , H 5 pip), 1.21 (dt, J = 7.0, 0.4 Hz, 6H, CH3).13 C NMR (101 MHz, MeOD) δ 150.88 (C quat ), Hz, CH2-P), 29.67 (C 3 , C 5 pip), 15.24 (d, J = 6.0 Hz, CH3).31 P NMR (162 MHz, MeOD) δ 27.43. 19 F NMR (376 MHz, MeOD) δ -59.35. HRMS-ESI (m/z) [M+H] + calcd for C39H42F3N3O6P 724.2760, found 724.2759.

	150.06 (C quat ), 149.71 (d, J = 2.0 Hz, 1H, C Ar ), 147.15 (C quat ), 136.29 (d, J = 3.9 Hz,
	C quat ), 131.78 (C Ar ), 131.00 (d, J = 9.5 Hz, C quat ), 130.69 (C quat ), 129.66 (d, J = 6.7 Hz,
	C Ar ), 127.51 (d, J = 3.2 Hz, C Ar ), 125.01 (C Ar ), 122.29 (C Ar ), 122.21 (C Ar ), 121.82
	(C Ar ), 121.45 (C Ar ), 119.27 (C Ar ), 118.92 (C Ar ), 118.31 (C Ar ), 115.33 (C Ar ), 70.50 (CH2-
	O), 62.43 (CH2-N), 62.31 (d, J = 7.0 Hz, CH2-O-P), 49.34 (C 2 , C 6 pip), 32.02 (d, J =
	138.0

1 H NMR (400 MHz, MeOD) δ 8.08 (d, J = 8.0 Hz, 1H, H Ar ), 8.03 (s, 1H, H Ar ), 7.62 (m, 3H, H Ar ), 7.41 (m, 3H, H Ar ), 7.31 (m, 3H, H Ar ), 6.99 (m, 2H, H Ar ), 6.88 (m, 2H, H Ar ), 5.02 (s, 2H, CH2-O), 4.39 (s, 1H, H 4 pip), 3.99 (dqd,

.15. 2-(2-Bromophenoxy)tetrahydropyran (18). Under

  J = 7.0 Hz, C Ar ), 128.32 (d, J = 3.4 Hz, C Ar ), 126.44 (C Ar ), 125.92 (d, J = 3.7 Hz, C Ar ), 122.36 (C Ar ), 121.44 (C Ar ), 118.51 (C Ar ), 115.19 (C Ar ), 70.54 (CH2-O), 62.35 (d, J = 6.9 Hz, CH2-O-P), 62.21 (CH2-N), 49.29 (C 2 , C 6 pip), 32.32 (d, J = CH2-P), 29.75 (C 3 , C 5 pip), 15.26 (d, J = 6.0 Hz, CH3). 31 P NMR (162 MHz, MeOD) δ 27.36 19 F NMR (376 MHz, MeOD) δ -64.31. HRMS-ESI (m/z) [M+H] + calcd for C39H42F3N3O5P 708.2811, found 708.2808. Ar ), 131.61 (d, J = 9.3 Hz, C quat ), 130.71 (C Quat ), 129.10 (d, J = 6.5 Hz, C Ar ), 128.72 (d, J = 6.7 Hz, C Ar ), 128.31 (d, J = 3.2 Hz, C Ar ), 125.90 (d, J = 3.6 Hz, C Ar ), 125.01 (C Ar ), 122.34 (C Ar ), 121.44 (C Ar ), 118.93 (C Ar ), 118.48 (C Ar ), 115.20 J = 6.9 Hz, CH2-O-P), 44.28(C 2 , C 6 pip), 37.34 (CH2), 36.66 (C 4 pip), 33.82 (d, J = 138.0Hz, CH2-P), 32.15 (C 3 , C 5 pip), 28.46 (CH3 Boc), 16.37 (d, J = 6.7 Hz, CH3) 31 P NMR (162 MHz, MeOD) δ 26.22. HRMS-ESI (m/z) [M+H] + calcd for C29H43NO6P 532.2828, found 532.2819. Following general procedure 2, trifluoroacetic acid (18.9 mL, 100 eq., 245 mmol) was added to a solution of 23a in DCM (15 mL). Pure compound 24a was obtained after flash column chromatography (DCM/MeOH 95:5), affording desired product as a light brown solid. (356 mg, 88%) 1 H NMR (400 MHz, MeOD) δ 7.43 (d, J = 8.3 Hz, 2H, H Ar ), 7.34 (dd, J = 8.0, 2.4 Hz, 2H, H Ar ), 7.15 (m, 2H, H Ar ), 7.01 (dd, J = 8.0 Hz, 1H, H Ar ), 6.88 (d, J = 7.2 Hz, 1H, H Ar ), 5.10 (s, 2H, CH2-O), 4.04 (dq, J = 7.3, 7.2 Hz, 4H, CH2-O-P), 3.35 (under MeOD peak, m, 2H, H 2 , H 6 pip), 3.26 (under MeOD peak, 2H, CH2-P), 2.86 (dt, J = 12.5, 2.7 Hz, 2H, H 2 , H 6 pip), 2.66 (d, J = 7.0 Hz, 2H, CH2), 1.93 (m, 1H, H 4 pip), 1.82 (bd, J = 15.4 Hz, 2H, H 3 , H 5 pip), 1.42 (dq, J = 12.4, 3.4 Hz, 2H, H 3 , H 5 pip), 1.26 (t, J = 7.2 Hz, 6H, CH3). Hz, C quat ), 130.60(C Ar ), 129.76(d, J = 6.8 Hz, C Ar ), 127.62(C Ar ), 127.38(C Ar ), 127.32 (C Ar ), 120.44(C Ar ), 120.35(C Ar ), 111.87(C Ar ), 69.36(CH2-O), 63.33 (d, J = 7.1 Hz, CH2-O-P), 43.88 (C 2 , C 6 pip), 36.09(CH2), 34.35(C 4 pip), 31.96(d, J = 138.2 Hz, CH2-P), 28.56 (C 3 , C 5 pip), 15.24(d, J = 6.2 Hz, CH3). 31 P NMR (162 MHz, MeOD) δ 27.49. HRMS-ESI (m/z) [M+H] + calcd for C24H35NO4P 432.2304, found 432.2306. Following general procedure 2, trifluoroacetic acid (4.5 mL, 100 eq., 58.3 mmol) was added to a solution of compound 23b (310 mg, 1 eq., 0.58 mmol) in DCM (9 mL). Pure compound 24b was obtained after flash column chromatography (DCM/MeOH 95:5), affording desired product colorless oil. (235 mg, 94%) 1 H NMR (400 MHz, MeOD) δ 7.39 (s, 1H, H Ar ), 7.26 (m, 3H, H Ar ), 7.11 (dt, J = 7.6, 1.6 Hz, 1H, H Ar ), 7.06 (dd, J = 7.6, 1.6 Hz, 1H, H Ar ), 6.93 (d, J = 8.1 Hz, 1H, H Ar ), 6.83 (dt, J = 7.5, 0.7 Hz, 1H, H Ar ), 5.01 (s, 2H, CH2-O), 3.96 (m, 4H, CH2-O-P), 3.27 (m, 2H, H 2 , H 6 pip), 3.21 (d, J = 21.6 Hz, 2H, CH2-P), 2.80 (dt, J = 12.9, 2.3 Hz, 2H, H 2 , H 6 pip), 2.61 (d, J = 7.1 Hz, 2H, CH2), 1.86 (m, 1H, H 4 pip), 1.75 (bd, J = 14.1 Hz,

	4.1.14.9. Diethyl {[3-(2-{[1-({2-[4-(trifluoromethoxy)phenyl]-1H-1,3-benzodiazol-6-and then compound 11b (38 mg, 1 eq., 0.088 mmol), diisopropylethylamine (79 µL, 4.1.16. tert-Butyl 4-[hydroxy-(2-tetrahydropyran-2-yloxyphenyl)methyl] 4.1.19. tert-Butyl 4-{[2-(benzyloxy)phenyl](hydroxy)methyl}piperidine-1-4.1.20. tert-Butyl 4-{[2-({4-NMR (400 MHz, CDCl3) δ 7.24 (m, 4H, H Ar ), 7.07 (m, 2H, H Ar ), 6.82 (m, 2H, H Ar ), 5.01
	yl}methyl)-piperidin-4-yl]oxy}-phenoxymethyl)phenyl]methyl}phosphonate 5.3 eq., 0.47 mmol) in ACN (2 mL). After purification by silica gel column piperidine-1-carboxylate (19). Under Ar atmosphere, compound 18 (1 g, 1 eq., 3.89 carboxylate (22). Method A : In an autoclave, piperidine derivative 21 (1 g, 1 eq., [(diethoxyphosphoryl)methyl]phenyl}methoxy)phenyl] methyl}piperidine-1-(s, 2H, CH2-O), 3.96 (m, 6H, CH2-O-P, H 2 , H 6 pip), 3.10 (d, J = 21.6 Hz, 2H, CH2-P),
	(16d). The title compound was obtained following the general procedure 5 from chromatography, eluting DCM/MeOH 95:5, the clean compound 16e was obtained as mmol) was dissolved in THF (8 mL) and cooled at -78 °C. After stirring for 5 minutes, 2.55 mmol) was dissolved in ethyl acetate (43 mL). The solution and the atmosphere carboxylate (23a). In a 10-20 mL microwave vial, phosphonate derivative 2a (1.32 2.55 (d, J = 7.1 Hz, 4H, CH2-CH,H 2 , H 6 pip), 1.73 (m, 1H, H 4 pip), 1.56 (bd,J = 14.4
	1 H NMR (400 MHz, MeOD) δ 8.09 (d, J = 7.2 Hz, 2H, H Ar ), 7.57 (m, 5H, H Ar ), 7.33 (m, 5H, H Ar ), 7.03 (m, 2H, H Ar ), 6.91 (m, 2H, H Ar ), 5.06 (s, 2H, CH2-O), 4.43 (s, 1H, H 4 pip), 3.98 (ddq, J = 8.0, 7.0, 1.0 Hz, 4H, CH2-O-P), 3.84 (s, 2H, CH2-N), 3.23 (d, J = 21.7 Hz, 2H, CH2-P), 2.99 (bs, 2H, H 2 , H 6 pip), 2.62 (bs, 2H, H 2 , H 6 pip), 1.97 (m, 4H, H 3 , H 5 pip), 1.20 (td, J = 7.0, 1.0 Hz, 6H, CH3). 13 C NMR (101 MHz, MeOD) δ 152.28 MeOD) δ 27.36 HRMS-ESI (m/z) [M+H] + calcd for C37H43N3O5P 640.2941, found benzimidazole 14b (34 mg, 1 eq., 0.115 mmol), SOCl2 (243 µL, 29 eq., 3.35 mmol) and then compound 11b (50 mg, 1 eq., 0.115 mmol), diisopropylethylamine (100 µL, 5.3 eq., 0.59 mmol) in ACN (3 mL). After purification by silica gel column chromatography, eluting DCM/MeOH 95:5, the clean compound 16b was obtained as an amorphous creamy solid. (19 mg, 22%) 1 H NMR (400 MHz, MeOD) δ 8.45 (bs, 1H, H Ar ), 8.36 (d, J = 7.8 Hz, 1H, H Ar ), 7.83 (m, 1H, H Ar ), 7.78 (m, 1H, H Ar ), 7.63 (m, 2H, H Ar ), 7.42 (bs, 1H, H Ar ), 7.32 (m, 4H, H Ar ), 7.02 (m, 2H, H Ar ), 6.91 (m, 2H, H Ar ), 5.06 (s, 2H, CH2-O), 4.42 (d, J = 7.4 Hz, 1H, H 4 pip), 3.99 (m, 4H, CH2-O-P), 3.80 (s, 2H, CH2-N), 3.25 (d, J = 21.7 Hz, 2H, CH2-P), 2.94 (bs, 2H, H 2 , H 6 pip), 2.55 (bs, 2H, H 2 , H 6 pip), 1.96 (m, 4H, H 3 , H 5 pip), 1.22 (t, J = 7.1 Hz, 6H, CH3). 13 C NMR (101 MHz, MeOD) δ 150.87 (C quat ), 150.11 (C quat ), 147.19 (C quat ), 137.94 (d, J = 3.0 Hz, C quat ), 131.58 (d, J = 9.5 Hz, C quat ), 131.39 (C quat ), 131.06 (C quat ), 130.63 (C quat ), 129.83 (C Ar ), 129.82 (C Ar ), 129.77 (C Ar ), 129.09 (d, J = 6.8 Hz, C Ar ), 128.71 (d, J = 6.9 Hz, C Ar ), 128.30 (d, J = 2.8 Hz, C Ar ), 126.40 (C Ar ), 125.89 (d, J = 3.7 Hz, C Ar ), 125.36 4.1.14.8. Diethyl {[3-(2-{[1-({2-[3-(trifluoromethyl)phenyl]-1H-1,3-benzodiazol-6-yl}methyl)piperidin-4-yl]-oxy}phenoxymethyl)phenyl]methyl}phosphonate chromatography, eluting DCM/MeOH 95:5, the clean compound 16c was obtained as an amorphous creamy solid. (20 mg, 24%) 1 H NMR (400 MHz, MeOD) δ 8.40 (bs, 1H, H Ar ), 8.31 (d, J = 7.9 Hz, 1H, H Ar ), 7.67 (m, 4H, H Ar ), 7.28 (m, 5H, H Ar ), 6.90 (m, 4H, H Ar ), 5.01 (s, 2H, CH2-O), 4.36 (s, 1H, H 4 pip), 3.94 (ddq, J = 8.0, 7.1, 1.0 Hz, 4H, CH2-O-P), 3.71 (s, 2H, CH2-N), 3.19 (d, J = 21.7 Hz, 2H, CH2-P), 2.86 (s, 2H, H 2 , H 6 pip), 2.44 (d, J = 8.7 Hz, 2H, H 2 , H 6 pip), 1.91 (dd, J = 12.9, 8.4 Hz, 4H, H 3 , H 5 pip), 1.16 (dt, J = 7.1, 1.0 Hz, 6H, CH3). 13 C NMR (101 MHz, MeOD) δ 150.79 (C quat ), 150.07 (C quat ), 147.25 (C quat ), 137.94 (d, J = 3.2 Hz, C quat ), 131.57 (d, J = 9.4 Hz, C quat ), 131.38 (C quat ), 131.06 (C quat ), 130.65 (C quat ), 129.81 (C Ar ), 129.79 (C Ar ), 129.07 (d, J = 6.7 Hz, C Ar ), 128.70 (d, J = 6.7 Hz, C Ar ), 128.29 (d, J = 3.1 Hz, C Ar ), 126.37 (C Ar ), 125.88 (d, J = 3.6 Hz, C Ar ), 123.08 (C Ar ), 122.15 (C Ar ), 121.45 (C Ar ), 118.31 (C Ar ), 115.31 (C Ar ), 70.57 (CH2-O), 62.53(CH2-N), 62.34 (d, J = 7.0 Hz, CH2-O-P), 49.56(C 2 , C 6 pip), 32.29 (d, J = 137.6Hz, CH2-P), 29.89 (C 3 , C 5 pip), 15.29, 15.26 (d, J = 6.0 Hz, CH3). 31 P NMR (162 MHz, MeOD) δ 27.36. 19 F NMR (376 MHz, MeOD) δ -64.31. HRMS-ESI (m/z) [M+H] + calcd for C39H42F3N3O5P 708.2811, found 708.2807. benzimidazole 14d (37 mg, 1 eq., 0.12 mmol), SOCl2 (246 µL, 29 eq., 3.34 mmol) and then compound 11b (50 mg, 1 eq., 0.12 mmol), diisopropylethylamine (104 µL, H Ar ), 5.07 (s, 2H, CH2-O), 4.44 (s, 1H, H 4 pip), 3.99 (dqd, J = 7.8, 6.8, 3.0 Hz, 4H, CH2-O-P), 3.83 (s, 2H, CH2-N), 3.25 (d, J = 21.6 Hz, 2H, CH2-P), 2.98 (bs, 2H, H 2 , H 6 pip), 2.60 (bs, 2H, H 2 , H 6 pip), 2.06 -1.84 (m, 4H, H 3 , H 5 pip), 1.22 (t, J = 6.8 Hz, 6H, CH3). 13 C NMR (101 MHz, MeOD) δ 151.43 (C quat ), 151.25 (C quat ), 150.14 (C quat ), 147.14 (C quat ), 137.91 (d, J = 3.3 Hz, C quat ), 131.60 (d, J = 9.1 Hz, C quat ), 129.10 (d, J = 6.4 Hz, C Ar ), 128.72 (d, J = 6.5 Hz, C Ar ), 128.60 (C Ar ), 128.32 (C Ar ), 128.30 (d, J = 2.7 Hz, C Ar ), 125.90 (d, J = 3.7 Hz, C Ar ), 122.31 (C Ar ), 121.45 (C Ar ), 121.20 (C Ar ), 118.46 (C Ar ), 115.24 (C Ar ), 70.55 (CH2-O), 62.35 (d, J = 6.9 Hz, CH2-O-P), 62.32 (CH2-N), 49.34 (C 2 , C 6 pip), 32.32 (d, J = 137.2 Hz, CH2-P), 29.57 (C 3 , C 5 pip), 15.25 (d, J = 6.1 Hz, CH3). 31 P NMR (162 MHz, MeOD) δ 27.36 19 F NMR (376 MHz, MeOD) δ -57.38 HRMS-ESI (m/z) [M+H] + calcd for C39H42F3N3O6P 724.2760, found 724.2755. 4.1.14.10. Diethyl {[3-(2-{[1-({2-[3-(trifluoromethoxy)phenyl]-1H-1,3-benzodiazol-6-yl}methyl)piperidin-4-yl]oxy}phenoxymethyl)phenyl]methyl}phosphonate (16e). The title compound was obtained following the general procedure 5 from an amorphous creamy solid. (22 mg, 35%) 1 H NMR (400 MHz, MeOD) δ 8.06 (ddd, J = 7.90, 1.6, 1.0 Hz, 1H, H Ar ), 8.01 (s, 1H, H Ar ), 7.61 (q, J = 8.2 Hz, 3H, H Ar ), 7.33 (m, 150.93 (C quat ), 150.15 (C quat ), 149.73 (C quat ), 147.09 (C quat ), 137.88 (d, J = 3.2 Hz, C quat ), 131.73 (C (C Ar ), 73.12 (C 4 pip), 70.53 (CH2-O), 62.34 (d, J = 6.9 Hz, CH2-O-P), 62.17 (CH2-N), 49.24 (C 2 , C 6 pip), 32.33 (d, J = 137.5 Hz, CH2-P), 29.45 (C 3 , C 5 pip), 15.25 (d, J = 6.0 Hz, CH3). 31 P NMR (162 MHz, MeOD) δ 27.36. 19 F NMR (376 MHz, MeOD) δ -59.38. HRMS-ESI (m/z) [M+H] + calcd for C39H42F3N3O6P 724.2760, found 724.2757. 4.1inert atmosphere, dihydropyran (3.96 mL, 1.5 eq., 43.35 mmol) was added to a solution of 2-bromophenol 17 (3.35 mL, 1 eq., 28.90 mmol) in dichloromethane (35 mL). A catalytic amount of pyridinium p-toluenesulfonate (726 mg, 0.1 eq., 2.89 mmol) was then inserted in the flask, and the mixture was stirred at room temperature for 12 hours. The volatiles were then removed under reduced pressure, and the residue was purified by silica gel column chromatography, eluting pure PE, to afford n-BuLi (2.5 M in hexane, 1.56 mL, 1 eq., 3.89 mmol) was added dropwise to the mixture and stirred 30 min. at -78 °C. A solution of 1-(tert-Butoxycarbonyl)-4-ethyl acetate (3 x 30 mL) and the resulted organic layers dried over MgSO4 and concentrated under reduced pressure. The resulting product was then loaded onto a silica gel column and purified eluting Petroleum ether / Ethyl Acetate 8:2 to afford desired piperidine derivative 19 as white solid. (914 mg, 60%) 1 H NMR (250 MHz, CDCl3) δ 7.18 (m, 3H, H Ar ), 6.97 (dt, J = 7.3, 1.3 Hz, 1H, H Ar ), 5.40 (m, 1H, O-CH-O), 4.62 (dt, J = 12.2, 6.8 Hz, 1H, CH-OH), 4.07 (m, 2H, H 2 , H 6 ), 3.81 (m, 1H, CH2-O), 3.59 (m, 1H, CH2-O), 2.54 (m, 3H, OH, H 2 , H 6 ), 1.79 (m, 9H, CH2, H 3 , H 4 , H 5 ) 1.42 (s, 9H, CH3 Boc), 1.21 (m, 2H, H 3 , H 5 ). HRMS (ESI): m/z [M+H] + calcd for C22H34NO5392.2438 found 392.2433. 4.1.17. 1-(Benzyloxy)-2-bromobenzene (20). To a solution of 2-bromophenol (17) (1.34 mL, 1 eq., 11.6 mmol) in DMF (20 mL), benzyl chloride (1.46 mL, 1.1 eq., 12.7 mmol) and potassium carbonate (3.19 g, 2 eq., 23.1 mmol) were added. The resulting mixture was stirred for 12h at 70 °C. After evaporation of all volatiles, the residue was dissolved in a mixture of EtOAc (80 mL) and water (40 mL). The aqueous phase was extracted thrice with EtOAc (3 x 80 mL), the organic phases in the apparatus were degassed with argon before the addition of 10% Pd/C (500 mg). The solution and the atmosphere were again saturated with argon, and then the dichloromethane (4 mL). Triethylsilane (408 µL, 5 eq., 2.55 mmol) and TFA (196 µL, 5 eq., 2.55 mmol) were successively added to this solution, and stirred at room temperature for 1 hour. The reaction was quenched with a saturated aqueous solution of NaHCO3 (5 mL), extracted with EtOAc (3 x 10 mL), washed with brine (10 mL), dried over MgSO4 and concentrated under reduced pressure. The product was then purified by a flash column chromatography (PE/EtOAc 95:5), affording desired product 22 as colorless crystals. (30 mg, 21%) 1 H NMR (400 MHz, CDCl3) δ 7.03 (m, 2H, H Ar ), 6.78 (m, 2H, H Ar ), 5.71 (s, 1H, OH), 4.01 (bd,J = 8.2 Hz, 2H, H 2 , H 6 pip), 4.01 (bt,J = 11.9 Hz, 2H, H 2 , H 6 pip), 2.53 (d,J = 7.1 Hz, 2H, CH2),1.69 (m, 1H, H 4 pip),1.59 (bd,J = 14.4 Hz, 2H, H 3 , H 5 pip), 1.43 (s, 9H, CH3 Boc), 1.15 (bd,J = 11.9, 4.1 Hz, 2H, H 3 , H 5 pip). 13 C NMR (101 MHz, CDCl3) δ 155.04 (C=O), 154.06 (C quat -CH2), 131.23 (C Ar ), 127.21 (C Ar ), 126.51 (C quat -OH), 120.22 (C Ar ), 115.26 (C Ar ), 79.45 (C quat Boc), 44.10 (C 4 pip), 36.88 (C 2 , C 6 pip), 36.80 (CH2), 31.98 (C 3 , C 5 pip), 28.50 (CH3 Boc). HRMS-ESI (m/z) [M+H] + calcd for C17H26NO3 292.1913, found 292.1906. mg, 1.5 eq., 4.12 mmol) was dissolved in DMA (20 mL). To this mixture were sequentially added potassium carbonate (760 mg, 2 eq., 5.49 mol), phenol 22 (800 phases washed with water (5 x 40 mL), once with brine (40 mL), dried over MgSO4 and evaporated. The residue was consequently purified by column chromatography (DCM/MeOH 99:1) to afford the intermediate 23a as a white solid, which was directly engaged in the next step. 4.1.21. tert-Butyl 4-{[2-({3-[(diethoxyphosphoryl)methyl]phenyl}methoxy)phenyl] methyl}piperidine-1-carboxylate (23b). In a 2-5 mL microwave vial, phosphonate derivative 2b (331 mg, 1.5 eq., 1.03 mmol) was dissolved in DMA (5 mL). To this mixture were sequentially added potassium carbonate (190 mg, 2 eq., 1.37 mol), phenol 22 (200 mg, 1 eq., 0.69 mmol) and finally a catalytic amount of sodium iodide (few crystals). This reaction was stirred for 30 min at 140 °C under microwave irradiation, and the obtained solution was dissolved in water (10 mL) and ethyl acetate (50 mL). The aqueous phase was then extracted with ethyl acetate (3 x 30 mL), and the organic phases washed with water (5 x 10 mL), once with brine (10 mL), dried over MgSO4 and evaporated. The residue was consequently purified by column chromatography Hz, 2H, H 3 , H 5 pip), 1.39 (s, 9H, CH3 Boc), 1.17 (m, 8H, CH3 Phosph, H 3 , H 5 pip). 13 C NMR (101 MHz, CDCl3) δ 156.58 (C quat -CH2), 154.86 (C=O), 137.79 (d, J = 3.0 Hz, (C 137.7Hz, CH2-P), 29.41(C 3 , C 5 pip), 15.25 (d, J = 6.0 Hz, CH3). 31 P NMR (162 MHz, 640.2938. 4.1.14.7. Diethyl {[3-(2-{[1-({2-[4-(trifluoromethyl)phenyl]-1H-1,3-benzodiazol-6-yl}methyl)-piperidin-4-yl]oxy}-phenoxymethyl)phenyl]methyl}phosphonate (16b). The title compound was obtained following the general procedure 5 from (16c). The title compound was obtained following the general procedure 5 from benzimidazole 14c (34 mg, 1 eq., 0.115 mmol), SOCl2 (243 µL, 29 eq., 3.35 mmol) and then compound 11b (50 mg, 1 eq., 0.115 mmol), diisopropylethylamine (100 µL, 5.3 eq., 0.59 mmol) in ACN (3 mL). After purification by silica gel column 5.3 eq., 0.64 mmol) in ACN (3 mL). After purification by silica gel column chromatography, eluting DCM/MeOH 95:5, the clean compound 16d was obtained as an amorphous creamy solid. (19 mg, 31%) 1 H NMR (400 MHz, MeOD) δ 8.20 (d, J = 8.8 Hz, 2H, H Ar ), 7.63 (s, 2H, H Ar ), 7.39 (m, 7H, H Ar ), 7.03 (m, 2H, H Ar ), 6.92 (m, 2H, 6H, H Ar ), 6.98 (m, 2H, H Ar ), 6.88 (m, 2H, H Ar ), 5.01 (s, 2H, CH2-O), 4.39 (s, 1H, H 4 pip), 3.94 (dqd, J = 8.2, 7.0, 1.1 Hz, 4H, CH2-O-P), 3.80 (s, 2H, CH2-N), 3.20 (d, J = 21.7 Hz, 2H, CH2-P), 2.95 (s, 2H, H 2 , H 6 pip), 2.57 (s, 2H, H 2 , H 6 pip), 1.91 (s, 4H, H 3 , H 5 pip), 1.21 -1.10 (dt, J = 7.0, 0.4 Hz, 6H, CH3). 13 C NMR (101 MHz, MeOD) δ piperidinecarboxaldehyde (830 mg, 1 eq., 3.89 mmol) in THF (8 mL) was then slowly introduced by cannulation into the flask. After 10 min at -78 °C, the solution was then allowed to stir at room temperature for 3 hours and quenched by a slow addition of water (10 mL). The aqueous phase was subsequently extracted three times with autoclave was sealed and filled with H2 until a pressure of 7 bars. The reaction mixture was stirred for 24h at room temperature, filtrated onto Celite ® .The filtrate was evaporated, giving pure product 22 as colorless crystals. (733 mg, quant.) Method B : Under inert atmosphere, compound 19 (200 mg, 1 eq., 0.51 mmol) was dissolved in mg, 1 eq., 2.45 mmol) and finally a catalytic amount of sodium iodide (few crystals). This reaction was stirred for 30 min at 140 °C under microwave irradiation, and the obtained solution was dissolved in water (20 mL) and diethyl ether (100 mL). The aqueous phase was then extracted twice ethyl acetate (2 x 50 mL), and the organic C quat ), 131.90 (d, J = 9.0 Hz, C quat ), 131.01 (C Ar ), 129.17 (d, J = 6.7 Hz, C Ar ), 129.04 (C quat ), 128.73 (d, J = 3.4 Hz, C Ar ), 128.35 (d, J = 6.6 Hz, C Ar ), 127.18 (C Ar ), 125.51 (d, J = 3.6 Hz, C Ar ), 120.48 (C Ar ), 111.74 (C Ar ), 79.11 (C quat Boc), 69.58 (CH2-O), Diethyl ({3-[2-(piperidin-4-ylmethyl)phenoxymethyl]phenyl} 62.15 (d, 4.1.22.2. methyl)phosphonate (24b).
	benzimidazole 14e (27 mg, 1 eq., 0.088 mmol), SOCl2 (186 µL, 29 eq., 2.56 mmol) compound 18 as a colorless oil. (7.43 g, quant.), [47]. CAS : 57999-46-9. were washed three times with water (3 x 40 mL), three times with brine (3 x 40 mL), (DCM/MeOH 99:1) to afford 23b compound as a colorless oil. (330 mg, 91%) 1 H

quat ), 150.16 (C quat ), 147.08 (C quat ), 137.88 (d, J = 3.3 Hz, C quat ), 131.61 (d, J = 9.4 Hz, C quat ), 130.13 (C Ar ), 129.47 (C quat ), 129.13 (d, J = 6.6 Hz, C Ar ), 128.78 (C Ar ), 128.73 (d, (C Ar ), 123.06 (C Ar ), 122.23 (C Ar ), 121.45 (C Ar ), 118.38 (C Ar ), 115.28 (C Ar ), 70.56 (CH2-O), 62.38 (CH2-N), 62.34 (d, J = 6.9 Hz, CH2-O-P), 49.43 (C 2 , C 6 pip), 32.28 (d, J = 138.1Hz, 4.1.22.1. Diethyl ({4-[2-(piperidin-4-ylmethyl)phenoxymethyl]phenyl} methyl)phosphonate (24a). 13 C NMR (101 MHz, MeOD) δ 156.65(C quat -CH2), 136.36 (d, J = 3.9 Hz, C quat ), 131.03 (d, J = 9.4

  The title an amorphous creamy solid. (31 mg, 24%)1 H NMR (400 MHz, MeOD) δ 8.21 (d, J = 8.9 Hz, 2H, H Ar ), 7.67 (m, 2H, H Ar ), 7.49 (d, J = 9.0 Hz, 2H, H Ar ), 7.44 (s, 1H, H Ar ), 7.31 (m, 4H, H Ar ), 7.16 (dt, J = 8.3, 1.5 Hz, 1H), 7.12 (dd, J = 7.6, 1.6 Hz, 1H, H Ar ), 7.00 (d, J = 8.3 Hz, 1H, H Ar ), 6.88 (td, J = 7.5, 1.0 Hz, 1H, H Ar ), 5.10 (s, 2H, CH2-O), 4.00 (m, 6H, CH2-O-P, CH2-N), 3.27 (d, J = 21.8 Hz, 2H, CH2-P), 3.18 (bd, J = 11.8 Hz, 2H, H 2 , H 6 pip), 2.67 (d, J = 6.8 Hz, 2H, CH2), 2.47 (bs, 2H, H 2 , H 6 pip), 1.81 (m, 1H, H 4 pip), 1.75 (bd, J = 15.4 Hz, 2H, H 3 , H 5 pip), 1.46 (bq, J = 10.4 Hz, 2H, H 3 , H 5 pip), 1.22 (t, J = 7.1 Hz, 6H, CH3). 13 C NMR (101 MHz, MeOD) δ 156.60 (C quat -CH2), 151.64 (C quat ), 150.52 (C quat ), 138.00 (d, J = 3.3 Hz, C quat ), 131.64 (d, J = 9.2 Hz, C quat ), 130.59 (C Ar ), 129.03 (d, J = 6.9 Hz, C Ar ), 128.50 (C Ar ), 128.43 (d, J = 6.6 Hz, C Ar ), 128.38 (C Ar

).

Acknowledgments

This work was supported by the University of Orleans and the CNRS; the research program fullfills the LabEx SYNORG (11-LABX-0029) objectives. Chemoinformatics

dried over MgSO4 and concentrated under reduced pressure. After a filtration on silica gel, eluting petroleum ether/ ethyl acetate 8:2, the desired product 20 was obtained as a colorless oil. (3.1 g, quant.), [START_REF] Salanouve | Tandem C-H activation/arylation catalyzed by low-valent iron complexes with bisiminopyridine ligands[END_REF]. CAS : 31575-75-4. 12.7 mmol) was added dropwise to the solution and stirred 30 min. at -78 °C. A mixture of 1-(tert-Butoxycarbonyl)-4-piperidinecarboxaldehyde (2.47 g, 1 eq., 11.6 mmol) in THF (19 mL) was then slowly introduced by cannulation into the flask. After 10 min at -78 °C, the solution was then allowed to stir at room temperature for 3 hours and quenched by the slow addition of water (20 mL). The aqueous phase was subsequently extracted three times with ethyl acetate (3 x 80 mL) and the resulted organic layers dried over MgSO4 and concentrated under reduced pressure. The resulting product was then loaded onto a silica gel column and purified eluting

4

Diethyl {[3-(2-{[1-({2-[4-(trifluoromethoxy)phenyl]-1H-1,3-benzodiazol-

6-yl}methyl)piperidin-4-yl]methyl}-phenoxymethyl)phenyl]methyl}phosphonate (26d).

The title compound 26d was obtained following the general procedure 5 from benzimidazole 14d (60 mg, 1 eq., 0.20 mmol), SOCl2 (452 µL, 29 eq., 6.20 mmol) and then compound 24b (80 mg, 1 eq., 0.

Assays for anti-EBOV activity and cytotoxicity

All work with infectious virus was conducted in a BSL-4 laboratory at the Centers for Disease Control and Prevention. All laboratorians adhered to international practices appropriate for this biosafety level. Anti-EBOV activities were determined in Huh7 cells (Apath LLC), using recombinant virus expressing the fluorescent reporter protein ZsGreen (EBOV-ZsG), as described previously [START_REF] Flint | A genome-wide CRISPR screen identifies N-acetylglucosamine-1-phosphate 285[END_REF][START_REF] Welch | Lassa and Ebola virus inhibitors identified using minigenome and recombinant virus reporter systems[END_REF]. Briefly, 3000 Huh7 cells were seeded in each well of a 384-well plate. The following day, the cells were treated with varying concentrations of compound for 2 h, before infection with EBOV-ZsG virus at a multiplicity of infection of 0.3. The ZsGreen fluorescence was determined 3 days post-infection using a Synergy H1MD plate reader (BioTek).

Cytotoxicity was determined on cells that received compound, but no virus, using CellTiter-Glo (Promega) according to the manufacturer's instructions. The 50% effective (EC50) and 50% cytotoxic concentrations (CC50) were determined using GraphPad Prism 7.0 (GraphPad Software) to fit a 4-parameter equation to semi-log plots of the concentration-response data. The Selectivity Index (SI) was calculated as the CC50/EC50.

Assays to test the inhibition of EBOV-GP-mediated entry were performed with pseudotyped HIV particles as described [START_REF] Flint | A genome-wide CRISPR screen identifies N-acetylglucosamine-1-phosphate 285[END_REF]. Briefly, particles were generated by cotransfection of Lenti-X 293T cells with plasmids expressing EBOV-GP and a HIV luciferase reporter vector. Huh7 cells in 384-well plates were treated with varying concentrations of compound for 1 h at 37 °C, then the pseudotyped particles were added. Three days later, firefly luciferase activity was determined using the Bright-Glo luciferase assay system (Promega).