WO2024084517A1 - 3-phenyl-3-(aryloxy) propan-1-amines and the process for preparation thereof - Google Patents

3-phenyl-3-(aryloxy) propan-1-amines and the process for preparation thereof Download PDF

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WO2024084517A1
WO2024084517A1 PCT/IN2023/050970 IN2023050970W WO2024084517A1 WO 2024084517 A1 WO2024084517 A1 WO 2024084517A1 IN 2023050970 W IN2023050970 W IN 2023050970W WO 2024084517 A1 WO2024084517 A1 WO 2024084517A1
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substituted
methyl
trifluoromethyl
phenyl
unsubstituted
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Halmuthur Mahabalarao SAMPATH KUMAR
Talati Mamta NATVARLAL
Vemireddy Sravanthi
Guruprasad R. MEDIGESHI
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Council Of Scientific And Industrial Research An Indian Registered Body Incorporated Under The Regn. Of Soc. Act (Act Xxi Of 1860)
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C229/00—Compounds containing amino and carboxyl groups bound to the same carbon skeleton
    • C07C229/02—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to acyclic carbon atoms of the same carbon skeleton
    • C07C229/04—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to acyclic carbon atoms of the same carbon skeleton the carbon skeleton being acyclic and saturated
    • C07C229/06—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to acyclic carbon atoms of the same carbon skeleton the carbon skeleton being acyclic and saturated having only one amino and one carboxyl group bound to the carbon skeleton
    • C07C229/10—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to acyclic carbon atoms of the same carbon skeleton the carbon skeleton being acyclic and saturated having only one amino and one carboxyl group bound to the carbon skeleton the nitrogen atom of the amino group being further bound to acyclic carbon atoms or to carbon atoms of rings other than six-membered aromatic rings
    • C07C229/14—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to acyclic carbon atoms of the same carbon skeleton the carbon skeleton being acyclic and saturated having only one amino and one carboxyl group bound to the carbon skeleton the nitrogen atom of the amino group being further bound to acyclic carbon atoms or to carbon atoms of rings other than six-membered aromatic rings to carbon atoms of carbon skeletons containing rings
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C229/00—Compounds containing amino and carboxyl groups bound to the same carbon skeleton
    • C07C229/02—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to acyclic carbon atoms of the same carbon skeleton
    • C07C229/04—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to acyclic carbon atoms of the same carbon skeleton the carbon skeleton being acyclic and saturated
    • C07C229/22—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to acyclic carbon atoms of the same carbon skeleton the carbon skeleton being acyclic and saturated the carbon skeleton being further substituted by oxygen atoms
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C229/00—Compounds containing amino and carboxyl groups bound to the same carbon skeleton
    • C07C229/02—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to acyclic carbon atoms of the same carbon skeleton
    • C07C229/34—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to acyclic carbon atoms of the same carbon skeleton the carbon skeleton containing six-membered aromatic rings
    • C07C229/36—Compounds containing amino and carboxyl groups bound to the same carbon skeleton having amino and carboxyl groups bound to acyclic carbon atoms of the same carbon skeleton the carbon skeleton containing six-membered aromatic rings with at least one amino group and one carboxyl group bound to the same carbon atom of the carbon skeleton
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C323/00—Thiols, sulfides, hydropolysulfides or polysulfides substituted by halogen, oxygen or nitrogen atoms, or by sulfur atoms not being part of thio groups
    • C07C323/50—Thiols, sulfides, hydropolysulfides or polysulfides substituted by halogen, oxygen or nitrogen atoms, or by sulfur atoms not being part of thio groups containing thio groups and carboxyl groups bound to the same carbon skeleton
    • C07C323/51—Thiols, sulfides, hydropolysulfides or polysulfides substituted by halogen, oxygen or nitrogen atoms, or by sulfur atoms not being part of thio groups containing thio groups and carboxyl groups bound to the same carbon skeleton having the sulfur atoms of the thio groups bound to acyclic carbon atoms of the carbon skeleton
    • C07C323/57—Thiols, sulfides, hydropolysulfides or polysulfides substituted by halogen, oxygen or nitrogen atoms, or by sulfur atoms not being part of thio groups containing thio groups and carboxyl groups bound to the same carbon skeleton having the sulfur atoms of the thio groups bound to acyclic carbon atoms of the carbon skeleton the carbon skeleton being further substituted by nitrogen atoms, not being part of nitro or nitroso groups
    • C07C323/58—Thiols, sulfides, hydropolysulfides or polysulfides substituted by halogen, oxygen or nitrogen atoms, or by sulfur atoms not being part of thio groups containing thio groups and carboxyl groups bound to the same carbon skeleton having the sulfur atoms of the thio groups bound to acyclic carbon atoms of the carbon skeleton the carbon skeleton being further substituted by nitrogen atoms, not being part of nitro or nitroso groups with amino groups bound to the carbon skeleton
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D201/00—Preparation, separation, purification or stabilisation of unsubstituted lactams

Definitions

  • the present invention relates to a group of L-amino acid esters substituted 3-phenyl-3-(aryloxy) propan- 1 -amine compounds.
  • the present invention particularly relates to L-amino acid esters substituted 3-phenyl-3-(aryloxy) propan- 1 -amine compounds having antiviral and immunomodulatory potential.
  • the clinically used drug is a racemic mixture. From a sterochemcial point of view, as individual enantiomer fluoxetine shows a moderate difference in terms of their serotonin reuptake inhibitory activity. Being a pharmacologically active entity on a wide spectrum of mood disorders fluoxetine has been a clinically accepted drug all over the world for the treatment of major depression (American Journal of Psychiatry, 2000. 157(3): p. 338-343).
  • fluoxetine has the ability to modify tumor cell viability as confirmed through in vivo experiments that tumor growth is inhibited through chronic fluoxetine treatment by enhancing the antitumor T-cell activity (Beneficial effect of fluoxetine and sertraline on chronic stress-induced tumor growth and cell dissemination in a mouse model of lymphoma: crucial role of antitumor immunity. Frontiers in immunology, 2018. 9: p. 1341). Thus, there has been ample evidence in literature regarding the ability of fluoxetine to amend the functionality of the immune system. These research findings point to the significance of the novel pharmacological action of fluoxetine and its analogues as immunomodulator aiding to treat several disorders related with immune deficiency and its deregulation.
  • Fluoxetine displayed potent inhibitory effect on enterovirus replication as revealed in drug repurposing screens in mice.
  • fluoxetine has been used to successfully treat immunocompromised children suffering from severe and lethal enterovirus encephalitis (Synthesis and antiviral effect of novel fluoxetine analogues as enterovirus 2C inhibitors. Antiviral Research, 2020. 178: p. 104781). It has been observed that structural modification of fluoxetine offers a potential strategy for evolving effective immunomodulators and antiviral therapeutics for clinical use.
  • the invention provides a focused library of novel fluoxetine analogues, in which amino acids have been introduced on the N-terminus of the original scaffold, to gain insight into the structure-activity relationships of fluoxetine vis-a-vis the antiviral and immunomodulatory potentials.
  • Previously reports pointed out that the structural features of the trifluoro-phenoxy moiety and the amino moiety are essential for the antiviral potency whereas the 3- phenyl moiety seems expendable.
  • Immunomodulators modify the immune responses either by enhancing or suppressing the immune responses and are classified as an immunostimulant or immunosuppressant respectively. Anti- inflammatory action of antidepressants is finding increasing attention in the field of immunotherapy .
  • Fluoxetine has been often utilized to treat obsessive-compulsive disorder, panic disorder and depression because of its tolerability and safety (Multiple autoimmune diseases in a young woman: tuberculosis and splenectomy as possible triggering factors Another example of the “mosaic ” of autoimmunity. The Journal of rheumatology, 2008. 35(6): p. 1224-1227.).
  • Clinically fluoxetine is utilized in a racemic form. It is postulated that this first-line anti-depressant drug can decrease the level of pro-inflammatory cytokines. Available works of literature demonstrate the anti-inflammatory characteristic of fluoxetine. Investigations revealed that fluoxetine noticeably reduces the INF y / IL- 10, suppresses TNF-a release, and increases the formation of anti-inflammatory cytokine IL- 10.
  • the present invention discloses designed fluoxetine analogues substituting the methylamine group with various L- alpha amino acids, to explore the need of modification across the basic nitrogen.
  • the newly synthesized compounds have been characterized spectroscopically and tested for their immunomodulatory and anti-viral activities.
  • Main objective of the present invention is to synthesize a series of novel aminoacid esters analogues of 3-phenyl-3-(aryloxy)propan-l-amine.
  • Another objective of the present invention is to evaluate the antiviral and immunomodulatory potentials of novel analogues.
  • the present invention provides a compound of the structural formula I or a pharmaceutically acceptable salt thereof, wherein, n is 1, 2 or 3; each R 1 is independently selected from the group consisting of substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy and halogen;
  • R 2 is selected from the group consisting of H, substituted or unsubstituted linear or branched alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl or R 2 together with the amine nitrogen may form a substituted or unsubstituted 5-6 membered ring and
  • R 3 is linear or branched alkyl.
  • the present invention provides a compound of the structural formula I, wherein R 1 is C 1 to 6 alkyl, C 1 to 6 alkoxy, halo or trifluoromethyl.
  • the present invention provides a compound of the structural formula I, wherein R 2 is H, C 1 to 4; linear or branched substituted or unsubstituted alkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, wherein the substituents are selected form the group consisting of alkyl, aryl, heteroaryl, hydroxy and thioalkyl.
  • R 2 is H, C 1 to 4; linear or branched substituted or unsubstituted alkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, wherein the substituents are selected form the group consisting of alkyl, aryl, heteroaryl, hydroxy and thioalkyl.
  • R 2 together with the amine nitrogen may form a substituted or unsubstituted 5 membered carbocyclic ring.
  • the present invention provides a compound of the structural formula I, wherein R 3 is C 1 to 3 alkyl.
  • the present invention provides compounds selected from the group consisting of a. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tryptophanate, b. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-valinate, c. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-alaninate, d. Methyl (2S)-2-phenyl-2-((3-phenyl-3-(4-
  • Ethyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tryptophanate n. Ethyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-valinate, o. Methyl (3-(4-methoxyphenoxy)-3-phenylpropyl)-L-tryptophanate, p. Methyl (3-(4-methoxyphenoxy)-3-phenylpropyl)-L-valinate, q. Methyl (3-(3,4-dichlorophenoxy)-3-phenylpropyl)-L-tryptophanate, and r. Methyl (3-(3,4-dichlorophenoxy)-3-phenylpropyl)-L-valinate.
  • the present invention also provides a process for preparing the compound of the structural formula I wherein, n is 1, 2 or 3; each R 1 is independently selected from the group consisting of substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy and halogen;
  • R 2 is selected from the group consisting of H, substituted or unsubstituted linear or branched alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl or R 2 together with the amine nitrogen may form a substituted or unsubstituted 5-6 membered ring and
  • R 3 is linear or branched alkyl, comprising the steps of: a. synthesizing an amino acid ester of formula 2 by reacting an amino acid of formula 1 with R 3 -OH in the presence of a solvent, wherein R 2 is selected from the group consisting of H, substituted or unsubstituted linear or branched alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl or R 2 together with the amine nitrogen may form a substituted or unsubstituted 5-6 membered ring, and R 3 is linear or branched alkyl; b.
  • step a of the process is carried out in presence of thionyl chloride and an anhydrous alcohol as solvent.
  • step b of the process is carried out in presence of diisopropyl azodicarboxylate (DIAD), triphenylphosphine and dry tetrahydrofuran (THF) under nitrogen environment.
  • DIAD diisopropyl azodicarboxylate
  • THF dry tetrahydrofuran
  • step c of the process is carried out in presence of sodium iodide(Nal), diisopropylethylamine (DiPEA) and dimethyl formamide (DMF).
  • the compound of the present invention has antiinflammatory and anti-viral activity.
  • C 1 to 6 alkoxy refers to the non-cyclic hydrocarbon of the linear chain or branched chain with more than one ether and 1 to 6 carbon atom(s).
  • alkyl refers to an alkane derived hydrocarbon radical that includes solely carbon and hydrogen atoms in the backbone, contains no unsaturation, has from one to six carbon atoms, and is attached to the remainder of the molecule by a single bond, for example C 1 to 6 alkyl, representative groups include e.g., methyl, ethyl, n-propyl, 1 -methylethyl (isopropyl), n-butyl, n-pentyl and the like. Unless set forth or recited to the contrary, all alkyl groups described or claimed herein may be straight chain or branched.
  • alkoxy denotes an alkyl group attached via an oxygen linkage to the rest of the molecule.
  • Representative examples of such groups are -OCH3 and -OC2H5. Unless set forth or recited to the contrary, all alkoxy groups described or claimed herein may be straight chain or branched.
  • aryl refers to an aromatic radical having 6 to 12 carbon atoms, including monocyclic, bicyclic ⁇ and tricyclic aromatic systems, such as phenyl, naphthyl, tetrahydronaphthyl, indanyl, biphenyl and the like.
  • heterocyclic refers to a substituted or unsubstituted 5 to 14 membered cyclic ring with one or more heteroatom/s independently selected from N, O or S.
  • the heteroaryl may be a mono, bi or tricyclic ring system.
  • the heteroaryl ring may be attached by any atom of the heteroaryl ring that results in the creation of a stable structure.
  • Non-limiting Examples of a heterocyclyl ring include oxazolyl, isoxazolyl, imidazolyl, furyl, indolyl, and the like.
  • the alkyl group can be unsubstituted or substituted with one or more substituents, for example, from one to four substituents, independently selected from the group consisting of halogen, hydroxy, cyano, nitro and amino.
  • substituents for example, from one to four substituents, independently selected from the group consisting of halogen, hydroxy, cyano, nitro and amino.
  • substituted alkyl include, but are not limited to hydroxymethyl, 2-chlorobutyl, trifluoromethyl and aminoethyl.
  • substituted refers to the form of a group wherein one or more other radicals are substituted over the group.
  • substituted C4 alkyl can be 2-hydroxy butyl group.
  • the substituted groups can be can be one or more groups selected from alkyl, alkenyl, aryl, heteroaryl, hydroxy, halo, cyano, amino, thioalkyl, alkoxy, and the like, which may be further optionally substituted with groups selected from alkyl, alkenyl, aryl, heteroaryl, hydroxy, halo, cyano, amino, thioalkyl, alkoxy, and the like.
  • each R 1 is independently selected from the group consisting of substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy and halogen;
  • R 2 is selected from the group consisting of H, substituted or unsubstituted linear or branched alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl or R 2 together with the amine nitrogen may form a substituted or unsubstituted 5-6 membered ring and
  • R 3 is linear or branched alkyl, is produced by a process summarized in the following schemes.
  • R 2 is selected from the group consisting of H, substituted or unsubstituted linear or branched C 1 to 6 alkyl, substituted or unsubstituted C 6 to 12 aryl, substituted or unsubstituted C 5 to 14 heteroaryl or R 2 together with the amine nitrogen may form a substituted or unsubstituted 5-6 membered ring and
  • R 3 is linear or branched C 1 to 6 alkyl.
  • R 2 is selected from the group consisting of H, substituted or unsubstituted linear or branched C 1 to 4 alkyl, substituted or unsubstituted C 6 to 10 aryl, unsubstituted C 6 to 10 heteroaryl or R 2 together with the amine nitrogen may form a substituted or unsubstituted 5-6 membered ring and
  • R 3 is linear or branched Cl to 4 alkyl.
  • R 2 is selected from the group consisting of H, substituted or unsubstituted linear or branched Cl to 4 alkyl, unsubstituted C 6 to 8 aryl, unsubstituted C 6 to 10 heteroaryl or R 2 together with the amine nitrogen may form a substituted or unsubstituted 5 membered ring and
  • R 3 is linear C 1 to 2 alkyl.
  • Compounds illustrative of the scope of this invention include the following: a. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tryptophanate b. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-valinate c. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-alaninate d. Methyl (2S)-2-phenyl-2-((3-phenyl-3-(4-
  • esters of amino acid were synthesized as per the general procedure A and B.
  • Thionyl chloride was the reagent of choice to convert amino acid into corresponding acid chloride following a literature procedure. Methanol and ethanol were used as the solvents as well as reactants to produce methyl and ethyl ester 2.
  • Mitsunobu reaction was performed between 3 -chloro- 1-phenylpropan-l-ol 3 and substituted phenol 4 to achieve 4-substituted l-(3-chloro-l-phenylpropoxy)-4-benzene 5 as colourless oil, in moderate to good yield.
  • R 2 and R 3 are as defined above.
  • R 1 is as defined above and the number of R 1 could be 1-3.
  • diisopropyl azodicarboxylate (DIAD) (17.58 mmol) and triphenylphosphine (17.58 mmol) were taken under nitrogen environment.
  • Dry THF (25 ml) was added into the reaction pot and this mixture was allowed to stir at room temperature for 20 minutes.
  • Phenol 4 (11.72 mmol) was dissolved in dry THF (5 ml) and added into the reaction pot and stirred for 4 hours.
  • 3 -chloro- 1-phenylpropan-l-ol 3 (11.72 mmol) was dissolved in dry THF (5 ml) and transferred into reaction pot and the reaction mixture was allowed to stir at room temperature for 16 hours under nitrogen atmosphere.
  • reaction progress was monitored on TLC (thin layer chromatography) plate. After completion of reaction, solvent was removed under reduced pressure. The crude mixture was purified by column chromatography technique, using hexane as a mobile phase and silica gel (60-120 mesh size) as stationary phase to afford the pure product 5 in moderate yields (65-70%).
  • R 1, R 2 and R 3 are as defined above and the number of R 1 could be 1-3.
  • R 1, R 2 and R 3 are as defined above and the number of R 1 could be 1-3.
  • reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). The organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give the final product with 70-85% yield. All analogues are confirmed by using various spectroscopic techniques like 1 H-NMR, 13 C-NMR, and HRMS spectrometry.
  • Step-1 Preparation of methyl L-tryptophanate (amino acid ester of formula 2): Thionyl chloride (0.41 m , 8.42 mmol) was added slowly to a mixture containing L- tryptophan (amino acid of formula 1; 1.72 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. The reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol, dried under high vacuum and used for the next reaction without further purification in 95% yield (1.70 g).
  • Step-2 Mitsunobu Reaction (Procedure for the synthesis of intermediate l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene; compound 5a): In a round bottom flask, diisopropyl azodicarboxylate (DIAD) (3.45 mL, 17.58 mmol) and triphenylphosphine (4.61 g, 17.58 mmol) were taken under nitrogen environment. Dry THF (25 ml) was added into the reaction pot and this mixture was allowed to stir at room temperature for 20 minutes.
  • DIAD diisopropyl azodicarboxylate
  • triphenylphosphine 4.61 g, 17.58 mmol
  • Step-3 Coupling of amino acid 2 and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl L- tryptophanate (0.17 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 Ml, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature.
  • DIPEA diisopropylethylamine
  • This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature.
  • This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate, and evaporated under reduced pressure to obtain crude product.
  • Huh 7 cells were cultured in 96-well plates (2 x 10 4 cells/well) for 16 h. Then differing concentrations of compounds are added to viral inoculums (minimal numbers required for causing infection) and incubated at 37 °C for 1 h. The cells were infected with these mixtures at 37 °C for 2 h. Afterwards, the virus was removed, and cells were washed three times with PBS, and the medium was replaced by complete DMEM. The cells were incubated for 48 h at 37 °C with 5% CO2. The reduction of viral cytopathic effect was determined by measuring cell viability measured using MTS.
  • the pellets so collected were cultured in high glucose DMEM and stored at 37°C.
  • the macrophages were treated with the analogues at four different concentrations (1000-lpg/ml) in ten-fold dilution and pro inflammatory cytokines were estimated.
  • Anti-dengue and immunomodulatory activity (IL- 10) of compound 6a was determined using the above methodology and was found to be EXAMPLE 2
  • Step-1 Preparation of methyl L-valinate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L- Valine (1; 0.99 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. The reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol, dried under high vacuum and used for the next reaction without further purification in 97% yield (0.96 g).
  • Step-2 Intermediate l-(3-chloro-l-phenylpropoxy)-4-
  • Step-3 Coupling of amino acid and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene (0.10 g, 0.32 mmol) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl L- valinate (0.10 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature.
  • DIPEA diisopropylethylamine
  • This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature.
  • This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate, and evaporated under reduced pressure to obtain crude product.
  • Anti-dengue and immunomodulatory activity (IL- 10) of compound 6b was determined using the above methodology and was found to be
  • Step-1 Preparation of methyl L-alaninate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L-alanine (1; 0.80 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. The reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride.
  • Step-2 Intermediate l-(3-chloro- l-phenylpropoxy)-4-
  • methyl L-alaninate (0.08 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature.
  • This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature.
  • This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate.
  • reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-alaninate (0.10 g, 82%).
  • Anti-dengue and immunomodulatory activity (IL- 10) of compound 6c was determined using the above methodology and was found to be
  • Step-1 Preparation of methyl (S)-2-amino-2-phenylacetate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L-(+)-a-phenylglycine (1; 1.27 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol, dried under high vacuum and used for the next reaction without further purification in 96% yield (1.30 g).
  • Step-2 Intermediate l-(3-chloro-l-phenylpropoxy)-4-
  • Step-3 Coupling of amino acid and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl) benzene (0.10 g, 0.32 mmol) and sodium iodide (0.09 g, 0.63 mmol) were taken, dissolved in DMF and stirred for 30 minutes at room temperature.
  • reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate, and evaporated under reduced pressure to obtain crude product.
  • the crude was purified by column chromatography to give final product methyl (2S)-2-phenyl-2-((3-phenyl-3-(4- (trifluoromethyl)phenoxy)propyl)amino)acetate (0.12 g, 85%). !
  • Step-1 Preparation of methyl L-leucinate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L-leucine (1.10 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely.
  • Step-2 Intermediate l-(3-chloro-l-phenylpropoxy)-4-
  • methyl L- leucinate (0.11 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature.
  • This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature.
  • This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate.
  • reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl 1 acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product.
  • the crude was purified by column chromatography to give final product methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-leucinate (0.12 g, 85%).
  • Antiviral and immunomodulatory activity (IL- 10) of compound 6e was determined using the above methodology and was found to be
  • Step-1 Preparation of methyl L-isoleucinate: Thionyl chloride
  • Step-2 Intermediate l-(3-chloro-l-phenylpropoxy)-4-
  • methyl L- isoleucinate (0.11 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature.
  • This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature.
  • This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate.
  • reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product.
  • the crude was purified by column chromatography to give final product methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-isoleucinate (0.12 g, 85%).
  • Antiviral and immunomodulatory activity (IL- 10) of compound 6f was determined using the above methodology and was found to be
  • Step-1 Preparation of methyl L-prolinate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L-proline (0.97 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 95% yield (1.00 g).
  • Step-2 Intermediate l-(3-chloro-l-phenylpropoxy)-4-
  • methyl L- prolinate (0.10 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature.
  • This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature.
  • This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate.
  • reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product.
  • the crude was purified by column chromatography to give final product methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)prolinate (0.11 g, 86%).
  • Antiviral and immunomodulatory activity (IE- 10) of compound 6g was determined using the above methodology and was found to be
  • Step-1 Preparation of methyl (2S)-4-hydroxypyrrolidine-2- carboxylate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing 4-hydroxy-L-proline (1.10 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. The reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 97% yield (1.20 g).
  • Step-2 Intermediate l-(3-chloro-l-phenylpropoxy)-4-
  • reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate, and evaporated under reduced pressure to obtain crude product.
  • the crude was purified by column chromatography to give final product methyl (2S)-4-hydroxy-l-(3-phenyl-3-(4- (trifluoromethyl)phenoxy)propyl)pyrrolidine-2-carboxylate (0.12 g, 88%).
  • Antiviral and immunomodulatory activity (IL- 10) of compound 6h was determined using the above methodology and was found to be
  • Step-1 Preparation of methyl L-phenylalaninate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L-phenylalanine (1.39 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride.
  • Step-2 Intermediate l-(3-chloro-l-phenylpropoxy)-4-
  • methyl L- phenylalaninate (0.14 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature.
  • This mixture was poured into the solution of 1 -(3 -chloro- 1- phenylpropoxy)-4-(trifluoromethyl)benzene and sodium iodide at room temperature.
  • This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate.
  • reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product.
  • the crude was purified by column chromatography to give final product methyl (3-phenyl-3-(4- (trifluoromethyl)phenoxy)propyl) -L-phenylalaninate (0.13 g, 87%). !
  • Antiviral and immunomodulatory activity (IL- 10) of compound 6i was determined using the above methodology and was found to be
  • Step-1 Preparation of methyl L-methioninate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L-methionine (1.26 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 96% yield (1.30 g).
  • Step-2 Intermediate l-(3-chloro-l-phenylpropoxy)-4-
  • methyl L- methioninate (0.13 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature.
  • This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature.
  • This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate.
  • reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate, and evaporated under reduced pressure to obtain crude product.
  • the crude was purified by column chromatography to give final product methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-methioninate (0.12 g, 85%).
  • Step-1 Preparation of methyl L-threoninate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L-threonine (1.00 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 98% yield (1.10 g).
  • Step-2 Intermediate l-(3-chloro-l-phenylpropoxy)-4-
  • Step-3 Coupling of amino acid and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl L- threoninate (0.11 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature.
  • DIPEA diisopropylethylamine
  • This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature.
  • This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate, and evaporated under reduced pressure to obtain crude product.
  • Antiviral and immunomodulatory activity (IL- 10) of compound 6k was determined using the above methodology and was found to be
  • Step-1 Preparation of methyl L-tyrosinate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L-tyrosine (1.53 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 96% yield (1.60 g).
  • Step-2 Intermediate l-(3-chloro-l-phenylpropoxy)-4-
  • Step-3 Coupling of amino acid and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature.
  • methyl L- tyrosinate (0.15 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mF, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature.
  • This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature.
  • This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate.
  • reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tyrosinate (0.12 g, 81%).
  • Step-1 Preparation of ethyl L-tryptophanate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L- tryptophan (1.72 g, 5.61 mmol) in anhydrous ethanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from ethanol and dried under high vacuum and used for the next reaction without further purification in 96% yield (1.90 g).
  • Step-2 Mitsunobu Reaction (Procedure for the synthesis of
  • Step-3 Coupling of amino acid and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, ethyl L- tryptophanate (0.18 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature.
  • DIPEA diisopropylethylamine
  • This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature.
  • This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product.
  • Antiviral and immunomodulatory activity (IL- 10) of compound 6m was determined using the above methodology and was found to be
  • Step-1 Preparation of ethyl L-valinate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L- valine (0.99 g, 5.61 mmol) in anhydrous ethanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from ethanol and dried under high vacuum and used for the next reaction without further purification in 98% yield (1.20 g).
  • Step-2 Intermediate l-(3-chloro-l-phenylpropoxy)-4-
  • Step-3 Coupling of amino acid and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, ethyl L-valinate (0.10 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature.
  • DIPEA diisopropylethylamine
  • This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature.
  • This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product.
  • Step-1 Preparation of methyl L-tryptophanate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L- tryptophan (1.72 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for the reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 95% yield (1.70 g).
  • Step-2 Mitsunobu Reaction (Procedure for the synthesis of Intermediate l-(3-chloro-l-phenylpropoxy)-4-methoxybenzene 5b): In a round bottom flask, diisopropyl azodicarboxylate (DIAD) (3.45 mL, 17.58 mmol) and triphenylphosphine (4.61 g, 17.58 mmol) were taken under nitrogen environment. Dry THF (25 ml) was added into the reaction pot and this mixture was allowed to stir at room temperature for 20 minutes. 4-methoxyphenol (1.46 g, 11.72 mmol) was dissolved in dry THF (5 ml) and added into the reaction pot and stirred for 4 hours.
  • DIAD diisopropyl azodicarboxylate
  • triphenylphosphine 4.61 g, 17.58 mmol
  • Step-3 Coupling of amino acid and 5b: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-methoxybenzene (0.09 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF, and stirred for 30 minutes at room temperature. In a separate flask, methyl L- tryptophanate (0.17 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature.
  • DIPEA diisopropylethylamine
  • This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- methoxybenzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate, and evaporated under reduced pressure to obtain crude product.
  • Step-1 Preparation of methyl L-valinate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L- valine (0.99 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. The reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol, dried under high vacuum and proceeded to be used for the next reaction without further purification in 97% yield (0.96 g).
  • Step-2 Intermediate l-(3-chloro-l-phenylpropoxy)-4- methoxybenzene was prepared according to procedure in example- 15.
  • Step-3 Coupling of amino acid and 5b: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-methoxybenzene (0.09 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl L-valinate (0.10 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature.
  • DIPEA diisopropylethylamine
  • This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- methoxybenzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product.
  • Step-1 Preparation of methyl L-tryptophanate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L- tryptophan (1.72 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. The reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 95% yield (1.70 g).
  • Step-2 Mitsunobu Reaction (Procedure for the synthesis of
  • Step-3 Coupling of amino acid and 5c: In a double neck round bottom flask, 1, 2-dichloro-4-(3 -chloro- 1 -phenylpropoxy )benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl L- tryptophanate (0.17 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature.
  • DIPEA diisopropylethylamine
  • This mixture was poured into the solution of l,2-dichloro-4-(3-chloro-l- phenylpropoxy)benzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product.
  • Antiviral and immunomodulatory activity (IL- 10) of compound 6q was determined using the above methodology and was found to be
  • Step-1 Preparation of methyl L-valinate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L- valine (0.99 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. The reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 97% yield (0.96 g).
  • Step-2 Intermediate 1 ,2-dichloro-4-(3 -chloro- 1 - phenylpropoxy )benzene was prepared according to procedure in example- 17 [000123]
  • Step-3 Coupling of amino acid and 5c: In a double neck round bottom flask, 1, 2-dichloro-4-(3 -chloro- 1 -phenylpropoxy )benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature.
  • methyl L-valinate (0.10 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature.
  • This mixture was poured into the solution of l,2-dichloro-4-(3 -chloro- 1- phenylpropoxy)benzene and sodium iodide at room temperature.
  • This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml).
  • Antiviral and immunomodulatory activity (IE- 10) of compound 6r was determined using the above methodology and was found to be
  • the present disclosure provides a group of L-amino acid esters substituted 3-phenyl-3-(aryloxy) propan- 1 -amine compounds which possess excellent antiviral and immunomodulatory potential. [000126] The present disclosure provides a convenient process for preparation of the L-amino acid esters substituted 3-phenyl-3-(aryloxy) propan- 1 -amine compounds, with good yield of at least 70% and appreciable purity.
  • the compounds disclosed in the present disclosure showed an immunomodulatory activity (IL- 10) of up to 5270+452 Pg/mL at Ipg.

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Abstract

This invention provides a group of novel L-amino acid esters substituted 3-phenyl- 3-(aryloxy)propan-1-amine derivatives of the following structural Formula I, wherein, the groups R1, R2 and R3 are defined in the specification having anti- inflammatory and anti-viral activity. This invention also provides a process of preparing the compounds of structural Formula I.

Description

3-PHENYL-3-(ARYLOXY) PROPAN-l-AMINES AND THE PROCESS FOR PREPARATION THEREOF
FIELD OF THE INVENTION
[0001] The present invention relates to a group of L-amino acid esters substituted 3-phenyl-3-(aryloxy) propan- 1 -amine compounds. The present invention particularly relates to L-amino acid esters substituted 3-phenyl-3-(aryloxy) propan- 1 -amine compounds having antiviral and immunomodulatory potential.
BACKGROUND OF THE INVENTION
[0002] Eli-Lily and company in 1976 discovered originally Fluoxetine hydrochloride (Prozac® ,(N -methyl-3 -phenyl-3 - [4- (trifuoromethyl)phenoxy ] propan- 1 -amine hydrochoride) a selective serotonin-reuptake inhibitor (SSRI), which was later approved by the FDA in 1987 for therapeutic management of depression (Fluoxetine: a serotonin-specific, second-generation antidepressant. Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy, 1987. 7(1): p. 1-14). It augments the serotoninergic tone by enhancing the concentration of the neurotransmitter in the synaptic cleft through restraining the serotonin transporter. The clinically used drug is a racemic mixture. From a sterochemcial point of view, as individual enantiomer fluoxetine shows a moderate difference in terms of their serotonin reuptake inhibitory activity. Being a pharmacologically active entity on a wide spectrum of mood disorders fluoxetine has been a clinically accepted drug all over the world for the treatment of major depression (American Journal of Psychiatry, 2000. 157(3): p. 338-343). Further research on fuoxetine indicated the possible protection aligned with the adverse effects of various types of stress factors of immune system, oxidative damage through a permutation of mechanisms. This is supposed to be a key role player in neuroprotection, since brain being a high energy demanding organ susceptible to oxidative stress. Abnormal increase in the generation of reactive oxygen species (ROS) results in oxidative stress, which might have implications in the pathogenesis of many neuro- degenerative and psychiatric disorders. [0003] Antidepressant therapy has been inseparably linked to immune disorders. Investigational research findings specify that lymphocytes express the serotonin transporter and ability of fluoxetine to alter the immune functioning through a serotonin-dependent pathway and through a novel independent way. In addition, fluoxetine has the ability to modify tumor cell viability as confirmed through in vivo experiments that tumor growth is inhibited through chronic fluoxetine treatment by enhancing the antitumor T-cell activity (Beneficial effect of fluoxetine and sertraline on chronic stress-induced tumor growth and cell dissemination in a mouse model of lymphoma: crucial role of antitumor immunity. Frontiers in immunology, 2018. 9: p. 1341). Thus, there has been ample evidence in literature regarding the ability of fluoxetine to amend the functionality of the immune system. These research findings point to the significance of the novel pharmacological action of fluoxetine and its analogues as immunomodulator aiding to treat several disorders related with immune deficiency and its deregulation.
[0004] Furthermore, Fluoxetine displayed potent inhibitory effect on enterovirus replication as revealed in drug repurposing screens in mice. In addition to this, fluoxetine has been used to successfully treat immunocompromised children suffering from severe and lethal enterovirus encephalitis (Synthesis and antiviral effect of novel fluoxetine analogues as enterovirus 2C inhibitors. Antiviral Research, 2020. 178: p. 104781). It has been observed that structural modification of fluoxetine offers a potential strategy for evolving effective immunomodulators and antiviral therapeutics for clinical use. The invention provides a focused library of novel fluoxetine analogues, in which amino acids have been introduced on the N-terminus of the original scaffold, to gain insight into the structure-activity relationships of fluoxetine vis-a-vis the antiviral and immunomodulatory potentials. Previously reports pointed out that the structural features of the trifluoro-phenoxy moiety and the amino moiety are essential for the antiviral potency whereas the 3- phenyl moiety seems expendable. Immunomodulators modify the immune responses either by enhancing or suppressing the immune responses and are classified as an immunostimulant or immunosuppressant respectively. Anti- inflammatory action of antidepressants is finding increasing attention in the field of immunotherapy .
[0005] Fluoxetine has been often utilized to treat obsessive-compulsive disorder, panic disorder and depression because of its tolerability and safety (Multiple autoimmune diseases in a young woman: tuberculosis and splenectomy as possible triggering factors Another example of the “mosaic ” of autoimmunity. The Journal of rheumatology, 2008. 35(6): p. 1224-1227.). Clinically fluoxetine is utilized in a racemic form. It is postulated that this first-line anti-depressant drug can decrease the level of pro-inflammatory cytokines. Available works of literature demonstrate the anti-inflammatory characteristic of fluoxetine. Investigations revealed that fluoxetine noticeably reduces the INF y / IL- 10, suppresses TNF-a release, and increases the formation of anti-inflammatory cytokine IL- 10.
[0006] Literature clearly indicates a remarkable increase in immunological diseases thus great attention is required for the development of immunomodulators (Learning about the safety of drugs — a half-century of evolution. New England journal of medicine, 2011. 365(23): p. 2151-2153.). There is a huge worldwide demand for efficient immunomodulatory/anti-inflammatory drugs for the adjunct therapy of viral infections. In this endeavour, the present invention reveals the synthesis and immunological and antiviral screening of a focused library of novel designer amino acid analogues of fluoxetine. Fluoxetine is reported as a potential serotonin re-uptake inhibitor used for the treatment of depression. Apart from this pharmacological attribute, fluoxetine is not used clinically as an antiviral and antiinflammatory drug.
[0007] The present invention discloses designed fluoxetine analogues substituting the methylamine group with various L- alpha amino acids, to explore the need of modification across the basic nitrogen. The newly synthesized compounds have been characterized spectroscopically and tested for their immunomodulatory and anti-viral activities.
OBJECTIVE OF THE INVENTION [0008] Main objective of the present invention is to synthesize a series of novel aminoacid esters analogues of 3-phenyl-3-(aryloxy)propan-l-amine.
[0009] Another objective of the present invention is to evaluate the antiviral and immunomodulatory potentials of novel analogues.
SUMMARY OF THE INVENTION
[00010] Accordingly, the present invention provides a compound of the structural formula I or a pharmaceutically acceptable salt thereof,
Figure imgf000005_0001
wherein, n is 1, 2 or 3; each R1 is independently selected from the group consisting of substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy and halogen;
R2 is selected from the group consisting of H, substituted or unsubstituted linear or branched alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl or R2 together with the amine nitrogen may form a substituted or unsubstituted 5-6 membered ring and
R3 is linear or branched alkyl.
[00011] In a preferred embodiment the present invention provides a compound of the structural formula I, wherein R1 is C 1 to 6 alkyl, C 1 to 6 alkoxy, halo or trifluoromethyl.
[00012] In a preferred embodiment the present invention provides a compound of the structural formula I, wherein R2 is H, C 1 to 4; linear or branched substituted or unsubstituted alkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, wherein the substituents are selected form the group consisting of alkyl, aryl, heteroaryl, hydroxy and thioalkyl. [00013] In a preferred embodiment the present invention provides a compound of the structural formula I, wherein R2 together with the amine nitrogen may form a substituted or unsubstituted 5 membered carbocyclic ring.
[00014] In a preferred embodiment the present invention provides a compound of the structural formula I, wherein R3 is C 1 to 3 alkyl.
[00015] In a preferred embodiment the present invention provides compounds selected from the group consisting of a. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tryptophanate, b. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-valinate, c. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-alaninate, d. Methyl (2S)-2-phenyl-2-((3-phenyl-3-(4-
(trifluoromethyl)phenoxy)propyl)amino)acetate, e. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-leucinate, f. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-isoleucinate, g. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)prolinate, h. Methyl (2S)-4-hydroxy-l-(3-phenyl-3-(4-
(trifluoromethyl)phenoxy)propyl)pyrrolidine-2-carboxylate, i. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L- phenylalaninate, j . Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-methioninate, k. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-threoninate, l. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tyrosinate, m. Ethyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tryptophanate, n. Ethyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-valinate, o. Methyl (3-(4-methoxyphenoxy)-3-phenylpropyl)-L-tryptophanate, p. Methyl (3-(4-methoxyphenoxy)-3-phenylpropyl)-L-valinate, q. Methyl (3-(3,4-dichlorophenoxy)-3-phenylpropyl)-L-tryptophanate, and r. Methyl (3-(3,4-dichlorophenoxy)-3-phenylpropyl)-L-valinate.
[00016] The present invention also provides a process for preparing the compound of the structural formula I
Figure imgf000007_0001
wherein, n is 1, 2 or 3; each R1 is independently selected from the group consisting of substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy and halogen;
R2 is selected from the group consisting of H, substituted or unsubstituted linear or branched alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl or R2 together with the amine nitrogen may form a substituted or unsubstituted 5-6 membered ring and
R3 is linear or branched alkyl, comprising the steps of: a. synthesizing an amino acid ester of formula 2 by reacting an amino acid of formula 1 with R3-OH in the presence of a solvent,
Figure imgf000007_0002
wherein R2 is selected from the group consisting of H, substituted or unsubstituted linear or branched alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl or R2 together with the amine nitrogen may form a substituted or unsubstituted 5-6 membered ring, and R3 is linear or branched alkyl; b. reacting 3 -chloro- 1-phenylpropan-l-ol of formula 3 with a phenol of formula 4 to obtain a compound of formula 5,
Figure imgf000008_0001
wherein R1 is selected from the group consisting of substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy and halogen; and c. synthesizing 3-phenyl-3-(aryloxy) propan- 1 -amine derivatives of formula I (6) by reacting the compound of formula 5 obtained in step b with the amino acid ester of formula 2 obtained in step a,
Figure imgf000008_0002
tructura ormu a- wherein n, R1, R2 and R3 are as defined above and the number of R1 could be 1-3.
[00017] In a preferred embodiment of the present invention step a of the process is carried out in presence of thionyl chloride and an anhydrous alcohol as solvent.
[00018] In a preferred embodiment of the present invention step b of the process is carried out in presence of diisopropyl azodicarboxylate (DIAD), triphenylphosphine and dry tetrahydrofuran (THF) under nitrogen environment.
[00019] In a preferred embodiment of the present invention step c of the process is carried out in presence of sodium iodide(Nal), diisopropylethylamine (DiPEA) and dimethyl formamide (DMF). [00020] In an embodiment, the compound of the present invention has antiinflammatory and anti-viral activity.
[00021] These and other features, aspects, and advantages of the present subject matter will be better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
DETAILED DESCRIPTION OF THE INVENTION
[00022] The foregoing detailed description of the disclosure is elaborated to provide a clear understanding to the person who is skilled in the art. Additional features, embodiments and advantages of the invention will be described hereinafter which form the subject of the claims of the disclosure, However, the set forth disclosure provide in the specification will best be understood in conjunction with the appended claims and figures as provide heretofore. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent processes do not depart from the spirit and scope of the disclosure as set forth in the appended claims. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.
[00023] While the invention has been disclosed with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made, and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt to a particular situation or material to the teachings of the invention without departing from its scope.
[00024] Throughout the specification and claims, the following terms take the meanings explicitly associated herein unless the context clearly dictates otherwise. The meaning of "a", "an", and "the" include plural references. The meaning of "in" includes "in" and "on."
[00025] The term "at least one" is used to mean one or more and thus includes individual components as well as mixtures/combinations.
[00026] The terms "comprise" and "comprising" are used in the inclusive, open sense, meaning that additional elements may be included. It is not intended to be construed as "consists of only". Throughout this specification, unless the context requires otherwise the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated element or step or group of element or steps but not the exclusion of any other element or step or group of element or steps. In the description, term "Cl to 6 alkyl" refer to the nonring filling of the linear chain or branched chain with 1 to 6 carbon atom(s). Hydrocarbon, term "C 1 to 6 alkoxy" refers to the non-cyclic hydrocarbon of the linear chain or branched chain with more than one ether and 1 to 6 carbon atom(s). [00027] The term “including” is used to mean “including but not limited to”, “including” and “including but not limited to” are used interchangeably.
[00028] The terms "halogen" or "halo" means fluorine, chlorine, bromine, or iodine. The term "alkyl" refers to an alkane derived hydrocarbon radical that includes solely carbon and hydrogen atoms in the backbone, contains no unsaturation, has from one to six carbon atoms, and is attached to the remainder of the molecule by a single bond, for example C 1 to 6 alkyl, representative groups include e.g., methyl, ethyl, n-propyl, 1 -methylethyl (isopropyl), n-butyl, n-pentyl and the like. Unless set forth or recited to the contrary, all alkyl groups described or claimed herein may be straight chain or branched.
[00029] The term "alkoxy" denotes an alkyl group attached via an oxygen linkage to the rest of the molecule. Representative examples of such groups are -OCH3 and -OC2H5. Unless set forth or recited to the contrary, all alkoxy groups described or claimed herein may be straight chain or branched.
[00030] The term "aryl" refers to an aromatic radical having 6 to 12 carbon atoms, including monocyclic, bicyclic^ and tricyclic aromatic systems, such as phenyl, naphthyl, tetrahydronaphthyl, indanyl, biphenyl and the like.
[00031] The term "heterocyclic" unless otherwise specified, refers to a substituted or unsubstituted 5 to 14 membered cyclic ring with one or more heteroatom/s independently selected from N, O or S. The heteroaryl may be a mono, bi or tricyclic ring system. The heteroaryl ring may be attached by any atom of the heteroaryl ring that results in the creation of a stable structure. Non-limiting Examples of a heterocyclyl ring include oxazolyl, isoxazolyl, imidazolyl, furyl, indolyl, and the like.
[00032] Furthermore, unless stated otherwise, the alkyl group can be unsubstituted or substituted with one or more substituents, for example, from one to four substituents, independently selected from the group consisting of halogen, hydroxy, cyano, nitro and amino. Examples of substituted alkyl include, but are not limited to hydroxymethyl, 2-chlorobutyl, trifluoromethyl and aminoethyl.
[00033] The term “substituted” refers to the form of a group wherein one or more other radicals are substituted over the group. For example, substituted C4 alkyl can be 2-hydroxy butyl group. The substituted groups can be can be one or more groups selected from alkyl, alkenyl, aryl, heteroaryl, hydroxy, halo, cyano, amino, thioalkyl, alkoxy, and the like, which may be further optionally substituted with groups selected from alkyl, alkenyl, aryl, heteroaryl, hydroxy, halo, cyano, amino, thioalkyl, alkoxy, and the like.
[00034] All percentages, parts and ratios are based upon the total weight of the compositions of the present disclosure unless otherwise indicated. Ratios, concentrations, amounts, and other numerical data may be presented herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited.
[00035] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure, the preferred methods and materials are now described. All publications mentioned herein are incorporated herein by reference.
[00036] The compound of the structural formula I or a pharmaceutically acceptable salt thereof
Figure imgf000012_0001
wherein, n is 1, 2 or 3; each R1 is independently selected from the group consisting of substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy and halogen;
R2 is selected from the group consisting of H, substituted or unsubstituted linear or branched alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl or R2 together with the amine nitrogen may form a substituted or unsubstituted 5-6 membered ring and
R3 is linear or branched alkyl, is produced by a process summarized in the following schemes.
Scheme 1: Alkyl ester synthesis of Amino acids
Figure imgf000012_0002
R3 = methyl, ethyl Scheme 2: Synthesis of Fluoxetine-amino acid derivatives
Scheme 2a
Figure imgf000013_0001
o
Scheme 2b
Figure imgf000013_0003
wherein n, R1, R2 and R3 are as defined above.
[00037] In an embodiment of the present disclosure, there is provided a compound of the structural formula I or a pharmaceutically acceptable salt thereof,
Figure imgf000013_0002
wherein, n is 1, 2 or 3; each R1 is independently selected from the group consisting of substituted unsubstituted C 1 to 6 alkyl, substituted or unsubstituted C 1 to 6 alkoxy and halogen;
R2 is selected from the group consisting of H, substituted or unsubstituted linear or branched C 1 to 6 alkyl, substituted or unsubstituted C 6 to 12 aryl, substituted or unsubstituted C 5 to 14 heteroaryl or R2 together with the amine nitrogen may form a substituted or unsubstituted 5-6 membered ring and
R3 is linear or branched C 1 to 6 alkyl.
[00038] In an embodiment of the present disclosure, there is provided a compound of the structural formula I or a pharmaceutically acceptable salt thereof,
Figure imgf000014_0001
wherein, n is 1, 2 or 3; each R1 is independently selected from the group consisting of substituted or unsubstituted C 1 to 4 alkyl, substituted or unsubstituted C 1 to 4 alkoxy, fluorine, chlorine, bromine, and iodine;
R2 is selected from the group consisting of H, substituted or unsubstituted linear or branched C 1 to 4 alkyl, substituted or unsubstituted C 6 to 10 aryl, unsubstituted C 6 to 10 heteroaryl or R2 together with the amine nitrogen may form a substituted or unsubstituted 5-6 membered ring and
R3 is linear or branched Cl to 4 alkyl.
[00039] In an embodiment of the present disclosure, there is provided a compound of the structural formula I or a pharmaceutically acceptable salt thereof,
Figure imgf000015_0001
wherein, n is 1, or 2; each R1 is independently selected from the group consisting of halogen substituted Ci alkyl, unsubstituted Ci alkoxy, and chlorine;
R2 is selected from the group consisting of H, substituted or unsubstituted linear or branched Cl to 4 alkyl, unsubstituted C 6 to 8 aryl, unsubstituted C 6 to 10 heteroaryl or R2 together with the amine nitrogen may form a substituted or unsubstituted 5 membered ring and
R3 is linear C 1 to 2 alkyl.
[00040] Compounds illustrative of the scope of this invention include the following: a. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tryptophanate b. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-valinate c. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-alaninate d. Methyl (2S)-2-phenyl-2-((3-phenyl-3-(4-
(trifluoromethyl)phenoxy)propyl)amino)acetate e. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-leucinate f. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-isoleucinate g. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)prolinate h. Methyl (2S)-4-hydroxy-l-(3-phenyl-3-(4-
(trifluoromethyl)phenoxy)propyl)pyrrolidine-2-carboxylate i. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L- phenylalaninate j . Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-methioninate k. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-threoninate l. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tyrosinate m. Ethyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tryptophanate n. Ethyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-valinate o. Methyl (3-(4-methoxyphenoxy)-3-phenylpropyl)-L-tryptophanate p. Methyl (3-(4-methoxyphenoxy)-3-phenylpropyl)-L-valinate q. Methyl (3-(3,4-dichlorophenoxy)-3-phenylpropyl)-L-tryptophanate r. Methyl (3-(3,4-dichlorophenoxy)-3-phenylpropyl)-L-valinate
Figure imgf000016_0001
Formula I (6(a-r)) [00041] The definition of n, R1, R2, and R3 are as defined above. The number of R1 in 4 and 5 could be 1-3.
[00042] The synthesis of the title compound depicted in structural formula-I was carried out following a convergent synthesis strategy. In one hand, esters of amino acid were synthesized as per the general procedure A and B. Thionyl chloride was the reagent of choice to convert amino acid into corresponding acid chloride following a literature procedure. Methanol and ethanol were used as the solvents as well as reactants to produce methyl and ethyl ester 2. Mitsunobu reaction was performed between 3 -chloro- 1-phenylpropan-l-ol 3 and substituted phenol 4 to achieve 4-substituted l-(3-chloro-l-phenylpropoxy)-4-benzene 5 as colourless oil, in moderate to good yield. Both the fragments; esters 2 and l-(3-chloro-l- phenylpropoxy)-4-benzene 5 were coupled together by A-alkylation reaction. Crude obtained from reaction mixture was subjected for column chromatographic purification to afford compound 6 (a-r) in good yield. All the synthesized analogues were structurally confirmed by XH-NMR, 13C-NMR, and HRMS spectrometry techniques and subjected for biological evaluation. Anti-viral activity was performed on Huh 7 cell lines using dengue virus, wherein the viral inoculums were treated with novel analogues and the viral IC50 was determined using plate reader. The immunomodulatory activity of the novel analogues was determined using in vitro macrophage assay, wherein novel analogues at three different concentrations were added, incubated and supernatant was used to quantify the IL- 10 produced.
General procedure A: Synthesis of esters of different amino acids 2
Figure imgf000017_0001
[00043] The definition of R2 and R3 are as defined above.
[00044] Thionyl chloride (8.42 mmol) was added slowly to a mixture containing amino acid (5.61 mmol) in anhydrous alcohols (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. The reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with respective alcohol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from respective alcohols and dried under high vacuum to afford compound 2 in good yields (95-99%).
General procedure B: Synthesis of Compound 5
Figure imgf000018_0001
[00045] The definition of R1 is as defined above and the number of R1 could be 1-3.
[00046] In a round bottom flask, diisopropyl azodicarboxylate (DIAD) (17.58 mmol) and triphenylphosphine (17.58 mmol) were taken under nitrogen environment. Dry THF (25 ml) was added into the reaction pot and this mixture was allowed to stir at room temperature for 20 minutes. Phenol 4 (11.72 mmol) was dissolved in dry THF (5 ml) and added into the reaction pot and stirred for 4 hours. 3 -chloro- 1-phenylpropan-l-ol 3 (11.72 mmol) was dissolved in dry THF (5 ml) and transferred into reaction pot and the reaction mixture was allowed to stir at room temperature for 16 hours under nitrogen atmosphere. Reaction progress was monitored on TLC (thin layer chromatography) plate. After completion of reaction, solvent was removed under reduced pressure. The crude mixture was purified by column chromatography technique, using hexane as a mobile phase and silica gel (60-120 mesh size) as stationary phase to afford the pure product 5 in moderate yields (65-70%).
General procedure C: Synthesis of 3-phenyl-3-(aryloxy) propan- 1 -amine derivatives Formula I (6 (a-r))
Figure imgf000018_0002
[00047] The definition of R1, R2 and R3 are as defined above and the number of R1 could be 1-3. [00048] In a double neck round bottom flask, 5 (0.32 mmol.) and sodium iodide (0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, aliphatic ester of amino acid (0.79 mmol.) and diisopropylethylamine (DiPEA) (0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of 5 and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). The organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give the final product with 70-85% yield. All analogues are confirmed by using various spectroscopic techniques like 1 H-NMR, 13C-NMR, and HRMS spectrometry.
EXAMPLE 1
Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tryptophanate
(6a, 80%)
Figure imgf000019_0001
[00049] Step-1: Preparation of methyl L-tryptophanate (amino acid ester of formula 2): Thionyl chloride (0.41 m , 8.42 mmol) was added slowly to a mixture containing L- tryptophan (amino acid of formula 1; 1.72 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. The reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol, dried under high vacuum and used for the next reaction without further purification in 95% yield (1.70 g).
[00050] Step-2 : Mitsunobu Reaction (Procedure for the synthesis of intermediate l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene; compound 5a): In a round bottom flask, diisopropyl azodicarboxylate (DIAD) (3.45 mL, 17.58 mmol) and triphenylphosphine (4.61 g, 17.58 mmol) were taken under nitrogen environment. Dry THF (25 ml) was added into the reaction pot and this mixture was allowed to stir at room temperature for 20 minutes. 4-(trifluoromethyl) phenol (1.90 g, 11.72 mmol) was dissolved in dry tetrahydrofuran (THF, 5 ml) and added into the reaction pot and stirred for 4 hours. 3 -chloro- 1-phenylpropan-l-ol 3 (2.00 g, 11.72 mmol) was dissolved in dry THF (5 ml) and transferred into reaction pot and the reaction mixture was allowed to stir at room temperature for 16 hours under nitrogen atmosphere. Reaction progress was monitored on TLC plate. After completion of reaction, solvent was removed under reduced pressure. The crude mixture was purified by column chromatography technique, using hexane as a mobile phase and silica gel (60-120 mesh size) as stationary phase to afford the pure product l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene as colourless oil. (2.40 g, Yield = 65 %). 1 H NMR (500 MHz, CDC13) 6 7.37 (d, J = 4.4 Hz, 4H), 7.33 - 7.28 (m, 1H), 4.95 (dd, J = 8.5, 4.7 Hz, 1H), 3.78 - 3.70 (m, 1H), 3.60 - 3.54 (m, 1H), 2.29 - 2.20 (m, 1H), 2.14 - 2.05 (m, 1H). 13C NMR (101 MHz, CDCI3) 6 143.8, 128.8, 128.1, 125.9, 71.5, 41.9, 41.6.
[00051] Step-3: Coupling of amino acid 2 and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl L- tryptophanate (0.17 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 Ml, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate, and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give the final product methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tryptophanate (0.13 g, 80%). ’H NMR (500 MHz, CDC13) 6 8.O1 (s, 1H), 7.57 (d, J = 7.9 Hz, 1H), 7.30 (d, 7 = 8.6 Hz, 3H), 7.16 - 7.11 (m, 4H), 7.09 - 7.04 (m, 1H), 7.00 - 6.98 (m, 3H), 6.64 (d, J = 8.6 Hz, 2H), 5.03 (dd, J = 8.0, 5.0 Hz, 1H), 3.57 (s, 3H), 3.21 - 3.13 (m, 1H), 3.03 - 2.96 (m, 1H), 2.82 - 2.74 (m, 1H), 2.51 - 2.42 (m, 1H), 2.05 - 1.96 (m, 1H), 1.89 - 1.79 (m, 2H). 13C NMR (101 MHz, CDC13) 6 175.2, 160.6, 140.8, 136.4, 128.8, 127.8, 126.8, 125.9, 123.1, 122.4, 119.8, 118.9, 115.83, 111.4, 78.2, 61.9, 52.0, 44.2, 38.3, 29.4. HRMS (ESI-ToF): m/z [M+H]+ calcd for C28H28F3N2O3 : 496.1974; found : 497.2053
Biological evaluation:
[00052] The antiviral and immunomodulatory properties of the above novel molecules were carried out using in vitro assays-
[00053] Anti-viral activity: Huh 7 cells were cultured in 96-well plates (2 x 10 4 cells/well) for 16 h. Then differing concentrations of compounds are added to viral inoculums (minimal numbers required for causing infection) and incubated at 37 °C for 1 h. The cells were infected with these mixtures at 37 °C for 2 h. Afterwards, the virus was removed, and cells were washed three times with PBS, and the medium was replaced by complete DMEM. The cells were incubated for 48 h at 37 °C with 5% CO2. The reduction of viral cytopathic effect was determined by measuring cell viability measured using MTS.
[00054] Immunomodulatory activity: Dweller macrophages were accessed by peritoneal bath of crude mice. 2% starch solution was prepared by adding starch to the sterile Millipore water and making it clear solution by sonication. The starch solution was stored for 2 to 3 weeks at room temperature and then was used at same concentration. 2ml of 2% starch injection was given to mice at intra peritoneal site. After 4-5 days of immunization, the mice were sacrificed by CO2 asphyxiation and 5 ml PBS injection was given to same site. After 5 min the fluid was collected from peritoneal site either through syringe or dropper. The suspension was centrifuged at 2000rpm, 621g for 10 min at RT. The pellets so collected were cultured in high glucose DMEM and stored at 37°C. The macrophages were treated with the analogues at four different concentrations (1000-lpg/ml) in ten-fold dilution and pro inflammatory cytokines were estimated.
Cytokine estimation- Sandwich ELISA
[00055] Quantification of anti-inflammatory cytokines IL- 10 from cell supernatant of macrophages was carried out by Opti Elisa Kit (BD) according to manufacturer’s protocol. The supernatant was collected from treated well separately for cytokine estimation by coating ELISA plates with purified antimouse antibody diluted with bicarbonate - carbonate buffer and incubated at 4°C overnight. Plates were washed thrice with PBST 20 and blocked with lOOpl of 1% BSA. After 1 hour incubation at RT, plates were again washed thrice with same washing buffer. lOOpl of cell supernatant sample was added along with serially diluted recombinant antibody. Plates were incubated for 3 hours at 37°C. Post incubation was followed by four times washing and then addition of detection antibody prepared in BSA with 1 hour incubation at RT. After four times washing, HRP streptavidin (1 :3000) in 1% BSA was added lOOpl each and kept for incubation for 30 min at RT. TMB substrate (TMBA:TMBB; 1:1) was added after thrice washing and kept for incubation till development of colour or for 15 min. The reaction was stopped by adding 50pl of 2N H2SO4 and the absorbance was measured at 450 nm in ELISA reader (Tecan, Infinite pro).
[00056] Anti-dengue and immunomodulatory activity (IL- 10) of compound 6a was determined using the above methodology and was found to be
Figure imgf000022_0001
EXAMPLE 2
Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-valinate (6b, 86%):
Figure imgf000023_0001
[00057] Step-1: Preparation of methyl L-valinate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L- Valine (1; 0.99 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. The reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol, dried under high vacuum and used for the next reaction without further purification in 97% yield (0.96 g).
[00058] Step-2: Intermediate l-(3-chloro-l-phenylpropoxy)-4-
(trifluoromethyl)benzene (5a) was prepared according to the procedure explained in example- 1.
[00059] Step-3: Coupling of amino acid and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene (0.10 g, 0.32 mmol) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl L- valinate (0.10 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate, and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-valinate (0.11 g, 86%). 1 H NMR (500 MHz, CDC13) 6 7.35 (d, J = 8.9 Hz, 2H), 7.28 - 7.23 (m, 4H), 7.21 - 7.16 (m, 1H), 6.84 - 6.80 (m, 2H), 5.32 - 5.26 (m, 1H), 3.61 (d, J = 4.8 Hz, 3H), 2.89 (dd, J = 15.1, 6.1 Hz, 1H), 2.77 - 2.69 (m, 1H), 2.56 - 2.39 (m, 1H), 2.15 - 2.05 (m, 1H), 1.91 - 1.80 (m, 2H), 0.89 (dd, J = 6.8, 4.2 Hz, 3H), 0.83 (dd, J = 13.3, 6.8 Hz, 3H). 13C NMR (101 MHz, CDCI3) 6 175.9, 160.7, 141.1, 128.9, 128.0, 126.8, 126.9, 126.0, 123.2, 123.0, 122.7, 122.3, 115.9, 115.9, 78.6, 78.5, 67.7, 67.5, 51.6, 44.7, 38.9, 31.8, 31.8, 19.5, 19.3, 18.9. HRMS (ESI-ToF): m/z [M+H]+ calcd for C22H27F3NO3 : 409.1865; found : 410.1933.
[00060] Anti-dengue and immunomodulatory activity (IL- 10) of compound 6b was determined using the above methodology and was found to be
Figure imgf000024_0002
EXAMPLE 3
Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-alaninate (6c, 82%):
Figure imgf000024_0001
[00061] Step-1: Preparation of methyl L-alaninate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L-alanine (1; 0.80 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. The reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol, dried under high vacuum and used for the next reaction without further purification in 98% yield (0.85 g).
[00062] Step-2: Intermediate l-(3-chloro- l-phenylpropoxy)-4-
(trifluoromethyl)benzene (5a) was prepared according to procedure in example- 1 [00063] Step-3: Coupling of amino acid and 5a: In a double neck round bottom flask, 1 -(3 -chloro- 1 -phenylpropoxy )-4-(trifluoromethyl)benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl L-alaninate (0.08 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-alaninate (0.10 g, 82%). 1 H NMR (400 MHz, CDC13) 6 7.35 (d, J = 8.7 Hz, 2H), 7.26 (d, J = 4.4 Hz, 4H), 7.22 - 7.16 (m, 1H), 6.83 (d, J = 8.6 Hz, 2H), 5.25 (dd, J = 8.5, 4.5 Hz, 1H), 3.61 (d, J = 6.2 Hz, 3H), 3.29 - 3.20 (m, 1H), 2.75 - 2.67 (m, 1H), 2.62 - 2.54 (m, 1H), 2.16 - 2.06 (m, 1H), 1.95 - 1.87 (m, 1H), 1.23 - 1.17 (m, 4H). 13C NMR (101 MHz, CDCI3) 6 176.3, 160.7, 141.1, 128.9, 128.0, 126.8, 126.8, 125.9, 123.4, 123.2, 123.1, 122.8, 115.9, 78.8, 56.8, 51.9, 44.5, 39.3, 19.2. HRMS (ESI-ToF): m/z [M+H]+ calcd for C20H23F3NO3 : 381.1552; found : 381.1622.
[00064] Anti-dengue and immunomodulatory activity (IL- 10) of compound 6c was determined using the above methodology and was found to be
Figure imgf000026_0002
EXAMPLE 4
Methyl (2S)-2-phenyl-2-((3-phenyl-3-(4-
(trifluoromethyl)phenoxy)propyl)amino)acetate (6d, 85%):
Figure imgf000026_0001
[00065] Step-1: Preparation of methyl (S)-2-amino-2-phenylacetate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L-(+)-a-phenylglycine (1; 1.27 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol, dried under high vacuum and used for the next reaction without further purification in 96% yield (1.30 g).
[00066] Step-2: Intermediate l-(3-chloro-l-phenylpropoxy)-4-
(trifluoromethyl)benzene (5a) was prepared according to procedure in example- 1. [00067] Step-3: Coupling of amino acid and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl) benzene (0.10 g, 0.32 mmol) and sodium iodide (0.09 g, 0.63 mmol) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl (S)-2- amino-2-phenylacetate (0.13 g, 0.79 mmol) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of 1 -(3 -chloro- 1- phenylpropoxy)-4-(trifluoromethyl)benzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate, and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product methyl (2S)-2-phenyl-2-((3-phenyl-3-(4- (trifluoromethyl)phenoxy)propyl)amino)acetate (0.12 g, 85%). !H NMR (400 MHz, CDC13) 6 7.41 (dd, J = 8.6, 4.3 Hz, 2H), 7.35 - 7.24 (m, 10H), 6.90 - 6.83 (m, , 2H), 5.38 - 5.28 (m, 1H), 4.33 (s, 1H), 3.67 (d, J = 4.4 Hz, 3H), 2.82 - 2.73 (m, 1H), 2.72 - 2.58 (m, 1H), 2.26 - 2.14 (m, 1H), 2.03 - 1.97 (m, 1H). 13C NMR (101 MHz, CDCI3) 6 173.6, 160.7, 160.6, 141.2, 141.0, 138.3, 138.2, 128.9, 128.3, 128.2, 127.9, 127.5, 126.8, 125.9, 123.0, 122.7, 115.9, 78.7, 78.5, 65.7, 52.4, 44.2, 44.1, 39.1, 38.9. HRMS (ESI-ToF): m/z [M+H]+ calcd for C25H25F3NO3 : 444.1787; found : 444.1778.
[00068] Antiviral and immunomodulatory activity (IE- 10) of compound 6d was determined using the above methodology and was found to be
Figure imgf000027_0001
EXAMPLE 5
Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-leucinate (6e, 85%):
Figure imgf000028_0001
[00069] Step-1: Preparation of methyl L-leucinate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L-leucine (1.10 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 98% yield (1.20 g). [00070] Step-2: Intermediate l-(3-chloro-l-phenylpropoxy)-4-
(trifluoromethyl)benzene (5a) was prepared according to procedure in example- 1 [00071] Step-3: Coupling of amino acid and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl) benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl L- leucinate (0.11 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After the completion of the reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl 1 acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-leucinate (0.12 g, 85%). ’ H NMR (400 MHz, CDC13) 6 7.42 (d, J = 8.7 Hz, 2H), 7.35 - 7.31 (m, 4H), 7.28 - 7.24 (m, 1H), 6.92 - 6.87 (m, 2H), 5.38 - 5.31 (m, 1H), 3.67 (d, J
= 6.8 Hz, 3H), 3.28 - 3.18 (m, 1H), 2.83 - 2.75 (m, 1H), 2.65 - 2.50 (m, 1H), 2.23
- 2.10 (m, 1H), 1.99 - 1.90 (m, 1H), 1.78 - 1.64 (m, 1H), 1.48 - 1.41 (m, 2H), 0.94
- 0.91 (m, 2H), 0.88 (d, J = 6.6 Hz, 2H), 0.81 (d, J = 6.6 Hz, 2H). 13C NMR (101 MHz, CDCI3) 6 176.7, 160.8, 141.3, 128.9, 127.9, 126.9, 126.8, 125.9, 123.2, 123.0, 123.0, 122.7, 115.9, 78.5, 60.3, 51.8, 44.6, 43.0, 39.4, 25.1, 22.8, 22.3. HRMS (ESI- ToF): m/z [M+H]+ calcd for C23H29F3NO3 : 423.2021; found : 424.2089.
[00072] Antiviral and immunomodulatory activity (IL- 10) of compound 6e was determined using the above methodology and was found to be
Figure imgf000029_0002
EXAMPLE 6
Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-isoleucinate(6f, 85%) :
Figure imgf000029_0001
[00073] Step-1: Preparation of methyl L-isoleucinate: Thionyl chloride
(0.41 mL, 8.42 mmol) was added slowly to a mixture containing L-isoleucine (1.10 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 98% yield (1.20 g).
[00074] Step-2: Intermediate l-(3-chloro-l-phenylpropoxy)-4-
(trifluoromethyl)benzene (5a) was prepared according to procedure in example- 1 [00075] Step-3: Coupling of amino acid and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl L- isoleucinate (0.11 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After the completion of the reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-isoleucinate (0.12 g, 85%). 1 H NMR (400 MHz, CDC13) 6 7.35 (d, J = 8.8 Hz, 2H), 7.28 - 7.23 (m, 4H), 7.21 - 7.16 (m, 1H), 6.83 (d, J = 8.5 Hz, 2H), 5.32 - 5.25 (m, 1H), 3.60 (d, J = 4.3 Hz, 3H), 3.00 - 2.92 (m, 1H), 2.76 - 2.68 (m, 1H), 2.55 - 2.38 (m, 1H), 2.15 - 2.03 (m, 1H), 1.92 - 1.82 (m, 1H), 1.62 - 1.55 (m, 1H), 1.48 - 1.38 (m, 1H), 1.19 - 1.04 (m, 1H), 0.86 - 0.80 (m, 3H), 0.79 - 0.74 (m, 3H). 13C NMR (101 MHz, CDCI3) 6 175.9, 175.8, 160.9, 160.8, 141.4, 141.1, 128.8, 128.0, 127.9, 126.9, 126.8, 125.9, 123.3, 123.2, 123.0, 122.7, 122.6, 115.9, 78.6, 78.5, 66.5, 66.3, 51.5, 45.1, 44.7, 39.4, 38.9, 38.5, 25.7, 15.9, 15.7, 11.6, 11.5. HRMS (ESI-ToF): m/z [M+H]+ calcd for C23H29F3NO3 : 423.2021; found : 424.2092.
[00076] Antiviral and immunomodulatory activity (IL- 10) of compound 6f was determined using the above methodology and was found to be
Figure imgf000031_0002
EXAMPLE 7
Methyl (3-phenyl-3-(4-(trifhioromethyl)phenoxy)propyl)prolinate (6g, 86%):
Figure imgf000031_0001
[00077] Step-1: Preparation of methyl L-prolinate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L-proline (0.97 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 95% yield (1.00 g).
[00078] Step-2: Intermediate l-(3-chloro-l-phenylpropoxy)-4-
(trifluoromethyl)benzene (5a) was prepared according to procedure in example- 1 [00079] Step-3: Coupling of amino acid and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl L- prolinate (0.10 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)prolinate (0.11 g, 86%). 1 H NMR (500 MHz, CDC13) 6 7.35 (d, J = 8.6 Hz, 2H), 7.29 - 7.23 (m, 4H), 7.20 - 7.16 (m, 1H), 6.84 (d, J = 8.5 Hz, 2H), 5.23 (dd, J = 7.7, 5.4 Hz, 1H), 3.63 (s, 3H), 3.12 - 3.04 (m, 2H), 2.77 - 2.68 (m, 1H), 2.54 - 2.47 (m, 1H), 2.35 - 2.29 (m, 1H), 2.18 - 2.10 (m, 1H), 2.07 - 2.00 (m, 1H), 1.95 - 1.82 (m, 3H), 1.77 - 1.69 (m, 1H). 13C NMR (101 MHZ, CDCI3) 6 175.0, 160.8, 141.2, 128.8, 127.9, 126.8, 126.8, 126.1, 123.3, 123.2, 123.0, 122.6, 115.9, 78.5, 66.2, 53.9, 51.9, 51.2, 37.7, 29.7, 23.5. HRMS (ESI-ToF): m/z [M+H]+ calcd for C22H25F3NO3 : 407.1708; found : 408.1779.
[00080] Antiviral and immunomodulatory activity (IE- 10) of compound 6g was determined using the above methodology and was found to be
Figure imgf000032_0001
EXAMPLE 8 Methyl (2S)-4-hydroxy-l-(3-phenyl-3-(4-
(trifluoromethyl)phenoxy)propyl)pyrrolidine-2-carboxylate (6h, 88%) :
Figure imgf000033_0001
[00081] Step-1: Preparation of methyl (2S)-4-hydroxypyrrolidine-2- carboxylate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing 4-hydroxy-L-proline (1.10 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. The reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 97% yield (1.20 g).
[00082] Step-2: Intermediate l-(3-chloro-l-phenylpropoxy)-4-
(trifluoromethyl)benzene (5a) was prepared according to procedure in example- 1 [00083] Step-3: Coupling of amino acid and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl (2S)-4- hydroxypyrrolidine-2-carboxylate (0.11 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of l-(3-chloro-l- phenylpropoxy)-4-(trifluoromethyl)benzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate, and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product methyl (2S)-4-hydroxy-l-(3-phenyl-3-(4- (trifluoromethyl)phenoxy)propyl)pyrrolidine-2-carboxylate (0.12 g, 88%). ’ H NMR (400 MHz, CDC13) 6 7.42 (d, J = 8.7 Hz, 2H), 7.35 - 7.30 (m, 4H), 7.27 - 7.25 (m, 1H), 6.90 (dd, J = 8.5, 4.4 Hz, 2H), 5.34 - 5.27 (m, 1H), 4.52 - 4.45 (m, 1H), 3.69 (s, 2H), 3.59 - 3.52 (m, 1H), 3.49 (s, 1H), 3.46 - 3.36 (m, 1H), 2.97 - 2.80 (m, 1H), 2.71 - 2.64 (m, 1H), 2.54 - 2.44 (m, 1H), 2.26 - 2.12 (m, 2H), 2.10 - 1.94 (m, 2H). 13C NMR (101 MHz, CDCI3) 6 174.3, 160.8, 160.7, 141.1, 128.9, 128.0, 126.8, 126.1, 125.9, 123.0, 122.7, 115.9, 78.4, 78.2, 70.7, 64.4, 61.7, 61.5, 51.9, 50.8, 50.6, 39.8, 37.8, 37.5. HRMS (ESI-ToF): m/z [M+H]+ calcd for C22H25F3NO4 : 423.1657; found : 424.1728.
[00084] Antiviral and immunomodulatory activity (IL- 10) of compound 6h was determined using the above methodology and was found to be
Figure imgf000034_0002
EXAMPLE 9
Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-phenylalaninate (6i, 87%):
Figure imgf000034_0001
[00085] Step-1: Preparation of methyl L-phenylalaninate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L-phenylalanine (1.39 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 98% yield (1.50 g).
[00086] Step-2: Intermediate l-(3-chloro-l-phenylpropoxy)-4-
(trifluoromethyl)benzene (5a) was prepared according to procedure in example- 1 [00087] Step-3: Coupling of amino acid and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl L- phenylalaninate (0.14 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of 1 -(3 -chloro- 1- phenylpropoxy)-4-(trifluoromethyl)benzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product methyl (3-phenyl-3-(4- (trifluoromethyl)phenoxy)propyl) -L-phenylalaninate (0.13 g, 87%). !H NMR (500 MHz, CDC13) 67.37 - 7.30 (m, 2H), 7.25 - 7.12 (m, 8H), 7.09 - 7.03 (m, 2H), 6.75 - 6.69 (m, 2H), 5.17 - 5.09 (m, 1H), 3.56 (d, J = 4.3 Hz, 3H), 3.42 - 3.37 (m, 1H), 2.95 - 2.87 (m, 1H), 2.84 - 2.67 (m, 2H), 2.48 - 2.33 (m, 1H), 2.09 - 1.99 (m, 1H), 1.87 - 1.77 (m, 1H). 13C NMR (101 MHz, CDCI3) 6 175.1, 160.6, 140.9, 137.8, 129.5, 128.8, 128.6, 127.9, 126.9, 126.8, 126.0, 123.3, 123.2, 123.0, 122.7, 115.9, 78.1, 63.0, 51.9, 44.1, 39.9, 38.6. HRMS (ESI-ToF): m/z [M+H]+ calcd for C26H27F3NO3 : 457.1865; found : 458.1937.
[00088] Antiviral and immunomodulatory activity (IL- 10) of compound 6i was determined using the above methodology and was found to be
Figure imgf000036_0002
EXAMPLE 10
Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-methioninate (6j, 85%):
Figure imgf000036_0001
[00089] Step-1: Preparation of methyl L-methioninate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L-methionine (1.26 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 96% yield (1.30 g).
[00090] Step-2: Intermediate l-(3-chloro-l-phenylpropoxy)-4-
(trifluoromethyl)benzene (5a) was prepared according to procedure in example- 1 [00091] Step-3: Coupling of amino acid and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl L- methioninate (0.13 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate, and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-methioninate (0.12 g, 85%). 1 H NMR (400 MHz, CDC13) 6 7.42 (d, J = 8.8 Hz, 2H), 7.36 - 7.32 (m, 4H), 7.28 - 7.23 (m, 1H), 6.92 - 6.88 (m, 2H), 5.38 - 5.32 (m, 1H), 3.73 - 3.67 (m, 3H), 3.42 - 3.31 (m, 1H), 2.87 - 2.78 (m, 1H), 2.67 - 2.50 (m, 3H), 2.22 - 2.12 (m, 1H), 3.70 (d, J = 4.0 Hz, 3H), 1.99 - 1.87 (m, 2H), 1.85 - 1.74 (m, 1H). 13C NMR (101 MHz, CDCI3) 6 175.7, 160.8, 141.3, 141.1, 128.9, 128.0, 126.9, 125.9, 123.2, 123.0,
122.7, 115.9, 115.9, 78.5, 78.4, 60.5, 60.0, 52.0, 44.7, 44.2, 41.3, 39.4, 38.9, 32.9,
32.7, 30.7, 30.7, 15.5, 15.5. HRMS (ESI-ToF): m/z [M+H]+ calcd for C22H27F3NO3S : 442.1664; found : 442.1654.
[00092] Antiviral and immunomodulatory activity (IE- 10) of compound 6j was determined using the above methodology and was found to be
Figure imgf000037_0001
EXAMPLE 11
Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-threoninate (6k, 81%):
Figure imgf000038_0001
[00093] Step-1: Preparation of methyl L-threoninate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L-threonine (1.00 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 98% yield (1.10 g).
[00094] Step-2: Intermediate l-(3-chloro-l-phenylpropoxy)-4-
(trifluoromethyl)benzene was prepared according to procedure in example- 1
[00095] Step-3: Coupling of amino acid and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl L- threoninate (0.11 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate, and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-threoninate (0.11 g, 81%). ’ H NMR (500 MHz, CDCI3) 6 7.43 (d, 7 = 8.9 Hz, 2H), 7.36 - 7.31 (m, 4H), 7.29 - 7.25 (m, 1H), 6.91 - 6.86 (m, 2H), 5.32 - 5.27 (m, 1H), 3.72 (d, J = 3.7 Hz, 3H), 3.68 - 3.63 (m, 1H), 2.99 - 2.93 (m, 1H), 2.92 - 2.85 (m, 1H), 2.71 - 2.58 (m, 1H), 2.24 - 2.14 (m, 1H), 2.04 - 1.96 (m, 1H), 1.19 (dd, J = 21.4, 6.2 Hz, 3H). 13C NMR (126 MHz, CDCI3) 6 174.4, 160.6, 141.0, 140.7, 129.0, 128.1, 126.9, 125.9,
125.9, 123.4, 123.2, 122.9, 122.7, 115.9, 78.6, 78.4, 68.2, 68.2, 68.1, 52.1, 45.4,
44.9, 39.4, 38.9, 19.5. HRMS (ESI-ToF): m/z [M+H]+ calcd for C21H25F3NO4 : 411.1657; found : 412.1729.
[00096] Antiviral and immunomodulatory activity (IL- 10) of compound 6k was determined using the above methodology and was found to be
Figure imgf000039_0002
EXAMPLE 12
Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tyrosinate (61, 81%):
Figure imgf000039_0001
[00097] Step-1: Preparation of methyl L-tyrosinate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L-tyrosine (1.53 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 96% yield (1.60 g).
[00098] Step-2: Intermediate l-(3-chloro-l-phenylpropoxy)-4-
(trifluoromethyl)benzene was prepared according to procedure in example- 1 [00099] Step-3: Coupling of amino acid and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl L- tyrosinate (0.15 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mF, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tyrosinate (0.12 g, 81%). ’ H NMR (400 MHz, CDC13) 67.47 - 7.36 (m, 2H), 7.35 - 7.16 (m, 5H), 7.07 - 6.94 (m, 2H), 6.91 - 6.62 (m, 4H), 5.27 - 5.16 (m, 1H), 3.63 (d, J = 2.1 Hz, 3H), 3.47 - 3.41 (m, 1H), 2.91 - 2.73 (m, 3H), 2.67 - 2.44 (m, 1H), 2.18 - 2.07 (m, 1H), 1.97 - 1.86 (m, 1H). 13C NMR (101 MHz, CDCI3) 6 175.2, 160.6, 154.8, 141.0, 130.5, 128.9, 127.9, 126.8, 125.9, 123.2, 123.0, 122.7, 122.4, 115.9, 115.5, 78.6, 78.3, 63.3, 51.9, 44.6, 44.3, 38.9, 38.5. HRMS (ESI-ToF): m/z [M+H]+ calcd for C26H27F3NO4 : 473.1814; found : 474.1886. [000100] Antiviral and immunomodulatory activity (IL- 10) of compound 61 was determined using the above methodology and was found to be
Figure imgf000041_0002
EXAMPLE 13
Ethyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tryptophanate (6m, 82%):
Figure imgf000041_0001
[000101] Step-1: Preparation of ethyl L-tryptophanate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L- tryptophan (1.72 g, 5.61 mmol) in anhydrous ethanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from ethanol and dried under high vacuum and used for the next reaction without further purification in 96% yield (1.90 g).
[000102] Step-2 : Mitsunobu Reaction (Procedure for the synthesis of
Intermediate 5a): In a round bottom flask, diisopropyl azodicarboxylate (DIAD) (3.45 mL, 17.58 mmol) and triphenylphosphine (4.61 g, 17.58 mmol) were taken under nitrogen environment. Dry THF (25 ml) was added into the reaction pot and this mixture was allowed to stir at room temperature for 20 minutes. 4- (trifluoromethyl) phenol (1.90 g, 11.72 mmol) was dissolved in dry THF (5 ml) and added into the reaction pot and stirred for 4 hours. 3 -chloro- 1-phenylpropan-l-ol 3 (2.00 g, 11.72 mmol) was dissolved in dry THF (5 ml) and transferred into reaction pot and the reaction mixture was allowed to stir at room temperature for 16 hours under nitrogen atmosphere. Reaction progress was monitored on TLC plate. After completion of reaction, solvent was removed under reduced pressure. The crude mixture was purified by column chromatography technique, using hexane as a mobile phase and silica gel (60-120 mesh size) as stationary phase to afford the pure product l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene as colourless oil. (2.40 g, Yield = 65 %). 1 H NMR (500 MHz, CDC13) 6 7.37 (d, J = 4.4 Hz, 4H), 7.33 - 7.28 (m, 1H), 4.95 (dd, J = 8.5, 4.7 Hz, 1H), 3.78 - 3.70 (m, 1H), 3.60 - 3.54 (m, 1H), 2.29 - 2.20 (m, 1H), 2.14 - 2.05 (m, 1H). 13C NMR (101 MHz, CDCI3) 6 143.8, 128.8, 128.1, 125.9, 71.5, 41.9, 41.6.
[000103] Step-3: Coupling of amino acid and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, ethyl L- tryptophanate (0.18 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product ethyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tryptophanate (0.13 g, 82%).^ NMR (400 MHz, CDCI3) 6 7.63 (d, J = 17.6 Hz, 1H), 7.39 (d, J = 7.1 Hz, 1H), 7.31 (t, J = 9.3 Hz, 2H), 7.26 - 7.20 (m, 4H), 7.19 - 7.11 (m, 2H), 7.07 - 6.95 (m, 2H), 6.84 - 6.76 (m, 2H), 5.35 - 5.25 (m, 1H), 4.22 - 4.08 (m, 1H), 4.05 - 3.82 (m, 2H), 3.80 - 3.62 (m, 1H), 3.11 - 2.95 (m, 1H), 2.92 - 2.74 (m, 2H), 2.20 - 2.04 (m, 1H), 2.02 - 1.90 (m, 1H), 1.37 (d, J = 6.7 Hz, 1H), 1.19 (dd, J = 6.1, 2.9 Hz, 2H), 1.10 (t, J = 7.1 Hz, 1H), 1.01 (t, J = 7.1 Hz, 1H). 13C NMR (75 MHz, CDC13) 8 173.2, 160.7, 141.5, 136.6, 136.2, 128.9, 127.9, 127.2, 126.8, 125.9, 122.9, 122.7, 122.5, 121.6, 119.5, 118.1, 115.9, 110.8, 106.1, 78.1, 60.6, 59.5, 58.3, 57.2, 51.8, 46.6, 41.3, 38.4, 29.8, 23.6, 22.4, 21.3, 14.3. HRMS (ESI-ToF): m/z [M+H]+ calcd for C29H3oF3N2Na03 : 510.2130; found : 535.2198.
[000104] Antiviral and immunomodulatory activity (IL- 10) of compound 6m was determined using the above methodology and was found to be
Figure imgf000043_0002
EXAMPLE 14 Ethyl (3-phenyl-3-(4-(trifhioromethyl)phenoxy)propyl)-L-valinate (6n, 82%):
Figure imgf000043_0001
[000105] Step-1: Preparation of ethyl L-valinate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L- valine (0.99 g, 5.61 mmol) in anhydrous ethanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. Reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from ethanol and dried under high vacuum and used for the next reaction without further purification in 98% yield (1.20 g).
[000106] Step-2: Intermediate l-(3-chloro-l-phenylpropoxy)-4-
(trifluoromethyl)benzene was prepared according to procedure in example- 1.
[000107] Step-3: Coupling of amino acid and 5a: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-(trifluoromethyl)benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, ethyl L-valinate (0.10 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- (trifluoromethyl)benzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product ethyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-valinate (0.11 g, 82%). 1 H NMR (400 MHz, CDC13) 6 7.42 (d, J = 8.8 Hz, 2H), 7.36 - 7.30 (m, 4H), 7.29 - 7.23 (m, 1H), 6.90 (d, J = 8.3 Hz, 2H), 5.42 - 5.34 (m, 1H), 4.21 - 4.10 (m, 2H), 2.92 (dd, J = 11.5, 6.1 Hz, 1H), 2.85 - 2.77 (m, 1H), 2.62 - 2.45 (m, 1H), 2.23 - 2.11 (m, 1H), 2.00 - 1.84 (m, 1H), 1.28-1.21 (m, 4H), 0.97 (d, J = 6.8 Hz, 3H), 0.91 (dd, 7 = 8.4, 6.8 Hz, 3H). 13C NMR (75 MHz, CDCI3) 6 175.4, 160.9, 141.4, 128.9, 127.9, 126.8, 125.9, 123.0, 122.7, 122.6, 122.1, 115.9, 78.6, 67.7, 60.5, 45.0, 39.4, 31.8, 19.4, 18.8, 14.5. HRMS (ESI-ToF): m/z [M+H]+ calcd for C23H29F3NO3 : 423.2021; found : 424.2095.
[000108] Antiviral and immunomodulatory activity (IE- 10) of compound 6n was determined using the above methodology and was found to be
Figure imgf000044_0001
Figure imgf000045_0002
EXAMPLE 15
Methyl (3-(4-methoxyphenoxy)-3-phenylpropyl)-L-tryptophanate (6o, 78%):
Figure imgf000045_0001
[000109] Step-1: Preparation of methyl L-tryptophanate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L- tryptophan (1.72 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for the reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 95% yield (1.70 g).
[000110] Step-2: Mitsunobu Reaction (Procedure for the synthesis of Intermediate l-(3-chloro-l-phenylpropoxy)-4-methoxybenzene 5b): In a round bottom flask, diisopropyl azodicarboxylate (DIAD) (3.45 mL, 17.58 mmol) and triphenylphosphine (4.61 g, 17.58 mmol) were taken under nitrogen environment. Dry THF (25 ml) was added into the reaction pot and this mixture was allowed to stir at room temperature for 20 minutes. 4-methoxyphenol (1.46 g, 11.72 mmol) was dissolved in dry THF (5 ml) and added into the reaction pot and stirred for 4 hours. 3 -chloro- 1-phenylpropan-l-ol 3 (2.00 g, 11.72 mmol) was dissolved in dry THF (5 ml) and transferred into reaction pot and the reaction mixture was allowed to stir at room temperature for 16 hours under nitrogen atmosphere. Reaction progress was monitored on TLC plate. After completion of reaction, solvent was removed under reduced pressure. The crude mixture was purified by column chromatography technique, using hexane as a mobile phase and silica gel (60-120 mesh size) as stationary phase to afford the pure product l-(3-chloro-l- phenylpropoxy)-4-methoxybenzene as colourless oil. (2.30 g, Yield: 70 %). ’ H NMR (400 MHz, CDC13) 6 7.38 - 7.30 (m, 4H), 7.28 - 7.24 (m, 1H), 6.81 - 6.69 (m, 4H), 5.25 (dd, J = 8.7, 4.4 Hz, 1H), 3.85 - 3.77 (m, 1H), 3.70 (s, 3H), 3.64 - 3.57 (m, 1H), 2.49 - 2.39 (m, 1H), 2.23 - 2.13 (m, 1H). 13C NMR (126 MHz, CDCI3) 6 154.2, 152.2, 141.2, 128.8, 128.0, 126.2, 117.3, 114.6, 77.9, 55.8, 41.6, 41.5.
[000111] Step-3: Coupling of amino acid and 5b: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-methoxybenzene (0.09 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF, and stirred for 30 minutes at room temperature. In a separate flask, methyl L- tryptophanate (0.17 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- methoxybenzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate, and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product methyl (3-(4-methoxyphenoxy)-3-phenylpropyl)-L-tryptophanate (0.15 g, 78%). ’ H NMR (400 MHz, CDCI3) 6 8.12 (s, 1H), 7.55 (d, J = 7.8 Hz, 1H), 7.27 (d, J = 8.1 Hz, 1H), 7.16 - 6.96 (m, 8H), 6.64 - 6.57 (m, 2H), 6.55 - 6.49 (m, 2H), 4.89 (dd, J = 7.9, 4.9 Hz, 1H), 3.62 (s, 3H), 3.61 - 3.57 (m, 1H), 3.56 (s, 3H), 3.23 - 3.14 (m, 1H), 3.06 - 2.98 (m, 1H), 2.84 - 2.74 (m, 1H), 2.57 - 2.49 (m, 1H), 2.04 - 1.94 (m, 1H), 1.91 - 1.81 (m, 1H). 13C NMR (101 MHz, CDC13) 6 174.9, 153.8, 152.1, 141.7, 136.4, 128.5, 127.5, 126.1, 123.3, 122.2, 119.6, 118.8, 117.1, 114.5, 111.4, 79.0, 61.8, 55.7, 52.0, 44.5, 38.2, 29.2. HRMS (ESI-ToF): m/z [M+H]+ calcd for C28H31N2O4 : 458.2206; found : 459.2277. [000112] Antiviral and immunomodulatory activity (IL- 10) of compound 60 was determined using the above methodology and was found to be
Figure imgf000047_0002
EXAMPLE 16
Methyl (3-(4-methoxyphenoxy)-3-phenylpropyl)-L-valinate (6p, 85%)
Figure imgf000047_0001
[000113] Step-1: Preparation of methyl L-valinate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L- valine (0.99 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. The reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol, dried under high vacuum and proceeded to be used for the next reaction without further purification in 97% yield (0.96 g).
[000114] Step-2: Intermediate l-(3-chloro-l-phenylpropoxy)-4- methoxybenzene was prepared according to procedure in example- 15.
[000115] Step-3: Coupling of amino acid and 5b: In a double neck round bottom flask, l-(3-chloro-l-phenylpropoxy)-4-methoxybenzene (0.09 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl L-valinate (0.10 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of 1 -(3 -chloro- 1 -phenylpropoxy )-4- methoxybenzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product methyl (3-(4-methoxyphenoxy)-3-phenylpropyl)-L-valinate (0.10 g, 85%). !H NMR (500 MHz, CDC13) 6 7.28 - 7.22 (m, 4H), 7.18 - 7.14 (m, 1H), 6.72 - 6.68 (m, 2H), 6.66 - 6.62 (m, 2H), 5.15 - 5.09 (m, 1H), 3.63 (s, 3H), 3.62 (d, J = 1.6 Hz, 3H), 2.94 (d, J = 6.0 Hz, 1H), 2.79 - 2.72 (m, 1H), 2.62 - 2.46 (m, 1H), 2.14 - 2.05 (m, 1H), 1.94 - 1.83 (m, 2H), 0.90 - 0.83 (m, 6H). 13C NMR (101 MHz, CDCI3) 6 175.2, 154.0, 152.3, 142.0, 128.6, 127.6, 126.2, 117.1, 114.6, 79.6, 79.1, 67.4, 55.7, 51.6, 45.5, 45.0, 38.6, 31.5, 29.8, 19.3, 19.0. HRMS (ESI-ToF): m/z [M+H]+ calcd for C22H30NO4 : 371.2097; found : 372.2166.
[000116] Antiviral and immunomodulatory activity (IE- 10) of compound 6p was determined using the above methodology and was found to be
Figure imgf000048_0001
Figure imgf000049_0002
EXAMPLE 17
Methyl (3-(3,4-dichlorophenoxy)-3-phenylpropyl)-L-tryptophanate (6q, 71%)
Figure imgf000049_0001
[000117] Step-1; Preparation of methyl L-tryptophanate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L- tryptophan (1.72 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. The reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 95% yield (1.70 g).
[000118] Step-2 : Mitsunobu Reaction (Procedure for the synthesis of
Intermediate l,2-dichloro-4-(3-chloro-l-phenylpropoxy)benzene 5c): In a round bottom flask, diisopropyl azodicarboxylate (DIAD) (3.45 mL, 17.58 mmol) and triphenylphosphine (4.61 g, 17.58 mmol) were taken under nitrogen environment. Dry THF (25 ml) was added into the reaction pot and this mixture was allowed to stir at room temperature for 20 minutes. 3,4-dichlorophenol (1.91 g, 11.72 mmol) was dissolved in dry THF (5 ml) and added into the reaction pot and stirred for 4 hours. 3 -chloro- 1-phenylpropan-l-ol 3 (2.00 g, 11.72 mmol) was dissolved in dry THF (5 ml) and transferred into reaction pot and the reaction mixture was allowed to stir at room temperature for 16 hours under nitrogen atmosphere. Reaction progress was monitored on TLC plate. After completion of reaction, solvent was removed under reduced pressure. The crude mixture was purified by column chromatography technique, using hexane as a mobile phase and silica gel (60-120 mesh size) as stationary phase to afford the pure product l,2-dichloro-4-(3-chloro- 1 -phenylpropoxy )benzene as colourless oil. (2.50 g, Yield: 68 %) . ’ H NMR (400 MHz, CDC13) 6 7.37 (d, J = 8.5 Hz, 2H), 7.28 (d, J = 4.4 Hz, 4H), 7.25 - 7.19 (m, 1H), 6.84 (d, J = 8.5 Hz, 2H), 5.36 (dd, J = 8.5, 4.5 Hz, 1H), 3.76 - 3.67 (m, 1H), 3.56 - 3.49 (m, 1H), 2.46 - 2.36 (m, 1H), 2.21 - 2.11 (m, 1H). 13C NMR (101 MHz, CDCI3) 6 160.4, 140.1, 129.1, 128.3, 127.0, 126.9, 126.0, 123.8, 123.4, 123.1, 122.8, 122.6, 115.9, 41.4, 41.2.
[000119] Step-3: Coupling of amino acid and 5c: In a double neck round bottom flask, 1, 2-dichloro-4-(3 -chloro- 1 -phenylpropoxy )benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl L- tryptophanate (0.17 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of l,2-dichloro-4-(3-chloro-l- phenylpropoxy)benzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product methyl (3-(3,4-dichlorophenoxy)-3-phenylpropyl)-L-tryptophanate (0.11 g, 71%). ’ H NMR (400 MHz, CDCI3) 6 8.15 (s, 1H), 7.65 (d, J = 7.8 Hz, 1H), 7.38 (d, J = 8.0 Hz, 1H), 7.23 - 7.12 (m, 6H), 7.04 (s, 1H), 6.92 (s, 2H), 6.77 (d, J = 2.2 Hz, 1H), 6.53 - 6.47 (m, 1H), 4.91 (dd, J = 7.7, 5.1 Hz, 1H), 3.66 (s, 3H), 3.64 - 3.59 (m, 1H), 3.25 (dd, J = 14.3, 4.9 Hz, 1H), 3.03 (dd, J = 14.3, 8.1 Hz, 1H), 2.89 - 2.80 (m, 1H), 2.54 - 2.45 (m, 1H), 2.05 - 1.96 (m, 1H), 1.90 - 1.80 (m, 1H). 13C NMR (101 MHz, CDC13) 6 175.2, 157.2, 140.6, 136.4, 132.5, 130.5, 128.7, 127.8, 125.9, 123.2, 122.4, 119.8, 118.9, 117.9, 115.9, 111.5, 78.5, 61.6, 52.0, 44.0, 38.0,
29.5. HRMS (ESI-ToF): m/z [M+H]+ calcd for C27H27CI2N2O3 : 496.1320; found : 497.1393.
[000120] Antiviral and immunomodulatory activity (IL- 10) of compound 6q was determined using the above methodology and was found to be
Figure imgf000051_0002
EXAMPLE 18
Methyl (3-(3,4-dichlorophenoxy)-3-phenylpropyl)-L-valinate (6r, 83%)
Figure imgf000051_0001
[000121] Step-1; Preparation of methyl L-valinate: Thionyl chloride (0.41 mL, 8.42 mmol) was added slowly to a mixture containing L- valine (0.99 g, 5.61 mmol) in anhydrous methanol (20 ml) at 0 °C. After the removal of the ice bath, the mixture was stirred at room temperature for 16 h. The reaction mixture was concentrated under reduced pressure to remove excess thionyl chloride. The resultant white solid was combined twice with methanol, and this was again removed under reduced pressure to remove adhered thionyl chloride completely. The product was then recrystallized from methanol and dried under high vacuum and used for the next reaction without further purification in 97% yield (0.96 g).
[000122] Step-2: Intermediate 1 ,2-dichloro-4-(3 -chloro- 1 - phenylpropoxy )benzene was prepared according to procedure in example- 17 [000123] Step-3: Coupling of amino acid and 5c: In a double neck round bottom flask, 1, 2-dichloro-4-(3 -chloro- 1 -phenylpropoxy )benzene (0.10 g, 0.32 mmol.) and sodium iodide (0.09 g, 0.63 mmol.) were taken, dissolved in DMF and stirred for 30 minutes at room temperature. In a separate flask, methyl L-valinate (0.10 g, 0.79 mmol.) and diisopropylethylamine (DiPEA) (0.17 mL, 0.95 mmol.) were dissolved in DMF and stirred for 30 minutes at room temperature. This mixture was poured into the solution of l,2-dichloro-4-(3 -chloro- 1- phenylpropoxy)benzene and sodium iodide at room temperature. This reaction mixture was refluxed at 130 °C for 5 hours. Reaction progress was monitored on TLC plate. After completion of reaction, the reaction mixture was cooled down at room temperature, quenched with ice cold water and extracted with ethyl acetate (2x25 ml). Organic layers were combined, washed with brine solution, dried with anhydrous sodium sulphate and evaporated under reduced pressure to obtain crude product. The crude was purified by column chromatography to give final product methyl (3-(3,4-dichlorophenoxy)-3-phenylpropyl)-L-valinate (0.11 g, 83%) !H NMR (400 MHz, CDC13) 6 7.28 - 7.22 (m, 4H), 7.21 - 7.16 (m, 1H), 7.12 (d, J = 8.9 Hz, 1H), 6.89 (d, J = 2.9 Hz, 1H), 6.64 - 6.59 (m, 1H), 5.23 - 5.17 (m, 1H), 3.62 (d, J = 4.4 Hz, 3H), 2.90 (dd, J = 7.5, 6.1 Hz, 1H), 2.76 - 2.68 (m, 1H), 2.55 - 2.38 (m, 1H), 2.12 - 2.04 (m, 1H), 1.91 - 1.79 (m, 2H), 0.91 - 0.82 (m, 6H). 13C NMR (101 MHz, CDCI3) 6 175.5, 157.4, 140.8, 132.7, 130.6, 128.9, 128.0, 126.0, 124.1, 124.1, 118.3, 115.8, 79.1, 79.0, 67.6, 51.6, 45.1, 39.1, 31.7, 19.3, 18.9. HRMS (ESI-ToF): m/z [M+H]+ calcd for C21H26CI2NO3 : 409.1211; found : 410.1283.
[000124] Antiviral and immunomodulatory activity (IE- 10) of compound 6r was determined using the above methodology and was found to be
Figure imgf000053_0001
ADVANTAGES OF THE PRESENT INVENTION
[000125] The present disclosure provides a group of L-amino acid esters substituted 3-phenyl-3-(aryloxy) propan- 1 -amine compounds which possess excellent antiviral and immunomodulatory potential. [000126] The present disclosure provides a convenient process for preparation of the L-amino acid esters substituted 3-phenyl-3-(aryloxy) propan- 1 -amine compounds, with good yield of at least 70% and appreciable purity.
[000127] The compounds disclosed in the present disclosure showed an immunomodulatory activity (IL- 10) of up to 5270+452 Pg/mL at Ipg.

Claims

I/We Claim:
1. A compound of the structural formula I or a pharmaceutically acceptable salt thereof
Figure imgf000054_0001
wherein, n is 1, 2 or 3; each R1 is independently selected from the group consisting of substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy and halogen;
R2 is selected from the group consisting of H, substituted or unsubstituted linear or branched alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl or R2 together with amine nitrogen may form a substituted or unsubstituted 5-6 membered ring and
R3 is linear or branched alkyl.
2. The compound as claimed in claim 1, wherein R1 is C 1 to 6 alkyl, C 1 to 6 alkoxy, halo or trifluoromethyl.
3. The compound as claimed in claim 1, wherein R2 is H, C 1 to 4 linear or branched, substituted or unsubstituted alkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl, wherein the substituents are selected form the group consisting of alkyl, aryl, heteroaryl, hydroxy and thioalkyl.
4. The compound as claimed in claim 1, wherein R2 together with the amine nitrogen may form a substituted or unsubstituted 5 membered heterocyclic ring.
5. The compound as claimed in claim 1, wherein R3 is C 1 to 3 alkyl.
6. The compound as claimed in claim 1, wherein the compound is selected from the group consisting of: a. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tryptophanate, b. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-valinate, c. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-alaninate, d. Methyl (2S)-2-phenyl-2-((3-phenyl-3-(4-
(trifluoromethyl)phenoxy)propyl)amino)acetate, e. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-leucinate, f. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-isoleucinate, g. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)prolinate, h. Methyl (2S)-4-hydroxy-l-(3-phenyl-3-(4-
(trifluoromethyl)phenoxy)propyl)pyrrolidine-2-carboxylate, i. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L- phenylalaninate, j . Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-methioninate, k. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-threoninate, l. Methyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tyrosinate, m. Ethyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-tryptophanate, n. Ethyl (3-phenyl-3-(4-(trifluoromethyl)phenoxy)propyl)-L-valinate, o. Methyl (3-(4-methoxyphenoxy)-3-phenylpropyl)-L-tryptophanate, p. Methyl (3-(4-methoxyphenoxy)-3-phenylpropyl)-L-valinate, q. Methyl (3-(3,4-dichlorophenoxy)-3-phenylpropyl)-L-tryptophanate, and r. Methyl (3-(3,4-dichlorophenoxy)-3-phenylpropyl)-L-valinate.
7. A process for preparing the compound of the structural formula I,
Figure imgf000056_0001
wherein n is 1, 2 or 3; each R1 is independently selected from the group consisting of substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy and halogen;
R2 is selected from the group consisting of H, substituted or unsubstituted linear or branched alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl or R2 together with the amine nitrogen may form a substituted or unsubstituted 5-6 membered ring and
R3 is linear or branched alkyl, comprising the steps of: a. synthesizing an amino acid ester of formula 2 by reacting an amino acid of formula 1 with R3-OH in the presence of a solvent, o o
H,N. A Thionyl chloride II r3
T ^0H H2N^O,R
R2 R2
1 2 wherein R2 is selected from the group consisting of H, substituted or unsubstituted linear or branched alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl or R2 together with the amine nitrogen may form a substituted or unsubstituted 5-6 membered ring, and
R3 is linear or branched alkyl; b. reacting 3 -chloro- 1-phenylpropan-l-ol of formula 3 with a phenol of formula 4 to obtain a compound of formula 5,
Figure imgf000057_0001
wherein R1 is selected from the group consisting of substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy and halogen; and c. synthesizing 3-phenyl-3-(aryloxy) propan- 1 -amine derivatives of formula I (a-r) by reacting the compound of formula 5 obtained in step b with the amino acid ester of formula 2 obtained in step a,
Figure imgf000057_0002
wherein n, R1, R2 and R3 are as defined above.
8. The process as claimed in claim 7, wherein step a is carried out in the presence of thionyl chloride and an anhydrous alcohol as solvent and step b is carried out in the presence of diisopropyl azodicarboxylate (DIAD), triphenylphosphine and dry tetrahydrofuran (THF) under nitrogen environment.
9. The process as claimed in claim 7, wherein step c is carried out in the presence of sodium iodide, diisopropylethylamine (DiPEA) and dimethylformamide (DMF).
10. The compound as claimed in claim 1, wherein the compound has antiinflammatory and anti-viral activity.
PCT/IN2023/050970 2022-10-21 2023-10-20 3-phenyl-3-(aryloxy) propan-1-amines and the process for preparation thereof WO2024084517A1 (en)

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US20120016124A1 (en) * 2007-09-21 2012-01-19 Baylor University Serotonin reuptake inhibitors
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Title
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