WO2018069857A1

WO2018069857A1 - C-3 novel triterpenone with c-17 reverse amide heterocycle derivatives as hiv inhibitors

Info

Publication number: WO2018069857A1
Application number: PCT/IB2017/056307
Authority: WO
Inventors: Parthasaradhi Reddy BANDI; Rathnakar Reddy KURA; David Krupadanam GAZULA LEVI; Bhaskar Reddy KASIREDDY
Original assignee: Hetero Labs Ltd
Current assignee: Hetero Labs Ltd
Priority date: 2016-10-12
Filing date: 2017-10-12
Publication date: 2018-04-19
Anticipated expiration: 2019-04-12

Abstract

The present invention relates to C-3 novel triterpenone with C-17 reverse amide heterocycle compounds of formula (I); and pharmaceutically acceptable salts thereof, wherein R₁, R₂, R₃, R₄, R₅, and n are as defined in formula (I). The invention also relates to C-3 novel triterpenone with C-17 reverse amide heterocycle derivatives, related compounds, and pharmaceutical compositions useful for the therapeutic treatment of viral diseases and particularly HIV mediated diseases.

Description

C-3 NOVEL TRITERPENONE WITH C-17 REVERSE AMIDE HETEROCYCLE

DERIVATIVES AS HIV INHIBITORS

This application claims the benefit of Indian provisional application no 201641034825 filed on 12^th October 2016 which is hereby incorporated by reference in its entirety.

Field of the Invention

The present invention relates to C-3 novel triterpenone with C-17 reverse amide heterocycle derivatives and related compounds, compositions useful for therapeutic treatment of viral diseases and particularly HIV mediated diseases.

Background of the Invention

The Human Immunodeficiency Virus (HIV) has now been established as the causative agent of the Acquired Immunodeficiency Syndrome (AIDS) for over 20 years (Science 1983, 220,868-871; N.Eng.J.Med.1984, 311, 1292-1297). AIDS is characterized by the destruction of the immune system, particularly of CD4+T-cells. HIV is a retrovirus, and the HIV life cycle encompasses several crucial steps, starting from the attachment of the virus to the host cell membrane and finishing with the release of progeny virons from the cell.

The natural compound betulinic acid, isolated from Syzygium clavifolium and several other plant species was found to possess anti-HIV activity. Chemical modifications were undertaken by several research groups in an attempt to identify potent anti-HIV agents by making semi-synthetic analogs of betulinic acid, leading to the discovery of bevirimat as a compound with a novel mechanism of action (J. Nat. Prod. 199457(2):243-7; J. Med. Chem. 1996,39(5), 1016). Further studies shown that bevirimat acts by disrupting Gag processing (Proc. Natl. Acad. Sci. USA 2003, 100(23): 13555-60; Antimicrob. Agents. Chemother. 2001,45(4),1225-30; J. Virol. 2004,78(2): 922-9; J. Biol. Chem. 2005,280(51):42149-55; J. Virol. 2006,80(12): 5716-22) and to be a first-in-class maturation inhibitor with a potent activity against HIV-1. Bevirimat went up to phase 2 clinical trials, in clinic despite optimal plasma concentrations, not all patients given bevirimat have a robust viral load reduction. It was reported that non-respondant patients had more frequent base line Gag polymorphisms near the capsid SP-1 cleavage site than responders. (HIV gag polymorphism determines treatment response to bevirimat. XVII international HIV drug resistance work shop June 10- 14, 2008, Sitges, Spain).

Encouraged by these developments, medicinal chemists started exploring betulinic acid derivatives and related compounds intensively for their therapeutic activities. For example, WO 2014/093941 describes pharmaceutical compositions of betulin derivatives; WO 2009/082819 describes preparation of 17-amino lupane derivatives as anti-HIV agents; WO 2013/117137 describes lupane triterpenoids derivatives and pharmaceutical use thereof; WO 2013/020245 describes carbonyl derivatives of betulin; WO 2009/082818 describes preparation of C21-keto lupane derivatives for the treatment of HIV infections; WO 2011/100308 describes preparation of betulin derivatives for treatment of HIV-1; WO 2013/090664 describes preparation of betulin derivatives for the treatment of HIV; WO 2013/091144 describes preparation of propenoate derivatives of betulin useful for the treatment of HIV; WO 2013/090683 describes preparation of betulin propenoate derivatives for the treatment of HIV.

Some additional references disclose betulinic acid related compounds. For example,

WO 2007/141383 describes betulin derivatives as antifeedants for plant pests; US 6670345 describes use of betulinic acid and its derivatives for inhibiting cancer growth and process for the manufacture of betulinic acid; WO 2002/091858 describes anxiolytic marcgraviaceae compositions containing betulinic acid, betulinic acid derivatives, and methods of preparation and use; WO 2000/046235 describes preparation of novel betulinic acid derivatives for use as cancer growth inhibitors; WO 2007/141392 describes cosmetic and pharmaceutical compositions comprising betulonic acid and betulin derivatives; and Pharmaceutical Chemistry Journal, 2002, 36(9), 29-32 describes synthesis and anti-inflammatory activity of new acylated betulin derivatives.

Given the fact of the world wide epidemic level of AIDS, there is a strong continued need for new effective drugs for treatment of HIV infected patients, disease conditions and/or disorders mediated by HIV by discovering new compounds with novel structures and/or mechanism of action(s).

SUMMARY OF THE INVENTION

In one aspect, the present invention relates to the compounds of the formula (I):

wherein,

C₆ alkyl, or optionally substituted C₃-C₈ cycloalkyl);

R₂ is hydrogen, optionally substituted Ci-C₆ alkyl, optionally substituted C₂-C₆ alkoxylalkoxy, or optionally substituted Ci-C₆ amino alkyl;

R₃ and R₄ are independently selected from optionally substituted Ci-C₆ alkyl, optionally substituted amine, optionally substituted C₃-C₈ cycloalkyl, optionally substituted heterocyclyl, or optionally substituted heteroaryl; or R₃ and R4 are taken together with the carbon atom to which they are attached to form optionally substituted C₃-C₈ cycloalkyl, epoxide, oxetane or azetidine;

4-7 membered heterocyclyl or 5-7 membered heteroaryl;

R5 is independently selected from hydrogen, alkyl, optionally substituted aminoalkyl, alkylaminoalkyl, optionally substituted C₆-Ci₂ aryl, optionally substituted C₆-Ci₂ aralkyl, or optionally substituted 5-15 membered heteroaryl; wherein the optional substituents are one or more R₆;

R₆ is independently selected from alkyl, alkoxy, halo, amino, cyano, nitro, or -O- (CH₂)_m-heterocyclyl;

'm' is an integer 0,lor 2; and

'n' is an integer 1, 2, 3, or 4; or

pharmaceutically acceptable salts, tautomers, stereoisomers, prodrugs, or combination thereof.

In another aspect, the present invention relates to pharmaceutical composition comprising C-3 novel triterpenone with C-17 reverse amide heterocycle derivatives and related compounds of formula (I) and processes for preparing thereof.

In yet another aspect, the present invention relates C-3 novel triterpenone with C-17 reverse amide heterocycle derivatives and related compounds, compositions useful for therapeutic treatment of viral diseases and particularly HIV mediated diseases. DETAILED DESCRIPTION OF THE INVENTION

In one embodiment, the present invention relates to C-3 novel triterpenone with C-17 reverse amide heterocycle derivatives and related compounds, compositions useful for therapeutic treatment of viral diseases and particularly HIV mediated diseases.

Each embodiment is provided by way of explanation of the invention, and not by way of limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made to the compounds, compositions, and methods described herein without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be applied to another embodiment to yield a still further embodiment. Thus it is intended that the present invention include such modifications and variations and their equivalents. Other objects, features, and aspects of the present invention are disclosed in, or are obvious from, the following detailed description. It is to be understood by one of ordinary skilled in the art that the present discussion is a description of exemplary embodiments only, and is not to be construed as limiting the broader aspects of the present invention.

In one embodiment, the present invention relates to compounds of formula (I):

wherein, optionally substituted Ci-C₆ alkyl,

^c j . Ρ^ -f* ^■¾¾

^ΗΟΟΟγ f

\Υ f

^ ₅ Hooc^^ , or Hooc _y J ¥

(wherein R_a is hydrogen, optionally substituted Q-

C₆ alkyl, or optionally substituted C3-C8 cycloalkyl);

R₂ is hydrogen, optionally substituted Ci-C₆ alkyl, optionally substituted C₂-C₆ alkoxylalkoxy or optionally substituted Ci-C₆ amino alkyl; R₃ and R₄ are independently selected from optionally substituted Ci-C₆ alkyl, optionally substituted amine, optionally substituted C₃-C₈ cycloalkyl, optionally substituted heterocyclyl or optionally substituted heteroaryl; or R₃ and R₄ are taken together with the carbon atom to which they are attached to form optionally substituted C₃-C₈ cycloalkyl, epoxide, oxetane or azetidine;

/

C Hy I

is 4-7 membered heterocyclyl or 5-7 membered heteroaryl;

R5 is independently selected from hydrogen, alkyl, optionally substituted aminoalkyl, alkylaminoalkyl, optionally substituted C₆-Ci₂ aryl, optionally substituted C₆-Ci₂ aralkyl or optionally substituted 5-15 membered heteroaryl; wherein the optional substituents are one or more R₆;

'm' is an integer 0,1 or 2; and

'n' is an integer 1, 2, 3, or 4; or

In another embodiment, the present invention relates to compounds of formula (IA):

wherein,

C₆ alkyl, or optionally substituted C₃-C₈ cycloalkyl); /

C Hy :

is 4-7 membered heterocyclyl or 5-7 membered heteroaryl;

'm' is an integer 0,1 or 2; and

'n' is an integer 1, 2, 3, or 4; or

It should be understood that the formula (I) and (IA) structurally encompasses all stereoisomers, including enantiomers, diastereomers, racemates, and combinations thereof, which may be contemplated from the chemical structure of the genus described herein.

It should be understood that the formula (I) and (IA) structurally encompasses all tautomers.

Also contemplated that the prodrugs of the compounds of the formula (I) includes esters of the compounds.

The embodiments below are illustrative of the present invention and are not intended to limit the claims to the specific embodiments exemplified.

o one embodiment, there is provided a compound of formula (I), wherein

According to another embodiment, there is provided a compound of formula (I), wherein R₂ is hydrogen.

According to yet another embodiment there is provided a compound of formula (I), wherein R₃ and R₄ are methyl.

According to yet another embodiment there is provided a compound of formula (I), wherein

is 5-7 membered heteroaryl.

According to yet another embodiment there is provided a compound of formula (I), wherein the above said 5-7 membered heteroaryl is imidazole. According to yet another embodiment there is provided a compound of formula (I), wherein the above said 5-7 membered heteroaryl is 1,3,4-oxadiazole.

According to yet another embodiment there is provided a compound of formula (I), wherein R5 is optionally substituted C₆-Ci2 aryl; wherein the optional substituent is one or more R₆.

According to yet another embodiment there is provided a compound of formula (I), wherein the above said C₆-Ci2 aryl is phenyl.

According to yet another embodiment there is provided a compound of formula (I), wherein the above said R₆ is halo (chloro).

In certain embodiments, the compounds of formula (I) can also contain unnatural proportions of atomic isotopes at one or more of the atoms that constitute such compounds. For example, the present invention also embraces isotopically-labeled variants of the present invention which are identical to those recited herein, but for the fact that one or more atoms of the compound are replaced by an atom having the atomic mass or mass number different from the predominant atomic mass or mass number usually found in nature for the atom. All isotopes of any particular atom or element as specified are contemplated within the scope of the compounds of the invention, and their uses. The present invention is meant to include all suitable isotopic variations of the compounds of generic formula (I). For example, different isotopic forms of hydrogen (H) include protium ( 1H) and deuterium ( 2 H). Protium is the predominant hydrogen isotope found in nature. Enriching for deuterium may provide certain therapeutic advantages, such as increasing in vivo half -life or reducing dosage requirements, or may provide a compound useful as a standard for characterization of biological samples.

Isotopically-enriched compounds of formula (I) can be prepared without undue experimentation by conventional techniques well known to those skilled in the art or by processes analogous to those described in the Schemes and Examples herein using appropriate isotopically-enriched reagents and/or intermediates. In one embodiment, a compound of formula (I) has one or more of its hydrogen atoms replaced with deuterium.

The representative compounds according to the present invention including the compounds disclosed in the experimental section are illustrative in nature only and are not intended to limit to the scope of the invention. (Nomenclature wherever applicable has been generated from ChemBioDraw Ultra 13.0 version).

(lR,3S)-3-((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a-(2-(5-(4-chlorophenyl)-

1,3,4 -oxadiazol-2-yl)-2-methylpropanamido)-l-isopropyl-5a,5b,8,8,l la-pentamethyl-2-oxo- 3,3a, 4,5,5a,5b,6,7,7a,8,9,10,l 1,1 la,l lb, 12,13, 13a-octadecahydro-2H-cyclopenta[a]chrysen- 9-yl) oxy)carbonyl)-2,2-dimethylcyclobutane-l-carboxylic acid (Example 1),

sodium (lR,3S)-3-((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a-(2-(5-(4-chloro phenyl)- lH-imidazol-2-yl)-2-methylpropanamido)- l-isopropyl-5a,5b, 8, 8,11 a-pentamethyl-2- oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,l 1,1 la,l lb, 12,13, 13a-octadecahydro-2H-cyclopenta[a] chrysen-9-yl)oxy)carbonyl)-2,2-dimethylcyclobutane- 1-carboxylate (Example 2),

or pharmaceutically acceptable salts, solvates, stereoisomers, tautomers, including hydrates and prodrugs of compounds are also contemplated.

In further yet another embodiment, the compounds of formula (I) structurally encompasses all stereoisomers, enantiomers and diastereomers, and pharmaceutically acceptable salts that may be contemplated from the chemical structure of the general formula (I) described herein.

The absolute configuration at an asymmetric atom is specified by either R or S. Resolved compounds whose absolute configuration is not known can be designated by (+) or (-) depending on the direction in which they rotate plane polarized light. When a specific stereoisomer is identified, this means that said stereoisomer is substantially free, i.e. associated with less than 50%, preferably less than 20%, more preferably less than 5%, in particularly less than 2% or 1 % of the other isomers. Thus when a compound of formula (I) is for instance specified as (R), this means that the compound is substantially free of (S) isomer; when the compound of formula (I) is for instance specified as E, this means that the compound is free of the Z isomer; when the compound of formula (I) is for instance specified as cis isomer, this means that the compound is free of the trans isomer.

In further yet another embodiment, the prodrugs of present invention are the compounds of formula (I) and its pharmaceutically acceptable salts, stereoisomers, solvates thereof containing an hydroxyl group; wherein hydrogen atom of the hydroxyl group are replaced with (Ci-C₆)alkanoyloxymethyl, l-((Ci-C₆)alkanoyloxy)ethyl, 1 -methyl- l-((Ci- C₆)alkanoyloxy)ethyl, (Ci-C₆)alkoxycarbonyloxymethyl, N-(Ci-C₆)alkoxycarbonyl aminomethyl, succinoyl, (Ci-C₆)alkanoyl, a-amino(Ci-C₄)alkyl, a-amino(Ci-C₄)alkylene- aryl, arylacyl and a-aminoacyl, where each a -aminoacyl group is independently selected from the naturally occurring L-amino acids, or glycosyl (the radical resulting from the removal of a hydroxyl group of the hemiacetal form of a carbohydrate).

In further yet another embodiment, the prodrugs of present invention are the compounds of formula (I) and its pharmaceutically acceptable salts, stereoisomers, hydrates, solvates thereof containing an amine group; wherein one or more hydrogen atoms of the amine group is replaced with (Ci-C₆)alkylcarbonyl, (Ci-C₆)alkoxycarbonyl, aminocarbonyl, (C3-C₆)cycloalkylcarbonyl, benzylcarbonyl and the like.

The present invention also provides a pharmaceutical composition that includes at least one compound according to formula (I) and at least one pharmaceutically acceptable excipient (such as a pharmaceutically acceptable carrier or diluent). Specifically, the pharmaceutical composition comprises a therapeutically effective amount of at least one compound according to formula (I). The compound(s) present in the composition may be associated with a pharmaceutically acceptable excipient (such as a carrier or a diluent) or may be diluted by a carrier, or enclosed within a carrier which may be in the form of a capsule, sachet, or other container.

The compounds and pharmaceutical compositions described herein are useful in the treatment of diseases, conditions and/or disorders mediated by viral infections.

The present invention further provides a method of treating a disease, condition and/or disorder mediated by viral infections in a subject in need thereof by administering to the subject one or more compounds described herein in a therapeutically effective amount to treat that infection, specifically in the form of a pharmaceutical composition.

In another aspect, the present invention relates to combinations comprising a compound of the formula (I) and a second therapeutic agent that is an anti-HIV agent, an anti-HCV agent or anti-TB agents.

In another aspect, the present invention relates to pharmaceutical compositions comprising the compound of formula (I) and one or more second anti-HIV agents and their pharmaceutically acceptable salts and stereoisomers thereof.

In another aspect, the present invention relates to combinations comprising a compound of the formula (I) and one or more second anti-HIV agents selected from the group consisting of Protease inhibitors, Integrase inhibitors, Nucleoside Reverse Transcriptase inhibitors, Non-Nucleoside Reverse Transcriptase Inhibitors, Fusion/Entry inhibitors, Pharmacokinetic enhancers, and combinations thereof.

The present invention relates to methods of treatment of HIV infection, AIDS, and AIDS-related conditions by administering to a subject a compound of formula (I) and one or more second therapeutic agents selected from the group consisting of Protease inhibitors, Integrase inhibitors, Nucleoside Reverse Transcriptase inhibitors, Non-Nucleoside Reverse Transcriptase Inhibitors, Fusion/Entry inhibitors, Pharmacokinetic enhancers, and combinations thereof. In another aspect, the present invention relates to combinations comprising a compound of the formula (I) and one or more second anti-HIV agents wherein the second anti-HIV agent is Abacavir, Didanosine, Emtricitabine, Lamivudine, Stavudine, Tenofovir disoproxil Fumarate, Tenofovir Alafenamide Fumarate, Zidovudine, Efavirenz, Elsufavirine, Etravirine, Nevirapine, Rilpivirine, Atazanavir, Darunavir, Fosamprenavir, Indinavir, Nelfinavir, Ritonavir, Cobicistat, Saquinavir, Tipranavir, Enfuvirtide, Maraviroc, Fostemsavir, Dolutegravir, Elvitegravir, Raltegravir, Bictegravir, Cabotegravir or a combination thereof.

In another aspect of the present invention provides a method for preventing; ameliorating or treating a HIV mediated disease, disorder or syndrome in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a compound of the invention. The invention further provides a method, wherein the HIV mediated disease, disorder or syndrome is like AIDS, AIDS related complex, or a syndrome characterized by symptoms such as persistent generalized lymphadenopathy, fever and weight loss, or a retroviral infection genetically related to AIDS.

Anti HIV inhibitory potential of the compounds of present invention may be demonstrated by any one or more methodologies known in the art, such as by using the assays described in Mossman T, December 1983, Journal of immunological methods, 65 (1- 2), 55-63 and SPC Cole, cancer chemotherapy and Pharmacology, 1986, 17, 259-263.

The following definitions apply to the terms as used herein:

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of the skilled in the art to which the subject matter belongs herein. As used in the present invention, unless specified to the contrary, the following terms have the meaning indicated in order to facilitate the understanding of the present invention.

The terms "halogen" or "halo" includes fluorine, chlorine, bromine, or iodine.

The term "cyano" refers to -CN.

The term "nitro" refers to -N0₂.

The term "alkyl" refers to a straight or branched hydrocarbon chain radical consisting solely of carbon and hydrogen atoms, containing no unsaturation, having from one to eight carbon atoms, and which is attached to the rest of the molecule by a single bond, e.g., methyl, ethyl, n-propyl, 1-methylethyl (isopropyl), n-butyl, n-pentyl, and 1,1-dimethylethyl (t-butyl).

The term "alkoxy" refers to a straight or branched hydrocarbon chain with oxygen radical consisting carbon and hydrogen atoms, containing saturation or unsaturation, having from one to eight carbon atoms, and which is attached through oxygen atom to the rest of the molecule by a single bond, e.g., methyloxy, ethyloxy, n-propyloxy, 1-methylethyloxy (isopropyloxy), n-butyloxy, n-pentyloxy, and 1,1-dimethylethyloxy (t-butyloxy).

The term "alkoxylalkoxy" refers to a straight or branched hydrocarbon chain with oxygen radical consisting carbon atom, hydrogen atom and alkoxy groups, containing saturation or unsaturation, having from one to eight carbon atoms, and which is attached through oxygen atom to the rest of the molecule by a single bond, e.g., 2- (methyloxy)ethyloxy, 2-(ethyloxy)ethyloxy, 2-(n-propyloxy)ethyloxy, and 3- (isopropyloxy)butyloxy.

The term "amine" refers to an organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group these may respectively be called alkylamines and arylamines; amines in which both types of substituent are attached to one nitrogen atom may be called alkylarylamines. Important amines include amino acids, trimethylamine, and aniline.

The term "aminoalkyl" refers to any amino derivative of an alkyl radical more specifically dimethylamino.

The term "alkylaminoalkyl" refers aminoalkyl radicals having the nitrogen atom substituted with an alkyl radical.

The term "cycloalkyl" denotes a non-aromatic mono or multicyclic ring system of from 3 to about 12 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. Examples of multicyclic cycloalkyl groups include, but are not limited to, perhydronapththyl, adamantyl and norbornyl groups, bridged cyclic groups and spirobicyclic groups, e.g., spiro (4,4) non-2-yl.

The term "aryl" refers to an aromatic radical having from 6 to 14 carbon atoms such as phenyl, naphthyl, tetrahydronapthyl, indanyl, and biphenyl.

The term "aralkyl" refers to an aryl group as defined above directly bonded to an alkyl group as defined above, e.g., -CH₂C₆H₅ and -C₂H₅C₆H₅.

The terms "heterocyclyl" and "heterocyclic ring" refer to a stable 3- to 15-membered ring radical which consists of carbon atoms and from one to five heteroatoms selected from nitrogen, phosphorus, oxygen and sulfur. For purposes of this invention, the heterocyclic ring radical may be a monocyclic, bicyclic or tricyclic ring system, which may include fused, bridged or spiro ring systems, and the nitrogen, phosphorus, carbon, oxygen or sulfur atoms in the heterocyclic ring radical may be optionally oxidized to various oxidation states. In addition, the nitrogen atom may be optionally quaternized; and the ring radical may be partially or fully saturated (i.e., heterocyclic or heteroaryl). Examples of such heterocyclic ring radicals include, but are not limited to, tetrazoyl, tetrahydroisouinolyl, piperidinyl, piperazinyl, 2-oxopiperazinyl, 2-oxopiperidinyl, 2-oxopyrrolidinyl, 2-oxoazepinyl, azepinyl, pyrrolyl, 4-piperidonyl, pyrrolidinyl, pyrazinyl, pyrimidinyl, pyridazinyl, oxazolyl, oxazolinyl, oxazolidinyl, triazolyl, isoxazolyl, isoxasolidinyl, morpholinyl, thiazolyl, thiazolinyl, thiazolidinyl, isothiazolyl, quinuclidinyl, isothiazolidinyl, indolyl, isoindolyl, indolinyl, isoindolinyl, octahydroindolyl, octahydroisoindolyl, quinolyl, isoquinolyl, decahydroisoquinolyl, benzimidazolyl, thiadiazolyl, benzothiazolyl, benzooxazolyl, furyl, tetrahydrofurtyl, tetrahydropyranyl, thienyl, benzothienyl, thiamorpholinyl, thiamorpholinyl sulfoxide, thiamorpholinyl sulfone, dioxaphospholanyl, oxadiazolyl and l,4-Thiazine-l,l- dione. The heterocyclic ring radical may be attached to the main structure at any heteroatom or carbon atom that results in the creation of a stable structure.

The term "heteroaryl" refers to an aromatic heterocyclic ring radical. Examples of such heteroaryl include, but are not limited to pyridyl, pyrazinyl, furanyl, quinolinyl, tetrazoyl, triazolyl, 1,3-diaza-lH-indenyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, pyrazolo[l,5-a]pyrimidinyl, 1,3,4-oxadiazolyl, thiazolidinyl, isothiazolyl, quinuclidinyl, isothiazolidinyl, indolyl, isoindolyl, indolinyl and isoindolinyl. The heteroaryl ring radical may be attached to the main structure at any heteroatom or carbon atom that results in the creation of a stable structure.

The term "optionally substituted" refers to replacement of one or more hydrogen radicals in a given structure with a radical of a specified substituent including, but are not limited to: hydroxy, halo, carboxyl, cyano (CN), nitro, oxo (=0), thio (=S), alkyl, methyl sulfonyl, haloalkyl, alkoxy, alkenyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, amino, heterocyclyl, heteroaryl, heterocyclylalkyl, heteroarylalkyl, alkylthio, arylthio, aryloxy, amino carbonyl, alkoxycarbonyl, alkylamino, arylamino, acyl, carboxylic acid, sulfonic acid, sulfonyl, phosphonic acid, and aliphatic. It is understood that the substituent may be further substituted.

The term "stereoisomer" or "stereoisomers" refer to compounds that differ in the chirality of one or more stereo centers. Stereoisomers include enantiomers and diastereomers.

The term "tautomer" refer to alternate forms of a compound that differ in the position of a proton, such as but are not limited to, enol-keto, imine-enamine tautomers, or the like or the tautomeric forms of heteroaryl groups containing a ring atom attached to both a ring - NH- moiety and a ring =N- moiety or the like such as but are not limited to, pyrazoles, imidazoles, benzimidazoles, triazoles, and tetrazoles.

The term "regioisomer" or "positional isomer" refer to that have the same carbon skeleton and the same functional groups but differ from each other in the location of the functional groups on or in the carbon chain.

The term "prodrug" denotes a derivative of a compound, which derivative, when administered to warm -blooded animals, e.g. humans, is converted into the compound (drug). The enzymatic and/or chemical hydrolytic cleavage of the compounds of the present invention occurs in such a manner that the proven drug form (parent carboxylic acid drug) is released, and the moiety or moieties split off remain nontoxic or are metabolized so that nontoxic metabolic products are produced. For example, a carboxylic acid group can be esterified, e.g., with a methyl group or ethyl group to yield an ester. When an ester is administered to a subject, the ester is cleaved, enzymatically or non-enzymatically, reductively, oxidatively, or hydrolytically, to reveal the anionic group. An anionic group can be esterified with moieties (e.g., acyloxymethyl esters) which are cleaved to reveal an intermediate compound which subsequently decomposes to yield the active compound. A discussion of the use of prodrugs is provided by T. Higuchi and W. Stella, "Pro-drugs as Novel Delivery Systems," Vol. 14 of the A.C.S. Symposium Series, and in Bioreversible Carriers in Drug Design, ed. Edward B. Roche, American Pharmaceutical Association and Pergamon Press, 1987.

The term "treating" or "treatment" of a state, disease, disorder or condition includes:

(1) preventing or delaying the appearance of clinical symptoms of the state, disease, disorder or condition developing in a subject that may be afflicted with or predisposed to the state, disease, disorder or condition but does not yet experience or display clinical or subclinical symptoms of the state, disease, disorder or condition;

(2) inhibiting the state, disease, disorder or condition, i.e., arresting or reducing the development of the state, disease, disorder or condition or at least one clinical or subclinical symptom thereof; or

(3) relieving the state, disease, disorder or condition, i.e., causing regression of the state, disease, disorder or condition or at least one of its clinical or subclinical symptoms.

The benefit to a subject receiving treatment is either statistically significant or at least perceptible to the subject or to the physician. The term "subject" includes mammals (especially humans) and other animals, such as domestic animals (e.g., household pets including cats and dogs) and non-domestic animals (such as wildlife).

A "therapeutically effective amount" means the amount of a compound that, when administered to a subject for treating a state, disease, disorder or condition, is sufficient to effect such treatment. The "therapeutically effective amount" will vary depending on the compound, the state, disease, disorder or condition and its severity and the age, weight, physical condition and responsiveness of the subject receiving treatment.

The compounds of the present invention may form salts. Non-limiting examples of pharmaceutically acceptable salts forming part of this invention include salts derived from inorganic bases, salts of organic bases, salts of chiral bases, salts of natural amino acids and salts of non-natural amino acids. Certain compounds of the present invention are capable of existing in stereoisomeric forms (e.g., diastereomers, enantiomers, racemates, and combinations thereof). With respect to the overall compounds described by the Formula (I), the present invention extends to these stereoisomeric forms and to mixtures thereof. To the extent prior art teaches synthesis or separation of particular stereoisomers, the different stereoisomeric forms of the present invention may be separated from one another by the methods known in the art, or a given isomer may be obtained by stereo specific or asymmetric synthesis. Tautomeric forms and mixtures of compounds described herein are also contemplated.

Pharmaceutically acceptable solvates includes hydrates and other solvents of crystallization (such as alcohols). The compounds of the present invention may form solvates with low molecular weight solvents by methods known in the art.

PHARMACEUTICAL COMPOSITIONS

The pharmaceutical compositions provided in the present invention include at least one compound described herein and at least one pharmaceutically acceptable excipient (such as a pharmaceutically acceptable carrier or diluent). Specifically, the contemplated pharmaceutical compositions include a compound(s) described herein in an amount sufficient to treat viral infection in a subject.

The subjects contemplated include, for example, a living cell and a mammal, including human. The compound of the present invention may be associated with a pharmaceutically acceptable excipient (such as a carrier or a diluent) or be diluted by a carrier, or enclosed within a carrier which can be in the form of a capsule, sachet, or other container. Examples of suitable carriers include, but are not limited to, water, salt solutions, alcohols, polyethylene glycols, peanut oil, olive oil, gelatin, lactose, terra alba, sucrose, dextrin, magnesium carbonate, sugar, amylose, magnesium stearate, talc, gelatin, agar, pectin, acacia, stearic acid, lower alkyl ethers of cellulose, silicic acid, fatty acids, fatty acid amines, fatty acid monoglycerides and diglycerides, fatty acid esters, and polyoxyethylene.

The carrier or diluent may include a sustained release material, such as, for example, glyceryl monostearate or glyceryl distearate, alone or mixed with a wax.

The pharmaceutical composition may also include one or more pharmaceutically acceptable auxiliary agents, wetting agents, emulsifying agents, suspending agents, preserving agents, salts for influencing osmotic pressure, buffers, sweetening agents, flavoring agents, colorants, or any combination of the foregoing. The pharmaceutical composition of the invention may be formulated so as to provide quick-, sustained-, or delayed-release of the active ingredient after administration to the subject by employing procedures known in the art.

The pharmaceutical compositions described herein may be prepared, e.g., as described in Remington: The Science and Practice of Pharmacy, 20^th Ed., 2003 (Lippincott Williams & Wilkins). For example, the active compound can be mixed with a carrier, or diluted by a carrier, or enclosed within a carrier, which may be in the form of an ampule, capsule, or sachet. When the carrier serves as a diluent, it may be a solid, semi- solid, or liquid material that acts as a vehicle, excipient, or medium for the active compound.

The pharmaceutical compositions may be in conventional forms, for example, capsules, tablets, solutions, suspensions, injectables or products for topical application. Further, the pharmaceutical composition of the present invention may be formulated so as to provide desired release profile.

The route of administration may be any route which effectively transports the active compound to the appropriate or desired site of action. Suitable routes of administration include, but are not limited to, oral, nasal, pulmonary, buccal, subdermal, intradermal, transdermal, parenteral, rectal, depot, subcutaneous, intravenous, intraurethral, intramuscular, intranasal, ophthalmic (such as with an ophthalmic solution) or topical (such as with a topical ointment). The oral route is specifically suitable.

Solid oral formulations include, but are not limited to, tablets, capsules (soft or hard gelatin), dragees (containing the active ingredient in powder or pellet form), troches and lozenges. Tablets, dragees, or capsules having talc and/or a carbohydrate carrier or binder or the like are particularly suitable for oral application. Exemplary carriers for tablets, dragees, or capsules include lactose, cornstarch, and/or potato starch. A syrup or elixir can be used in cases where a sweetened vehicle can be employed.

A typical tablet that may be prepared by conventional tableting techniques.

Liquid formulations include, but are not limited to, syrups, emulsions, soft gelatin and sterile injectable liquids, such as aqueous or non-aqueous liquid suspensions or solutions.

For parenteral application, particularly suitable are injectable solutions or suspensions, specifically aqueous solutions with the active compound dissolved in polyhydroxylated castor oil.

METHODS OF TREATMENT

The present invention provides compounds and pharmaceutical formulations thereof that are useful in the treatment of diseases, conditions and/or disorders mediated by viral infections. The connection between therapeutic effect and antiviral is illustrated. For example, PCT publication Nos. WO01//07646, WO01/65957, or WO03/037908; US publication Nos. US 4,598,095 or US 2002/0068757; EP publication No. EP 0989862 or EP 0724650; Bioorganic & Medicinal Chemistry Letters, 16, (6), 1712-1715, 2006; and references cited therein, all of which are incorporated herein by reference in their entirety and for the purpose stated.

The present invention further provides a method of treating a disease, condition and/or disorder mediated by viral infections in a subject in need thereof by administering to the subject a therapeutically effective amount of a compound or a pharmaceutical composition of the present invention.

Diseases, conditions, and/or disorders that are mediated by viral infections are believed to include, but are not limited to, ΗΓ infection, HBV, HCV, a retroviral infection genetically related to HIV, AIDS, inflammatory disease, respiratory disorders (including adult respiratory distress syndrome (ARDS), bronchitis, chronic bronchitis, chronic obstructive pulmonary disease, cystic fibrosis, asthma, emphysema, rhinitis and chronic sinusitis), inflammatory bowel disease (including Crohn's disease and ulcerative colitis), multiple sclerosis, rheumatoid arthritis, graft rejection (in particular but not limited to kidney and lung allografts), endometriosis, type I diabetes, renal diseases, chronic pancreatitis, inflammatory lung conditions, chronic heart failure and bacterial infections (in particular but not limited to tuberculosis).

The compounds of the present invention may obtain more advantageous effects than additive effects in the prevention or treatment of the above diseases when using suitably in combination with the available drugs. Also, the administration dose can be decreased in comparison with administration of either drug alone, or adverse effects of co administrated drugs other than antiviral can be avoided or declined.

METHODS OF PREPARATION

The compounds described herein may be prepared by techniques known in the art. In addition, the compounds described herein may be prepared by following the reaction sequence as depicted in scheme 1 and 2. Further, in the following schemes, where specific bases, acids, reagents, solvents, coupling agents, etc., are mentioned, it is understood that other bases, acids, reagents, solvents, coupling agents etc., known in the art may also be used and are therefore included within the present invention. Variations in reaction conditions, for example, temperature and/or duration of the reaction, which may be used as known in the art, are also within the scope of the present invention. All the stereoisomers of the compounds in these schemes, unless otherwise specified, are also encompassed within the scope of this invention.

Compounds of the present invention can be synthesized from naturally occurring Betulin. Key intermediates required for synthesizing analogues are either commercially available or can be prepared by the methods published in the literature. For example, the key intermediates in the present invention were prepared by modifying the procedures published in Journal of organic chemistry 2010, 75, 1285-1288; Journal of organic chemistry 2000, 65, 3934-3940; Tetrahedron: asymmetry 2008, 19, 302-308; or Tetrahedron: asymmetry 2003, 14, 217-223.

Another embodiment of the present invention provides process for preparation of the compounds of general formula (I) are set forth in the below generalized schemes. One of skill in the art will recognize that below generalised schemes can be adapted to produce the compounds of general formula (I) and pharmaceutically acceptable salts of compounds of general formula (I) according to the present invention. Wherein all symbols/variables are as defined earlier unless otherwise stated.

General Synthetic Procedures:

Scheme-1

The compounds of formula (I) (wherein, R₃, R4, R5 and 'n' are same as defined above) can be prepared as described in Scheme 1. The C-3 & C-28 di hydroxy compounds of formula (i) can be protected in different ways like

(a) With a suitable ester forming reagents such as anhydrides with or without addition of base or solvent or catalyst under heating conditions or

(b) with a suitable ester forming reagents such as anhydrides, acid halides or mixed anhydrides or the like in the presence of base such as triethylamine (TEA) or N,N- diisopropylethylamine (DIPEA) or pyridine or the like in solvents such as dichloromethane (DCM) or tetrahydrofuran (THF) or toluene or the like with or without addition of catalyst such as 4-(Dimethylamino)pyridine (DMAP) under heating conditions or the like to give the C-3 & C-28 di hydroxy protected compounds of formula (ii) (Pi and P₂ are protecting groups such as acetyl, benzyl or the like).

The compounds of formula (ii) can be converted to the ring-E ene compounds of formula (iii) in the presence of hydrogen bromide (HBr) in acetic acid (AcOH), acetic acid (AcOH) and acetic anhydride (Ac₂0) in solvents such as toluene or benzene or xylene or the like. The ring-E ene compounds of formula (iii) can be converted to the ring-E enone compounds of formula (iv) in the presence of sodium dichromate dihydrate (Na₂Cr₂0₇.2H₂0), sodium acetate (NaOAc), acetic acid (AcOH) and acetic anhydride (Ac₂0) in solvents such as toluene or benzene or the like. The ring-E enone compounds of formula

(iv) can be selectively deprotected at C-28 to give the C-28 hydroxy compounds of formula

(v) in the presence of potassium hydroxide (KOH) or the like in the combination of solvents such as toluene: ethanol (EtOH) (1 : 1) or with reagent like Aluminium isopropoxide [Al(OCH(CH₃)2)3] in a solvent such as 2-propanol or the like. The C-28 hydroxy compounds of formula (v) can be converted to the C-28 acid compounds of formula (vi) in the presence of oxidizing agents such as 2,2,6,6-Tetramethylpiperidine-l-oxyl (TEMPO), sodium chlorite (NaC10₂), 10% sodium hypochlorite solution (10% NaOCl), buffer such as Sodium dihydrogen phosphate (NaH₂P0₄) and inorganic bases such as sodium bicarbonate or the like in the combination of solvents such as tert-butanol (t-BuOH) and water (H₂0) or the like. The C-28 acid compounds of formula (vi) can be converted to the C-17 carbamate compounds of formula (vii) by using the reagent like diphenylphosphoryl azide (DPPA) or combination of ethylchloroformate and sodium azide (NaN₃) in the presence of bases such as triethylamine (TEA) or Ν,Ν-Diisopropylethylamine (DIPEA) or the like in the solvents such as 1,2-DCE or Toluene or the like in the presence of alcohol such as 4-methoxybenzyl alcohol (PMBOH) or the like. The C-3 hydroxy compounds of formula (viii) can be achieved by deprotection at C- 3 of compounds of formula (vii) in the presence of aqueous solution of inorganic bases such as sodium hydroxide (NaOH) or potassium hydroxide (KOH) or the like in the combination of solvents such as methanol (MeOH): tetrahydrofuran (THF): water (H₂0) (4:2: 1) or 1,4- dioxane: water (H₂0) (4: 1) or the like. The C-3 hydroxy compounds of formula (viii) can be coupled with the acid of compounds of formula (ix) to give the C-3 ester compounds of formula (x) in different ways like

(a) The coupling of compounds of formula (viii) and (ix) with reagent like 2,4,6- trichlorobenzoyl chloride or the like in the presence of bases such as triethylamine (TEA) or Ν,Ν-Diisopropylethylamine (DIPEA) or the like and catalyst such as 4-dimethylaminopyridine (DMAP) in solvents such as N,N- dimethylformamide (DMF) or dichloromethane (DCM) or the like.

(b) The coupling of compounds of formula (viii) and (ix) with reagent such as EDCI or the like in the presence of catalyst such as 4-dimethylaminopyridine (DMAP) or the like in the solvents such as dichloromethane (DCM) or N,N- dimethylformamide (DMF) or the like. The compounds of formula (x) containing the carbamate group at C-17 can be converted to the C-17 amine compounds of formula (xi) in the presence of acid medium such as trifluoroacetic acid (TFA) or HCl/l,4-dioxane or the like in the solvents such as dichloromethane (DCM) or chloroform (CHCI₃) or the like. The C-17 amine compounds of formula (xi) can be coupled with the acid compounds of formula (xii) in the presence of coupling reagents such as 0-(7-Azabenzotriazol-l-yl)-N,N,N ,N -tetramethyluronium hexafluorophosphate (HATU) or 0-(Benzotriazol- l-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HBTU) or combination of l-Ethyl-3-(3- dimethylaminopropyl)carbodiimide (EDCI) and 1-Hydroxybenzotriazole hydrate (HOB t) or the like in the presence of bases such as triethylamine (TEA) or N,N-Diisopropylethylamine (DIPEA) or the like in the solvents such as 1,2-dichloroethane (1,2-DCE) or N,N- dimethylformamide (DMF) or the like to give the C-17 amide compounds of formula (xiii). The compounds of formula (xiii) containing the ester group can be deprotected to the acid of compounds of formula (xiv) in the presence of acid medium such as trifluoroacetic acid (TFA) or HCl/l,4-dioxane or the like in the solvents such as dichloromethane (DCM) or chloroform (CHCI₃) or the like. The compounds of formula (xiv) can be coupled with the compounds of formula (xv) in the presence of bases such as triethylamine (TEA) or N,N- Diisopropylethylamine (DIPEA) or the like in the solvents such as 1,2-dichloroethane (1,2- DCE) or dichloromethane (DCM) or the like to give the ester compounds of formula (xvi).

The compounds of formula (xvi) can be converted to the compounds of formula (xvii) by using ammonium acetate in toluene under reflux conditions. The compounds of formula (xvii) can be hydrolyzed to the acids of compounds of formula (xviii) in the presence of aqueous solution of inorganic bases such as Lithium hydroxide (LiOH) or sodium hydroxide (NaOH) or potassium hydroxide (KOH) or the like in the combination of solvents such as tetrahydrofuran (THF): methanol (MeOH) (1: 1) or the like. The compounds of formula (I) can be prepared by reacting the compounds of formula (xviii) with sodium hydroxide in the presence of methanol (MeOH), water and ethyl acetate (EtOAc).

Scheme-2

The compounds of formula (I) (wherein, R₃, R4, R5 and 'n' are same as defined above) can be prepared as described in Scheme 2.

The compounds of formula (xiv) can be coupled with the compounds of formula (xix) in the presence of coupling reagents such as 0-(7-Azabenzotriazol-l-yl)-N,N,N ,N- tetramethyluronium hexafluorophosphate (HATU) or 0-(Benzotriazol-l-yl)-N,N,N',N'- tetramethyluronium hexafluorophosphate (HBTU) or the like in the presence of bases such as triethylamine (TEA) or Ν,Ν-Diisopropylethylamine (DIPEA) or the like in the solvents such as 1,2-dichloroethane (1,2-DCE) or Ν,Ν-dimethylformamide (DMF) or the like to give the compounds of formula (xx). The compounds of formula (xxi) can be prepared by reacting the compounds of formula (xx) with para-toluenesulfonyl chloride in the presence of bases such as triethylamine (TEA) or Ν,Ν-Diisopropylethylamine (DIPEA) or the like in the solvents such as dichloromethane (DCM) or the like. The compounds of formula (xxi) can be hydrolyzed to the acids of compounds of formula (I) in the presence of aqueous solution of inorganic bases such as Lithium hydroxide (LiOH) or sodium hydroxide (NaOH) or potassium hydroxide (KOH) or the like in the combination of solvents such as tetrahydrofuran (THF): methanol (MeOH) (1: 1) or the like.

The abbreviations used in the entire specification may be summarized herein below with their particular meaning: DIPEA (Ν,Ν-Diisopropylethylamine); °C (degree Celsius); δ (delta); ppm (parts per million); % (percentage); DMSO-d6 (Deuterated DMSO); d (Doublet); dd (Doublet of doublet); EtOH (Ethanol); g or gr (gram(s)); H or H₂ (Hydrogen); HC1 (Hydrochloric acid); h or hr (hour(s)); HATU (0-(7-Azabenzotriazol-l-yl)-N,N,N',N'- tetramethyluronium hexafluorophosphate); Hz (Hertz); HPLC (High-performance liquid chromatography); mol (mole(s)); mmol (Millimole); N (Normal); ml (Millilitre); mg (Milli gram); m (Multiplet); MHz (Megahertz); ESI-MS (Electron spray Ionization Mass Spectrometry); m/z (mass-to-charge ratio); M+H⁺ (parent mass spectrum peak plus H⁺); M+Na⁺ (parent mass spectrum peak plus sodium^"1"); min (Minutes); NaOH (Sodium hydroxide); NMR (Nuclear magnetic resonance spectroscopy); s (singlet); TEA (Triethylamine); TLC (Thin Layer Chromatography); THF (Tetrahydrofuran); tert (Tertiary), TFA/CF₃COOH (Trifluoro acetic acid); t (triplet); IC (Inhibitory concentration), nM (Nano molar); pH (Pouvoir hydrogen); DCM (dichloromethane); DMF (N,N-dimethylformamide); DMAP (4-(Dimethylamino)pyridine); eq (equivalent); Ltr or L (Liter(s)); CDCI₃ (Deuterated chloroform); (Coupling constant); JAB (Coupling constant); NaH₂P0₄ (Sodium dihydrogen phosphate); AcOH (Acetic acid); ABq (AB quartet); MTBE (Methyl tert-butyl ether); HBr (Hydrogen bromide); Ac₂0 (Acetic anhydride); NaHC0₃ (Sodium bicarbonate); Na₂S0₄ (Sodium sulphate); 1,2-DCE (1,2-dichloroethane); HBTU (0-(Benzotriazol-l-yl)-N,N,N',N'- tetramethyluronium hexafluorophosphate); KOH (Potassium hydroxide); MeOH (methanol); EDCI (l-Ethyl-3-(3-dimethylaminopropyl)carbodiimide); HOBt (1-Hydroxybenzotriazole); DPPA (Diphenyl phosphoryl azide); TEMPO (2,2,6,6-Tetramethylpiperidine 1-oxyl); NaC10₂ (sodium chlorite), NaOCl (sodium hypochlorite).

INTERMEDIATES

Intermediate 1: Preparation of 3-((4-methoxybenzyl)oxy)-2,2-dimethyl-3-oxopropanoic acid:

Step 1: Synthesis of 4-methoxybenzyl 3-hydroxy-2,2-dimethylpropanoate:

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To a stirred solution of 3-hydroxy-2,2-dimethylpropanoic acid (15.0 g, 126.978 mmol, 1.0 eq) in DMF (150 mL) at 0 °C was added triethylamine (53.16 mL, 380.936 mmol, 3.0 eq) and l-(chloromethyl)-4-methoxybenzene (21.693 mL, 152.37 mmol, 1.2 eq). The reaction mixture was allowed to stir at room temperature for overnight. TLC indicated starting material was consumed and the desired product was observed. The reaction mixture was diluted with water (2000 mL) and extracted with ethyl acetate (3x500 mL). The combined organic layers were washed with water (500 mL), dried over sodium sulfate, filtered and evaporated under reduced pressure. The residue was purified by silicagel column chromatography by using 0-1% methanol in DCM gradient. The fractions containing the expected product were combined and concentrated under reduced pressure to obtain the title compound (22.0 g, yield: 72.84%) as a colourless oil. ¹H NMR (300 MHz, CDC1₃): δ ppm 7.27 (d, = 8.7 Hz, 2H), 6.88 (d, = 8.7 Hz, 2H), 5.07 (s, 2H), 3.80 (s, 3H), 3.55 (s, 2H), 1.18 (s, 6H). Synthesis of 3-((4-methoxybenzyl)oxy)-2,2-dimethyl-3-oxopropanoic acid:

To a stirred solution of 4-methoxybenzyl 3-hydroxy-2,2-dimethylpropanoate (step 1, 22.0 g, 92.328 mmol, 1.0 eq) in THF (220 mL) at room temperature was added TEMPO (1.44 g, 9.232 mmol, 0.1 eq), stirred for about 10 minutes, then sodium dihydrogen phosphate monohydrate (38.221 g, 276.985 mmol, 3.0 eq) dissolved in water (330 mL) was added followed by NaHC0₃ (15.51 g, 184.656 mmol, 2.0 eq) was added and stirred for about 10 minutes. NaC10₂ (24.928 g, 276.985 mmol, 3.0 eq) was added slowly portion wise over a period of 30 minutes and stirred for about another 10 minutes. The reaction mixture was cooled to 0-5 °C and added 10% NaOCl solution (34 mL) slowly over a period of 30 minutes and stirred at the same temperature for about another 30 minutes. The reaction mixture was allowed to stir at room temperature for overnight. After completion of the reaction monitored by TLC, IN HCl solution (200 mL) was added and stirred at 0 °C for about 30 minutes. Ethyl acetate (400 mL) was added to the reaction mixture and stirred for about 30 minutes. Organic layer was separated and the aqueous layer was extracted with ethyl acetate (2x400 mL). The combined organic layer was washed with water (300 mL) and brine solution (200 mL). The organic layer was dried over sodium sulfate, filtered and evaporated under reduced pressure to obtain the title compound (18.0 g, yield: 77.2%) as an off-white solid. 1H NMR (300 MHz, CDC1₃): δ ppm 7.17 (d, J = 8.1 Hz, 2H), 6.78 (d, = 8.1 Hz, 2H), 5.02 (s, 2H), 3.70 (s, 3H), 1.37 (s, 6H).

Intermediate 2: Preparation of 3-(((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-9-(((lS,3R)-3- ((benzyloxy)carbonyl)-2,2-dimethylcvclobutane-l-carbonyl)oxy)-l-isopropyl-5a,5b,8,8 J la- pentamethyl-2-oxo-2,3,4,5,5a,5b,6,7,7a,8,9,10,l l,l la,l lb,12,13,13a-octadecahvdro-3aH- cyclopentaralchrysen-3a-yl)amino)-2,2-dimethyl-3-oxopropanoic acid:

Step 1: Synthesis of (3aR,5aR,5bR, 7aR,9S,llaR,llbR,13aS)-9-acetoxy-l-isopropyl- 5 a, 5b, 8,8,11a -pentamethyl-2-oxo -2,3,4,5, 5 a, 5b, 6, 7, 7a, 8, 9, 10,11,1 la, lib, 12, 13, 13 a- octadecahydro-3aH-cyclopenta[a ]chrysene-3a-carboxylic acid:

To a stirred solution of (3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a-(hydroxymethyl)- l-isopropyl-5a,5b,8,8,l la-pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,l l,l la,l lb,12, 13,13a-octadecahydro-2H-cyclopenta[a]chrysen-9-yl acetate (prepared as described in WO 2016/147099 A2, 75 g, 150.37 mmol, 1.0 eq) in THF (750 mL) at room temperature was added TEMPO (2.34 g, 15.037 mmol, 0.1 eq), stirred for about 10 minutes, then NaH₂P0₄ (54.13 g, 451.12 mmol, 3.0 eq) dissolved in 450 mL of water was added followed by NaHC0₃ (25.26 g, 300.75 mmol, 2 eq) was added and stirred for about 10 minutes. NaC10₂ (40.6 g, 451.12 mmol, 3.0 eq) was added slowly portion wise over a period of 30 minutes and stirred for another 10 minutes. The reaction mixture was cooled to 0-5 °C and added 10% NaOCl solution (112.5 mL) over a period of 30 minutes and stirred at the same temperature for 30 minutes. The reaction mixture was allowed to stir at room temperature for about 3 hours. After completion of the reaction (monitored by TLC), IN HCl solution (300 mL) was added and stirred at 0 °C for about 30 minutes. Ethyl acetate (750 mL) was added to the reaction mixture and stirred for about 30 minutes. Organic layer was separated and the aqueous layer was extracted with ethyl acetate (2x450 mL). The combined organic layer was washed with water (350 mL) and brine solution (350 mL). The organic layer was dried over sodium sulfate, filtered and evaporated under reduced pressure. The residue was triturated with heptane (300 mL) and stirred for about 1 hour at room temperature. The precipitates formed were filtered, washed with heptane (75 mL) and dried under vacuum to obtain the desired product (60 g, yield: 77.82%) as an off-white solid. 1H NMR (300 MHz, CDC1₃): δ ppm 4.49 (dd, = 10.5, 6.0 Hz, 1H), 3.27-3.15 (m, 1H), 2.75 (dd, = 12.6, 2.4 Hz, 1H), 2.59 (d, = 18.6 Hz, 1H), 2.49-2.43 (m, 1H), 2.20 (d, / = 18.6 Hz, 1H), 2.05 (s, 3H), 2.02-1.03 (m, 22H), 1.05 (s, 3H), 0.94 (s, 3H), 0.91 (s, 3H), 0.85 (s, 3H), 0.84 (s, 3H), 0.80 (m, 1H); ESI- MS: m z 513.23 (M+H)⁺.

Step 2: Synthesis of (3aR,5aR,5bR,7aR,9S,llaR,llbR,13aS)-l-isopropyl-3a-((((4-methoxy benzyl)oxy)carbonyl)amino)-5a,5b,8,8,lla-pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7, 7a,8,9,10, 11 ,11 a,l lb, 12,13,13a-octadecahydro-2H-cyclopenta[a] ' chrysen-9-yl acetate:

To a stirred solution of (3a ?,5a ?,5b ?,7a ?,9S,l la ?,l lb ?,13aS)-9-acetoxy-l-isopropyl -5a,5b,8,8,l la-pentamethyl-2-oxo-2,3,4,5,5a,5b,6,7,7a,8,9,10,l 1,1 la,l lb, 12,13, 13a-octadeca hydro-3aH-cyclopenta[a]chrysene-3a-carboxylic acid (step 1, 40.0 g, 78.013 mmol, 1.0 eq) in toluene (400 mL) was added triethyl amine (27.41 mL, 195.03 mmol, 2.5 eq), followed by diphenylphosphonic azide (23.26 mL, 101.416 mmol, 1.3 eq). After 15 minutes stirring at room temperature, the solution was heated to reflux for about 100 minutes. After which it was converted completely to the isocyanate by TLC, /?-methoxybenzyl alcohol (12.58 mL, 101.416 mmol, 1.3 eq) was added and reflux was continued for about 4 hours. TLC indicated starting material was consumed and the desired product was observed. The reaction mixture was evaporated under reduced pressure, the residue was taken in methanol (400 mL) and stirred at room temperature for about 1 hour. The precipitates formed were collected by filtration and dried under vacuum to obtain the title compound (46.0 g, yield: 91%) as an off- white solid. 1H NMR (300 MHz, CDC1₃): δ ppm 7.25 (d, = 8.7 Hz, 2H), 6.88 (d, = 8.4 Hz, 2H), 4.98 (s, 2H), 4.86 (s, 1H), 4.48 (dd, = 10.2, 5.7 Hz, 1H), 3.80 (s, 3H), 3.05-2.94 (m, 1H), 2.83-2.74 (m, 1H), 2.73-2.57 (m, 1H), 2.36-2.14 (m, 2H), 2.05 (s, 3H), 1.96-1.0 (m, 22H), 1.07 (s, 3H), 0.98-0.76 (m, 13H); ESI-MS: m/z 648.50 (M+H)⁺.

Step 3: Synthesis of 4-methoxybenzyl ((3aR,5aR,5bR, 7aR,9S,llaR,llbR,13aS)-9-hydroxy-l- isopropyl-5a, 5b, 8, 8, 11 a-pentamethyl-2-oxo-2, 3, 4, 5, 5 a, 5b, 6, 7, 7a,8,9,10,ll,lla,llb,12,13,l 3 a -octadecahydro-3aH-cyclopenta[a]chrysen-3a-yl)carbamate:

To a stirred solution of (3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-l-isopropyl-3a-((((4- methoxybenzyl)oxy)carbonyl)amino)-5a,5b,8,8,l la-pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a, 8,9,10,11,1 la,l lb, 12,13, 13a-octadecahydro-2H-cyclopenta[a]chrysen-9-yl acetate (step 2, 46.0 g, 70.998 mmol, 1.0 eq) in MeOH (460 mL), THF (460 mL) and water (115 mL) at 0 °C was added KOH (39.83 g, 709.986 mmol, 10.0 eq). The reaction mixture was removed from the ice bath and was stirred at room temperature for overnight. TLC indicated starting material was consumed and the desired product was observed. The organic phase was evaporated under reduced pressure and diluted with water (100 mL). The mixture was cooled to 0 °C, neutralized with IN HC1 and extracted with DCM (3x400 mL). The combined organic extracts were washed with water (200 mL), dried over sodium sulfate, filtered and evaporated under reduced pressure to obtain the title compound (42.0 g, yield: 97.65%) as an off-white solid. 1H NMR (300 MHz, CDC1₃): δ ppm 7.27 (d, J = 8.1 Hz, 2H), 6.87 (d, = 8.4 Hz, 2H), 4.98 (s, 2H), 4.83 (s, 1H), 3.80 (s, 3H), 3.25-3.17 (m, 1H), 3.17-3.05 (m, 1H), 2.83- 2.74 (m, 1H), 2.65 (d, J = 18.0 Hz, 1H), 2.30-2.15 (m, 2H), 1.95-1.10 (m, 22H), 1.07 (s, 3H), 0.97 (s, 3H), 0.92 (s, 3H), 0.89 (s, 3H), 0.77 (s, 3H), 0.73-0.67 (m, 1H); ESI-MS: m/z 606.50 (M+H)⁺.

Step 4: Synthesis of 1-benzyl 3-((3aR,5aR,5bR,7aR,9S,llaR,llbR,13aS)-l-isopropyl-3a- ((((4-methoxybenzyl)oxy)carbonyl)amino)-5a,5b,8,8,lla-pentamethyl-2-oxo-3,3a,4,5,5a,5b, 6,7, 7a,8,9,10,ll,lla,llb,12,13,13a-octadecahydro-2H-cyclopenta[a]chrysen-9-yl) (1R,3S)- 2,2-dimethylcyclobutane- -dicarboxylate:

To a stirred solution of 4-methoxybenzyl ((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-9- hydroxy-l-isopropyl-5a,5b,8,8,l la-pentamethyl-2-oxo-2,3,4,5,5a,5b,6,7,7a,8,9,10,l l,l la, l ib, 12,13, 13a-octadecahydro-3aH-cyclopenta[a]chrysen-3a-yl)carbamate (step 3, 42.0 g, 69.322 mmol, 1.0 eq) in DCM (420 mL) was added EDCI (53.80 g, 346.61 mmol, 5.0 eq), DMAP (25.40 g, 207.966 mmol, 3.0 eq) and (lS,3R)-3-((benzyloxy)carbonyl)-2,2- dimethylcyclobutane-l-carboxylic acid (prepared as described in WO 2011/007230 A2, 27.27 g, 103.98 mmol, 1.5 eq). The reaction mixture was stirred at room temperature for overnight. TLC indicated starting material was consumed and the desired product was observed. The reaction mixture was diluted with water (400 mL) and extracted with DCM (3x500 mL). The combined organic extracts were washed with water (500 mL), dried over sodium sulfate, filtered and evaporated under reduced pressure to obtain the title compound (53.0 g, yield: 89.93%) as an off-white solid. 1H NMR (300 MHz, CDCI3): δ ppm 7.38-7.26 (m, 7H), 6.88 (d, = 8.4 Hz, 2H), 5.15, 5.09 (ABq, J_m = 12.3 Hz, 2H), 4.98 (s, 2H), 4.82 (s, 1H), 4.44 (dd, = 11.1, 4.5 Hz, 1H), 3.80 (s, 3H), 3.20-3.05 (m, 1H), 2.87-2.58 (m, 5H), 2.32-2.18 (m, 2H), 2.10-2.0 (m, 1H), 1.96-1.0 (m, 22H), 1.34 (s, 3H), 1.06 (s, 3H), 0.98-0.76 (m, 16H); ESI-MS: m/z 850.73 (M+H)⁺. Step 5: Synthesis of l-((3aR,5aR,5bR, 7aR,9S,llaR,llbR,13aS)-3a-amino-l-isopropyl-5a,5b, 8,8,lla-pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7, 7a,8,9,10,ll,lla,llb,12,13,13a-octadeca hydro-2H-cyclopenta[a]chrysen-9-yl) 3 -benzyl (lS,3R)-2,2-dimethylcyclobutane-l,3- dicarboxylate:

To a stirred solution of 1-benzyl 3-((3aR,5aR,5bR,7aR,9S, l laR,l lbR,13aS)- l- isopropyl-3a-((((4-methoxybenzyl)oxy)carbonyl)amino)-5a,5b,8,8,l la-pentamethyl-2-oxo- 3,3a,4,5,5a,5b,6,7,7a,8,9, 10,l l, l la, l lb,12, 13,13a-octadecahydro-2H-cyclopenta[a]chrysen- 9-yl) (lR,3S)-2,2-dimethylcyclobutane- l,3-dicarboxylate (step 4, 53.0 g, 62.34 mmol, 1.0 eq) in DCM (424 mL) at 0 °C was added trifluoroacetic acid (106 mL). The reaction mixture was allowed to stir at room temperature for overnight. TLC indicated starting material was consumed and the desired product was observed. The reaction mixture was evaporated under reduced pressure and diluted with water (200 mL). The mixture was cooled to 0 °C, pH adjusted to 8.0 with saturated sodium bicarbonate solution and extracted with DCM (3x500 mL). The combined organic extracts were washed with water (500 mL), dried over sodium sulfate, filtered and evaporated under reduced pressure. The residue was triturated with acetonitrile (400 mL) and stirred at room temperature for about 1 hour. The precipitates formed were collected by filtration, washed with acetonitrile (100 mL) and dried under vacuum to obtain the title compound (36.0 g, yield: 84.19%) as an off-white solid. 1H NMR (300 MHz, CDC1₃): δ ppm 7.35 (m, 5H), 5.15, 5.09 (ABq, _AB = 12.3 Hz, 2H), 4.45 (dd, = 11.4, 4.8 Hz, 1H), 3.17-3.06 (m, 1H), 2.86-2.58 (m, 3H), 2.33, 2.23 (ABq, _AB = 18.9 Hz, 2H), 2.10- 1.81 (m, 5H), 1.78- 1.13 (m, 22H), 1.34 (s, 3H), 1.02-0.77 (m, 17H); ESI-MS: m/z 686.63 (M+H)⁺.

Step 6: Synthesis of 1-benzyl 3-((3aR,5aR,5bR,7aR,9S,llaR,llbR,13aS)-l-isopropyl-3a-(3- ((4-methoxybenzyl)oxy)-2,2-dimethyl-3-oxopropanamido)-5a,5b,8,8,lla-pentamethyl-2-oxo- 3,3a,4,5,5a,5b,6,7, 7a,8,9,10,ll,lla,llb,12,13,13a-octadecahydro-2H-cyclopenta[a]chrysen- 9-yl) ( lR,3S)-2,2-dimethylcyclobutane-l,3-dicarboxylate:

To a stirred solution of 3-((4-methoxybenzyl)oxy)-2,2-dimethyl-3-oxopropanoic acid (Intermediate 1, 5.29 g, 20.991 mmol, 1.6 eq) in DMF (180 mL) was added HBTU (9.94 g, 26.22 mmol, 2.0 eq) followed by TEA (9.21 mL, 65.55 mmol, 5.0 eq). The reaction mixture was stirred at room temperature for 30 minutes, then l-((3aR,5aR,5bR,7aR,9S,l laR,l lbR, 13aS)-3a-amino-l-isopropyl-5a,5b,8,8,l la-pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10, l l,l la,l lb,12,13,13a-octadecahydro-2H-cyclopenta[a]chrysen-9-yl) 3-benzyl (lS,3R)-2,2- dimethylcyclobutane-l,3-dicarboxylate (step 5, 9.0 g, 13.119 mmol, 1.0 eq) was added and stirred at same temperature for overnight. TLC indicated starting material was consumed and the desired product was observed. The reaction mixture was diluted with water (1000 mL) and stirred at room temperature for about 30 minutes. The precipitates formed were collected by filtration, washed with water (100 mL) and dried under vacuum. The crude compound was purified by silicagel column chromatography by using 0-30% ethyl acetate in hexane gradient. The fractions containing the expected product were combined and concentrated under reduced pressure to obtain the title compound (4.5 g, yield: 37.28%) as an off-white solid. 1H NMR (300 MHz, CDC1₃): δ ppm 7.35 (m, 5H), 7.28 (d, = 8.7 Hz, 2H), 6.89 (d, = 8.7 Hz, 2H), 6.56 (s, 1H), 5.20-5.07 (m, 4H), 4.45 (dd, = 11.4, 4.5 Hz, 1H), 3.81 (s, 3H), 3.18-3.09 (m, 1H), 2.87-2.52 (m, 5H), 2.24-2.0 (m, 3H), 1.97-1.0 (m, 22H), 1.45 (s, 3H), 1.44 (s, 3H), 1.34 (s, 3H), 1.04 (s, 3H), 0.96 (s, 3H), 0.93-0.77 (m, 13H); ESI-MS: m/z 942.08 (M+Na)⁺.

Step 7: Synthesis of 3-(((3aR,5aR,5bR,7aR,9S,llaR,llbR,13aS)-9-(((lS,3R)-3-((benzyloxy) carbonyl)-2, 2 -dimethylcyclobutane-l -carbonyl )oxy )-l -isopropyl-5a, 5b, 8, 8, 11 a-pentamethyl- 2 -oxo-2, 3, 4, 5, 5 a, 5b, 6,7, 7a,8,9,10,ll,lla,llb,12,13,13a -octadecahydro -3aH-cyclopenta[a] chrysen-3a-yl)amino)- -dimethyl-3-oxopropanoic acid:

To a stirred solution of 1-benzyl 3-((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-l- isopropyl-3a-(3-((4-methoxybenzyl)oxy)-2,2-dimethyl-3-oxopropanamido)-5a,5b,8,8,l la- pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,l 1,1 la,l lb, 12,13, 13a-octadecahydro-2H- cyclopenta[a]chrysen-9-yl) (lR,3S)-2,2-dimethylcyclobutane-l,3-dicarboxylate (step 6, 4.5 g, 4.89 mmol, 1.0 eq) in DCM (38 mL) was added trifluoroacetic acid (6.75 mL). The reaction mixture was stirred at room temperature for overnight. TLC indicated starting material was consumed and the desired product was observed. The reaction mixture was evaporated under reduced pressure, triturated with MTBE (100 mL) and stirred at room temperature for about 30 minutes. The precipitates formed were collected by filtration, washed with MTBE (20 mL) and dried under vacuum to obtain the title compound (3.0 g, yield: 76.72%) as an off- white solid. 1H NMR (300 MHz, CDC1₃): δ ppm 7.35 (m, 5H), 6.58 (s, 1H), 5.15, 5.09 (ABq, J_AB = 12.3 Hz, 2H), 4.45 (dd, = 11.1, 4.5 Hz, 1H), 3.22-3.10 (m, 1H), 2.87-2.60 (m, 5H), 2.37-2.17 (m, 2H), 2.10-1.0 (m, 23H), 1.51 (s, 3H), 1.49 (s, 3H), 1.34 (s, 3H), 1.10 (s, 3H), 0.96 (s, 3H), 0.95 (s, 3H), 0.90 (s, 3H), 0.88-0.77 (m, 7H); ESI-MS: m/z 821.95 (M+Na)⁺.

EXAMPLES

Example 1: Preparation of (lR,3S)-3-((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a-(2-(5-(4- chlorophenyl)-L3,4-oxadiazol-2-yl)-2-methylpropanamido)-l-isopropyl-5a,5b,8,8 J la-penta methyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,l l,l la,l lb,12,13,13a-octadecahvdro-2H-cvclo pentaralchrvsen-9-yl)oxy)carbonyl)-2,2-dimethylcvclobutane-l-carboxylic acid:

i

Step 1: Synthesis of 1-benzyl 3-((3aR,5aR,5bR, 7aR,9S,llaR,llbR,13aS)-3a-(3-(2-(4-chloro benzoyl)hydrazinyl)-2,2-dimethyl-3-oxopropanamido)-l-isopropyl-5a,5b,8,8,lla-penta methyl-2-oxo-3, 3 a, 4, 5, 5 a, 5b, 6, 7, 7a,8,9,10,ll,lla,llb,12,13,l 3a-octadecahydro-2H-cyclo penta[a] chrysen-9-yl) (lR,3S)-2,2-dimethylcyclobutane-l,3-dicarboxylate:

To a stirred solution of 3-(((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-9-(((lS,3R)-3- ((benzyloxy)carbonyl)-2,2-dimethylcyclobutane-l-carbonyl)oxy)-l-isopropyl-5a,5b,8,8,l la- pentamethyl-2-oxo-2,3,4,5, 5a,5b, 6,7 ,7a,8,9, 10,11,1 la,l lb, 12,13, 13a-octadecahydro-3aH- cyclopenta[a]chrysen-3a-yl)amino)-2,2-dimethyl-3-oxopropanoic acid (Intermediate 2, 1.5 g, 1.874 mmol, 1.0 eq) in DMF (15 mL) was added HBTU (1.066 g, 2.811 mmol, 1.5 eq) followed by triethylamine (1.046 mL, 7.496 mmol, 4.0 eq). The reaction mixture was stirred at room temperature for about 30 minutes, and then 4-chlorobenzohydrazide (0.479 g, 2.811 mmol, 1.5 eq) was added and stirred at room temperature for overnight. After completion of the reaction (monitored by TLC), the reaction mixture was diluted with water (30 mL) and stirred at room temperature for about 30 minutes. The precipitates formed were collected by filtration, washed with water (200 mL) and dried under vacuum. The resulting solid was stirred with hexane (20 mL) at room temperature for about 30 minutes, filtered, washed with hexane (10 mL) and dried under vacuum to obtain the title compound (1.5 g, yield: 83.9%) as an off-white solid. 1H NMR (300 MHz, CDC1₃): δ ppm 8.86 (brs, IH), 7.77 (d, = 7.8 Hz, 2H), 7.43 (d, = 7.2 Hz, 2H), 7.35 (m, 5H), 7.04 (s, IH), 5.14, 5.09 (ABq, JAB = 12.3 Hz, 2H), 4.46-4.41 (m, IH), 3.20-3.10 (m, IH), 2.90-2.58 (m, 5H), 2.42-2.25 (m, 2H), 2.10-1.0 (m, 23H), 1.53 (s, 6H), 1.34 (s, 3H), 1.05 (s, 3H), 0.98-0.89 (m, 6H), 0.87-0.75 (m, 10H). Step 2: Synthesis of 1 -benzyl 3-((3aR,5aR,5bR, 7aR,9S,llaR,llbR,13aS)-3a-(2-(5-(4-chloro phenyl)-l,3,4-oxadiazol-2-yl)-2-methylpropanamido)-l-isopropyl-5a,5b,8,8,lla-pentamethyl -2-oxo-3,3a,4,5,5a,5b,6, 7, 7a,8,9,10,ll,lla,llb,12,13,13a-octadecahydro-2H-cyclopenta[a] chrysen-9-yl) ( 1 R,3S )-2,2-dimethylcyclobutane-l ,3 -dicarboxylate :

l

To a stirred solution of 1-benzyl 3-((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a-(3-(2- (4-chlorobenzoyl)hydrazinyl)-2,2-dimethyl-3-oxopropanamido)-l-isopropyl-5a,5b,8,8,l la- pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,l 1,1 la,l lb, 12,13, 13a-octadecahydro-2H- cyclopenta[a]chrysen-9-yl) (lR,3S)-2,2-dimethylcyclobutane-l,3-dicarboxylate (step 1, 1.5 g, 1.574 mmol, 1.0 eq) in DCM (15 mL) were added triethylamine (0.65 mL, 4.722 mmol, 3.0 eq) and /?ara-toluenesulfonyl chloride (0.359 g, 1.888 mmol, 1.2 eq). The reaction mixture was stirred at room temperature for about 3 hours. TLC indicated starting material was consumed and the desired product was observed. The reaction mixture was diluted with water (100 mL) and extracted with DCM (2x100 mL). The combined organic extracts were washed with 0.5N HCl (15 mL) and water. The organic layer was dried over sodium sulfate, filtered and evaporated under reduced pressure. The residue was purified by silicagel column chromatography by using 50-60% ethyl acetate in hexane gradient. The fractions containing the expected product were combined and concentrated under reduced pressure to obtain the title compound (0.800 g, yield: 54.42%) as an off-white solid. 1H NMR (300 MHz, CDC1₃): δ ppm 7.99 (d, J = 8.4 Hz, 2H), 7.52 (d, J = 8.4 Hz, 2H), 7.34 (m, 5H), 7.03 (s, 1H), 5.14, 5.09 (ABq, JAB = 12.3 Hz, 2H), 4.46-4.41 (m, 1H), 3.18-3.08 (m, 1H), 2.87-2.58 (m, 5H), 2.33- 2.24 (m, 2H), 2.10-1.0 (m, 23H), 1.73 (s, 3H), 1.72 (s, 3H), 1.34 (s, 3H), 0.96 (s, 3H), 0.90 (s, 3H), 0.87-0.80 (m, 9H), 0.75 (m, 4H); ESI-MS: m z 934.96 (M+H)⁺.

Step 3: Synthesis of (lR,3S)-3-((((3aR,5aR,5bR, 7aR,9S,llaR,nbR,13aS)-3a-(2-(5-(4-chloro phenyl)-l,3,4-oxadiazol-2-yl)-2-methylpropanamido)-l-isopropyl-5a,5b,8,8,lla-pentamethyl -2-oxo-3,3a,4,5,5a,5b,6, 7, 7a,8,9,10,ll,lla,llb,12,13,13a-octadecahydro-2H-cyclopenta[a] chrysen-9-yl)oxy)carbonyl)-2,2-dimethylcyclobutane-l-carboxylic acid:

To a stirred solution of 1-benzyl 3-((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a-(2-(5- (4-chlorophenyl)-l,3,4-oxadiazol-2-yl)-2-methylpropanamido)-l-isopropyl-5a,5b, 8,8,1 la- pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,l 1,1 la,l lb, 12,13, 13a-octadecahydro-2H- cyclopenta[a]chrysen-9-yl) (lR,3S)-2,2-dimethylcyclobutane-l,3-dicarboxylate (step 2, 0.800 g, 0.855 mmol, 1.0 eq) in MeOH (8 mL) and THF (8 mL) was added aqueous 2.5N KOH solution (2.56 mL, 6.412 mmol, 7.5 eq). The reaction mixture was stirred at room temperature for overnight. TLC indicated starting material was consumed and the desired product was observed. The reaction mixture was evaporated under reduced pressure and diluted with water (20 mL). The mixture was cooled to 0 °C, ptl adjusted to 5.0 with IN HCl and extracted with DCM (3x50 mL). The combined organic extracts were washed with water (50 mL), dried over sodium sulfate, filtered and evaporated under reduced pressure. The residue was purified by silicagel column chromatography by using 60-70% ethyl acetate in hexanes gradient. The fractions containing the expected product were combined and concentrated under reduced pressure. The obtained solid was stirred with ethyl acetate (3 mL) and hexane (15 mL) at room temperature for about 30 minutes. The solid was filtered, washed with hexane (5 mL) and dried under vacuum to obtain the title compound (0.305 g, yield: 42.24%) as an off-white solid. 1H NMR (300 MHz, CDC1₃): δ ppm 8.0 (d, = 8.4 Hz, 2H), 7.52 (d, = 8.4 Hz, 2H), 7.06 (s, 1H), 4.44 (dd, = 11.1, 3.9 Hz, 1H), 3.19-3.08 (m, 1H), 2.87-2.75 (m, 2H), 2.69-2.52 (m, 3H), 2.33-2.24 (m, 2H), 2.10-1.0 (m, 23H), 1.73 (s, 3H), 1.72 (s, 3H), 1.37 (s, 3H), 1.07 (s, 3H), 0.90 (s, 3H), 0.87-0.80 (m, 9H), 0.74 (m, 4H); ESI-MS: m/z 844.80 (M+H)⁺; HPLC: 98.1%.

Example 2: Preparation of sodium (lR,3S)-3-((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a- (2-(5-(4-chlorophenyl)-lH-imidazol-2-yl)-2-methylpropanamido)-l-isopropyl-5a,5b,8,8 J la- pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,l l,l la,l lb,12,13,13a-octadecahvdro-2H- cvclopentaralchrvsen-9-yl)oxy)carbonyl)-2,2-dimethylcvclobutane-l-carboxylate:

i

Step 1: Synthesis of 1-benzyl 3-((3aR,5aR,5bR, 7aR,9S,llaR,llbR,13aS)-3a-(3-(2-(4-chloro phenyl)-2-oxoethoxy)-2,2-dimethyl-3-oxopropanamido)-l-isopropyl-5a,5b,8,8,lla-penta methyl-2-oxo-3, 3 a, 4, 5, 5 a, 5b, 6, 7, 7a,8,9,10,ll,lla,llb,12,13,l 3a-octadecahydro-2H-cyclo penta[a] chrysen- -yl) (lR,3S)-2,2-dimethylcyclobutane-l,3-dicarboxylate:

To a stirred solution of 3-(((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-9-(((lS,3R)-3- ((benzyloxy)carbonyl)-2,2-dimethylcyclobutane-l-carbonyl)oxy)-l-isopropyl-5a,5b, 8,8,1 la- pentamethyl-2-oxo-2,3,4,5, 5a,5b, 6,7 ,7a,8,9, 10,11,1 la,l lb, 12,13, 13a-octadecahydro-3aH- cyclopenta[a]chrysen-3a-yl)amino)-2,2-dimethyl-3-oxopropanoic acid (Intermediate 2, 0.9 g, 1.124 mmol, 1.0 eq) in DCM (9 mL) was added triethylamine (0.628 mL, 4.499 mmol, 4.0 eq) followed by 2-bromo-l-(4-chlorophenyl)ethan-l-one (0.315 g, 1.349 mmol, 1.2 eq). The reaction mixture was stirred at room temperature for overnight. After completion of the reaction (monitored by TLC), the reaction mixture was diluted with DCM (100 mL), washed with 0.5N HCl (50 mL) and water (100 mL). The organic layer was dried over sodium sulfate, filtered and evaporated under reduced pressure. The residue was purified by silicagel column chromatography by using 0-40% ethyl acetate in hexane gradient. The fractions containing the expected product were combined and concentrated under reduced pressure to obtain the title compound (0.800 g, yield: 74.6%) as a yellow solid. 1H NMR (300 MHz, CDC1₃): δ ppm 7.84 (d, J = 8.4 Hz, 2H), 7.51 (d, J = 8.4 Hz, 2H), 7.34 (m, 5H), 7.22 (s, 1H), 5.44, 5.37 (ABq, /AB = 16.5 Hz, 2H), 5.15, 5.09 (ABq, _AB = 12.3 Hz, 2H), 4.44 (dd, J = 11.4, 4.5 Hz, 1H), 3.23-3.12 (m, 1H), 2.95-2.87 (m, 1H), 2.86-2.72 (m, 2H), 2.70-2.58 (m, 3H), 2.34 (d, = 18.6 Hz, 1H), 2.10-1.0 (m, 23H), 1.52 (s, 3H), 1.51 (s, 3H), 1.34 (s, 3H), 1.07 (s, 3H), 0.95 (s, 3H), 0.92 (s, 3H), 0.90-0.78 (m, 10H); ESI-MS: m/z 952.45 (M+H)⁺.

Step 2: Synthesis of 1 -benzyl 3-((3aR,5aR,5bR, 7aR,9S,llaR,llbR,13aS)-3a-(2-(5-(4-chloro phenyl)-! H-imidazol-2-yl)-2-methylpropanamido)-l-isopropyl-5a,5b, 8, 8,11 a-pentamethyl-2- oxo-3,3a,4,5,5a,5b,6, 7,7a,8,9,10,ll,lla,llb,12,13,13a-octadecahydro-2H-cyclopenta[a] chrysen-9-yl) ( 1 R,3S )-2,2-dimethylcyclobutane-l ,3 -dicarboxylate :

i

To a stirred solution of 1-benzyl 3-((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a-(3-(2- (4-chlorophenyl)-2-oxoethoxy)-2,2-dimethyl-3-oxopropanamido)-l-isopropyl-5a,5b,8,8,l la- pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,l 1,1 la,l lb, 12,13, 13a-octadecahydro-2H- cyclopenta[a]chrysen-9-yl) (lR,3S)-2,2-dimethylcyclobutane-l,3-dicarboxylate (step 1, 0.8 g, 0.839 mmol, 1.0 eq) in toluene (16 mL) was added ammonium acetate (0.970 g, 12.596 mmol, 15.0 eq). The reaction mixture was heated to reflux for overnight. TLC indicated starting material was consumed and the desired product was observed. The reaction mixture was concentrated under reduced pressure, diluted with ethyl acetate (150 mL) and washed with water (2x100 mL). The organic layer was dried over sodium sulfate, filtered and evaporated under reduced pressure. The residue was purified by silicagel column chromatography by using 0-50% ethyl acetate in hexane gradient. The fractions containing the expected product were combined and concentrated under reduced pressure to obtain the title compound (0.600 g, yield: 76.6%) as a brown solid. 1H NMR (300 MHz, CDCI3): δ ppm 9.24 (s, 1H), 8.56 (s, 1H), 7.68 (d, = 8.4 Hz, 2H), 7.50-7.30 (m, 7H), 7.22 (s, 1H), 5.14, 5.09 (ABq, /AB = 12.6 Hz, 2H), 4.42 (dd, / = 10.8, 3.6 Hz, 1H), 3.18-3.08 (m, 1H), 2.84-2.58 (m, 5H), 2.52-2.43 (m, 1H), 2.33 (d. = 18.9 Hz, 1H), 2.08-1.08 (m, 23H), 1.66 (s, 3H), 1.64 (s, 3H), 1.33 (s, 3H), 0.95 (s, 3H), 0.88 (s, 3H), 0.85-0.78 (m, 9H), 0.78-0.70 (m, 4H); ESI- MS: m/z 955.51 (M+Na)⁺.

Step 3: Synthesis of (lR,3S)-3-((((3aR,5aR,5bR, 7aR,9S,llaR,nbR,13aS)-3a-(2-(5-(4-chloro phenyl)-! H-imidazol-2-yl)-2-methylpropanamido)-l-isopropyl-5a,5b,8,8,lla-pentamethyl-2- oxo-3,3a,4,5,5a,5b,6, 7,7a,8,9,10,ll,lla,llb,12,13,13a-octadecahydro-2H-cyclopenta[a] chrysen-9-yl)oxy)carbonyl)-2,2-dimethylcyclobutane-l-carboxylic acid:

i

To a stirred solution of 1-benzyl 3-((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a-(2-(5- (4-chlorophenyl)-lH-imidazol-2-yl)-2-methylpropanamido)-l-isopropyl-5a,5b,8,8,l la- pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,l l,l la,l lb,12,13,13a-octadecahydro-2H- cyclopenta[a]chrysen-9-yl) (lR,3S)-2,2-dimethylcyclobutane-l,3-dicarboxylate (step 2, 0.600 g, 0.643 mmol, 1.0 eq) in MeOH (6 mL) and THF (6 mL) was added aqueous 2.5N KOH solution (1.929 mL, 4.824 mmol, 7.5 eq). The reaction mixture was stirred at room temperature for overnight. TLC indicated starting material was consumed and the desired product was observed. The reaction mixture was evaporated under reduced pressure and diluted with water (10 mL). The mixture was cooled to 0 °C, acidified with IN HCl and extracted with DCM (2x100 mL). The combined organic layer was dried over sodium sulfate, filtered and evaporated under reduced pressure. The residue was purified by silicagel column chromatography by using 0-3% methanol in DCM gradient. The fractions containing the expected product were combined and concentrated under reduced pressure. The obtained solid was further purified by recrystallization over acetonitrile (10 mL) followed by 10% ethyl acetate in hexane gave the title compound (0.180 g, yield: 33.21%) as an off-white solid. 1H NMR (300 MHz, CDC1₃): δ ppm 11.43 (s, 1H), 9.53 (s, 1H), 8.39 (s, 1H), 7.68 (d, = 8.4 Hz, 2H), 7.33 (d, = 8.4 Hz, 2H), 7.22 (s, 1H), 4.44 (dd, = 11.1, 5.1 Hz, 1H), 3.15- 3.02 (m, 1H), 2.88-2.78 (m, 2H), 2.68-2.50 (m, 2H), 2.50-2.0 (m, 4H), 1.98-1.0 (m, 28H), 1.67 (s, 3H), 1.62 (s, 3H), 0.98-0.66 (m, 16H); ESI-MS: m/z 842.49 (M+H)⁺.

Step 4: Synthesis of sodium (lR,3S)-3-((((3aR,5aR,5bR,7aR,9S,llaR,llbR,13aS)-3a-(2-(5- (4-chlorophenyl)-lH-imidazol-2-yl)-2-methylpropanamido)-l-isopropyl-5a,5b,8,8,lla-penta methyl-2-oxo-3, 3 a, 4, 5, 5 a, 5b, 6, 7, 7a,8,9,10,ll,lla,llb,12,13,l 3a-octadecahydro-2H-cyclo penta[a]chrysen-9-yl)oxy)carbonyl)-2,2-dimethylcyclobutane-l-carboxylate:

To a stirred solution of (lR,3S)-3-((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a-(2- (5-(4-chlorophenyl)-lH-imidazol-2-yl)-2-methylpropanamido)-l-isopropyl-5a,5b,8,8,l la- pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9, 10,11,1 la, 1 lb, 12,13, 13a-octadecahydro-2H- cyclopenta[a]chrysen-9-yl)oxy)carbonyl)-2,2-dimethylcyclobutane-l-carboxylic acid (step 3, 0.150 g, 0.178 mmol, 1.0 eq) in MeOH (1.87 mL) and water (0.1 mL) was added NaOH (0.007 g, 0.178 mmol, 1.0 eq). After the reaction mixture was stirred at room temperature for about 2.5 hours, distil out around 90% methanol under reduced pressure. Ethyl acetate (2.5 mL) and hexane (2.5 mL) were added to the reaction mixture and stirred at room temperature for overnight. The reaction mixture was filtered, solid was washed with hexane (2.5 mL), followed by ethyl acetate (2.5 mL) and dried under vacuum to obtain the title compound (0.145 g, yield: 94.15%) as a white solid. 1H NMR (300 MHz, CD₃OD): δ ppm 7.76 (d, = 8.7 Hz, 2H), 7.44 (s, 1H), 7.37 (d, = 8.7 Hz, 2H), 4.42-4.35 (m, 1H), 3.23-3.15 (m, 1H), 2.72-2.58 (m, 4H), 2.55-2.40 (m, 2H), 2.38-2.25 (m, 1H), 1.98-1.0 (m, 23H), 1.629 (s, 3H), 1.599 (s, 3H), 1.33 (s, 3H), 1.01 (s, 3H), 0.93 (s, 3H), 0.90-0.73 (m, 13H); ESI-MS: m/z 842.54 (M-Na+H)⁺.

Although the present application has been illustrated by certain of the preceding examples, it is not to be construed as being limited thereby; but rather, the present application encompasses the generic area as hereinbefore disclosed. Various modifications and embodiments can be made without departing from the spirit and scope thereof. For example, the following compounds are also included in the scope of the present application and can be prepared by procedure similar to the one described in above synthetic procedures with appropriate variations in reactants, quantities of reagents and reaction conditions.

octadecahydro-2H-cyclopenta[a]chrysen-9- yl)oxy)carbonyl)-2,2-dimethylcyclobutane-l- carboxylic acid

(lR,3S)-3-

((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-l- isopropyl-5 a,5b,8 , 8,11 a-pentamethyl-3 a-(2-methyl-2- (5-(6-methylpyridin-3-yl)-l,3,4-oxadiazol-2- yl)propanamido)-2-oxo-

HOOCT 3,3a,4,5,5a,5b,6,7,7a,8,9,10,l l,l la,l lb,12,13,13a- octadecahydro-2H-cyclopenta[a]chrysen-9- yl)oxy)carbonyl)-2,2-dimethylcyclobutane-l- carboxylic acid

(lR,3S)-3-

((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-l- isopropyl-5 a,5b,8 , 8,11 a-pentamethyl-3 a-(2-methyl-2-

(5-methyl-l,3,4-oxadiazol-2-yl)propanamido)-2-oxo-

3,3a,4,5,5a,5b,6,7,7a,8,9,10,l l,l la,l lb,12,13,13a-

HOOCT octadecahydro-2H-cyclopenta[a]chrysen-9- yl)oxy)carbonyl)-2,2-dimethylcyclobutane-l- carboxylic acid

(lR,3S)-3-

((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-l- isopropyl-5 a,5b,8 , 8,11 a-pentamethyl-3 a-(2-methyl-2- (5-(5-methylpyrazin-2-yl)-l,3,4-oxadiazol-2- yl)propanamido)-2-oxo-

(lR,3S)-3-

HOOCT (5-(pyrimidin-2-yl)- 1 ,3 ,4-oxadiazol-2- yl)propanamido)-2-oxo-

3,3a,4,5,5a,5b,6,7,7a,8,9,10,l l,l la,l lb,12,13,13a- octadecahydro-2H-cyclopenta[a]chrysen-9- yl)oxy)carbonyl)-2,2-dimethylcyclobutane-l- carboxylic acid

(lR,3S)-3-

((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a-(2-(5- (4-chloro-2-methoxyphenyl)- 1 ,3 ,4-oxadiazol-2-yl)-2- methylpropanamido)-l-isopropyl-5a,5b,8,8,l la- pentamethyl-2-oxo-

3,3a,4,5,5a,5b,6,7,7a,8,9,10,l l,l la,l lb,12,13,13a-

(lR,3S)-3-

((((3 aR,5aR,5bR,7aR,9S , 11 aR, 1 IbR, 13aS)- 1 - isopropyl-3a-(2-(5-(4-methoxyphenyl)- 1,3,4- oxadiazol-2-yl)-2-methylpropanamido)- 5a,5b,8,8,l l a-pentamethyl-2-oxo- 3,3a,4,5,5a,5b,6,7,7a,8,9,10,l l,l la,l lb,12,13,13a- octadecahydro-2H-cyclopenta[a]chrysen-9- yl)oxy)carbonyl)-2,2-dimethylcyclobutane-l- carboxylic acid

(lR,3S)-3-

((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a-(2-(5- ( 1 H-benzo [d] imidazol-2-yl)- 1 ,3 ,4-oxadiazol-2-yl)-2- methylpropanamido)-l-isopropyl-5a,5b,8,8,l la- pentamethyl-2-oxo-

3,3a,4,5,5a,5b,6,7,7a,8,9,10,l l,l la,l lb,12,13,13a- octadecahydro-2H-cyclopenta[a]chrysen-9- yl)oxy)carbonyl)-2,2-dimethylcyclobutane-l- carboxylic acid (lR,3S)-3-

((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a-(2-(5- (lH-benzo[d]imidazol-6-yl)-l,3,4-oxadiazol-2-yl)-2- methylpropanamido)-l-isopropyl-5a,5b,8,8,l la- pentamethyl-2-oxo-

(lR,3S)-3-

((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a-(2-(5- (4-chloro-2-(((S)-tetrahydrofuran-3-yl)oxy)phenyl)- l,3,4-oxadiazol-2-yl)-2-methylpropanamido)-l- isopropyl-5 a,5b,8 , 8,11 a-pentamethyl-2-oxo- 3,3a,4,5,5a,5b,6,7,7a,8,9,10,l l,l la,l lb,12,13,13a- octadecahydro-2H-cyclopenta[a]chrysen-9- yl)oxy)carbonyl)-2,2-dimethylcyclobutane-l- carboxylic acid

(lR,3S)-3-

((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a-(2-(5- (4-chloro-2-(((R)-tetrahydrofuran-3-yl)oxy)phenyl)- l,3,4-oxadiazol-2-yl)-2-methylpropanamido)-l- isopropyl-5 a,5b,8 , 8,11 a-pentamethyl-2-oxo- 3,3a,4,5,5a,5b,6,7,7a,8,9,10,l l,l la,l lb,12,13,13a- octadecahydro-2H-cyclopenta[a]chrysen-9- yl)oxy)carbonyl)-2,2-dimethylcyclobutane-l- carboxylic acid

(lR,3S)-3-

((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a-(2-(5- (4-chloro-2-(2-(pyrrolidin-l-yl)ethoxy)phenyl)-l,3,4- oxadiazol-2-yl)-2-methylpropanamido)-l-isopropyl- 5a,5b,8,8,l l a-pentamethyl-2-oxo- 3,3a,4,5,5a,5b,6,7,7a,8,9,10,l l,l la,l lb,12,13,13a-

methylpropanamido)-l-isopropyl-5a,5b,8,8,l la- pentamethyl-2-oxo-

(lR,3S)-3-

((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a-(2-(5- (4-chlorophenyl)-4-(2-(dimethylamino)ethyl)-4H- l,2,4-triazol-3-yl)-2-methylpropanamido)-l- isopropyl-5 a,5b,8 , 8,11 a-pentamethyl-2-oxo- 3,3a,4,5,5a,5b,6,7,7a,8,9,10,l l,l la,l lb,12,13,13a- octadecahydro-2H-cyclopenta[a]chrysen-9- yl)oxy)carbonyl)-2,2-dimethylcyclobutane-l- carboxylic acid

(lR,3S)-3-

((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-l- isopropyl-5 a,5b,8 , 8,11 a-pentamethyl-3 a-(2-methyl-2- (5-(6-methylpyridin-3-yl)-lH-imidazol-2- yl)propanamido)-2-oxo-

(lR,3S)-3-

((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-l- isopropyl-3a-(2-(5-(4-methoxyphenyl)-lH-imidazol- 2-yl)-2-methylpropanamido)-5a,5b,8,8, 1 la- pentamethyl-2-oxo-

((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-l- isopropyl-5 a,5b,8 , 8,11 a-pentamethyl-3 a-(2-methyl-2- (5-(4-(((S)-tetrahydrofuran-3-yl)oxy)phenyl)-lH- imidazol-2-yl)propanamido)-2-oxo-

(lR,3S)-3-

((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-l- isopropyl-5 a,5b,8 , 8,11 a-pentamethyl-3 a-(2-methyl-2- (5-(4-(((R)-tetrahydrofuran-3-yl)oxy)phenyl)-lH- imidazol-2-yl)propanamido)-2-oxo- 3,3a,4,5,5a,5b,6,7,7a,8,9,10,l l,l la,l lb,12,13,13a- octadecahydro-2H-cyclopenta[a]chrysen-9- yl)oxy)carbonyl)-2,2-dimethylcyclobutane-l- carboxylic acid

PHARMACOLOGICAL ACTIVITY

The compounds described herein can be tested for their antiviral activity following procedures known to a person of ordinary skill in the art. For example, the following protocols can be employed for testing the compounds. These protocols are illustrative and do not limit to the scope of the invention.

Example 3: Evaluation of compounds antiviral activity:

MT2 cells were infected with HIV-1 strain 92HT599 (15TCID 50/ 30000 cells). The infected cells were plated at the concentration of -30 000 cells per well in 96 well plate. Test compound was added to the micro plate in defined format with the final concentration of DMSO (vehicle) is not more than 1%. Assay was carried out with and without human serum/human serum albumin (HSA 45 mg/ml) for the serum shift. Incubation was carried out in C0₂ incubator for - 96 hours for viral infection. At the end of incubation period an aliquot from each well was taken for p24 estimation. The quantitation of p24 is an index for antiviral activity of the compound. Percent inhibition was calculated with reference to control values (vehicle controls).

P-24 estimation was carried out using Advance biosciences kit as per the procedure detailed by supplier.

For 0% serum binding assay, Example 2 have IC₅₀ value of less than 10 nM.

For 40% serum binding assay, compound 2 Example 2 have IC₅₀ value of less than 80 nM.

References:

1. Antiviral methods and protocols (Eds: D Kinchington and R. F. Schinazi) Humana Press Inc., 2000.

2. HIV protocols (Eds: N. L. Michael and J. H. Kim) Humana Press Inc, 1999.

3. DAIDS Virology manual from HIV laboratories, Publication NIH-97-3838, 1997.

4. HIV-1 p24 antigen capture assay, enzyme immunoassay for detection of Human immunodeficiency Virus Type 1 (HIV-1) p24 in tissue culture media - Advanced bio science laboratories, Inc kit procedure.

Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as described above.

All publications and patent applications cited in this application are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated herein by reference.

Claims

1. A com ound of the formula (I)

C₆ alkyl, or optionally substituted C₃-C₈ cycloalkyl);

R₃ and R₄ are independently selected from optionally substituted Ci-C₆ alkyl, optionally substituted amine, optionally substituted C₃-C₈ cycloalkyl, optionally substituted heterocyclyl, or optionally substituted heteroaryl; or R₃ and R4 are taken together with the carbon atom to which they are attached to form optionally substituted C₃-C₈ cycloalkyl, epoxide, oxetane, or azetidine;

C Hy !

is 4-7 membered heterocyclyl or 5-7 membered heteroaryl;

'm' is an integer 0,1 or 2; and 'n' is an integer 1, 2, 3, or 4; or

pharmaceutically acceptable salts, prodrugs, tautomers, stereoisomers or combination thereof.

2. The compound according to claim 1, is a compound of the formula (IA):

wherein,

C Hy )

Ri, , R5 and 'n' are same as defined in claim 1; or

3. The compound of claim 1-2, wherein

4. The compound of claim 1-3, wherein

is imidazole or oxadiazole;.

5. The compound of claim 1-4 wherein R5 is phenyl substituted with chloro.

6. A compound selected from the group consisting of:

(lR,3S)-3-((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a-(2-(5-(4-chlorophenyl)-l,3,4 -oxadiazol-2-yl)-2-methylpropanamido)-l-isopropyl-5a,5b,8,8,l la-pentamethyl-2-oxo-3,3a, 4,5,5a,5b,6,7,7a,8,9,10,l 1,1 la,l lb, 12,13, 13a-octadecahydro-2H-cyclopenta[a]chrysen-9-yl) oxy)carbonyl)-2,2-dimethylcyclobutane- 1 -carboxylic acid;

sodium (lR,3S)-3-((((3aR,5aR,5bR,7aR,9S,l laR,l lbR,13aS)-3a-(2-(5-(4-chloro phenyl)- lH-imidazol-2-yl)-2-methylpropanamido)-l-isopropyl-5a,5b, 8, 8,11 a-pentamethyl-2- oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,l 1,1 la,l lb, 12,13, 13a-octadecahydro-2H-cyclopenta[a] chrysen-9-yl)oxy)carbonyl)-2,2-dimethylcyclobutane-l-carboxylate; or

7. A pharmaceutical composition comprising a compound according to any one of claims 1-6 and at least one pharmaceutically acceptable excipient.

8. The pharmaceutical composition according to claim 7, wherein the pharmaceutically acceptable excipient is a carrier or diluent.

9. A method for preventing, ameliorating or treating a viral mediated disease, disorder or syndrome in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a compound according to any one of claims 1-6.

10. The method according to claim 9, wherein the viral mediated disease, disorder or syndrome is HIV infection, HBV infection, HCV infection, a retroviral infection genetically related to AIDS, respiratory disorders (including adult respiratory distress syndrome (ARDS)), inflammatory disease.

11. A method of treating HIV in a subject in need thereof comprising administering to the subject a therapeutically effective amount of a compound according to any one of claims 1-6.

12. The method according to claim 9 and 11, wherein the subject is a mammal including human.

13. Use of a compound according to any of claims 1-6, in the manufacture of a medicament for the treatment of viral mediated diseases.