WO2019150300A1 - Crystalline forms of 4-(((3ar,5ar,5br,7ar,9s,11ar,11br,13as)-3a-((r)-2-((4-chlorobenzyl)(2-(dimethylamino)ethyl)amino)-1-hydroxyethyl)-1-isopropyl-5a,5b,8,8,11a-pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,11,11a,11b,12,13,13a-octadecahydro-2h-cyclopenta[a]chrysen-9-yl)oxy)-2,2-dimethyl-4-oxobutanoic acid - Google Patents

Abstract

The present invention discloses certain sulphonic acid salts of 4-(((3aR,5aR,5bR,7aR,9S,11aR,11bR,13aS)-3a-((R)-2-((4-chlorobenzyl)(2-(dimethylamino)ethyl)amino)-1-hydroxyethyl)-1-isopropyl-5a,5b,8,8,11a-pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,11,11a,11b,12,13,13a-octadecahydro-2H-cyclopenta[a]chrysen-9-yl)oxy)-2,2-dimethyl-4-oxobutanoic acid or a solvate thereof. Also described are synthetic routes and crystalline forms. 26

Description

CRYSTALLINE FORMS OF 4-(((3aR,5aR,5bR,7aR,9S,11 aR,11 bR,13aS)-3a-((R)-2-((4- CHLOROBENZYL)(2-(DIMETHYLAMINO)ETHYL)AMINO)-1 -HYDROXYETHYL)-1- ISOPROPYL-5a,5b,8,8,11 a-PENTAMETHYL-2-OXO- 3, 3a, 4, 5, 5a, 5b, 6, 7, 7a, 8, 9, 10,11 ,1 1 a,11 b,12,13,13a-OCTADECAHYDRO-2H- CYCLOPENTA[a]CHRYSEN-9-YL)OXY)-2,2-DIMETHYL-4-OXOBUTANOIC ACID

FIELD OF THE INVENTION

The present invention provides salts and solid-state forms of 4- (((3aR,5aR,5bR,7aR,9S,1 1 aR,1 1 bR,13aS)-3a-((R)-2-((4-chlorobenzyl)(2- (dimethylamino)ethyl)amino)-1-hydroxyethyl)-1 -isopropyl-5a,5b,8,8,11 a-pentamethyl-2- oxo-3, 3a, 4, 5, 5a, 5b, 6, 7, 7a, 8, 9, 10,1 1 ,1 1 a, 11 b,12,13,13a-octadecahydro-2H- cyclopenta[a]chrysen-9-yl)oxy)-2,2-dimethyl-4-oxobutanoic acid. These salts and solid- state forms can be incorporated into novel compositions and pharmaceutical compositions that are useful for the treatment of HIV infections in patients having an HIV infection or AIDS.

BACKGROUND OF THE INVENTION

The human immunodeficiency virus (HIV) is a retrovirus that causes the infection of HIV in the human immune system. Over time, an untreated HIV infection leads to acquired immunodeficiency syndrome (AIDS) through the destruction of the human immune system. HIV and AIDS are still a major public health threat and can cause death through the opportunistic infections that result from AIDS. There is currently no vaccine to prevent HIV infection but only antiretroviral treatments to extend the lives of those infected.

HIV infects T4 lymphocytes in the human immune system. The immune response in the human body produces HIV antibodies and cytotoxic lymphocytes to induce the immune system to respond and seek out and destroy invading viruses or bacteria.

However, once the lymphocyte becomes infected with HIV, the virus is able to replicate increasing its ability to kill T4 cells. As the number of T4 lymphocytes are infected by HIV, the body’s immunity system is compromised and becomes more susceptible to opportunistic infections. There is no known cure for AIDS, but advancement in treatment delays the onset of symptoms and prolongs the lives of those infected with HIV.

Highly active antiretroviral therapy (HAART) is also an existing treatment that combines several antiretroviral medicines to slow the rate of HIV-1 replicating in the body. This combination of antiretroviral medicines includes nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs), nonnucleoside reverse transcriptase inhibitors (NNRTIs), Protease inhibitors (Pis), entry inhibitors, and integrase inhibitors. However, the combination of antiretroviral medicines over a prolonged period of time may lead to drug resistance.

Therefore, what is needed are newer classes of HIV antiviral medicines that, along with HAART, can reduce the likelihood of develop drug resistance over prolonged periods of administration. One such newer class, are maturation inhibitors. Maturation inhibitors interfere at a late stage of viral replication, blocking protease cleavage. Betulin is a naturally occurring maturation inhibitor, which is a class of antiviral drugs for the treatment of HIV. See Published PCT Application No. WO 2013/090664. Maturation inhibitors are unlike the existing protease inhibitors class of HIV drugs due to their ability to bind the group-specific antigen (gag) protein, and not the protease.

One particular maturation inhibitor having the chemical name, 4- (((3aR,5aR,5bR,7aR,9S,1 1 aR,1 1 bR,13aS)-3a-((R)-2-((4-chlorobenzyl)(2- (dimethylamino)ethyl)amino)-1-hydroxyethyl)-1 -isopropyl-5a,5b,8,8,11 a-pentamethyl-2- oxo-3, 3a, 4, 5, 5a, 5b, 6, 7, 7a, 8, 9, 10,1 1 ,1 1 a, 11 b,12,13,13a-octadecahydro-2H- cyclopenta[a]chrysen-9-yl)oxy)-2,2-dimethyl-4-oxobutanoic acid, is disclosed in U.S. Patent No. 9,102,685 (published PCT Application No. WO 2013/090664A1).

Polymorphs are different forms of a specific chemical composition that can crystallize in more than one solid-state form. Crystalline forms of this compound are important as they could lead to new pharmaceutical compositions and formulations for the purpose of inhibiting HIV replication and treating HIV patients. Polymorphs can be identified and characterized by X-Ray Powder Diffraction (XRPD) or Infrared Reflection Absorption Spectroscopy (IR) or even Differential Scanning Calorimetry (DSC), etc. XRPD is used to characterize crystalline material through a plot of scattering intensity vs. the scatter angle 2Q or the corresponding d-spacing. Samples are prepared in a crystalline form and X-ray beams are scattered in various intensities and directions from the crystalline lattice. The peak positions, intensities, widths, and shapes of the plot provide important information about the material structure.

The integrated intensity of a diffraction peak is proportional to the amount of the component present. The presence of a new polymorph is detected from small changes in the X-ray powder patterns, such as new peaks, additional shoulders or shifts in the peak positions. Crystalline structuring is important because the x-rays scatter from atoms in the material and therefore contain information about the atomic arrangement. This scattering of X-rays produces a diffraction pattern, which is a product of the unique crystal structure of a material. The inter-atomic distances determine the positions of the diffraction peaks and the atom types and positions determine the diffraction peak intensities. The diffraction pattern of a material is important because it is as unique for each phase as a fingerprint. Phases with the same chemical composition may have different diffraction patterns. The electrons in each atom scatter light and the strength with which an atom scatters light is proportional to the number of electrons around the atom. The diffraction pattern calculations treat a crystal as a collection of planes of atoms and each peak is attributed to the scattering from a specific set of parallel planes of atoms.

Crystalline forms 0f 4-(((3aR,5aR,5bR,7aR,9S,11 aR,1 1 bR,13aS)-3a-((R)-2-((4- chlorobenzyl)(2-(dimethylamino)ethyl)amino)-1-hydroxyethyl)-1-isopropyl-5a,5b,8,8,1 1 a- pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,1 1 ,11 a, 11 b,12,13,13a-octadecahydro-2H- cyclopenta[a]chrysen-9-yl)oxy)-2,2-dimethyl-4-oxobutanoic acid are important to characterize because it could lead to pharmaceutical composition and formulations and methods for the purpose of inhibiting HIV replication and treating HIV patients.

Characterization of its crystalline forms could provide an increase in the bioavailability of any resulting pharmaceuticals resulting from differences in solubility and dissolution. Such a crystalline format may offer improvements in the treatment of HIV and HIDS and could address the continuing need of drug options for HIV and AIDS patients.

SUMMARY OF THE INVENTION

In one embodiment, the present invention discloses sulfonic acid salts of the compound 4-(((3aR,5aR,5bR,7aR,9S,11 aR,11 bR,13aS)-3a-((R)-2-((4-chlorobenzyl)(2- (dimethylamino)ethyl)amino)-1-hydroxyethyl)-1 -isopropyl-5a,5b,8,8,11 a-pentamethyl-2- oxo-3, 3a, 4, 5, 5a, 5b, 6, 7, 7a, 8, 9, 10,1 1 ,1 1 a, 11 b,12,13,13a-octadecahydro-2H- cyclopenta[a]chrysen-9-yl)oxy)-2,2-dimethyl-4-oxobutanoic acid, shown below as the compound of Formula (I).

This compound will be referred to as the compound of Formula (I) or as compound A.

In another embodiment, the present invention discloses crystalline forms of sulfonic acid salts of compound A.

In another aspect, the present invention discloses pharmaceutical compositions comprising a sulfonic acid salt of compound A. In another aspect, the present invention provides a method for treating HIV comprising the administration of a sulfonic acid salt of compound A.

In another aspect, the present invention provides a sulfonic acid salt of compound A for use in therapy.

In another aspect, the present invention provides use of a sulfonic acid salt of compound A thereof in the manufacture of a medicament for use in treating HIV.

In another aspect, the present invention provides a method for the preparation of intermediate 5

comprising the step of allylic oxidation of Intermediate 1

comprising the use of N-bromosuccinimide.

In another aspect, the present invention provides a method for the preparation of Intermediate 4

comprising the selective oxidation of Intermediate 5

comprising the use of 1 ,3-dichloro-5,5-dimethylhydantoin and 2, 2,6,6- tetramethylpiperidine-1 -oxyl.

In another aspect, the present invention provides a method for the preparation of Intermediate 6

comprising the acylation of Intermediate 4

comprising the use of 2-methylbenzoyl chloride.

In another aspect, the present invention provides a method for the preparation of

Intermediate 7

from Intermediate 6

comprising the use of a chiral ligand derived from (S)-camphor and 2-picolylamine.

In another aspect, the present invention provides a method for the preparation of Intermediate 4 from Intermediate 3

comprising the use of butylamine.

BRIEF DESCRIPTION OF THE FIGURES FIG. 1 shows X-ray powder diffraction patterns of Form 1 of Compound B.

FIG. 2 shows Differential Scanning Calorimetry (DSC) of Compound B, crystalline Form 1 .

FIG. 3 shows solution proton NMR of Compound B, crystalline Form 1 .

FIG. 4 shows X-ray powder diffraction patterns of Form 1 of Compound A.

FIG. 5 shows X-ray powder diffraction patterns of Form 2 of Compound A.

FIG. 6 shows X-ray powder diffraction patterns of Form 3 of Compound A.

FIG. 7 shows the x-ray powder diffraction pattern of Compound B, Form 1 in tablets as explained in Example 4.

DETAILED DESCRIPTION OF THE INVENTION

A preferred sulfonic acid salt of compound A is a camphor sulfonic acid salt (also referred to as camsylate or CSA) and will be referred to as compound B and is illustrated below in Formula (IA):

Preferred compositions of this invention include tablets.

The method of this invention for treating HIV may also include the administration of an additional agent active against an HIV virus, wherein said agent active against the HIV virus is selected from the group consisting of Nucleotide reverse transcriptase inhibitors; Non-nucleotide reverse transcriptase inhibitors; Protease inhibitors; Entry, attachment and fusion inhibitors; Integrase inhibitors; Maturation inhibitors; CXCR4 inhibitors; and CCR5 inhibitors.

While it is possible for the compound of the invention to be administered as the raw chemical, it is preferable and advantageous to present the compound of the invention as a pharmaceutical formulation and represents a further feature of the invention. The pharmaceutical formulation comprises the compound of the invention together with one or more acceptable carrier(s) therefor and optionally other therapeutic agents. The carrier(s) must be "acceptable" in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipients thereof.

As with all pharmaceutical compounds and compositions, chemical and physical properties of the compound of Formula I are important in its commercial development as a novel HIV therapeutic. These properties include, but are not limited to: (1) packing properties such as molar volume, density and hygroscopicity, (2) thermodynamic properties such as melting temperature, vapor pressure and solubility, (3) kinetic properties such as dissolution rate and stability (including stability at ambient conditions, especially to moisture, and under storage conditions), (4) surface properties such as surface area, wettability, interfacial tension and shape, (5) mechanical properties such as hardness, tensile strength, compactibility, handling, flow and blend; and (6) filtration properties. These properties can affect, for example, processing and storage of pharmaceutical compositions comprising the compound of Formula I. Solid state forms of the compound of Formula I that provide an improvement in one or more of these properties relative to other solid-state forms of the compound of Formula I are desirable.

US Patent No. 9,102,685 describes the compound A, its HIV maturation inhibitor properties, and its antiviral use, especially against HIV infections. Compound A is currently under evaluation and investigation as an anti-HIV pharmaceutical agent, in particular, as an HIV maturation inhibitor. There exists a need for the compound to be prepared in a form suitable for ease of isolation in large scale manufacture, and for ease of formulating into an acceptable product for administration to humans. We have found that manufacture of the free base of the compound has a tendency to form an amorphous solid during milling and compaction, and is, therefore, suboptimal for large commercial manufacture. We have found that the camphor sulfonic acid salt of compound A (i.e. compound B), in particular the crystalline Form 1 of compound B, has certain advantages over the parent free base, Compound A. For example, Compound B, form 1 has a higher resistance to amorphization than Compound a Form 1 during milling and compaction. Amorphous material a disordered unstable phase and is known to be prone to chemical and physical transformation including degradation and transition to more stable crystalline forms. In addition, amorphous materials are typical more hygroscopic than crystalline solids required more controls over humidity during storage. The higher solubility of amorphous materials combined with their inherent lower stability than crystalline materials increases the risk of lack of control of bioavailability.

Furthermore, Compound B, form 1 has a higher melting point and a higher enthalpy of fusion than the Form 1 of Compound A. The higher melting temperature and higher enthalpy of fusion are indicators of strongly bound molecules within the crystal lattice which increases resistance to degradation and enhances chemical and physical stability.

In addition, Compound B, has only one other solid form which is suspected to be a 2-Butanone solvate compared to Compound A which has several polymorphs and numerous solvates. In addition, it was proven that the 2-Butanone solvate of Compound B converts readily to camphor sulfonic acid form of the Compound B Form 1 even in 2- Butanone. This feature improves significantly risk to quality compared to Compound A which requires a stringent control of process parameters to ensure no form contamination.

EXAMPLES

Amorphous compound A can be prepared, for example, as disclosed in US 9,102,685.

Amorphous compound A can also be prepared by the following new methods illustrated by the scheme below. In previous synthetic methods, Intermediate 1 was converted to Intermediate 4 by a four-step sequence involving allylic oxidation, selective hydrolysis of the primary acetate followed by oxidation to the aldehyde and hydrolysis of the secondary acetate.

Allylic oxidation of intermediate 1 is described in the patent literature (US201 1/77227, US201 1/77228, WO201 1/100308, WO2013/20245, WO2013/90664, WO2013/90683,

WO2013/91 144, WO2013/1 17137, US2015/1 1517, WO2016/178092, WO2017/64628,

WO2017/1 15329, WO2018/29602) using chromium-based reagents such as sodium dichromate. Chromium reagents such as sodium dichromate are highly toxic and require overnight heating at 60°C for reaction completion. It has now been found that aqueous N- bromosuccinimide can be used as a replacement with reaction complete in a few minutes at room temperature and both acetates removed in a single step to give Intermediate 5.

Preparation of Intermediate 5

Intermediate 1 (25 g), 2-methyltetrahydrofuran (450 ml) and water (50 ml) were added to a 1 L vessel under nitrogen. N-Bromosuccinimide (25.32 g, 3 eq) was added in 6 portions at approximately 5 minutes intervals. The reaction mixture was quenched by addition of sodium bisulphite (25 g) and water (50 ml). After stirring for 10 minutes the aqueous phase was removed and the organic phase washed with 2M aqueous sodium hydroxide (2 x 125 ml) and brine (125 ml). Methanol (50 ml) was added and the mixture heated to 50°C. Potassium hydroxide (13.32 g, 5 eq) was added in two portions and the mixture stirred for 2.5 hr. The reaction was quenched by addition of 25% w/w aqueous ammonium chloride (75 ml). The layers were separated, and the organic layer washed with 25% w/w ammonium chloride (75 ml) and water (125 ml). The organic layer was concentrated to 125 ml by distillation then cooled to 50°C over 2 hours and stirred for a further 2 hours. Ethyl acetate (125 ml) was added over 4 hours and the mixture stirred for a further 2 hours at 50°C. After cooling to 20°C over 2 hours the product was filtered and washed with 2: 1 ethyl acetate:2- methyltetrahydrofuran (50 ml) and ethyl acetate (50 ml). Drying under vacuum at 40°C gave a white solid (17.45 g, 83%).

Conversion of Intermediate 2 to Intermediate 4 is described in the patent literature using pyridinium chlorochromate in dichloromethane for the oxidation (WO201 1/100308, WO2013/20245, WO2013/90664, WO2013/90683, WO2013/91 144, WO2013/1 17137,

US2015/1 1517, WO2016/178092, WO2017/64628, WO2017/1 15329, WO2018/29602). Chromium reagents are highly toxic and dichloromethane is an undesirable solvent to use. Zirconium chloride in methanol and dichloromethane is used for the deacetylation involving transient protection of the sensitive aldehyde as a dimethyl acetal (WO2013/90664,

WO2017/64628, WO2017/1 15329). This method requires portion wise addition of a hygroscopic solid, takes 14-36 hours and requires a protracted work-up procedure. It has now been found that butylamine can be used to provide transient protection of the aldehyde, allowing base catalysed deacetylation and avoiding use of zirconium chloride and

dichloromethane and distillation.

Preparation of Intermediate 4

Intermediate 3 (7.5 g), tetrahydrofuran (67.5 ml), methanol (7.5 ml) and n-butylamine (3 ml, 2 eq) were charged to a 250 ml reactor and heated to 40°C. After 1 hour potassium hydroxide (1 .457 g, 1 .7 eq) was added and stirring continued for a further 1 .5 hours. The reaction mixture was cooled to 15-20°C and 2M aqueous hydrochloric acid (30 ml) added to adjust the pH to <1 . Acetonitrile (25 ml) was added dropwise followed by water (100 ml). The product was filtered, washed with water (3 x 25 ml) and dried under vacuum at 40°C to give Intermediate 4 (5.62 g, 82%).

As a further improvement selective oxidation of the primary alcohol can be achieved using 2,2,6,6-tetramethylpiperidine-1 -oxyl (TEMPO) in combination with 1 ,3-dichloro-5,5- dimethylhydantoin (DCH) and triethylamine (TEA) to eliminate a stage from the process and avoid use of chromium reagents or dichloromethane.

Preparation of Intermediate 4

Intermediate 5 (9 g) was dissolved in tetrahydrofuran (180 ml) and cooled to -10°C. 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) (0.231 g, 0.075 eq) and triethylamine (6.87 ml, 2.5 eq) were added followed by 1 ,3-dichloro-5,5-dimethylhydantoin (4.66 g, 1.2 eq). After 20 minutes the reaction mixture was quenched by dropwise addition of 10% w/w aqueous sodium bisulphite (50 ml). After heating to 40°C the aqueous phase was removed and the organic phase cooled to 20°C. The organic phase was washed with twice with 1 :1 2M aqueous sodium hydroxide:saturated brine (2 x 50 ml) and concentrated to 27 ml by distillation. The solution was cooled to 50°C and acetonitrile (27 ml) added over 1 hour. After stirring for 2 hours water (54 ml) was added over 3 hours. After stirring for 2 hours the mixture was cooled to 20°C over 3 hours. The product was filtered, washed with 1 :1 acetonitrile:water (18 ml) and acetonitrile (18 ml). Drying under vacuum at 40°C gave a white powder (7.98 g, 89%).

Conversion of Intermediate 4 to Intermediate 6 is described in the patent literature (WO 2013/090664) using benzoyl chloride, triethylamine and DMAP in THF.

Intermediate 4 Intermediate 6

This reaction takes 18 hours and is highly voluminous, with a maximum working volume in excess of 50 L/kg. Replacement of 4-methoxybenzoyl chloride in THF with cheaper 2-methylbenzoyl chloride in toluene, cuts the reaction time to 2 hours and reduces the maximum working volume to 15 L/kg.

Preparation of Intermediate 6

Intermediate 4 (5 g) and t-butyl 3,3-deimthylsuccinate (2.89 g, 1 .3 eq) were dissolved in toluene (50 ml) and N-methylpyrrolidine (4.68 g, 5 eq) added. The solution was cooled to 0°C and 2-methylbenzoyl chloride (2.55 g, 1 .5 eq) added. After 1 hour 4- dimethylaminopyridine (336 mg, 0.25 eq) was added and the mixture warmed to room temperature. After 2 hours HPLC showed <1 % starting material remaining. After a further 4 hours the solution was washed with water (25 ml), 7% sodium bicarbonate (2 x 25 ml) and water (25 ml). The solution was dried over sodium sulphate and concentrated to 10 ml under vacuum. Heptane (35 ml) was added and the slurry concentrated to 10 ml under vacuum. Heptane (50 ml) was added and the slurry heated at 90°C for 1 hour, then cooled to room temperature. After 1 hour at 0-5C the product was filtered and washed with heptane (2 x 10 ml). Drying under vacuum at 40C gave a cream coloured solid (5.4 g, 77%). Asymmetric Henry reaction of Intermediate 6 to Intermediate 7 is described in the patent literature (WO 2013/090664) using a chiral ligand derived from (S)-camphor and ethylenediamine with copper (II) acetate.

However, the reaction takes 5 days to reach completion using 6% catalyst loading. It has been found that using the ligand derived from (S)-camphor and 2-picolylamine instead cuts the reaction time to a few hours with a 3% catalyst loading using half the amount of (S)- camphor.

Preparation of Intermediate 7

(S)-1 ,7,7-Trimethyl-N-(pyridin-2-ylmethyl)bicyclo[2.2.1]heptan-2-amine (0.149 g, 0.03 eq) and copper(ll)acetate monohydrate (0.094 g, 0.03 eq) were suspended in tert- amyl alcohol (50 ml_). Potassium tert- butoxide (0.105 g, 0.06 eq) was added followed by toluene (20 ml). The reaction mixture was warmed to 30 °C for 90 minutes. Afterwards Intermediate 6 (10 g, 1 eq) was added and it was cooled to -10 °C. L/,/V-Diisopropylethylamine (4.10 ml_, 1 .5 eq) was added followed by nitromethane (8.44 ml_, 10 eq). The reaction mixture was stirred at -10 °C for 7 hours after which HPLC indicated complete consumption of starting material. The reaction was quenched by addition of 40 ml. of a cold (0 °C) mixture of brine and 2M HCI (1 : 1 , v/v). After addition of TBME (100 ml.) the layers were separated and the organic layer washed with sat. NaHC0₃ solution (40 ml.) and with water (30 ml_). The organic layer was concentrated to 40 ml. under reduced pressure at 30 °C. Heptane (80 ml.) was added over 1 hour at room temperature. After 2 hours at 0 °C the product was filtered and washed with heptane (2 x 25 ml). Drying under vacuum at 40 °C gave an off-white solid (9.15 g, 84%). Preparation of Compound A Crystalline Form 1

400g of amorphous compound A were suspended in 1600ml (4 volumes) of dimethyl sulfoxide (DMSO). The slurry was then heated to 75°C and held at that temperature until full dissolution was achieved. Then a clarifying filtration was performed into another vessel. The temperature of the solution was adjusted to 75°C then 560ml (1 .4 volumes) of DMSO/water 1/1 v:v at a rate of 2-3 ml/min. Then the slurry was mixed at 75°C for 1 -1 5h, then cooled to 20°C at a rate of 0.2 °C/min. Then the slurry was mixed at 20°C overnight. The suspension was then filtered under vacuum and the cake was subsequently washed with 1600ml (4 volumes) of DMSO/water 1/1 v:v followed by 800ml (2 volumes) of water twice. The cake was then dried in vacuum at 56°C over night to afford Compound A, Form 1 .

Preparation of Compound A Crystalline Form 2

10mg of Compound A amorphous were dissolved in Dichloromethane at elevated temperature. Then Heptane was added as anti-solvent. The solution was cooled and seeded with Compound A Form 1 . The then solids were isolated. XRPD analysis revealed that 1 ^st crystals of Compound A Form 2 were obtained.

Preparation of Compound A Crystalline Form 2

0.514g of amorphous compound A was suspended in 5.1 ml (10 volumes) of

Acetonitrile/Water 15/1 v:v. The slurry was heated to 50°C. Then 1 mg (~0.2%) of Compound A Form 2 were added as seeds at 50°C. The slurry was then mixed at 50°C for 90min. The solid was then isolated by filtration and confirmed to be Compound A Form 2 by XRPD.

Preparation of Compound A Crystalline Form 2

28.95kg of amorphous compound A were suspended in 174 litres (6 volumes) of 2- propanol. The slurry was then heated to 70-80°C and held at that temperature until full dissolution was achieved. Then a clarifying filtration was performed into another vessel and the filtration lines were then rinsed with 17.4 litres (0.6 volumes) of 2-propanol. Then solvent was evaporated under vacuum until the volume of the solution was decreased to 4 volumes. Then 159 litres (5.5 volumes) of Acetonitrile were added. The mixture was then heated to 70- 80°C and mixed for 0.5-2h. The mixture was then cooled to 45-55°C in 2.5h then mixed at 45- 55°C for 5h. The mixture was then cooled to 23-27°C over 2.5h. Then 60g (0.2%) of

Compound A Form 2 were added as seeds. The slurry was then mixed at 23-27°C for 23h. Then the slurry was cooled to (-5°C)-(0°C). Then the slurry was mixed at (-5°C)-(0°C) for 4h. Then the slurry was filtered under vacuum and the wet cake was washed with (2 volumes) of Acetonitrile to afford wet Compound A Form 2.

Preparation of Compound A Crystalline Form 3

6.5 g of Compound A amorphous were suspended in 8.5 volumes of 15/1

Acetonitrile/water. Then the suspension was heated to 50 °C. After that 1 % wt of crystals of Compound A Form 2, with respect to the input material, was added to the mixture. The resulting slurry was held for 2 hours then cooled to 0 °C at a rate of 0.1 °C/min. The solids were isolated and analyzed by XRPD which indicated that the 1 ^st crystals of Compound A Form 3 were obtained.

Preparation of Compound A Crystalline Form 3

28.95kg of amorphous compound A were suspended in 174 litres (6 volumes) of 2- propanol. The slurry was then heated to 70-80°C and held at that temperature until full dissolution was achieved. Then a clarifying filtration was performed into another vessel and the filtration lines were then rinsed with 17.4 litres (0.6 volumes) of 2-propanol. Then solvent was evaporated under vacuum until the volume of the solution was decreased to 4 volumes. Then 159 litres (5.5 volumes) of Acetonitrile were added. The mixture was then heated to 70- 80°C and mixed for 0.5-2h. The mixture was then cooled to 45-55°C in 2.5h then mixed at 45- 55°C for 5h. The mixture was then cooled to 23-27°C over 2.5h. Then 60g (0.2%) of

Compound A Form 2 were added as seeds. The slurry was then mixed at 23-27°C for 23h. Then the slurry was cooled to (-5°C)-(0°C). Then the slurry was mixed at (-5°C)-(0°C) for 4h. Then the slurry was filtered under vacuum and the wet cake was washed with (2 volumes) of Acetonitrile to afford wet Compound A Form 2. The wet cake was then mixed with 405 litres (14 volumes Acetonitrile/water 9.6/4.1 v:v). Then 87g (0.3 %) of Compound A Form 3 were added to the slurry as seeds. Then the suspension was mixed at 25-30°C for 35h. The suspension was then cooled to 10-15°C and mixed at that temperature for several days. The suspension was then filtered under vacuum and the cake was washed with 29 litres (1 volume) of Acetonitrile/water 1/1 v:v. The cake was then dried under vacuum at 30-35°C for 30h. Then the cake was treated with humidified Nitrogen until the water content of the solid (KF) was 3.4-5.1 % to afford Compound A Form 3. A preferred sulfonic acid salt is the camphor sulfonic acid salt, or the“camsylate” salt and is referred to in this application as“compound B”.

Preparation of Compound B Crystalline Form 1

Amorphous compound A (1 g) was mixed with 4ml (4 volumes) of 1-propanol. The suspension was then heated under stirring to 75°C and full dissolution was achieved at that temperature. Then the solution was cooled to 65°C and 0.3g of (1 S)-(+)-10-Camphor Sulfonic Acid (CSA) (1 .05 mole equivalent) was added as a solid to the solution. Then 12ml (12 volumes) of heptane were added to the solution. The solution was then cooled to 39°C. 4ml (4 volumes) of Heptane were then added which resulted in liquid-liquid phase separation. Then the mixture was heated to 75°C and full dissolution and homogeneous solution was obtained. Solvent evaporation was then initiated under atmospheric pressure and 75°C. The first crystals of Compound B Crystalline Form 1 appeared after evaporation of approximated 20% of the solvent in 1 .5h. The suspension was then cooled down to 25°C. Then the suspension was filtered using a centrifuge and the solid obtained were dried in vacuum at 50°C for 14h to afford the first and original Compound B, crystalline Form 1 as evidenced by XRPD and DSC. 1 mole equivalent of CSA in the crystals was confirmed by NMR analysis. Absence of solvent in the crystals was confirmed by NMR and TGA.

Preparation of Compound B Crystalline Form 1

Amorphous compound A (6g) was mixed with 24ml (4 volumes) of 1 -propanol. The suspension was then heated under stirring to 76°C and full dissolution was achieved at that temperature. Then 48ml (8 volumes) of heptane were added to the solution in 10min. After the addition of heptane full dissolution was maintained. Then 1 .808g of (1 S)-(+)-10-Camphor Sulfonic Acid (CSA) (1 .05 mole equivalent) was added as a solid to the solution. After full dissolution of CSA, 0.12g of Compound B Crystalline Form 1 (2 wt% based on input

Compound A) were added as seeds. The resulting slurry was then aged for 2h then 26ml (4.3 volumes) of heptane were added to the suspension in 2h. Then the suspension was cooled down to 20°C in 1 h. The suspension was then filtered under vacuum and the wet cake was washed with 12ml (2 volumes) of heptane twice. The wet cake was dried under vacuum at 50°C overnight to afford 87% of Compound B, crystalline Form 1 as evidenced by XRPD and DSC. Preparation of Compound B Crystalline Form 1

Amorphous compound A (6g) was mixed at 25°C with 24ml (4 volumes) of 1 -propanol and 48 ml (8 volumes based on input Compound A) of a solution of (2.51 g of (1 S)-(+)-10- Camphor Sulfonic Acid (CSA) dissolved in 100ml water (40 volumes based on CSA)). The 48ml solution contains 0.7 mole equivalent of CSA. Then 0.18g of Compound B Crystalline Form 1 (3wt% based on input Compound A) were added as seeds. The slurry obtained was then aged under mixing at 25°C for 1 h. Then 24ml of the solution of (2.51 g of (1 S)-(+)-10- Camphor Sulfonic Acid (CSA) dissolved in 100ml water (40 volumes based on CSA)) was added to the slurry in 2h. The 24ml solution contains 0.35 mole equivalent of CSA. The suspension was then aged for 25min then filtered under vacuum. The cake was washed with 12g (2 volumes) water twice then dried in vacuum at 60°C over night to afford Compound B, crystalline Form 1 in 88.5% yield.

Preparation of Compound B Crystalline Form 1

Amorphous compound A (45g) was mixed at with 450ml (10 volumes) of 2-butanone. The slurry was heated under mixing at 76°C. The mixture was held at 76°C until full dissolution occurred. Then the solution was cooled to 60°C and a clarifying filtration was performed. The filtrate was mixed and its temperature adjusted to 60°C. Then 1 15ml (2.6 volumes based on input Compound A) of a solution of (13.6g of (1 S)-(+)-10-Camphor Sulfonic Acid (CSA) dissolved in 360ml 2-Butanone (8 volumes based on input Compound A)). Then 1 35g of Compound B Crystalline Form 1 (3wt% based on input Compound A) were added as seeds. The resulting slurry was then aged for 1 h. Then 253ml (5.6 volumes based on input Compound A) of the solution of (13.6g of (1 S)-(+)-10- Camphor Sulfonic Acid (CSA) dissolved in 360ml 2-Butanone (8 volumes based on input Compound A)) was added to the slurry in 2h. The slurry was then held under stirring at 60°C for 1 h, then cooled to 10°C in 1 h, then held under stirring at 10°C for 30min. Then the slurry was filtered under vacuum and the cake was washed with 90ml (2 volumes) of 2-butanone twice. The cake was then dried in vacuum at 50°C over night to afford 84.4% of Compound B, crystalline Form 1 as evidenced by XRPD.

Preparation of Compound B Crystalline Form 1

Amorphous compound A (60g) was mixed at with 600ml (10 volumes) of 2-butanone. The slurry was heated under mixing at 76°C. The mixture was held at 76°C until full dissolution occurred. Then the solution was cooled to 60°C and a clarifying filtration was performed. The filtrate was mixed and its temperature was adjusted to 60°C. Then 60ml (1 volume based on input Compound A) of a solution of (25.1 1 g of (1 S)-(+)-10- Camphor Sulfonic Acid (CSA) dissolved in 250ml 2-Butanone (3 volumes based on input Compound A)) was added to the solution. The 60ml solution of CSA in 2-butanone contains 0.315 mole equivalent of CSA. Then 1 .2g of Compound B Crystalline Form 1 (2wt% based on input Compound A) were added as seeds. The resulting slurry was then aged for 1 h. Then 140ml (2.3 volume based on input Compound A) of the solution of 25.1 1 g of (1 S)-(+)-10-Camphor Sulfonic Acid (CSA) dissolved in 250ml 2-Butanone (3 volumes based on input Compound A)) was added to the slurry in 2h. The 60ml solution of CSA in 2-butanone contains 0.735 mole equivalent of CSA. The slurry was then held under stirring at 60°C for 1 h, then cooled to 10°C in 1 h, then held under stirring at 10°C for 20min. Then the slurry was filtered under vacuum and the cake was washed with 120ml (2 volumes) of 2-butanone twice. The cake was then dried in vacuum at 50°C over night to afford 82% of Compound B, crystalline Form 1 as evidenced by XRPD.

Preparation of Compound B Crystalline Form 1

Amorphous compound A intermediate grade (100g) was mixed with 10OOnl (10 volumes) of 2-Butanone and heated to 65-75°C. Then the suspension was mixed at 65-75°C for 10-30 mins. The temperature of the suspension was then adjusted to 55-65°C over 30min and the suspension was then mixed at that temperature for 10-30 mins. Then 4.5ml (0.045 volumes) of purified water was added slowly. Then 0.5g (0.5 wt%) of Compound A crystalline Form 1 were added as seeds. The resulting suspension was then mixed for 0.5-1 h at 55- 60°C. Then 75ml (0.75 volumes) of water were added and the suspension over 2 to 3h. The suspension was then mixed for 0.5-1 h at 55-60°C then cooled to 23-27°C over 4h. Then the suspension was stirred at 23-27°C for 2h then 1200ml (12 volumes) of heptane was added at 23-27°C over 3h. The suspension was then stirred for 2h, then filtered under vacuum. The wet cake was washed with 50ml (5volumes) of Heptane then dried in vacuum at 45~55°C for 18~24h to afford pure Compound A Form 1 . Then 10g of that purified Compound A Form 1 was mixed with 100ml (10 volumes) of 2-butanone and 7.5ml (0.75 volumes) of water. The slurry was heated under mixing to 55~60°C. The mixture was held under stirring at 55~60°C for 20min. Then a solution consisting of 3g (1.05 mole equivalent based on input Compound A) of (1 S)-(+)-10- Camphor Sulfonic Acid (CSA) dissolved in 30ml (3 volumes based on input Compound A) were added slowly. Then the mixture was stirred at 55~60°C until full dissolution occurred. The resulting solution was then filtered. The filtrate was then mixed and its temperature adjusted to 45~55°C in 1 h. Then 40ml (4 volumes) of heptane were added to the solution in 30min at 45~55°C. Then 0.5g of Compound B Crystalline Form 1 (5wt% based on input Compound A) were added as seeds. The resulting suspension was then stirred at 45~55°C for 1 h to 2h. Then 90ml (9 volumes) of Heptane were added to the suspension in 2h to 3h. The suspension was then stirred at 45~55°C for 0.5~1 ,5h, then cooled to 23~27°C in 0.75~1 h. Then the suspension was stirred at 23~27°C for 30min, then filtered under vacuum. The cake was washed with a mixture of 10ml (1 volume) of 2-butanone and 10ml (1 volume) of Heptane followed 20ml (2 volumes) of Heptane twice. The cake was then dried in vacuum at 45~55°C for 24h to afford pure Compound B, Crystalline Form 1 .

EXAMPLE 1 : PROCESS FOR PRODUCTION OF COMPOUND B CRYSTALLINE FORM 1.

A glass vial was charged with the Compound A and 4 vol_eq (volume equivalents) of 1 - propanol. The resulting suspension was heated to 75°C (degrees Celsius) under mixing to achieve dissolution. After complete dissolution at 75°C, the solution was cooled down to 65°C. Then 1.05 mol_eq (molar equivalents) of S-(+)-Camphorsulfonic Acid (CSA) was added as a solid to the clear solution. After that, 12 vol_eq of heptane was added to the clear solution. Then the solution was cooled down to 39°C. After that 4vol_eq of heptane were added to the clear solution resulting in a hazy mixture. The hazy mixture was heated to 75°C to achieve clear solution. After complete dissolution at 75°C, solvent was evaporated from the clear solution by distillation at atmospheric pressure and 75°C. Nucleation of the first crystals of crystals of the CSA salt compound A was achieved after removal of approximately 20% of solvent in volume in approximately 1 .5h. (Note: NMR analysis indicated that nucleation of crystals of the CSA salt compound A occurred at a solvent composition of 27.93 w/w% PrOH and a concentration of ca 10.97 w/w% of Compound B). The heating and mixing of the suspension was then stopped. The suspension was then filtered and the collected wet cake was dried in a vacuum oven at 50°C to afford a white crystalline solid, (top heating and mixing. The actual yield based on the mass of crystals recovered was 68.4% and the NMR analysis of the mother liquor indicated that a maximum yield of a 93% is achievable. NMR analysis of dry solid also indicated 1/1 molar ration between CSA and compound A was obtained confirming the production of the CSA salt of compound A, which is referred to as compound B. The unique and novel crystalline form of compound B was confirmed by XRPD and DSC. Polarized Light Microscopy indicated birefringence confirming the crystallinity of solids of compound B.

XRPD characteristic peaks diffraction angles for the different crystalline forms are shown below and are determined with an uncertainty of 0.2°:

Compound A, Form 1 : 4.8, 10.3, 1 1 .3, 15.1 , 15.6, 16.6, 16.9, 17.6, 18.3, 21.2, 29.1 . Compound A, Form 2: 8.3, 8.5, 8.8, 1 1 , 1 1 .6, 12.7, 16.8, 18.6, 18.7, 18.9, 19.6.

Compound A, Form 3: 10, 1 1 .2, 15.7, 16.3.

Compound B Form 1 : 6.1 , 9.6, 10.7, 12, 13.9, 14.4, 15.4, 15.6, 16.1 , 17.2, 17.3, 17.7, 17.9, 20.3, 20.9, 24.9, 26.2, 27.7, 28.1

EXAMPLE 2: DIFFERENTIAL SCANNING CALORIMETRY (DSC) COMPARISON CSA

SALT FORM 1 AND FORM 1 FREE BASE

DSC analyses were preformed comparing the CSA Salt Form 1 of the Compound and the Parent Base Form 1 of the Compound. The amount of amorphous material generated upon milling is shown in Table 1.

Table 1

As previously mentioned above, amorphous material is a disordered unstable phase, and is known to be prone to chemical and physical transformation including degradation and transition to more stable crystalline forms. Amorphous materials are also typically more hygroscopic than crystalline solids, and therefore required more controls over humidity during storage. The higher solubility of amorphous materials combined with their inherent lower stability than crystalline materials increases the risk of lack of control of bioavailability in a drug product. The DSC information provided in Table 1 demonstrates that Compound B Form 1 has a higher resistance to amorphization than Compound A Form 1 during milling and compaction. EXAMPLE 3: MELTING POINT AND ENTHALPY OF FUSION COMPARISON CSA SALT

FORM 1 AND FORM 1 FREE BASE

Melting point and enthalpy of fusion measurements were preformed comparing the Compound B Form 1 of the Compound and Compound A Form 1 based on DSC analyses. Results are shown in Table 2.

Table 2

As discussed earlier, a high melting temperature and high enthalpy of fusion are indicators of strongly bound molecules within the crystal lattice which increases resistance to degradation and enhances chemical and physical stability.

The results of Table 2 indicate that Compound B Form 1 has a higher melting point and a higher enthalpy of fusion than Compound A Form 1 . EXAMPLE 4: XRPD ANANLYSIS OF COMPOUND B FORM 1 TABLET COMPACTS

The potential to create amorphous material during secondary processing is not limited to milling as shown in example 2. Compound B, form 1 was compressed with 0.5% Mg Stearate using a compaction simulator and the Xray Diffractogram (FIG. 7) does not show any trend to create amorphous material when higher compression forces are applied.

Claims

CLAIMS What is claimed is:

1 . A sulfonic acid salt of the compound 4-(((3aR,5aR,5bR,7aR,9S,1 1 aR, 1 1 bR, 13aS)-3a- ((R)-2-((4-chlorobenzyl)(2-(dimethylamino)ethyl)amino)-1 -hydroxyethyl)-1 -isopropyl-

5a, 5b, 8, 8,1 1 a-pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10, 1 1 , 1 1 a, 1 1 b, 12, 13, 13a- octadecahydro-2H-cyclopenta[a]chrysen-9-yl)oxy)-2,2-dimethyl-4-oxobutanoic acid.

2. A salt according to Claim 1 wherein the salt is a camphor sulfonic acid salt.

3. A crystalline form of the salt according to Claim 2.

4. A crystalline form according to Claim 3 providing an X-ray powder diffraction (XRPD) pattern, exhibiting substantially very strong, strong and medium diffraction peaks at the following diffraction angles, determined with an uncertainty of 0.2°: 6.1 , 9.6, 10.7, 12, 13.9, 14.4, 15.4, 15.6, 16.1 , 17.2, 17.3, 17.7, 17.9, 20.3, 20.9, 24.9, 26.2, 27.7, 28.1 .

5. A pharmaceutical composition comprising a salt according to any one of claims 1 to 4.

6. The composition of Claim 5 further comprising a second agent useful for treating HIV.

7. The composition of Claim 6 wherein said second agent is selected from the group consisting of Nucleotide reverse transcriptase inhibitors; Non-nucleotide reverse transcriptase inhibitors; Protease inhibitors; Entry, attachment and fusion inhibitors; Integrase inhibitors; Maturation inhibitors; CXCR4 inhibitors; and CCR5 inhibitors.

8. The composition of Claim 7 wherein said second agent is a Protease inhibitor.

9. A pharmaceutical composition according to any of Claims 5-8 in the form of a tablet.

10. A pharmaceutical composition according to any of Claims 5-8 adapted for parenteral administration.

1 1 . A method for the treatment of HIV in a human which comprises administering to said human a composition according to any of Claims 5-8.

12. The method of Claim 1 1 further comprising the administration of at least one other agent useful for treating HIV.

13. The method of Claim 12 wherein said other agent is selected from the group consisting of selected from the group consisting of Nucleotide reverse transcriptase inhibitors; Non-nucleotide reverse transcriptase inhibitors; Protease inhibitors; Entry, attachment and fusion inhibitors; Integrase inhibitors; Maturation inhibitors; CXCR4 inhibitors; and CCR5 inhibitors.

14. The method of Claim 13 wherein said other agent is a Protease inhibitor.

15. A salt according to any of claims 1 -4 for use in medicine.

16. Use of a salt according to any of claims 1 -4 in the manufacture of a medicament for the treatment of HIV.

17. A method for the preparation of intermediate 5

comprising the step of allylic oxidation of Intermediate 1

comprising the use of N-bromosuccinimide.

18. A method for the preparation of Intermediate 4

comprising the selective oxidation of Intermediate 5

comprising the use of 1 ,3-dichloro-5,5-dimethylhydantoin and 2,2,6,6-tetramethylpiperidine-1- oxyl.

19. A method for the preparation of Intermediate 6

comprising the acylation of Intermediate 4

comprising the use of 2-methylbenzoyl chloride.

20. A process for the preparation of Intermediate 7

from Intermediate 6

comprising the use of a chiral ligand derived from (S)-camphor and 2-picolylamine.

21 . A process for the preparation of Intermediate 4

from Intermediate 3

comprising the use of butylamine.