Field of the Invention

The present invention relates to a crystalline Form B of {(\R,2S,3S,4R,5S)-5-[4- chloro-3-(4-ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-dioxab icyclo[3.2. l]oct- 1- yl} methyl acetate of Formula II and

Formula II

a process for its preparation. The present invention further relates to a process for the conversion of a crystalline Form B of {(\R,2S,3S,4R,5S)-5-[4-c loro-3-(4- ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-dioxabicyclo[3.2. l]oct-l-yl} methyl acetate of Formula II to ertugliflozin.

Background of the Invention

Ertugliflozin chemically is (15 ^, ,25 ^, ,35 ^, ,4R,55)-5-(4-chloiO-3-(4- ethoxybenzyl)phenyl)-l-hydroxymethyl-6,8-dioxabicyclo[3.2.1] octane-2,3,4-triol, represented by Formula I.

Formula I

Ertugliflozin is a selective sodium/glucose cotransporter 2 inhibitor for the treatment of type 2 diabetes mellitus. U.S. Patent No. 8,080,580 provides processes for the preparation of ertugliflozin and its conversion to ertugliflozin-L-proline (1 : 1) co-crystal and ertugliflozin-L- pyroglutamic acid (1 : 1) co-crystal.

U.S. Patent No. 8,669,380 provides a process for the preparation of

{(li?,2,S ^* ,3 ₁ S ^* ,4i?,5 ₁ S)-5-[4-chloro-3-(4-ethoxybenzyl)phenyl]-2,3,4-trihydr oxy-6,8- dioxabicyclo[3.2.1]oct-l-yl}methyl acetate which involves purification by flash chromatography over silica gel. The present inventors on repeating the experiment found that {(li?,25',35',4i?,55)-5-[4-chloro-3-(4-ethoxybenzyl)phenyl]- 2,3,4-trihydroxy-6,8- dioxabicyclo[3.2.1]oct-l-yl}methyl acetate was obtained as an oil.

PCT Publication No. WO 2014/159151 provides a crystalline form of

{ ( \R,2S,3S,4R,5S)-5 -[4-chloro-3 -(4-ethoxybenzyl)phenyl] -2,3 ,4-trihydroxy-6, 8- dioxabicyclo[3.2. l]oct-l-yl} methyl acetate having an X-ray powder diffraction pattern (CuKa radiation, wavelength of 1.54056 A) comprising 2-theta values of 5.8±0.2, 11.6±0.2, 16.0±0.2, 16.6±0.2, and 21.6±0.2.

The discovery of new forms of a compound, in particular a drug substance, may improve desirable processing properties of the drug, such as ease of handling, storage stability, and ease of purification.

Summary of the Invention

The present invention provides a crystalline Form B of {(\R,2S,3S,4R,5S)-5-[4- chloro-3-(4-ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-dioxab icyclo[3.2. l]oct- 1- yl} methyl acetate of Formula II.

Formula II

Brief Description of the Drawings

Figure 1 depicts an X-ray powder diffraction (XRPD) pattern of crystalline Form B of {(li?,2,S ^* ,3 ₁ S ^* ,4i?,5 ₁ S)-5-[4-chloro-3-(4-ethoxybenzyl)phenyl]-2,3,4-trihydr oxy-6,8- dioxabicyclo[3.2.1]oct-l-yl}methyl acetate of Formula II prepared as per Example 1. Figure 2 depicts an XRPD pattern of crystalline Form B of {(lR,2S,3S,4R,5S)-5- [4-chloro-3-(4-ethoxybenzyl)phenyl] -2,3 ,4-trihydroxy-6, 8-dioxabicyclo [3.2.1 ]oct- 1 - yl} methyl acetate of Formula II prepared as per Example 2.

Figure 3 depicts an XRPD pattern of crystalline Form B of {(\R,2S,3S,4R,5S)-5- [4-chloro-3-(4-ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-dio xabicyclo[3.2.1]oct-l- yl}methyl acetate of Formula II prepared as per Example 3.

Figure 4 depicts a Differential Scanning Calorimetry (DSC) thermogram of crystalline Form B of {(li?,25',35',4i?,55)-5-[4-chloro-3-(4-ethoxybenzyl)phenyl]- 2,3,4- trihydroxy-6,8-dioxabicyclo[3.2.1]oct-l-yl}methyl acetate of Formula II prepared as per Example 1.

Figure 5 depicts a DSC thermogram of crystalline Form B of {(l i^^S^^^S^-S- [4-chloro-3-(4-ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-dio xabicyclo[3.2.1]oct-l- yl}methyl acetate of Formula II prepared as per Example 2.

Figure 6 depicts a DSC thermogram of crystalline Form B of {(\R,2S,3S,4R,5S)-5- [4-chloro-3-(4-ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-dio xabicyclo[3.2.1]oct-l- yl}methyl acetate of Formula II prepared as per Example 3.

Detailed Description of the Invention

Various embodiments and variants of the present invention are described hereinafter.

The term "about," as used herein, refers to any value which lies within the range defined by a number up to ±10% of the value.

The term "treating," as used herein, refers to bringing two or more components together by dissolving, mixing, suspending, blending, slurrying, or stirring.

The term "solvent," as used herein, includes water, esters, alkanols,

halogenated hydrocarbons, ketones, ethers, polar aprotic solvents, saturated or unsaturated hydrocarbons, and mixtures thereof.

Examples of esters include ethyl acetate, ^-propyl acetate, isopropyl acetate, and «-butyl acetate. Examples of alkanols include those primary, secondary, and tertiary alcohols having from one to six carbon atoms. Examples of alkanols include methanol, ethanol, «-propanol, isopropanol, butanol, 2-methoxyethanol, and 2- ethoxyethanol. Examples of halogenated hydrocarbons include dichloromethane, chloroform, and 1,2-dichloroethane. Examples of ketones include acetone, 2- butanone, diethyl ketone, ethyl methyl ketone, and methyl isobutyl ketone. Exampli of ethers include diethyl ether, ethyl methyl ether, methyl tertiary butyl ether,

diisopropyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, and 1,4-dioxane.

Examples of polar aprotic solvents include N,N-dimethylformamide, NN- dimethylacetamide, dimethylsulphoxide, acetonitrile, and N-methylpyrrolidone.

Examples of saturated or unsaturated hydrocarbons include benzene, toluene,

cyclohexane, and xylenes.

A first aspect of the present invention provides a crystalline Form B of

{(li?,2,S ^* ,3 ₁ S ^* ,4i?,5 ₁ S)-5-[4-chloro-3-(4-ethoxybenzyl)phenyl]-2,3,4-trihydr oxy-6,8- dioxabicyclo[3.2.1]oct-l-yl}methyl acetate of Formula II.

Formula II

In one embodiment of this aspect, the crystalline Form B of {(\R,2S,3S,4R,5S)-5- [4-chloro-3-(4-ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-dio xabicyclo[3.2.1]oct-l- yl}methyl acetate of Formula II is characterized by an X-ray powder diffraction (XRPD) pattern having characteristic peak values at 5.6, 14.7, 16.8, 20.7, and 24.4 ±0.2° 2Θ.

In another embodiment of this aspect, the crystalline Form B of {(l i^^S^^ ?^^)- 5-[4-chloro-3-(4-ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-d ioxabicyclo[3.2.1]oct-l- yl}methyl acetate of Formula II is further characterized by an XRPD pattern having characteristic peak values at 11.0, 12.0, 13.2, 13.9, 17.4, 18.9, 19.4, 22.5, 23.5, 28.0, and 29.4 ±0.2° 2Θ.

In another embodiment of this aspect, the crystalline Form B of {(l i^^S^^ ?^^)- 5-[4-chloro-3-(4-ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-d ioxabicyclo[3.2.1]oct-l- yl}methyl acetate of Formula II is characterized by an XRPD pattern substantially as depicted in Figure 1, Figure 2, or Figure 3. Table 1 provides the 2Θ values, the corresponding d-spacing values (A), and the relative intensity of the crystalline Form B of {(\R,2S,3S,4R,5S)-5-[4-c loro-3-(4- ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-dioxabicyclo[3.2. l]oct-l-yl} methyl acetate of Formula II prepared as per Example 1.

*The relative peak intensities may vary depending on the crystal size and habit.

Table 2 provides the 2Θ values, the corresponding d-spacing values (A), and the relative intensity of the crystalline Form B of {(\R,2S,3S,4R,5S)-5-[4-c loro-3-(4- ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-dioxabicyclo[3.2. l]oct-l-yl} methyl acetate of Formula II prepared as per Example 2.

The relative peak intensities may vary depending on the crystal size and habit. Table 3 provides the 2Θ values, the corresponding d-spacing values (A), and the relative intensity of the crystalline Form B of {(\R,2S,3S,4R,5S)-5-[4-c loro-3-(4- ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-dioxabicyclo[3.2. l]oct-l-yl} methyl acetate of Formula II prepared as per Example 3.

*The relative peak intensities may vary depending on the crystal size and habit.

In one embodiment of this aspect, the crystalline Form B of {(ϋϊ^,Β^^Λ^^)^- [4-chloro-3-(4-ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-dio xabicyclo[3.2.1]oct-l- yl} methyl acetate of Formula II is characterized by a differential scanning calorimetric (DSC) thermogram having an endothermic peak at about 171°C.

In another embodiment of this aspect, the crystalline Form B of {(l i^^S^^ ?^^)- 5-[4-chloro-3-(4-ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-d ioxabicyclo[3.2.1]oct-l- yl}methyl acetate of Formula II is characterized by a DSC thermogram substantially as depicted in Figure 4, Figure 5, or Figure 6.

A second aspect of the present invention provides a process for the preparation of a crystalline Form B of {(li?,25',35',4i?,55)-5-[4-chloro-3-(4-ethoxybenzyl)phenyl]- 2,3,4- trihydroxy-6,8-dioxabicyclo[3.2.1]oct-l-yl}methyl acetate of Formula II,

Formula II

comprising the steps of:

a) treating {(li?,2,S',3 ₁ S',4i?,5 ₁ S)-5-[4-chloro-3-(4-e1hoxybenzyl)phenyl]-2,3,4- trihydroxy-6,8-dioxabicyclo[3.2.1]oct-l-yl}methyl acetate of Formula II with a solvent; and

b) isolating the crystalline Form B of {(lR,2S,3S,4R,5S)-5-[4-c loro-3-(4- ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-dioxabicyclo[3.2.1 ]oct-l-yl}methyl acetate of Formula II.

In one embodiment of this aspect, the present invention provides a process for the preparation of the crystalline Form B of {(\R,2S,3S,4R,5S)-5-[4-c loro-3-(4- ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-dioxabicyclo[3.2. l]oct-l-yl} methyl acetate of Formula II comprising the steps of:

a) dissolving {(li?,2,S ^* ,3^4i?,5 ₁ S)-5-[4-chloro-3-(4-ethoxybenzyl)phenyl]-2,3,4- trihydroxy-6,8-dioxabicyclo[3.2.1]oct-l-yl}methyl acetate in an alcohol solvent;

b) stirring the reaction mixture of step a) to obtain a solid; and

c) isolating the crystalline Form B of {(lR,2S,3S,4R,5S)-5-[4-c loro-3-(4- ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-dioxabicyclo[3.2.1 ]oct-l-yl}methyl acetate. {(li?,2 ₁ S ^* ,3 ₁ S ^* ,4i?,5 ₁ S)-5-[4-Chloro-3-(4-e1hoxybenzyl)phenyl]-2,3,4-trihydr oxy-6,8- dioxabicyclo[3.2.1]oct-l-yl}methyl acetate of Formula II used as the starting material can be prepared by methods known in the art, for example, PCT Publication No. WO

2014/159151.

Preferably, the alcohol solvent is selected from the group comprising primary, secondary, and tertiary alcohols having from one to six carbon atoms. More preferably, the alcohol solvent is selected from the group comprising methanol, ethanol, «-propanol, isopropanol, butanol, 2-methoxy ethanol, and 2-ethoxy ethanol.

Step a) includes dissolving {(1^2S,3S,4R,5S)-5-[4-cMoro-3-(4- ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-dioxabicyclo[3.2. l]oct- 1-yl} methyl acetate of Formula II in an alcohol solvent at a temperature of about 25°C to about 80°C to obtain a clear solution.

Step b) includes cooling the solution to about 5°C to about 25 °C, and then stirring at a temperature of about 5°C to about 25°C for about 45 minutes to about 90 minutes to obtain a solid.

Step c) of isolating the crystalline Form B of {(lR,25 ^, ,35 ^, ,4R,55)-5-[4-chloro-3-(4- ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-dioxabicyclo[3.2. l]oct- 1-yl} methyl acetate of Formula II includes employing one or more techniques selected from the group consisting of filtration, decantation, extraction, distillation, evaporation, chromatography, precipitation, concentration, crystallization, centrifugation, and recrystallization. The crystalline Form B of {(li?,25',35',4i?,55)-5-[4-chloro-3-(4-ethoxybenzyl)phenyl]- 2,3,4- trihydroxy-6,8-dioxabicyclo[3.2.1]oct-l-yl}methyl acetate of Formula II may further be dried using conventional techniques, for example, drying, drying under reduced pressure, spray drying, freeze drying, air drying, or agitated thin film drying.

A third aspect of the present invention provides a pharmaceutical composition comprising a crystalline Form B of {(\R,2S,3S,4R,5S)-5-[4-c loro-3-(4- ethoxybenzyl)phenyl]-2,3,4-trihydroxy-6,8-dioxabicyclo[3.2. l]oct- 1-yl} methyl acetate of Formula II and one or more pharmaceutically acceptable carriers, diluents, or excipients.

A fourth aspect of the present invention provides the use of a crystalline Form B of {(li?,2,S ^* ,3 ₁ S ^* ,4i?,5 ₁ S)-5-[4-chloro-3-(4-ethoxybenzyl)phenyl]-2,3,4-trihydr oxy-6,8- dioxabicyclo[3.2.1]oct-l-yl}methyl acetate of Formula II for the treatment of type 2 diabetes mellitus. A fifth aspect of the present invention provides a process comprising converting a crystalline Form B of {(li?,25',35',4i?,55)-5-[4-chloro-3-(4-ethoxybenzyl)phenyl]- 2,3,4- trihydroxy-6,8-dioxabicyclo[3.2.1]oct-l-yl}methyl acetate of Formula II to ertugliflozin.

In one embodiment of this aspect, the conversion of the crystalline Form B of {(li?,2,S ^* ,3 ₁ S ^* ,4i?,5 ₁ S)-5-[4-chloro-3-(4-ethoxybenzyl)phenyl]-2,3,4-trihydr oxy-6,8- dioxabicyclo[3.2.1]oct-l-yl}methyl acetate of Formula II to ertugliflozin may be carried out using deacetylating agents. Preferably, the deacetylating agent is sodium methoxide.

In one embodiment of this aspect, the conversion of the crystalline Form B of { ( \R,2S,3S,4R,5S)-5 -[4-chloro-3 -(4-ethoxybenzyl)phenyl] -2,3 ,4-trihydroxy-6, 8- dioxabicyclo[3.2. l]oct-l-yl} methyl acetate of Formula II to ertugliflozin may be carried by methods known in the art, for example, PCT Publication No. WO 2014/159151.

While the present invention has been described in terms of its specific aspects, certain modifications and equivalents will be apparent to those skilled in the art and are intended to be included within the scope of the present invention.

Methods:

XRPD patterns of the samples were recorded using a PANalytical ^® X'pert PRO with X'celerator ^® as the detector, 0.02 as step size, and 3-40° 2Θ as range, using CuKa radiation.

DSC thermograms of the samples were recorded using a Mettler Toledo ^® Stai*, SW 11.0, temperature range 30°C to 300°C, heating rate: 10°C/min., nitrogen flow: 20.0 mL/min.

The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention in any way.

EXAMPLES

Example 1 : Preparation of a crystalline Form B of {(Ti?.2<S'.3iS'.4i?.5iS')-5-r4-chloro-3-(4- ethoxybenzyl)phenyll-2.3.4-trihydroxy-6.8-dioxabicvclor3.2. Hoct-l-yl} methyl acetate of Formula II

{(li?,2 ₁ S ^* ,3,S ^* ,4i?,5 ₁ S)-5-[4-Chloro-3-(4-e1hoxybenzyl)phenyl]-2,3,4-trihydr oxy-6,8- dioxabicyclo[3.2.1]oct-l-yl}methyl acetate (1 g) was added to ethanol (7 mL), and the mixture was heated to 65°C to 70°C to obtain a clear solution. The solution was cooled to 20°C, and then stirred at 20°C to 25°C for 60 minutes. The solid obtained was filtered, and then washed with ethanol (3 mL). The solid was dried under reduced pressure at 40°C to 45°C for 2 hours to obtain the title compound.

Yield: 0.214 g

Example 2: Preparation of a crystalline Form B of UlR.2S,3SAR.5S)-5-\4-c loro-3-(4- ethoxybenzvnphenyll-2.3.4-trihvdroxy-6.8-dioxabicvclor3.2. Hoct-l-yl} methyl acetate of Formula II

{(li?,2 ₁ S ^* ,3,S ^* ,4i?,5 ₁ S)-5-[4-Chloro-3-(4-e1hoxybenzyl)phenyl]-2,3,4-trihydr oxy-6,8- dioxabicyclo[3.2.1]oct-l-yl}methyl acetate (1 g) was added to methanol (7 mL), and the mixture was heated to 57°C to 60°C to obtain a clear solution. The solution was cooled to 21°C, and then stirred at 20°C to 25°C for 60 minutes. The solid obtained was filtered, and then washed with methanol (3 mL). The solid was dried under reduced pressure at 40°C to 45°C for 2 hours to obtain the title compound.

Yield: 0.224 g

Example 3: Preparation of a crystalline Form B of (lR.2S,3SAR.5S)-5-\4-c loro-3-(4- ethoxybenzyl)phenyll-2.3.4-trihydroxy-6.8-dioxabicvclor3.2. Hoct-l-yl} methyl acetate of Formula II

{(li?,2 ₁ S ^* ,3,S ^* ,4i?,5 ₁ S)-5-[4-Chloro-3-(4-e1hoxybenzyl)phenyl]-2,3,4-trihydr oxy-6,8- dioxabicyclo[3.2.1]oct-l-yl}methyl acetate (1.2 g) was added to isopropyl alcohol (24 mL), and the mixture was heated to 75°C to obtain a clear solution. The solution was cooled to 5°C, and then stirred at 5°C to 10°C for 60 minutes. The solid obtained was filtered, and then washed with isopropyl alcohol (3 mL). The solid was dried under reduced pressure at 40°C to 45°C for 2 hours to obtain the title compound.

Yield: 0.38 g