WO2015090259A1

WO2015090259A1 - Method of preparing anhydrous polymorphic form n-6 of dasatinib

Info

Publication number: WO2015090259A1
Application number: PCT/CZ2014/000160
Authority: WO
Inventors: Jan RYMES; Michal Zapadlo; Ondrej Dammer
Original assignee: Zentiva, K.S.
Priority date: 2013-12-19
Filing date: 2014-12-18
Publication date: 2015-06-25
Also published as: CZ306732B6; CZ20131046A3

Abstract

A method for the preparation of the crystalline Form N-6 of dasatinib, characterized by the following reflexions in the X-ray powder pattern, measured with the beam radiation CuKα: 6.8; 12.3; 13.2; 13.8; 16.7; 21.0; 24.3, and 24.8 ± 0.2° 2-theta. The method consists in drying a solvate of dasatinib from the group of the ethanol solvate, methanol solvate, and acetonitrile solvate of dasatinib, or their mixtures.

Description

Method of preparing anhydrous polymorphic Form N-6 of dasatinib Technical Field

The invention relates to a new method of preparing the polymorphic anhydrous form N-6 of dasatinib ; chemically: (N-(2-cbioro-6-methylphenyl)-2- [[6-[4-(2-hydroxyethyl)- 1 - piperazinyl]-2-me1hyl-4-pyrirriidinyl]amino]-5-thiazole carboxamide, CAS: 302962-49-8)), described by the formula (1), and its key solvates, enabling formation of the chemically highly pure Form N-6.

State of the art During the recent decade, the therapy of the chronic myeloid leukaemia (CML) has significantly changed. Great turn in the therapy of CML was the discovery of imatinib (Gleevec), an inhibitor of BCR-ABL tyrosine kinase. Nevertheless, in spite of efficiency of imatinib, a group of patients with CML still remains who are resistant to or do not tolerate therapy with imatinib. It is these patients that the therapy with dasatinib (BMS-354825), an inhibitor of BCR-ABL, Src, and other kinases, can be mdicated for. This drug has been developed by Bristol-Myers Squibb (WO0062778A1, 2000) and sold under the trade name Sprycel.

1

A large number of polymorphic forms of dasatinib are described in the literature, designated as: Hl-7, BU-2, E2-1, N-6, T1H1-7, and T1E2-1. Patent document WO2005/077975 A2 describes the preparation of dasatinib monohydrate (Hl-7) and butanol solvate (BU-2). Another patent document (US2006/0004067A1) linked up with the previous one describes two ethanol solvates (E2-1, T1E2-1) and further two anhydrous forms (N-6, T1H1-7). A large number of preparations of various polymorphic forms are also described in TEVA patent application WO 2009/053854 A2.

Disclosure of Invention The present invention relates to a new method of preparing the anhydrous Form N-6, in particular new use of selected solvate forms (MeOH, MeCN) and their mixtures, which allow conversion to the anhydrous Form N-6 under elevated temperature and vacuum. This phenomenon has also been observed under laboratory conditions, only with a lower conversion rate. From the viewpoint of industrial utilization, this is a very simple, robust, and relatively fast process of preparing the anhydrous Form N-6; its production has also been reproducibly tested in kilogram amounts.

Detailed description of invention

The preparation of the compound of formula (1) includes the following direct steps 1 to 3 (Scheme 1).

Scheme 1 : Synthesis of dasatinib

^SteP ¹ Molecular Weight: 163,00

Step 2

Molecular Weight: 394,28 Molecular Weight 130,19 ^{Molecu,ar We,}9^{ht: 438}·°1

In the first step, 2-ammo-N-(-(2-cMoro-6-memylphenyl)-thiazole-5-carboxamide (4) is reacted with 4,6-dicMoro-2-methylpyrirnidine (5). The reaction is carried out in tetrahydrofuran THF at temperature of 10 - 30°C. Sodium terc-butoxide (NaOtBu) is used as a base. The reaction is completed within 1 hour. The isolated yield ranged between 80 and 83%. Next step is reaction of the (SNAT) intermediate (3) 2-(6-chloro-2-methylpyrimidine-4-ylamino)-N-(2-chloro-6- methylphenyl)thiazole-5-carboxamide with l-(2-hydroxyethyl)-piperazine (2) in an environment of NMP. The reaction runs in the temperature range of 65 to 100°C. Acetonitrile is used as the anti-solvent for isolation of crude dasatinib (1). After isolation, the crude product is dried in vacuo at a temperature of 55 - 65°C. An NMP solvate is obtained with predominant amounts of two residual solvents NMP with an admixture of MeCN. The final step of the synthesis is crystallization from the mixture of solvents MeOH and MeCN at a temperature of 55 - 62°C. The obtained isolated wet crystalline product again shows the solvate structure corresponding to a MeCN solvate (Fig. 2) or a MeOH solvate (Fig. 3). The type to be isolated depends on the selected procedure of preparation and on the ratio of both solvents (examples 3 + 4). The crystallized wet product is further dried in vacuo at a temperature in the range of 55 - 65°C. After drying for 2 - 3 hours, the expected polymorphic Form N-6 is obtained. The duration of drying depends on residual moisture in the sample, type of the drying oven, attained vacuum, and heating rate to the final temperature of drying. Typically, as early as within 1 hour of drying at 55 °C in a shelf drier, majority of the starting MeCN/MeOH solvate has been transformed to the Form N-6 (Fig. 4). The isolated yield ranges between 73 and 77% (crude and crystallized product dasatinib). Total yield of the synthesis is then within the range of 58 - 63%. In addition, it has been verified that the polymorphic Form N-6 can be obtained under reduced vacuum and elevated temperature by drying other solvates, such as EtOH, acetone, IP A, and their mixtures. Similarly, the monohydrate, particularly containing MeCN, MeOH as residual solvents, can be converted to the Form N-6 under reduced pressure and elevated temperature.

The described process is an efficient method of preparing dasatinib that is also convenient for larger scales. The procedure according to Scheme 1 makes it possible to obtain, in a reproducible way, dasatinib (1) characterized by chemical purity higher than 99.8 % and containing individual impurities under 0.1 % (according to UPLC).

Brief Description of Drawings

Figure 1 : X-ray powder pattern of polymorphic anhydrous Form N-6 of dasatinib Figure 2: X-ray powder pattern of the MeCN solvate form of dasatinib

Figure 3: X-ray powder pattern corresponding to the MeOH solvate of dasatinib

Figure 4: Evolution of X-ray powder patterns in the course of conversion of the MeCN solvate form to the Form N-6 during drying in vacuo and at a temperature of 55 °C (shelf drier).

Examples

The following examples serve for a more detailed illustration of the method of producing dasatinib of the polymorphic anhydrous Form N-6 according to the present invention on the industrial scale. Example 1

The preparation of the intermediate (3) (2-(6-chloro-2-methylpyrimidine-4-ylamino)-N-(2- cUoro-6-methylphenyl)thiazole-5-carboxamide)

In a chemical reactor, 2-ammo-N-(-(2-chloro-6-methylphenyl)-thiazole-5-carboxamide (4) (3.750 kg) and 2,4-dichloro-2-methyIpyrimidine (5) (2.889 kg) are suspended in 50.0 1 of THF. The suspension is stirred until dissolved at 25 - 30°C; then it is cooled down to 10°C and a pre-prepared solution of 4.444 kg of NaOt-Bu in 25.0 1 of THF is added dropwise under N₂. The solution of NaOt-Bu is added dropwise under N₂ within 15 - 25 min (intensive stirring). Finally, the separating funnel is rinsed with 1.5 1 of THF. During the dropwise addition, the temperature of the reaction mixture is kept between 15 and 30°C. After the dosing is completed, the reaction mixture is stirred at 20 ± 2°C for 60 min. The reaction mixture is cooled to 10 - 15°C, 12.5 1 of demineralized water is added dropwise, and the mixture is stirred for 15 min. Then, its temperature is brought to 5°C and diluted 1.5 M HCl (2,550 ml of 35 % HCl + 16.5 1 of demi water) is added dropwise within about 35 - 45 min. The amount of the HCl solution is chosen in order to reach final pH of 4.0 - 6.5 (optimally 5.0 - 5.5). The stirring goes on at 5 - 8°C for 15 - 20 min (checking of pH, adjusted, as required). 22.5 1 of acetone is added, the mixture is heated to 40°C, and stirred at this temperature for 30 minutes. Then it is cooled down slowly to 10 - 15°C and stirred for 1.5 h. The separated product is centrifuged, washed with a warm (40 °C) 1 :1 mixture of acetone / demi water (1 x 5.0 1) and then with cold acetone (1 x 5.0 1). The product is dried in a vacuum drier at 55 - 65°C for 12 hours.

Yield: 4,610 g (83.5%), sum of impurities according to PLC: 1.4%; loss on drying: 0.3%.

Example 2

Preparation of crude dasatinib (NMP solvate)

In a chemical reactor, dasatinib intermediate (3), CAS: 302964-08-5 (4.500 kg) is suspended in 18.0 I of NMP. The suspension is heated to a temperature of 67 - 68°C. A solution of HEPIP (7.313 kg of HEPIP + 3.8 1 of NMP) is prepared and added dropwise to the reaction mixture within 5 - 10 min. During the addition the temperature is kept at 65 ± 3°C. After the addition is completed, the mixture is stirred at 65°C for 60 min. Then, temperature is brought to 100°C and stirring goes on for 20 min. All the time, the reaction is carried out under N₂ and access of light is prevented! After the reaction is completed, the reaction mixture is cooled down to 40 - 45°C and filtered. The filter is washed with 1.0 1 NMP. The filtered reaction mixture is added dropwise to MeCN (113 1), heated at 25 - 30°C, within 15 - 20 min. Stirring continues at 25 - 30°C for 30 min. The mixture is heated to 45 - 50°C and stirred for 0.5 h. Then, is slowly cooled down to 10 - 15°C within 75 - 90 min and stirred for 1.0 - 1.5 h. The separated product is centrifuged, and washed with cold (2 - 8°C) MeCN (2 x 6.0 1). It is dried in a vacuum drier at 60°C for 12 hours. Yield: 82%, sum of impurities according to UPLC: 0.2%; content of residual solvents: 30,000 ppm NMP, 17,000 ppm CH3OH; X-ray powder pattern corresponds to the NMP solvate.

Example 3 Preparation of crystallized dasatinib - wet (MeCN solvate)

The crude dasatinib (1.00 kg) is suspended in 10.5 1 of MeCN and 17.5 1 of MeOH. The suspension is heated up to 58 - 62°C and stirred for 0.5 h. Then, it is cooled down to 40 - 45°C and stirred for 1 hour. Cooling is continued to -5 to 0°C and stirred for 1.0 - 1.5 h. The separated product is centrifuged, and washed with cold MeCN (2 x 3.0 1). All the time, the crystallization is carried out under the inert atmosphere of N₂ and access of light is prevented! Drying is carried out as in Example 5. The X-ray pattern of the wet sample corresponds to the MeCN solvate. The MeCN solvate is characterized by the reflexions listed in Table 1:

Table 1: MeCN solvate

Position Inter-planar Rel. int.

[°2 Th.] distance [A] [%]

5.66 15.602 100.0

5.86 15.080 81.5

11.77 7.514 10.5

12.25 7.222 36.9

14.86 5.958 27.2

16.05 5.518 16.6

17.11 5.179 8.7

18.53 4.785 5.7

19.11 4.642 4.8

21.63 4.106 7.4

22.13 4.013 12.0

22,97 3.869 7.3

24.67 3.606 13.0

25.34 3.511 15.5 Example 4

Preparation of crystallized dasatinib - wet (MeOH solvate)

The crude dasatinib (1.00 kg) is suspended in 5.0 1 of MeCN and 25 1 of MeOH. The suspension is heated up to 58 - 62°C and stirred for 0.5 h. Then, it is cooled down to 30 - 35°C and stirred for 1 hour. Cooling is continued to -5 to 0 °C and stirred for 1.0 - 1.5 h. The separated product is centnfuged, and washed with cold MeCN (2 x 3.0 1). All the time, the crystallization is carried out under the inert atmosphere of N₂ and access of light is prevented! Drying is carried out as in Example 6. The X-ray pattern of the wet sample corresponds to the MeOH solvate and is characterized by the reflexions listed in Table 2: Table 2: MeOH solvate

Position Inter-planar Rel. int.

[°2 Th.] distance [A] [%]

7.36 11.994 74.4

12.20 7.252 21.5

13.43 6.585 19.7

14.58 6.069 36.7

16.39 5.404 100.0

16.99 5.215 15.1

19.02 4.662 17.8

19.44 4.562 13.0

20.86 4.256 5.3

21.95 4.047 11.6

24.54 3.624 45.0

25.44 3.498 28.6

30.94 2.888 9.9 Example 5

Preparation of crystallized dasatinib - dry (anhydrous Form N-6)

The wet crystalline dasatinib (solvate form - MeCN, Example 3) is dried in a vacuum tray drier with suction of N₂ at 55 - 65 °C for 16 h. Yield: 91% (from crude API); sum of impurities according to UPLC: 0.11%, content of residual solvents less than 500 ppm, content of water according to KF 0.5%; X-ray pattern of the dry sample corresponds to the pure anhydrous Form N-6.

Example 6 Preparation of crystallized dasatinib - dry (anhydrous Form N-6)

The wet crystallized dasatinib (solvate form - MeOH, Example 4) is dried in a stirred vacuum drier with suction of N₂ at 55— 65 °C for 1 h.

Yield: 85% (from crude API); sum of impurities according to UPLC: 0.13%, content of residual solvents less than 1500 ppm, content of water according to KF 0.7%; X-ray pattern of the dry sample corresponds to the pure anhydrous Form N-6.

Overview of analytical methods

The samples mentioned in the previous examples were characterized by the method of X-ray powder diffraction. The amounts of residual solvents were determined by GC. Chemical purity of the samples was determined by means of UPLC.

The measured parameters of the X-ray powder diffraction: Diffraction patterns were measured in a diffractometer X'PERT PRO MPD PANalytical, X-ray beam CuKa (λ = 1.542 A), excitation voltage: 45 kV, anodic current: 40 mA, measured range: 2 - 40° 2Θ, step size: 0.01° 2Θ. The measurement was performed on a flat powdered sample placed on an Si plate or X-ray holders with a cavity of the diameter 16 mm and height 2.4 mm (so-called back-loading technique) were used. Programmable divergent diaphragms with irradiated area of the sample of 10 mm, Soller diaphragms 0.02 rad, and an anti-scattering diaphragm ¼ were used for setting the primary optics. A detector X'Celerator with maximum opening of the detection slot, Soller diaphragms 0.02 rad, and an anti-scattering diaphragm 5.0 mm were used for setting the secondary optics.

Method A: The following solvents are monitored: methanol ethanoU acetonitrile

These residual solvents were determined using the method of head-space gas chromatography in an instrument PerkinElmer Autosystem XL with FI detection and a head-space autosampler TurboMatrix 40.

Chromatographic conditions:

Capillary column: CP Sil 5 CB (30 m x 0.32 mm x 3.0 μηι) or equivalent

Temperature program: 40°C - 3 min, gradient 20°C/min to 160°C - 2 min

Carrier gas: helium for chromatography R; 1.6 ml/min

Injector: splitting flow rate 4.0 ml/min, 165°C

Detector: FID, 300 °C, Range: 1, Attn: -3

Conditions ofHS autosampler:

Oven temperature: 110°C

Needle temperature: 115°C

Transfer line temperature: 120°C

Time at temperature: 30.0 min

Time of pressurization: 1,0 min

Time of injection: 0.05 min

Time of rinsing: 0.2 min

Pressure: 21 psi

GC cycle: 20 min

Preparation of solutions:

Basic solution:

Methanol lOO mg

Ethanol lOO mg

Acetonitrile 100 mg

Acetone 100 mg

Dichloromethane 100 mg These weights are dissolved in N,N-diraethylacetamide and the solution is made up to 25.0 ml with this solvent.

Reference solution: 2.5 ml of the basic solution is diluted with Ν,Ν-dimethylacetamide to 50.0 ml.

Reference sample: 1.0 ml of the reference solution is pipetted to the 20 ml HS vial and the vial is closed with a cap.

Blank experiment: 1.0 ml of N,N-dimethylacetamide is pipetted to the 20 ml HS vial and the vial is closed with a cap.

Tested sample: 20.0 mg of the tested substance is weighed into the 20 ml HS vial, 1.0 ml of N,N-dimethylacetamide is added, and the vial is closed with a cap.

Test of performance of the chromatographic system:

- Repeatability: relative standard deviation of areas of the peaks of the given residual solvent - max. 15.0 %, calculated from five consecutive injections of the reference sample;

- Resolution: at least 1.5 between the peaks of individual residual solvents in the fifth injection of the reference sample.

Evaluation:

The contents of the residual solvents expressed in % are evaluated by the method of external standard according to the formula: x = x 0,2 , wherein

Af ... peak area of the individual residual solvent in the chromatogram of the tested sample; A^r ... peak area of the individual residual solvent in the chromatogram of the reference sample;

.weight of the individual residual solvent in the basic solution

mf ...weight of the tested sample in mg. Method B: l-Methyl-2-pyrrolidinone ΓΝΜΡ^') is monitored

This residual solvent was determined by the method of gas chromatography in an instrument Agilent 6890 with direct injection and FI detection.

Chromatographic conditions:

Capillary column: Rtx-5 Amine (30 m ^χ 0.53 mm ^χ 3.0 μιη) or equivalent

Temperature program: 115°C - 0 min, gradient 15°C/min to 235°C - 0 min

Carrier gas: helium for chromatography R; 40 cm/s

Injector: splitting ratio 1: 2, 220°C

Injection: 1 μΐ

Detector: FID, 290°C

Preparation of solutions:

Basic solution: 53.0 mg of the reference substance N-methyl-2-pyrrolidone and 150.0 mg of the reference substance l-(2-hydroxyethyl)piperazine are dissolved in pyridine in a 10 ml volumetric flask and made up with pyridine to the mark.

Re ference solution: 125 μΐ of the basic solution is diluted with pyridine to 25 ml.

Blank sample: 1.0 ml of pyridine is pipetted to a 2 ml GC vial and the vial is closed with a cap.

Reference sample: 1.0 ml of the reference solution is pipetted to a 2 ml GC vial and the vial is closed with a cap.

Tested sample: 50.0 mg of the tested substance are dissolved in 1 ml of pyridine in a 2 ml GC vial and the vial is closed with a cap.

Orientation retention times:

N-methyl-2-pyrrolidone 4.5 min.

l-(2-hydroxyethyl)piperazine 5.6 min.

Test of performance of the chromatographic system:

- Repeatability: relative standard deviation of peak areas of N-methyl-2-pyrrolidone - at most 15.0%, calculated from five consecutive injections of the reference sample;

- Resolution: at least 10 between peaks of N-methyl-2-pyrrolidone and 1 -(2-hydroxyethyl) piperazine in the fifth injection of the reference sample. Evaluation:

The content of N-methyl-2-pyrroHdone expressed in ppm is evaluated by the method of external standard according to the formula:

A'^{esl ■} m^ref

x = - — r ^x °'⁰⁵. ^wherein

^Λχ ' ^mx

A* ⁵¹ ...peak area of N-methyl-2-pyrrolidone in the chromatogram of the tested sample;

A"^f ... peak area of N-methyl-2-pyrrolidone in the chromatogram of the reference sample; m^r ...weight of N-methyl-2-pyrrolidone in the basic solution in mg;

m' ...weight of the tested sample in mg

Method C: Impurities in the product are monitored

ChromatosraOhic conditions:

Instrument: UPLC UHPLC with UV/VIS or PDA detector

Column:

Stationary phase: ACQUITY CSH Phenyl-Hexyl (1.7 μιη)

Size: 1 = 0.100 m, 0 3.0 mm

Temperature: 35°C

Mobile phase A: 1 ml of HC10₄ R is dissolved in 1000 ml of water R.

Mobile phase B: Acetonitrile Rl Elution gradient:

Time Mobile phase A Mobile phase B

[min] [% V VJ [% V/VJ

0 90 10

10 50 50

11 50 50

12 90 10

Flow rate: 0.5 ml/min

Detection: UV 220 nm

Injection: 1.0 Temperature of autosampler 15°C

Time of analysis: 12 min

Delay of next injection: 2 min

Orientation retention time: "dasati ib " about 5.6 min

Relative retention time: (with reference to "dasatinib ")

Impurity "DAS 4" RRT 0.72 Impurity "DAS 6" RRT 0.93 Impurity "DAS 1" RRT 0.97 Impurity "DAS 3" RRT 1.07 Impurity "DAS 5" RRT 1.82

Sample solvent: Acetonitrile l / Water R 50/50 (V/V)

Test solution: 15 mg of the sample are dissolved in 25 ml of the sample solvent, the mixture is placed into an ultrasound bath for 5 minutes, and, after dissolving and cooling down to room temperature, the solution is made up to 50.0 ml with the sample solvent. The sample must be well protected against light!

Evaluation: The content of individual impurities is evaluated by the method of internal normalization:

Limits:

- Impurity DAS 1 NMT 0.15 %

- Impurity DAS 3 NMT 0.15 %

- Impurity DAS 4 NMT 0.15

- Impurity DAS 5 NMT 0.15 %

- Impurity DAS 6 NMT 0.15 %

- Any other impurity NMT 0.10 %

Water (2.5.32): Microdetermination: max. 2.0%, determination from 0.100 g.

Claims

1. A method of preparing the crystalline Form N-6 of dasatinib, characterized by the following reflexions in the X-ray powder pattern, measured with the beam radiation CuKa: 6.8; 12.3; 13.2; 13.8; 16.7; 21.0; 24.3, and 24.8 ± 0.2° 2-theta,

the method consisting in drying a dasatinib solvate from the group of the ethanol solvate, methanol solvate, and acetonitrile solvate of dasatinib, or their mixtures.

2. The method according to Claim 1, characterized in that the drying is carried out in vacuo at a temperature in the range of 55 - 65°C for at least 2 hours.