Preparation method of amorphous 3,4-dihydroquinazoline derivatives

Abstract

The present invention relates to a method for preparing an amorphous 3,4-dihydroquinazoline derivative. The amorphous form I compound prepared by the method has no detected esterification byproducts, and the particle size distribution of the obtained solid product is d 90 The particle size does not exceed 10 μm, and XRPD characterization shows that there is no detectable crystalline content / signal within the detection limit, which meets the preparation requirements. At the same time, the preparation process is simple to operate, safe and environmentally friendly, and easy to realize large-scale industrial production.

Description

Technical Field

[0001] The present invention relates to the field of medical technology, and in particular to an amorphous 3,4-dihydroquinazoline derivative and a preparation method thereof. Background Art

[0002] The compound of formula I is a novel non-nucleoside cytomegalovirus (CMV) inhibitor that inhibits viral replication by specifically targeting the viral terminase complex. It is currently being developed for the prevention of CMV infection and for the prevention of CMV infection and related diseases in adult patients who are CMV seropositive after allogeneic hematopoietic stem cell transplantation (HSCT). Its chemical name is (4S)-{8-fluoro-2-[4-(3-methoxyphenyl)piperazine-1-yl]-3-[2-methoxy-5-(trifluoromethyl)phenyl]-3,4-dihydroquinazolin-4-yl}acetic acid, and its chemical structure is as follows:

[0003]

[0004] The current studies have not found a way to reproducibly crystallize the compound in the zwitterionic form and to keep it crystallized in a stable polymorphic form, i.e. the compound of formula I is to be isolated in its amorphous state with sufficient yield and purity while maintaining its physicochemical properties, which allow to achieve adequate dissolution characteristics in a tablet or capsule formulation for oral administration.

[0005] Patent CN105555771A provides a process for preparing an amorphous compound of formula I suitable for solid oral dosage forms, which is separated by precipitation from a water-miscible solvent acetone or acetonitrile into excess water as an anti-solvent. Summary of the invention

[0006] The present invention provides a method for preparing an amorphous form I compound. No esterification by-product is detected in the amorphous form I compound prepared by the method.

[0007] In one aspect, the present invention provides a method for preparing an amorphous form of a compound I.

[0008]

[0009] The compound of formula I is added with an alcohol solvent to form a solution, which is then added to an anti-solvent for precipitation, and the precipitate is separated to obtain an amorphous compound of formula I, wherein the alcohol solvent is a C3-C6 alcohol solvent and the anti-solvent is water.

[0010] In some embodiments, the alcohol solvent is selected from one or more of isopropanol, n-propanol and butanol.

[0011] In some embodiments, the alcohol solvent is isopropanol.

[0012] In some embodiments, the mass volume ratio of the compound of formula I to the alcohol solvent is 35 mg / mL to 250 mg / mL, preferably 80 mg / mL to 200 mg / mL, further preferably 112 mg / mL to 200 mg / mL, and further preferably 200 mg / mL.

[0013] In some embodiments, the volume ratio of the alcohol solvent to the anti-solvent is 1:1 to 1:8, preferably 1:3 to 1:8, more preferably 1:4.5 to 1:8, and even more preferably 1:8.

[0014] In some embodiments, the compound of formula I needs to be stirred and dissolved after being added to an alcohol solvent.

[0015] In some typical embodiments, after the compound of formula I is added to the alcohol solvent, it needs to be stirred and dissolved under heating, and the heating temperature is 40-60°C, preferably 50-55°C.

[0016] In some embodiments, the method for preparing the compound of formula I further comprises eluting and drying steps after separation, wherein the separation step is suction filtration.

[0017] In some preferred embodiments, the present invention provides a method for preparing an amorphous form of a compound I, comprising the following steps:

[0018] (1) adding isopropanol to the compound of formula I, heating and stirring;

[0019] (2) cooling, filtering, adding the filtrate to an anti-solvent for precipitation;

[0020] (3) The suspension is stirred and filtered to obtain a solid.

[0021] (4) washing and drying to obtain the compound of formula I.

[0022] In some embodiments, the stirring time of step (1) is 0.5-2 hours, preferably 0.5 hours.

[0023] In some embodiments, the cooling in step (2) is natural cooling.

[0024] In some embodiments, the filtrate of step (2) is added to the anti-solvent while stirring.

[0025] In another aspect, the present invention provides an amorphous form I compound, whose XRPD spectrum is as follows Figure 1 shown.

[0026] In the present invention, unless otherwise specified, the following terms have the following meanings:

[0027] As used herein, "XRPD" means X-ray powder diffraction;

[0028] As used herein, "GC" refers to gas chromatography;

[0029] In the present invention, "h" means hour, "ml" means milliliter, and "μl" means microliter;

[0030] In the present invention, "room temperature" refers to 25°C;

[0031] In the present invention, "suction filtration" refers to filtration under reduced pressure;

[0032] In the present invention, "d 90 ” refers to the particle size corresponding to when the cumulative particle size distribution percentage of the sample reaches 90%;

[0033] In the present invention, "RSC" refers to residual solvent content;

[0034] In the present invention, "RRT" is relative retention time, which refers to the ratio of the corrected retention time of a component to the corrected retention time of the corresponding sample;

[0035] In the present invention, "glass transition temperature" refers to the temperature corresponding to the transition from a highly elastic state to a glassy state or vice versa;

[0036] In the present invention, "amorphous" is also called glass. The arrangement of atoms or molecules inside it is not periodic, and they are randomly distributed like liquids, which can be regarded as supercooled liquids, such as glass, rosin, gelatin, etc. Amorphous solids have the following general properties: macroscopic properties are uniform, and this uniformity comes from the statistical law of disordered distribution of atoms; physical properties generally do not change with the measurement direction, which is called isotropy; they cannot spontaneously form a polyhedral shape; they have no fixed melting point; and due to the non-periodic structure, they cannot produce diffraction effects on X-rays.

[0037] In the present invention, the determination method of XRPD is as follows:

[0038] Instrument model: D8 Advance

[0039] Test conditions:

[0040] X-ray generator: Cu, kα,

[0041] Tube voltage: 40kV, tube current: 40mA.

[0042] Scattering slit: 0.6mm

[0043] Detector slit: 5mm

[0044] Scanning range: 3-40 degrees

[0045] Step size: 0.02deg

[0046] Rate: 0.3S

[0047] It should be noted that in the X-ray powder diffraction spectrum (XRPD), the diffraction spectrum obtained by the crystalline compound is often characteristic for a specific crystal, wherein the relative intensity of the band (especially at low angles) may vary due to the difference in crystallization conditions, particle size and other measurement conditions resulting from the dominant orientation effect. Therefore, the relative intensity of the diffraction peak is not characteristic for the crystal targeted, and when judging whether it is the same as a known crystal, it is more important to pay attention to the relative position of the peak rather than their relative intensity. In addition, for any given crystal, the position of the peak may have a slight error, which is also well known in the field of crystallography. For example, due to changes in temperature, sample movement, or calibration of the instrument when analyzing the sample, the position of the peak may move, and the measurement error of the 2θ value is sometimes about ± 0.5°, preferably about ± 0.3°, and more preferably about ± 0.2°. Therefore, when determining each crystalline structure, this error should be taken into account, and the 2θ value within the error also belongs to the scope of the present invention. In XRPD spectra, the peak position is usually represented by the 2θ angle or the interplanar distance d, and there is a simple conversion relationship between the two: d = λ / 2sinθ, where d represents the interplanar distance (also known as "interplanar spacing"), λ represents the wavelength of the incident X-ray, and θ is the diffraction angle. For the same type of crystals of the same compound, the peak positions of their XRPD spectra are similar overall, and the relative intensity errors may be large. It should also be pointed out that in the identification of mixtures, some diffraction lines may be missing due to factors such as decreased content. At this time, there is no need to rely on all the bands observed in high-purity samples, and even one band may be characteristic for a given crystal.

[0048] The preparation method provided by the present invention does not detect the by-product of isopropanol esterification, and the particle size distribution of the obtained solid product is d 90 The particle size does not exceed 10 μm, and XRPD characterization shows that there is no detectable crystalline content / signal within the detection limit, which meets the preparation requirements. At the same time, the preparation process is simple to operate, safe and environmentally friendly, and easy to realize large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 The XRPD spectrum of the compound of formula I obtained in Example 4.

[0050] Figure 2 This is the XRPD spectrum of the compound of formula I obtained in Example 5.

[0051] Figure 3 This is the XRPD spectrum of the compound of formula (I) obtained in Example 7. DETAILED DESCRIPTION

[0052] In order to better understand the content of the invention, the present invention is further described below in conjunction with specific embodiments.

[0053] The reagents and raw materials used in the present invention are all commercially available products.

[0054] The analytical methods for the relevant substance analysis tests in the embodiments of the present invention are as follows:

[0055] Chromatographic column: YMC-Pack Pro C18 (4.6mm×150mm, 3μm)

[0056] Flow rate: 1.0mL / min

[0057] Column temperature: 35°C

[0058] Detection wavelength: 215nm

[0059] Injection volume: 2 μL;

[0060] Mobile phase A: 0.1% phosphoric acid solution;

[0061] Mobile phase B: acetonitrile

[0062] Gradient elution was as follows:

[0063]

[0064] The isopropanol solvent residual determination method of the embodiment of the present invention is as follows (GC):

[0065] Chromatographic column: CP-Volamine (30m×0.32mm);

[0066] Inlet temperature: 200°C;

[0067] Column flow rate: 0.8 mL / min;

[0068] Column temperature: starting at 35°C, increase the temperature to 90°C at a rate of 5°C per minute, maintain for 6 minutes, then increase the temperature to 240°C at a rate of 20°C per minute, maintain for 6 minutes;

[0069] Headspace bottle equilibrium temperature: 110°C, equilibrium time: 40 minutes

[0070] Particle size distribution test method of the embodiment described in the present invention:

[0071] Take an appropriate amount of the sample to be tested and refer to the particle size and particle size distribution determination method (Chinese Pharmacopoeia 2020 Edition Part IV General Rules 0982 Method 3): (Sympatec RODOS L-HR1 or laser particle size analyzer with equivalent performance), injection rate 20%, dispersion pressure 3.0 bar.

[0072] Example 1 Preparation of crude product of compound of formula I

[0073] The preparation of the crude product of the compound of formula I of the present invention is described in more detail with reference to patent CN104144916A as follows. This synthesis is only an example and should not be construed as limiting. The specific preparation method is as follows:

[0074] Step 1: A solution of the commercially available compound of formula I-1 in chlorobenzene (800 L) was heated to reflux and azeotropically dried. Phosphorus oxychloride (144 kg) was added and the reaction mixture was stirred at reflux for 3 h. Then, DBU (95 kg) and chlorobenzene (45 L) were added and stirred at reflux for another 9 h. The reaction mixture was cooled to room temperature, hydrolyzed by adding water, diluted with chlorobenzene (80 L), and neutralized with an aqueous solution of ammonia (25%). The phases were separated, the organic phase was washed with water and the solvent was distilled off. The remaining residue was dissolved in dioxane (170 L). 3-methoxyphenylpiperazine (66 kg), DBU (52 kg) and another 90 L of dioxane were added and the reaction mixture was heated at reflux for 4 h. The reaction mixture was cooled to room temperature, added to ethyl acetate (1300 L), washed once with water, three times with 0.2N HCl, once with an aqueous solution of NaCl, and the solvent was distilled off. The obtained residue was dissolved in ethyl acetate (800 L) and added to a solution of (2S, 3S)-2,3-bis[(4-methylbenzoyl)oxy]succinic acid (121 kg) in ethyl acetate (600 L). The obtained mixture was stirred at room temperature for about 60 minutes, then seeded with the compound of formula I-2 and stirred at room temperature for 3 days. It was then cooled to 0-5°C and stirred for another 3 hours. The suspension was filtered and the remaining solid was washed again with ethyl acetate in batches to obtain the compound of formula I-2.

[0075] Step 2: The compound of formula I-2 (1:1 salt) (141 kg, calculated as dry weight) was suspended in ethyl acetate (1400 L) and dissolved by heating to reflux (77 ° C). The solution was filtered and slowly cooled to room temperature, which resulted in spontaneous crystallization. The suspension was stirred at room temperature for 16 h, then cooled to 0-5 ° C and continued to stir for 3 h. The suspension was filtered and the remaining solid was washed again with cold ethyl acetate. The crystals were dried in a vacuum at about 40 ° C for 16 h to obtain a solid of the compound of formula I-2.

[0076] Step 3: A mixture of the compound of formula I-2 (30.8 kg), sodium bicarbonate (16.4 kg) and water (315 L) was mixed with MTBE (160 L). The phases were separated and the organic phase was treated with 35 L of an approximately 7% aqueous solution of sodium bicarbonate. The phases were separated and the organic phase was added to 125 L of an approximately 4% aqueous solution of sodium hydroxide. The reaction mixture was heated to reflux, the solution was evaporated to dryness, and the reactor contents were stirred for 5 h at 55-60 ° C. The reaction mixture was then added to MTBE (160 L) and water (65 L) at approximately 22 ° C and stirred. The phases were separated and the organic phase was extracted with an approximately 6% aqueous solution of sodium chloride (30 L). The combined aqueous phases were mixed with water (25 L) and MTBE (160 L), and the pH was adjusted to approximately 6.5 with approximately 1N hydrochloric acid. The organic phase was separated, the solvent was evaporated to dryness, and the residue was dissolved in acetone (approximately 75 L). The solvent was changed to acetone (6 distillations, about 130 L each time). The final product was then precipitated by adding water, separated by centrifugation, and dried to obtain a crude compound of formula I.

[0077]

[0078] Example 2

[0079] 8.0 mL of isopropanol was added to 303.8 mg of the crude product of the compound of formula I, and ultrasound was used to promote dissolution. 12 mL of anti-solvent purified water was added to the solution under stirring. The system became turbid. After stirring for half an hour, a colloidal precipitate appeared. The gelation phenomenon did not improve with continued stirring, and the experiment was terminated.

[0080] Example 3

[0081] 1.0 mL of 2-butanone was added to 300.9 mg of the crude compound of formula I, and the solution was promoted by ultrasound. 12 mL of purified water as an anti-solvent was added while stirring to precipitate a gel. The gelation phenomenon did not improve after stirring for another hour, and the experiment was terminated.

[0082] In addition, the inventors also tried to replace isopropanol with 1,4-dioxane, and the particle size of the obtained amorphous sample met the requirements. The analysis results of related substances showed that the purity of the main peak of the compound was 99.81%, but the residual 1,4-dioxane was difficult to remove, and the residual amount exceeded the limit of 380ppm by nearly 30 times, with a residual amount of about 11000ppm.

[0083] An attempt was made to use n-heptane as the anti-solvent to replace purified water, and the resulting amorphous sample met the particle size requirements. The analysis results of related substances showed that the purity of the main peak of the compound was 99.87%, but the sample yield was too low, only 31.3%, which was not conducive to large-scale production.

[0084] Example 4

[0085] 0.6 mL of isopropanol was added to 49.8 mg of the crude compound of formula I, and the solution was sonicated to promote dissolution. 2 mL of purified water as an antisolvent was added while stirring, and the product precipitated. The suspension was stirred for one hour. The solid was separated by filtration, rinsed with purified water, and vacuum dried at 45°C for 2 hours to collect the solid. Figure 1 As shown, the XRPD characterization results showed that the obtained solid sample was amorphous.

[0086] Example 5

[0087] 3.2 mL of isopropanol was added to 300.6 mg of the crude compound of formula I, and ultrasonic dissolution was promoted. 12 mL of purified water as an anti-solvent was added while stirring, and the product precipitated. The suspension was stirred for one hour. The solid was separated by suction filtration, rinsed with purified water, and vacuum dried at 45°C for 5 hours to collect the solid. The recovery rate was 79.6%. Figure 2 As shown, the XRPD characterization results show that the obtained solid sample is amorphous; the analysis results of the content of related substances show that the purity of the main peak of the compound is 99.86%; the particle size distribution test results show that the d 90 =4.88μm.

[0088] Example 6

[0089] 8.0 mL of isopropanol was added to 903.3 mg of the crude compound of formula I, and the solution was dissolved by ultrasound. The solution was filtered and the filtrate was added to 36 mL of purified water as an anti-solvent while stirring. The product was precipitated and the suspension was stirred for one hour. The solid was separated by suction filtration, rinsed with purified water, and vacuum dried at 45° C. for 9 hours to collect the solid. The yield was 84.11%. The GC analysis results showed that the residual amount of isopropanol solvent in the sample was 0.02%.

[0090] Example 7

[0091] 25 mL of isopropanol was added to 5 g of the crude compound of formula I, and the mixture was stirred magnetically at 50-55°C for about 0.5 hours to promote dissolution, and then cooled naturally at room temperature. The mixture was filtered, and the filtrate was added to 200 mL of purified water as an anti-solvent while stirring, after which the product precipitated. The suspension was stirred for another hour, and the solid was separated by suction filtration, rinsed twice with purified water, and the solid was collected after vacuum drying at 45°C for 10 hours, with a yield of 84.0%. The obtained solid sample was subjected to characterization analysis such as related substances, residual solvent content, particle size distribution, and XRPD.

[0092] The HPLC analysis results showed that the main peak purity of the compound was 99.91%, and the GC analysis results showed that the residual solvent isopropanol content in the sample was 0.05%. The particle size distribution test results showed that the d 90 =7.93μm. Figure 3As shown, the XRPD characterization results showed that the obtained solid sample was amorphous.

[0093] Example 8

[0094] 1. Preparation of amorphous samples with different residual amounts of isopropanol solvent

[0095] When a lower alcohol (such as methanol or ethanol) is used in the above precipitation step, it can be re-esterified with the carboxyl group in the structure of the compound of formula I under stress conditions (elevated temperature). In the amorphous preparation method currently developed, isopropanol is used in the precipitation step, which theoretically has a certain esterification risk. By carrying out a stability prediction test, the reliability of the preparation method can be examined and evaluated, so a sample with a large amount of isopropanol residue is prepared for subsequent stability prediction tests.

[0096] Specific preparation experimental scheme: add 6.5mL isopropanol to 1.1g crude compound of formula I, stir magnetically (about 500rpm / min) at 50-55℃ to promote dissolution for about 0.5 hours, then cool naturally at room temperature. Filter, add the filtrate to 52mL purified water as anti-solvent under stirring conditions (about 320rpm / min), and then the product precipitates. Stir the suspension for another hour, separate the solid by filtration, rinse twice with purified water, and collect the solid after natural drying. GC analysis results show that the residual solvent isopropanol content in the sample is 0.54%.

[0097] 2. Preparation of Isopropyl Ester Impurity

[0098] 0.71g of compound I, 0.4g of K2CO3 and 7mL of DMF were added to a 25mL three-necked flask, nitrogen was protected, the temperature was lowered to 0°C, 0.31g of iodoisopropyl was added dropwise, the reaction was transferred to room temperature or 25°C to continue the reaction, stirred overnight, and sampled for monitoring. The reaction was completed. 14mL of water and 7mL of ethyl acetate were added to the reaction solution, stirred for 5min, allowed to stand for separation, the upper organic layer was washed with water (14mL×3), concentrated, and dried in vacuo at 40°C to obtain compound II, MS: m / z=614.99 [(M+H) + ].

[0099]

[0100] 3. Take 20 mg of each solid powder sample of the amorphous form I compound with an isopropanol content of 0.54% and put them into respective 8-mL open sample bottles. Then take another 8-mL open sample bottle and put saturated saline (lithium chloride, anhydrous potassium fluoride, potassium carbonate, sodium chloride, potassium chloride) with different humidity. The humidity and the corresponding saturated saline are shown in Table 1:

[0101] Table 1 Preparation of saturated brine

[0102] Reagents Humidity (%RH) Preparation method Lithium chloride 11 Add 3 mL of water to 5 g of salt Anhydrous potassium fluoride 21 Add 3 mL of water to 7 g of salt Potassium carbonate 41，42 Add 3 mL of water to 4 g of salt Sodium chloride 74，75 Add 3 mL of water to 4 g of salt Potassium chloride 79，80 Add 3 mL of water to 4 g of salt

[0103] Place the sample bottle, saturated brine bottle and wireless temperature and humidity sensor (RH Temp 1000, MadgeTech) in a 125-mL wide-mouth Mason jar (Mason Ball Jar, USA), tighten the bottle cap to ensure that the bottle is sealed. Then place the sealed Mason jar in a high-temperature constant temperature incubator and record the actual placement time. After placing the sample bottle for the corresponding time in Table 1 and Table 2 under different temperature and humidity combinations, take out the sample bottle and place it in a sealed container with silica gel desiccant. After cooling to room temperature, seal the sample bottle and perform HPLC characterization on it (transfer to 4°C for storage before analysis) to detect whether the sample produces isopropyl ester impurities after being placed under the corresponding conditions.

[0104] Table 2 Stability test results

[0105]

[0106] Wherein, RRT=1.30 is the relative retention time of isopropyl ester; RRT=1.00 is the relative retention time of the compound of formula I; “ / ” means not detected.

[0107] The results showed that the isopropyl ester impurity was not detected under all conditions. Therefore, the amorphous form I compound sample prepared using the isopropanol solvent system had a low risk of esterification during storage.

Claims

1. A method for preparing an amorphous form of a compound I, The compound of formula I is added to an alcohol solvent to form a solution, and the solution is then added to an anti-solvent for precipitation, and the precipitate is separated to obtain an amorphous compound of formula I, wherein The alcohol solvent is isopropanol, and the anti-solvent is water; the mass volume ratio of the compound of formula I to the alcohol solvent is 80 mg / mL to 200 mg / mL; and the volume ratio of the alcohol solvent to the anti-solvent is 1:3 to 1:

8.

2. The method according to claim 1, wherein the mass volume ratio of the compound of formula I to the alcohol solvent is 112 mg / mL to 200 mg / mL.

3. The method according to claim 1, wherein the mass volume ratio of the compound of formula I to the alcoholic solvent is 200 mg / mL.

4. The method according to claim 1, wherein the volume ratio of the alcohol solvent to the anti-solvent is 1:4.5 to 1:

8.

5. The method according to claim 1, wherein the volume ratio of the alcohol solvent to the anti-solvent is 1:

8.

6. The method according to claim 1, wherein the compound of formula I is added to an alcoholic solvent and then stirred to dissolve.

7. The method according to claim 6, wherein the compound of formula I is added to the alcohol solvent and then stirred and dissolved under heating, and the heating temperature is 40-60°C.

8. The method according to claim 6, wherein the compound of formula I is added to the alcohol solvent and then stirred and dissolved under heating, and the heating temperature is 50-55°C.

9. The method according to claim 1, wherein the method for preparing the compound of formula I further comprises eluting and drying steps after separation, wherein the separation step is suction filtration.

10. A method for preparing the amorphous form I compound according to any one of claims 1 to 9, comprising the following steps: (1) adding isopropanol to the compound of formula I, heating and stirring; (2) cooling, filtering, adding the filtrate to an anti-solvent for precipitation; (3) stirring the suspension and filtering to obtain a solid; (4) washing and drying to obtain the compound of formula I.

11. The method according to claim 10, wherein the stirring time in step (1) is 0.5-2 hours.

12. The method according to claim 10, wherein the stirring time in step (1) is 0.5 hours.

13. The method according to claim 10, wherein the cooling in step (2) is natural cooling.

14. The method according to claim 10, wherein the filtrate in step (2) is added to the anti-solvent while stirring.

15. An amorphous form I compound according to any one of claims 1 to 14, whose XRPD spectrum is shown in Figure 1.

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