WO2025130951A1 - Ad-35 polymorphs, preparation methods therefor, and use thereof - Google Patents

Abstract

The present invention provides crystalline forms of 6-[2-[1-(2-pyridylmethyl)-4-piperidyl]ethyl]spiro[[1,3]dioxolo[4,5-f]isoindole-7,1'-cyclopropane]-5-one phosphate (AD-35), and preparation methods therefor. The invention further provides a use of the crystalline forms of AD-35 in the preparation of a drug for treating Alzheimer's disease.

Description

AD-35 polymorphs and preparation methods and uses thereof Technical Field

The present invention relates to a polymorph of AD-35 and a preparation method thereof, and is specifically embodied in a polymorph of 6-[2-[1-(2-pyridylmethyl)-4-piperidinyl]ethyl]spiro[[1,3]dioxol[4,5-f]isoindole-7,1'-cyclopropane]-5-one phosphate (AD-35) and a corresponding preparation method thereof.

Background Art

WO2014005421 reports a new class of benzodioxole compounds, which have the activity of inhibiting acetylcholinesterase and can be used to treat Alzheimer's disease. Particularly noteworthy among these compounds is compound AD-35, whose chemical name is: 6-[2-[1-(2-pyridylmethyl)-4-piperidinyl]ethyl]spiro[[1,3]dioxol[4,5-f]isoindole-7,1'-cyclopropane]-5-one phosphate, and its chemical structure is as follows:

Why is AD-35 so eye-catching? Because compared with donepezil, it is a relatively weak acetylcholinesterase inhibitor, and its in vitro acetylcholinesterase inhibitory activity is about one-tenth of donepezil's activity. However, the compound showed comparable efficacy to donepezil in the Morris water maze test, that is, the effect of improving memory and learning ability was comparable to donepezil. Further studies have found that in addition to inhibiting the activity of acetylcholinesterase, AD-35 can also significantly inhibit the production and release of proinflammatory cytokines TNF-α and IL-1β induced by Aβ _25-35 , thereby greatly reducing the toxicity of Aβ _25-35 to nerve cells and effectively protecting nerve cells. In vitro experiments have also found that AD-35 has a certain ability to chelate transition metal ions such as Cu ²⁺ , and can inhibit the aggregation of Aβ induced by Cu ²⁺ and depolymerize Aβ polymers in the presence of Cu ²⁺ . It can be seen that AD-35 is a multi-mechanism and multifunctional compound (Li et al. Journal of Alzheimer's Disease 2017, 56(4), 1403), which protects nerve cells through multiple mechanisms.

In addition, the safety of AD-35 is also very eye-catching. The completed Phase I clinical single-dose ascending tolerance trial (SAD) showed that the subjects took 90 mg of AD-35 once without adverse reactions; the multiple-dose ascending tolerance trial (MAD) showed that the subjects took 120 mg of AD-35 once a day for two consecutive weeks without adverse reactions.

In summary, AD-35 has great potential to become a new drug for the treatment of Alzheimer's disease with minimal side effects. Its multiple mechanisms of action are likely to enable this compound to not only alleviate the symptoms of Alzheimer's patients, but also delay the progression of the disease.

For drugs, different crystal forms of drugs make the physical and chemical properties of polymorphic drugs different, such as melting point, apparent solubility, dissolution rate, optical and mechanical properties, crystallinity, crystal habit, particle size and particle size distribution, particle aggregation state, density, filtration and grinding, crushing, powder making, etc., which in turn affect the characteristics of the dosage form, such as fluidity, dissolution, bioavailability and stability, etc. These physical and chemical properties directly determine whether a specific crystal form is a dominant crystal form, whether it can be made into a drug, and directly affect the quality of raw materials and preparations. Therefore, it is necessary to study the crystal form of AD-35 and the properties of each crystal form to meet the practical application of AD-35.

Summary of the invention

The present invention relates to stable polymorphs of 6-[2-[1-(2-pyridylmethyl)-4-piperidinyl]ethyl]spiro[[1,3]dioxol[4,5-f]isoindole-7,1'-cyclopropane]-5-one phosphate (AD-35), which are respectively crystal form (I), crystal form (II), crystal form (III), crystal form (IV), crystal form (V), crystal form (VI) and amorphous form (VII). A preparation method of the AD-35 polymorphs is also provided.

In one aspect of the present invention, a crystalline form (I) of AD-35 is provided, whose X-ray powder diffraction (XRPD) spectrum has characteristic peaks at the following diffraction angles 2θ: 7.2±0.2°, 7.8±0.2°, 14.2±0.2°, 16.1±0.2°, 16.5±0.2°, 21.0±0.2°, and 23.5±0.2°.

Further, the X-ray powder diffraction pattern of the AD-35 crystal form (I) has characteristic peaks at the following diffraction angles 2θ: 12.8±0.2°, 16.7±0.2°, 17.6±0.2°, 18.7±0.2°, 19.3±0.2°, 20.0±0.2°, 21.7±0.2°, 24.1±0.2°, 26.6±0.2°. Further, preferably, the X-ray powder diffraction spectrum of the crystal form (I) of AD-35 of the present invention has the 2θ, d value and relative intensity data shown in Table 1 below:

Table 1

Without limitation, the crystalline form (I) of AD-35 described in the present invention has an X-ray powder diffraction spectrum as shown in FIG1 .

In addition, the infrared absorption spectrum of the crystalline form (I) of AD-35 described in the present invention in potassium bromide is about 454.4cm ^-1 , 504.8cm ^-1 , 535.8cm ^-1 , 568.1cm ^-1 , 757.3cm ^-1 , 779.5cm ^-1 , 861.4cm ^-1 , 874.8cm ^-1 , 925.6cm ^-1 , 951.0cm ^-1 , 1027.9cm ^-1 , 1073.2cm ^-1 , 1127.9cm ^-1 , 1165.3cm ^-1 , 1247.6cm ^-1 , 1282.0cm ^-1 , 1368.2cm ^-1 , 1411.0cm ^-1 , 1475.2cm ^-1 , 1590.1cm ^-1 , 1620.7cm ^-1 There are absorption peaks at 1671.9cm ^-1 , 2859.6cm ^-1 , 2918.1cm ^-1 , 3047.8cm ^-1 , and 3440.8cm ^-1 .

Without limitation, the crystalline form (I) of AD-35 of the present invention has an infrared spectrum as shown in FIG8 .

The differential scanning calorimetry (DSC) spectrum of the crystal form (I) of AD-35 described in the present invention has a maximum endothermic peak at 223±5°C.

Without limitation, the crystalline form (I) of AD-35 of the present invention has a DSC spectrum as shown in FIG. 15 .

Without limitation, the crystalline form (I) of AD-35 of the present invention has a TGA spectrum as shown in FIG. 22 .

Another object of the present invention is to provide a method for preparing the AD-35 crystal form (I), which is selected from any one of the following methods:

The compound of formula A with the following structure is the free base of AD-35, namely 6-[2-[1-(2-pyridylmethyl)-4-piperidinyl]ethyl]spiro[[1,3]dioxol[4,5-f]isoindol-7,1'-cyclopropane]-5-one.

The method (1) comprises the following steps:

1) dissolving the compound represented by formula A in an organic solvent a; the dissolving temperature is 30 to 130° C., preferably 40 to 90° C.; the organic solvent a is selected from one or more of dichloromethane, tetrahydrofuran, acetonitrile, toluene, ethanol, ethyl acetate, N,N-dimethylformamide, methanol, chloroform, and acetone; the volume mass ratio (ml/g) of the organic solvent a to the compound represented by formula A is 8 to 100:1, preferably 10 to 50:1;

2) adding phosphoric acid in an organic solvent b dropwise; the molar ratio of the phosphoric acid to the compound of formula A is 0.95-1.05:1, and the organic solvent b is selected from one or more of ethanol, tetrahydrofuran, acetonitrile, methanol, N,N-dimethylformamide, and acetone; the volume mass ratio (ml/g) of the organic solvent b to the compound of formula A is 2-20:1;

3) stirring and crystallizing; the stirring rate is 60 to 1500 rpm, preferably 120 to 1000 rpm; the crystallization temperature is -25 to 30°C;

4) Filter to obtain the crystalline form (I) of AD-35.

Method (2), comprising the following steps:

1) Add AD-35 to a mixed solvent of an organic solvent and water, and heat under reflux to dissolve; the mass volume ratio (g/ml) of the AD-35 to the mixed solvent is 1:10.4-66; the volume ratio of the organic solvent to water is 5-30:1; the organic solvent is selected from one or more of ethanol, isopropanol, tetrahydrofuran, acetone, n-pentanol, ethyl acetate, n-butanol, N,N-dimethylformamide, dichloromethane, acetonitrile, and dimethyl sulfoxide;

2) standing or stirring at -25 to 30°C for crystallization; or, adding an organic solvent dropwise at -25 to 30°C for crystallization; the organic solvent is selected from one or more of methyl tert-butyl ether, isopropanol, tetrahydrofuran, and ethyl acetate; the volume ratio (ml/g) of the organic solvent to the mixed solvent in step (1) is 0.5 to 6:1;

3) Filter to obtain the crystalline form (I) of AD-35.

Method (3), comprising the following steps:

The AD-35 crystalline form (IV), or the AD-35 crystalline form (V), or the AD-35 amorphous form (VII) is stirred in ethanol at 40-80° C. for 4 h to 48 h, cooled to room temperature, and filtered to obtain the AD-35 crystalline form (I); the mass volume ratio (g/ml) of the AD-35 to ethanol is 1:20 to 50.

Method (4), comprising the following steps:

The AD-35 crystal form (IV) or the AD-35 crystal form (V) is heated at high temperature for 3h to 7h to obtain the AD-35 crystal form (I), wherein the high temperature heating temperature is 120°C to 200°C.

In another aspect of the present invention, a crystalline form (II) of AD-35 is provided, whose X-ray powder diffraction (XRPD) spectrum has characteristic peaks at the following diffraction angles 2θ: 6.8±0.2°, 12.7±0.2°, 16.6±0.2°, 20.2±0.2°, 20.8±0.2°, and 22.6±0.2°.

Further, the X-ray powder diffraction pattern of the AD-35 crystal form (II) has characteristic peaks at the following diffraction angles 2θ: 13.8±0.2°, 19.6±0.2°, 20.0±0.2°, 24.7±0.2°, 28.0±0.2°. Further, preferably, the X-ray powder diffraction spectrum of the crystal form (II) of AD-35 of the present invention has the 2θ, d and relative intensity data shown in Table 2 below:

Table 2

Without limitation, the crystalline form (II) of AD-35 described in the present invention has an X-ray powder diffraction spectrum as shown in FIG. 2 .

In addition, the infrared absorption spectrum of the crystalline form (II) of AD-35 described in the present invention in potassium bromide is about 529.1cm ^-1 , 762.6cm ^-1 , 777.1cm ^-1 , 866.4cm ^-1 , 934.5cm ^-1 , 955.6cm ^-1 , 1029.3cm ^-1 , 1128.2cm ^-1 , 1163.9cm ^-1 , 1245.9cm ^-1 , 1288.1cm ^-1 , 1352.0cm ^-1 , 1369.9cm ^-1 , 1413.2cm ^-1 , 1474.2cm ^-1 , 1600.4cm ^-1 , 1618.1cm ^-1 , ^{1677.7cm -1 ,} 2841.1cm ^-1 , 2923.9cm ^-1 , there is an absorption peak at 3424.7cm ^-1 .

Without limitation, the crystalline form (II) of AD-35 of the present invention has an infrared spectrum as shown in FIG9 .

The differential scanning calorimetry (DSC) spectrum of the crystal form (II) of AD-35 described in the present invention has a maximum endothermic peak at 224±5°C.

Without limitation, the crystalline form (II) of AD-35 of the present invention has a DSC spectrum as shown in FIG. 16 .

Without limitation, the crystalline form (II) of AD-35 of the present invention has a TGA spectrum as shown in FIG. 23 .

Another object of the present invention is to provide a method for preparing AD-35 crystalline form (II), the method comprising:

(1) dissolving the compound represented by formula A in an alcohol solvent; the dissolution temperature is 50-70°C; the mass volume ratio (g/ml) of the compound A to the alcohol solvent is 1:4-6; the alcohol solvent is a C ₂ -C ₄ alcohol, preferably ethanol and isopropanol;

(2) adding phosphoric acid under stirring; the molar ratio of the phosphoric acid to the compound of formula A is 0.4 to 0.85:1; the stirring rate is 10 to 180 rpm;

(3) adding ethyl acetate dropwise; the volume ratio (ml/g) of the alcohol solvent to ethyl acetate in step (1) is 1:1-2;

(4) Filtration to obtain the crystal form (II) of AD-35.

In another aspect of the present invention, a crystalline form (III) of AD-35 is provided, whose X-ray powder diffraction pattern has characteristic peaks at the following diffraction angles 2θ: 9.2±0.2°, 18.2±0.2°, 18.5±0.2°, 20.4±0.2°, and 23.9±0.2°.

Furthermore, the X-ray powder diffraction pattern of the AD-35 crystal form (III) has characteristic peaks at the following diffraction angles 2θ: 11.5±0.2°, 15.4±0.2°, 19.0±0.2°, 22.1±0.2°, 25.9±0.2°, and 26.8±0.2°.

Furthermore, preferably, the X-ray powder diffraction spectrum of the crystalline form (III) of AD-35 of the present invention has the 2θ, d and relative intensity data shown in Table 3 below:

Table 3 XRPD data of form (III) of AD-35

Without limitation, the crystalline form (III) of AD-35 described in the present invention has an X-ray powder diffraction spectrum as shown in FIG3 .

In addition, the infrared absorption spectrum of the crystalline form (III) of AD-35 in potassium bromide is at about 505.9 ^{cm -1} , 566.5 cm ^-1 , 733.2 cm ^-1 , 765.5 cm ^-1 , 778.6 cm ^-1 , 858.2 cm ^-1 , 873.0 cm ^-1 , 926.8 cm -1 , 952.8 cm ^-1 , 1037.6 cm ^-1 , 1068.3 cm ^-1 , 1130.8 cm ^-1 , 1164.6 cm ^-1 , 1246.6 cm ^-1 , 1277.3 cm ^-1 , 1290.5 cm ^-1 , 1368.8 cm ^-1 , 1411.4 cm ^-1 , 1473.4 ^{cm -1} , 1677.5 cm ^-1 , 2927.1 cm ^-1 . ^{- 1} , 3045.8cm ^-1 , 3420.2cm ^-1 .

Without limitation, the crystalline form (III) of AD-35 of the present invention has an infrared spectrum as shown in FIG10 .

The differential scanning calorimetry (DSC) spectrum of the crystal form (III) of AD-35 described in the present invention has endothermic peaks at 122±5°C and 213±5°C.

Without limitation, the crystalline form (III) of AD-35 of the present invention has a DSC spectrum as shown in FIG. 17 .

The TGA step weight loss of the crystalline form (III) of AD-35 described in the present invention is 10.8699%, and the gas phase result shows that the main residual solvent is dichloromethane (10.6092%), and the moisture result is 0.18%, indicating that it exists in the form of dichloromethane solvate and contains 0.5 dichloromethane.

Without limitation, the crystalline form (III) of AD-35 of the present invention has a TGA spectrum as shown in FIG. 24 .

Another object of the present invention is to provide a method for preparing AD-35 crystalline form (III), the method comprising:

(1) Adding AD-35 to a mixed solvent of methanol and dichloromethane, heating and refluxing to dissolve, wherein the mass volume ratio (g/ml) of AD-35 to the mixed solvent is 1:8-18; the volume ratio (ml/g) of methanol to dichloromethane is 1:3-8;

(2) adding dichloromethane at -25 to 25°C or optionally further adding AD-35 crystal form (III) seed crystals or adding dichloromethane in which AD-35 crystal form (III) seed crystals are suspended, and standing for 48 to 96 hours for crystallization; the volume ratio (ml/ml) of the dichloromethane to the methanol in step (1) is 1:20 to 40;

(3) Filtration to obtain the crystalline form (III) of AD-35.

In another aspect of the present invention, a crystalline form (IV) of AD-35 is provided, whose X-ray powder diffraction (XRPD) spectrum has characteristic peaks at the following diffraction angles 2θ: 6.5±0.2°, 9.8±0.2°, 14.4±0.2°, 19.1±0.2°, 20.3±0.2°, and 21.4±0.2°.

Furthermore, the X-ray powder diffraction pattern of the AD-35 crystal form (IV) has characteristic peaks at the following diffraction angles 2θ: 17.7±0.2°, 21.9±0.2°, 23.4±0.2°, 25.9±0.2°, and 27.6±0.2°.

Furthermore, preferably, the X-ray powder diffraction spectrum of the crystalline form (IV) of AD-35 of the present invention has the 2θ, d and relative intensity data shown in Table 4 below:

Table 4

Without limitation, the crystalline form (IV) of AD-35 of the present invention has an X-ray powder diffraction spectrum as shown in FIG4 .

In addition, the infrared absorption spectrum of the crystalline form (IV) of AD-35 described in the present invention in potassium bromide is at about 449.3cm ^-1 , 506.7cm ^-1 , 533.1cm ^-1 , 766.1cm ^-1 , 778.1cm ^-1 , 856.7cm ^-1 , 870.2cm ^{-1 , 920.0cm -1 ,} 936.4cm ^-1 , 1029.4cm ^-1 , 1052.3cm ^-1 , 1149.5cm ^-1 , 1162.0cm ^-1 , 1228.2cm ^-1 , 1250.7cm ^-1 , 1280.0cm ^-1 , 1320.5cm ^-1 , 1352.9cm -1 , 1370.2cm ^-1 , 1414.0cm ^{-1 ,} 1477.1cm ^{-1 -1} , 1599.5cm ^-1 , 1620.4cm ^-1 , 1667.9cm ^-1 , 2811.2cm ^-1 , 2864.9cm ^-1 , 2930.1cm ^-1 , 3002.8cm ^-1 , 3054.9cm ^-1 , 3218.9cm ^-1 , 3419.3cm ^-1 .

Without limitation, the crystalline form (IV) of AD-35 of the present invention has an infrared spectrum as shown in FIG. 11 .

The differential scanning calorimetry (DSC) spectrum of the crystal form (IV) of AD-35 described in the present invention has endothermic peaks at 143±5°C, 169±5°C and 223±5°C.

Without limitation, the crystalline form (IV) of AD-35 of the present invention has a DSC spectrum as shown in FIG. 18 .

The TGA spectrum of the crystalline form (IV) of AD-35 described in the present invention shows two steps, the total weight loss is 4.7402%, the gas phase results show that the main residual solvent is methanol (4.8840%), and the moisture result is 0.81%, indicating that it exists in the form of methanol solvate and contains 0.75 methanol.

Without limitation, the crystalline form (IV) of AD-35 of the present invention has a TGA spectrum as shown in FIG. 25 .

Another object of the present invention is to provide a method for preparing AD-35 crystalline form (IV), which is selected from any one of the following methods:

The method (1) comprises the following steps:

1) dissolving the compound represented by formula A in methanol or a mixed solvent of methanol and dichloromethane at room temperature; the mass volume ratio (g/ml) of the compound represented by formula A to methanol or a mixed solvent of methanol and dichloromethane is 1:5-9; the volume ratio (ml/ml) of methanol to dichloromethane is 1:4-8;

2) adding phosphoric acid or a methanol solution of phosphoric acid; the molar ratio of the phosphoric acid to the compound of formula A is 1:1; the volume mass ratio (ml/g) of the methanol to the compound of formula A in step (1) is 1-2:1;

3) adding a poor solvent dropwise for crystallization; the poor solvent is selected from one or more of ethyl acetate, dichloromethane, ether, and acetone; the volume mass ratio (ml/g) of the poor solvent to the compound represented by formula A in step (1) is 30 to 50:1;

(4) Filtration to obtain the crystalline form (IV) of AD-35.

Method (2), comprising the following steps:

(1) dissolving AD-35 in a mixed solvent of methanol and dichloromethane, wherein the volume ratio (ml/ml) of methanol to dichloromethane is 1:4; or dissolving AD-35 in a mixed solvent of methanol, water and dichloromethane, wherein the volume ratio (ml/ml) of methanol, water and dichloromethane is 10:1:80; or dissolving AD-35 in a mixed solvent of methanol and water, wherein the volume ratio (ml/ml) of methanol to water is 6:1; the dissolution temperature is 20 to 40°C; the mass volume ratio of AD-35 to the mixed solvent is 1:18.2 to 35;

(2) adding a poor solvent for crystallization; the poor solvent is selected from one or more of n-heptane, dichloromethane, ethyl acetate, and isopropyl ether; the volume mass ratio (ml/g) of the poor solvent to the AD-35 in step (1) is 40 to 100:1;

(3) Filtration to obtain the crystalline form (IV) of AD-35.

Method (3), comprising the following steps:

(1) Recrystallizing AD-35 by reflux stirring in methanol; the volume mass ratio (ml/g) of methanol to AD-35 is 10 to 30;

Alternatively, AD-35 is refluxed and stirred in a mixed solvent of methanol and water for recrystallization; the volume mass ratio (ml/g) of methanol to AD-35 is 10 to 30, and the volume mass ratio (ml/g) of water to AD-35 is 0.5 to 1.5;

Alternatively, AD-35 is refluxed and stirred in a mixed solvent of methanol and dichloromethane for recrystallization; the volume mass ratio (ml/g) of methanol to AD-35 is 1 to 2, and the volume mass ratio (ml/g) of dichloromethane to AD-35 is 1 to 6;

(2) Cool to room temperature and filter to obtain the crystalline form (IV) of AD-35.

In another aspect of the present invention, a crystalline form (V) of AD-35 is provided, whose X-ray powder diffraction (XRPD) spectrum has characteristic peaks at the following diffraction angles 2θ: 7.0±0.2°, 12.7±0.2°, 15.8±0.2°, 20.5±0.2°, 20.6±0.2°, and 22.1±0.2°.

Furthermore, the X-ray powder diffraction pattern of the AD-35 crystalline form (V) has characteristic peaks at the following diffraction angles 2θ: 9.8±0.2°, 19.5±0.2°, 21.1±0.2°, 24.6±0.2°, and 25.7±0.2°.

Furthermore, preferably, the X-ray powder diffraction spectrum of the crystalline form (V) of AD-35 of the present invention has the 2θ, d and relative intensity data shown in Table 5 below:

Table 5

Without limitation, the crystalline form (V) of AD-35 described in the present invention has an X-ray powder diffraction spectrum as shown in FIG5 .

In addition, the infrared absorption spectrum of the crystalline form (V) of AD-35 described in the present invention in potassium bromide is about 454.5cm ^-1 , 503.8cm ^-1 , 526.7cm ^-1 , 754.8cm ^-1 , 767.8cm ^-1 , 778.7cm ^-1 , 860.5cm ^-1 , 926.8cm ^-1 , 1034.9cm ^-1 , 1072.5cm ^-1 , 1131.8cm ^-1 , 1165.6cm ^-1 , 1250.2cm ^-1 , 1271.0cm ^-1 , ^{1285.2cm -1} , 1417.5cm ^-1 , 1474.4cm ^-1 , 1598.5cm ^-1 , 1617.8cm ^-1 , 1653.5cm ^-1 , 2937.2cm ^-1 , 3002.3cm ^-1 , 3396.3cm ^-1 .

Without limitation, the crystalline form (V) of AD-35 of the present invention has an infrared spectrum as shown in FIG. 12 .

The differential scanning calorimetry (DSC) spectrum of the crystal form (V) of AD-35 described in the present invention has endothermic peaks at 123±5°C and 225±5°C.

Without limitation, the crystalline form (V) of AD-35 of the present invention has a DSC spectrum as shown in FIG. 19 .

The TGA step weight loss of the crystalline form (V) of AD-35 described in the present invention is 2.48%, and the moisture result is 2.20%, indicating that it exists in the form of a hydrate and contains 0.5 water.

Without limitation, the crystalline form (V) of AD-35 of the present invention has a TGA spectrum as shown in FIG. 26 .

Another object of the present invention is to provide a method for preparing AD-35 crystalline form (V), the method comprising:

(1) Add AD-35 to an organic solvent selected from the group consisting of n-propanol, isopropanol, acetone, acetonitrile, and toluene, wherein the mass volume ratio (g/ml) of AD-35 to the organic solvent is 1:32 to 40; add water to dissolve the AD-35; wherein the mass volume ratio (g/ml) of AD-35 to water is 1:2 to 4.5;

(2) Stirring at 0-5°C for 24-48 hours;

Alternatively, add AD-35 Form (V) seed crystals at 0-5°C and stir for 4-8h;

(3) Filtration to obtain the crystalline form (V) of AD-35.

In another aspect of the present invention, a crystalline form (VI) of AD-35 is provided, whose X-ray powder diffraction (XRPD) spectrum has characteristic peaks at the following diffraction angles 2θ: 6.0±0.2°, 8.8±0.2°, 14.4±0.2°, 18.5±0.2°, 19.0±0.2°, 19.5±0.2°, and 23.9±0.2°.

Furthermore, the X-ray powder diffraction pattern of the AD-35 crystalline form (VI) has characteristic peaks at the following diffraction angles 2θ: 10.4±0.2°, 10.9±0.2°, 11.9±0.2°, 15.2±0.2°, and 22.3±0.2°.

Furthermore, preferably, the X-ray powder diffraction spectrum of the crystalline form (VI) of AD-35 of the present invention has the 2θ, d and relative intensity data shown in Table 6 below:

Table 6

Without limitation, the crystalline form (VI) of AD-35 described in the present invention has an X-ray powder diffraction spectrum as shown in FIG6 .

In addition, the infrared absorption spectrum of the crystalline form (VI) of AD-35 described in the present invention in potassium bromide is about 506.3cm ^-1 , 566.3cm ^-1 , 765.7cm ^-1 , 777.8cm ^-1 , 857.4cm ^-1 , 873.3cm ^-1 , 927.1cm ^-1 , 952.1cm ^-1 , 1038.5cm ^-1 , 1068.8cm ^-1 , 1131.7cm ^-1 , 1163.9cm ^-1 , 1254.2cm ^-1 , 1277.6cm ^-1 , 1290.9cm ^-1 , 1368.3cm ^-1 , 1411.0cm ^-1 , 1472.9cm ^-1 , 1677.1cm ^-1 , ^{2926.5cm -1} , 3443.6cm ^-1 .

Without limitation, the crystalline form (VI) of AD-35 of the present invention has an infrared spectrum as shown in FIG13 .

The differential scanning calorimetry (DSC) spectrum of the crystal form (VI) of AD-35 described in the present invention has a maximum endothermic peak at 215±5°C.

Without limitation, the crystalline form (VI) of AD-35 of the present invention has a DSC spectrum as shown in FIG. 20 .

Without limitation, the crystalline form (VI) of AD-35 of the present invention has a TGA spectrum as shown in FIG. 27 .

Another object of the present invention is to provide a method for preparing AD-35 crystalline form (VI), which is selected from any one of the following methods:

The method (1) comprises the following steps:

The crystal form (III) of AD-35 is heated at high temperature; the temperature of the high temperature heating is 120 to 150° C., and the time of the high temperature heating is 4 to 8 hours.

Method (2), comprising the following steps:

1) dissolving the compound represented by formula A in ethanol; the dissolving temperature is 50-70° C.; the mass volume ratio (g/ml) of the compound represented by formula A to ethanol is 1:4-5;

2) Add 0.5 equivalent of phosphoric acid;

3) adding ethyl acetate dropwise and stirring to crystallize; the volume ratio of the ethyl acetate to the ethanol in step (1) is 4 to 5:1;

4) Cool to 5-20°C and filter to obtain the crystalline form (VI) of AD-35.

Another aspect of the present invention provides an amorphous form (VII) of AD-35 having diffraction peaks of an X-ray powder diffraction (XRPD) pattern as shown in FIG. 7 .

In addition, the infrared absorption spectrum of the amorphous form (VII) of AD-35 described in the present invention in potassium bromide is at about 481.4 cm ^-1 , 501.6 cm ^-1 , 533.5 cm ^-1 , 778.2 cm ^-1 , 868.0 cm ^-1 , 926.0 ^{cm -1} , 1034.5 cm ^-1 , 1165.0 cm ^-1 , 1246.3 cm ^-1 , 1267.9 cm ^-1 , 1318.4 cm -1 , 1384.2 cm ^-1 , 1415.6 cm ^-1 , 1474.2 ^{cm -1} , 1574.6 cm ^-1 , 1652.9 cm ^-1 , 2850.7 cm ^-1 , 2921.5 cm ^-1 , 3421.8 cm ^{-1 .}

Without limitation, the amorphous form (VII) of AD-35 of the present invention has an infrared spectrum as shown in FIG. 14 .

Without limitation, the amorphous form (VII) of AD-35 of the present invention has a DSC spectrum as shown in FIG. 21 .

Without limitation, the amorphous form (VII) of AD-35 of the present invention has a TGA spectrum as shown in FIG. 28 .

Another object of the present invention is to provide a method for preparing AD-35 amorphous (VII), the method comprising:

AD-35 was dissolved in water, and the solution was vacuum dried at 40°C and -0.09 MPa.

In the present application, the dissolution and crystallization steps involved in all the above methods generally require stirring unless otherwise specified, and stirring can be performed in a known manner, such as magnetic stirring, mechanical stirring, etc.

In the present application, the normal temperature or room temperature refers to the temperature range of 20°C to 25°C.

The present invention provides a pharmaceutical composition, which contains an effective amount of the crystal form (I) or crystal form (II) or crystal form (III) or crystal form (IV) or crystal form (V) or crystal form (VI) or amorphous form (VII) of AD-35. The pharmaceutical composition can be administered in general dosage forms, such as oral dosage forms and injection dosage forms, including capsules, tablets, powders, cachets, suspensions and solutions, preferably administered in oral dosage forms, more preferably administered in tablets and capsules in oral dosage forms.

The pharmaceutical composition of the present invention may also contain a pharmaceutically suitable carrier or excipient. The dosage form and pharmaceutical composition may be prepared using commonly used pharmaceutically suitable excipients and additives and commonly used techniques. The pharmaceutically suitable excipients and additives include non-toxic compatible fillers, binders, disintegrants, buffers, preservatives, antioxidants, lubricants, flavoring agents, thickeners, colorants, emulsifiers, etc.

The present invention provides use of the crystal form (I) or crystal form (II) or crystal form (III) or crystal form (IV) or crystal form (V) or crystal form (VI) or amorphous form (VII) of AD-35 or the pharmaceutical composition thereof in the preparation of a drug for treating Alzheimer's disease.

Advantages of the present invention: the chemical stability of crystal forms I, II, III, IV, V and VI at 60° C. is better than that of the solids obtained in Preparation Examples 1 and 2, among which crystal form I is the most stable, and the preparation method of crystal form III has a good impurity removal effect, which can be used to solve impurities that are difficult to remove; and the six crystal forms are also less hygroscopic, which provides great convenience for the later product transportation, storage or preparation process.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a powder X-ray diffraction pattern of the crystalline form (I) obtained in Example 1.

FIG2 is a powder X-ray diffraction pattern of the crystalline form (II) obtained in Example 29.

Figure 3 is a powder X-ray diffraction pattern of Form (III) obtained in Example 32.

Figure 4 is a powder X-ray diffraction pattern of Form (IV) obtained in Example 35.

FIG5 is a powder X-ray diffraction pattern of Form (V) obtained in Example 48.

Figure 6 is a powder X-ray diffraction pattern of Form (VI) obtained in Example 52.

Figure 7 is a powder X-ray diffraction pattern of amorphous (VII) obtained in Example 56.

FIG8 is an infrared absorption spectrum of the crystal form (I) obtained in Example 1 in potassium bromide.

FIG9 is an infrared absorption spectrum of the crystal form (II) obtained in Example 29 in potassium bromide.

FIG10 is an infrared absorption spectrum of the crystalline form (III) obtained in Example 32 in potassium bromide.

FIG11 is an infrared absorption spectrum of the crystalline form (IV) obtained in Example 35 in potassium bromide.

FIG12 is an infrared absorption spectrum of the crystal form (V) obtained in Example 48 in potassium bromide.

FIG13 is an infrared absorption spectrum of Form (VI) obtained in Example 52 in potassium bromide.

Figure 14 is the infrared absorption spectrum of amorphous form (VII) obtained in Example 56 in potassium bromide.

FIG15 is a differential scanning calorimetry analysis spectrum of Form (I) obtained in Example 1.

FIG16 is a differential scanning calorimetry analysis spectrum of Form (II) obtained in Example 29.

FIG17 is a differential scanning calorimetry analysis spectrum of Form (III) obtained in Example 32.

FIG18 is a differential scanning calorimetry analysis spectrum of Form (IV) obtained in Example 35.

FIG19 is a differential scanning calorimetry analysis spectrum of Form (V) obtained in Example 48.

Figure 20 is a differential scanning calorimetry analysis spectrum of Form (VI) obtained in Example 52.

FIG. 21 is a differential scanning calorimetry analysis spectrum of amorphous (VII) obtained in Example 56.

Figure 22 is a thermogravimetric analysis spectrum of Form (I) obtained in Example 1.

FIG. 23 is a thermogravimetric analysis spectrum of Form (II) obtained in Example 29.

Figure 24 is a thermogravimetric analysis spectrum of Form (III) obtained in Example 32.

Figure 25 is a thermogravimetric analysis spectrum of Form (IV) obtained in Example 35.

FIG26 is a thermogravimetric analysis spectrum of Form (V) obtained in Example 48.

Figure 27 is a thermogravimetric analysis spectrum of Form (VI) obtained in Example 52.

Figure 28 is a thermogravimetric analysis spectrum of amorphous (VII) obtained in Example 56.

Figure 29 is the powder X-ray diffraction pattern of AD-35 obtained in Preparation Example 1.

Figure 30 is the powder X-ray diffraction pattern of AD-35 obtained in Preparation Example 2.

DETAILED DESCRIPTION

The following examples further illustrate the present invention; however, they are not intended to limit or define the scope of the present invention.

The compound represented by formula A and compound AD-35 used in the method of the present invention are prepared by referring to the preparation method disclosed in WO2017177816A1.

The solvent used in the present invention is not particularly limited, and a commercially available conventional solvent may be used.

The X-ray powder diffraction instrument and test conditions involved in the present invention are: X-ray diffraction instrument model Rigaku D/max-2200Cu target Operation method: scanning temperature 25°C, scanning speed 4°/min, scanning step width 0.01°.

The infrared spectrophotometer and test conditions involved in the present invention are: infrared spectrophotometer model: BRWKER VECTOR 22; operation method: using KBr tablet method, scanning range 400-4000cm-1.

The DSC test conditions involved in the present invention are: DSC detector model: NETZSCH DSC 200F3; operation method: heating rate 10℃/min, temperature range: 20-250℃.

The TGA test conditions involved in the present invention are: TGA detector model: PerkinElmer TGA 4000; operation method: heating rate 10℃/min, temperature range: 30-250℃.

The moisture testing conditions involved in the present invention are: the moisture detector model is: Metrohm 852Titrando+803Ti Stand; the operation method is: Karl Fischer volumetric moisture determination method.

It should be emphasized that the meaning or intended protection scope of the numerical values or numerical endpoints involved in the technical solution of the present invention is not limited to the numbers themselves. Those skilled in the art can understand that they include those allowable error ranges that have been widely accepted in the art, such as experimental errors, measurement errors, statistical errors, random errors, etc., and these error ranges are all included in the scope of the present invention.

Example 1: Preparation of Form (I) of AD-35

1.0g of the compound represented by formula A was added to 15ml of dichloromethane, heated at 30°C to dissolve, 5ml of ethanol solution containing 0.29g of phosphoric acid (85%) was added dropwise, stirred at 0°C for 1h, the stirring rate was 120rmp, and filtered to obtain 0.71g of the target crystal form, the solid was block particles, and the fluidity was good. Its X-ray powder diffraction spectrum is shown in Figure 1; the infrared absorption spectrum is shown in Figure 8; the differential scanning calorimetry analysis spectrum is shown in Figure 15; and the thermogravimetric analysis spectrum is shown in Figure 22.

Example 2: Preparation of Form (I) of AD-35

1.0 g of the compound represented by formula A was added to 20 ml of tetrahydrofuran, heated at 50°C to dissolve, 5 ml of tetrahydrofuran solution containing 0.27 g of phosphoric acid (85%) was added dropwise, stirred at 5°C for 1 h at a stirring rate of 1000 rpm, and filtered to obtain 0.80 g of the target crystal.

Example 3: Preparation of Form (I) of AD-35

1.0 g of the compound represented by formula A was added to 20 ml of acetonitrile, heated at 60°C to dissolve, 5 ml of acetonitrile solution containing 0.29 g of phosphoric acid (85%) was added dropwise, stirred at 0°C for 2 h at a stirring rate of 60 rpm, and filtered to obtain 1.11 g of the target crystal form.

Example 4: Preparation of Form (I) of AD-35

1.0 g of the compound represented by formula A was added to 50 ml of toluene, heated at 70°C to dissolve, 10 ml of ethanol solution containing 0.29 g of phosphoric acid (85%) was added dropwise, stirred at -10°C for 1 h at a stirring rate of 1500 rpm, and filtered to obtain 0.89 g of the target crystal.

Example 5: Preparation of Form (I) of AD-35

Add 40 g of the compound represented by formula A to 600 ml of ethanol, heat to 70°C to dissolve, add dropwise 80 ml of methanol solution containing 11.6 g of phosphoric acid (85%), continue stirring for 1 h, stir for 1 h under cooling at -5°C with a stirring rate of 300 rpm, filter, and obtain 47.7 g of the target crystal form.

Example 6: Preparation of Form (I) of AD-35

1.0 g of the compound represented by formula A was added to 10 ml of ethyl acetate, heated at 70°C to dissolve, 5 ml of ethanol solution containing 0.30 g of phosphoric acid (85%) was added dropwise, stirred at 30°C for 1 h at a stirring rate of 500 rpm, and filtered to obtain 0.82 g of the target crystal.

Example 7: Preparation of Form (I) of AD-35

Add 1.0 g of the compound represented by formula A to 100 ml of N,N-dimethylformamide, heat at 130°C to dissolve, add dropwise 0.29 g of phosphoric acid (85%) dissolved in 20 ml of N,N-dimethylformamide solution, stir at -25°C for 3 h at a stirring rate of 800 rpm, filter, and obtain 0.98 g of the target crystal.

Example 8: Preparation of Form (I) of AD-35

1.0 g of the compound represented by formula A was added to 20 ml of methanol, heated at 50°C to dissolve, 3 ml of methanol solution containing 0.29 g of phosphoric acid (85%) was added dropwise, stirred at 0°C for 1 hour at a stirring rate of 100 rpm, and filtered to obtain 0.99 g of the target crystal form.

Example 9: Preparation of Form (I) of AD-35

Add 1.0 g of the compound represented by formula A to 8 ml of chloroform, heat at 50°C to dissolve, add dropwise 0.29 g of phosphoric acid (85%) dissolved in 3 ml of ethanol solution, stir at 10°C for 2 h at a stirring rate of 200 rpm, filter, and obtain 0.99 g of the target crystal.

Example 10: Preparation of Form (I) of AD-35

1.0 g of the compound represented by formula A was added to 30 ml of acetone, heated at 50°C to dissolve, 2 ml of acetone solution containing 0.29 g of phosphoric acid (85%) was added dropwise, and the mixture was stirred at 5°C for 1 h at a stirring rate of 400 rpm. After filtering, 0.94 g of the target crystal was obtained.

Example 11: Preparation of Form (I) of AD-35

Add 1.0 g of the compound represented by formula A to a mixed solvent of 20 ml ethanol, 20 ml ethyl acetate and 10 ml N,N-dimethylformamide, heat at 60°C to dissolve, add dropwise 0.29 g phosphoric acid (85%) dissolved in 15 ml ethanol solution, stir at 0°C for 1 h at a stirring rate of 800 rpm, filter, and obtain 0.82 g of the target crystal.

Example 12: Preparation of Form (I) of AD-35

Add 0.5 g AD-35 to a mixed solvent of 10 ml ethanol and 0.9 ml water, heat under reflux to dissolve, stand at 25 °C for 48 h to crystallize, and filter to obtain 0.42 g of the target crystal.

Example 13: Preparation of Form (I) of AD-35

Add 0.5 g AD-35 to a mixed solvent of 10 ml isopropanol and 1.25 ml water, heat under reflux to dissolve, stand at 30 °C for 48 h to crystallize, and filter to obtain 0.43 g of the target crystal.

Example 14: Preparation of Form (I) of AD-35

Add 0.5 g AD-35 to a mixed solvent of 3 ml ethanol, 15 ml tetrahydrofuran and 3 ml water, heat under reflux to dissolve, stand at 20 °C for 48 h to crystallize, and filter to obtain 0.31 g of the target crystal.

Example 15: Preparation of Form (I) of AD-35

Add 0.5 g AD-35 to a mixed solvent of 10 ml acetone and 2 ml water, heat under reflux to dissolve, let stand at -25 °C for 48 h to crystallize, and filter to obtain 0.25 g of the target crystal.

Example 16: Preparation of Form (I) of AD-35

Add 0.5 g AD-35 to a mixed solvent of 10 ml n-pentanol, 7 ml acetone and 1 ml water, heat under reflux to dissolve, stand at 0°C for 48 hours to crystallize, and filter to obtain 0.44 g of the target crystal.

Example 17: Preparation of Form (I) of AD-35

Add 0.5 g AD-35 to a mixed solvent of 10 ml n-pentanol, 5 ml ethyl acetate, 5 ml ethanol and 1.6 ml water, heat to reflux to dissolve, stir at 0°C for 6 h, filter, and obtain 0.38 g of the target crystal.

Example 18: Preparation of Form (I) of AD-35

Add 0.5 g AD-35 to a mixed solvent of 30 ml n-butanol and 3 ml water, heat under reflux to dissolve, and stir at 5 °C for 6 h to obtain 0.34 g of the target crystal.

Example 19: Preparation of Form (I) of AD-35

Add 0.5 g AD-35 to a mixed solvent of 10 ml N,N-dimethylformamide and 0.5 ml water, heat to reflux to dissolve, stir at 30 °C for 48 h, filter, and obtain 0.45 g of the target crystal.

Example 20: Preparation of Form (I) of AD-35

Add 0.5 g AD-35 to a mixed solvent of 20 ml N,N-dimethylformamide and 3 ml water, heat under reflux to dissolve, add 20 ml methyl tert-butyl ether dropwise at 30°C with stirring to crystallize, filter and obtain 0.42 g of the target crystal.

Example 21: Preparation of Form (I) of AD-35

Add 0.5 g AD-35 to a mixed solvent of 1 ml ethanol, 0.2 ml water and 4 ml dichloromethane, heat under reflux to dissolve, add 31.2 ml isopropanol dropwise at -25 °C with stirring to crystallize, filter and obtain 0.39 g of the target crystal.

Example 22: Preparation of Form (I) of AD-35

Add 1.0 g of AD-35 into a mixed solvent of 20 ml of acetonitrile, 20 ml of N,N-dimethylformamide and 6 ml of water, heat under reflux to dissolve, add 23 ml of tetrahydrofuran dropwise at 20°C with stirring to crystallize, filter and obtain 0.78 g of the target crystal.

Example 23: Preparation of Form (I) of AD-35

Add 0.5 g AD-35 to a mixed solvent of 10 ml dimethyl sulfoxide, 5 ml ethanol and 0.5 ml water, heat under reflux to dissolve, add 20 ml ethyl acetate dropwise at 0°C with stirring to crystallize, and filter to obtain 0.42 g of the target crystal.

Example 24: Preparation of Form (I) of AD-35

Add 1.0 g of AD-35 crystal form (IV) into 20 ml of ethanol, reflux with stirring at 80°C for 4 h, cool to room temperature, and filter to obtain 0.92 g of the target crystal form.

Example 25: Preparation of Form (I) of AD-35

Add 1.0 g of AD-35 crystalline form (V) into 50 ml of ethanol, stir at 40 °C for 48 h, cool to room temperature, and filter to obtain 0.86 g of the target crystalline form.

Example 26: Preparation of Form (I) of AD-35

Add 1.0 g of amorphous form (VII) of AD-35 into 20 ml of ethanol, stir at 60 °C for 12 h, cool to room temperature, and filter to obtain 0.85 g of the target crystal form.

Example 27: Preparation of Form (I) of AD-35

0.5 g of AD-35 crystal form (IV) was spread on a watch glass and heated at 120 °C for 7 h to obtain 0.47 g of the target crystal form.

Example 28: Preparation of Form (I) of AD-35

Spread 0.5 g of AD-35 crystal form (V) on a watch glass and heat at 200 °C for 3 h to obtain 0.44 g of the target crystal form.

The X-ray powder diffraction pattern of the crystalline form (I) of AD-35 obtained in Example 2-28 is consistent with the X-ray powder diffraction pattern of the crystalline form (I) of AD-35 in Example 1.

Example 29: Preparation of Form (II) of AD-35

17.4g of the compound represented by formula A was added to 87ml of ethanol, heated at 70°C to dissolve, 4.2g of phosphoric acid (85%) was added at a speed of 180rpm, 87ml of ethyl acetate was added dropwise, cooled to room temperature, filtered, and 18.4g of the target crystal form was obtained, and the solid particles were agglomerated. Its X-ray powder diffraction spectrum is shown in Figure 2; its infrared absorption spectrum is shown in Figure 9; its differential scanning calorimetry analysis spectrum is shown in Figure 16; and its thermogravimetric analysis spectrum is shown in Figure 23.

Example 30: Preparation of Form (II) of AD-35

5.0 g of the compound represented by formula A was added to 20 ml of isopropanol, heated at 65° C. to dissolve, 0.57 g of phosphoric acid (85%) was added at a rotation speed of 100 rpm, 40 ml of ethyl acetate was added dropwise, cooled to room temperature, and filtered to obtain 2.18 g of the target crystal form.

Example 31: Preparation of Form (II) of AD-35

5.0 g of the compound represented by formula A was added to 30 ml of n-butanol, heated at 50°C to dissolve, 0.57 g of phosphoric acid (85%) was added at a rotation speed of 10 rpm, 50 ml of ethyl acetate was added dropwise, cooled to room temperature, filtered, and 2.01 g of the target crystal was obtained.

The X-ray powder diffraction patterns of the crystalline form (II) of AD-35 obtained in Examples 30 and 31 are consistent with the X-ray powder diffraction patterns of the crystalline form (II) of AD-35 in Example 29.

Example 32: Preparation of Form (III) of AD-35

2.0g AD-35 was added to a mixed solvent of 4ml methanol and 32ml dichloromethane, heated under reflux to dissolve, 160ml dichloromethane was added at -25℃, crystallized at -25℃ for 48h, filtered, and 1.91g of the target crystal was obtained. The solid was needle-shaped and flocculent. Its X-ray powder diffraction spectrum is shown in Figure 3; the infrared absorption spectrum is shown in Figure 10; the differential scanning calorimetry analysis spectrum is shown in Figure 17; and the thermogravimetric analysis spectrum is shown in Figure 24.

Example 33: Preparation of Form (III) of AD-35

Add 5.0g AD-35 to a mixed solvent of 15ml methanol and 45ml dichloromethane, heat under reflux to dissolve, add 450ml dichloromethane at 0°C, add a small amount of Form III seed crystals, let stand for 72h, filter, and obtain 4.83g of the target crystal.

Example 34: Preparation of Form (III) of AD-35

Add 20.0 g AD-35 to a mixed solvent of 40 ml methanol and 120 ml dichloromethane, heat under reflux to dissolve, add 800 ml dichloromethane with a small amount of Form III seed crystals suspended at 25°C, let stand at 25°C for 96 hours to crystallize, filter, and obtain 20.7 g of the target crystal.

The X-ray powder diffraction pattern of the crystalline form (III) of AD-35 obtained in Examples 33 and 34 is consistent with the X-ray powder diffraction pattern of the crystalline form (III) of AD-35 in Example 32.

Example 35: Preparation of Form (IV) of AD-35

At room temperature, 1.0 g of the compound represented by formula A was dissolved in 8 ml of methanol, 0.29 g of phosphoric acid (85%) was added, 40 ml of ethyl acetate was added dropwise for crystallization, and filtered to obtain 0.82 g of the target crystal form, the solid being large block particles. Its X-ray powder diffraction spectrum is shown in FIG4 ; its infrared absorption spectrum is shown in FIG11 ; its differential scanning calorimetry analysis spectrum is shown in FIG18 ; and its thermogravimetric analysis spectrum is shown in FIG25 .

Example 36: Preparation of Form (IV) of AD-35

At room temperature, 1.0 g of the compound represented by formula A was dissolved in a mixed solvent of 1 ml methanol and 8 ml dichloromethane, 0.29 g phosphoric acid (85%) dissolved in 1 ml methanol solution was added, 30 ml dichloromethane was added dropwise for crystallization, and 0.94 g of the target crystal was obtained by filtration.

Example 37: Preparation of Form (IV) of AD-35

At room temperature, 1.0 g of the compound represented by formula A was dissolved in a mixed solvent of 1 ml of methanol and 4 ml of dichloromethane, 2 ml of methanol solution containing 0.29 g of phosphoric acid (85%) was added, and a mixed solution of 30 ml of ether and 20 ml of acetone was added dropwise for crystallization. After filtering, 1.12 g of the target crystal was obtained.

Example 38: Preparation of Form (IV) of AD-35

Add 0.5 g AD-35 to a mixed solvent of 1 ml methanol, 0.1 ml water and 8 ml dichloromethane, stir and dissolve at 30 °C, add 40 ml n-heptane dropwise at 30 °C for crystallization, filter and obtain 0.45 g of the target crystal.

Example 39: Preparation of Form (IV) of AD-35

Add 0.5 g AD-35 to a mixed solvent of 1 ml methanol, 0.1 ml water and 8 ml dichloromethane, stir and dissolve at 25 °C, add 40 ml dichloromethane dropwise, filter and obtain 0.49 g target crystal.

Example 40: Preparation of Form (IV) of AD-35

Add 0.5 g AD-35 to a mixed solvent of 2 ml methanol and 8 ml dichloromethane, stir and dissolve at 20°C, add 50 ml ethyl acetate dropwise for crystallization, filter and obtain 0.45 g of the target crystal.

Example 41: Preparation of Form (IV) of AD-35

Add 1.0 g AD-35 to a mixed solvent of 30 ml methanol and 5 ml water, heat at 40°C to dissolve, add 40 ml isopropyl ether dropwise to crystallize, and filter to obtain 0.98 g of the target crystal.

Example 42: Preparation of Form (IV) of AD-35

Add 1.0 g AD-35 into 10 ml methanol, reflux with stirring for 2 h, cool to room temperature, filter, and obtain 0.70 g of the target crystal.

Example 43: Preparation of Form (IV) of AD-35

Add 1.0 g AD-35 into 30 ml methanol, reflux with stirring for 1.5 h, cool to room temperature, filter, and obtain 0.50 g of the target crystal.

Example 44: Preparation of Form (IV) of AD-35

Add 1.0 g AD-35 into a mixed solvent of 10 ml methanol and 0.5 ml water, reflux with stirring for 2 h, cool to room temperature, and filter to obtain 0.38 g of the target crystal.

Example 45: Preparation of Form (IV) of AD-35

Add 1.0 g AD-35 into a mixed solvent of 30 ml methanol and 1.5 ml water, reflux with stirring for 2 h, cool to room temperature, and filter to obtain 0.24 g of the target crystal.

Example 46: Preparation of Form (IV) of AD-35

Add 10.0 g of AD-35 into a mixed solvent of 10 ml of methanol and 60 ml of dichloromethane, reflux to dissolve and stir for 1 hour, cool to room temperature, and filter to obtain 3.8 g of the target crystal.

Example 47: Preparation of Form (IV) of AD-35

Add 10.0 g AD-35 into a mixed solvent of 20 ml methanol and 10 ml dichloromethane, reflux with stirring for 2 h, cool to room temperature, and filter to obtain 4.1 g of the target crystal.

The X-ray powder diffraction patterns of the crystalline form (IV) of AD-35 obtained in Examples 36-47 are consistent with the X-ray powder diffraction pattern of the crystalline form (IV) of AD-35 in Example 35.

Example 48: Preparation of Form (V) of AD-35

0.5g AD-35 was added to a mixed solvent of 10ml n-propanol and 10ml toluene, 1ml water was added to dissolve, stirred at 0℃ for 24h to crystallize, filtered, and 0.41g of the target crystal form was obtained. The solid was block particles. Its X-ray powder diffraction spectrum is shown in Figure 5; the infrared absorption spectrum is shown in Figure 12; the differential scanning calorimetry analysis spectrum is shown in Figure 19; and the thermogravimetric analysis spectrum is shown in Figure 26.

Example 49: Preparation of Form (V) of AD-35

Add 4.0 g AD-35 into a mixed solvent of 80 ml n-propanol and 80 ml toluene, add 8 ml water to dissolve, add Form V seed crystals (Form V prepared in Example 48) at 0°C, stir for 8 hours, filter, and obtain 3.1 g of the target crystal.

Example 50: Preparation of Form (V) of AD-35

Add 1.0 g AD-35 to a mixed solvent of 20 ml isopropanol and 20 ml toluene, add 3 ml water to dissolve, add Form V seed crystals (Form V prepared in Example 48) at 5°C, stir for 6 hours, filter, and obtain 0.74 g of the target crystal.

Example 51: Preparation of Form (V) of AD-35

Add 1.0 g AD-35 to a mixed solvent of 2 ml acetone and 30 ml acetonitrile, add 4.5 ml water to dissolve, add Form V seed crystals (Form V prepared in Example 48) at 0°C, stir for 4 hours, filter, and obtain 0.56 g of the target crystal.

The X-ray powder diffraction patterns of the crystalline form (V) of AD-35 obtained in Examples 49-51 are consistent with the X-ray powder diffraction patterns of the crystalline form (V) of AD-35 in Example 48.

Example 52: Preparation of Form (VI) of AD-35

6.0 g of AD-35 crystal form (III) was spread on a surface dish and heated at 150°C for 4 h to obtain 5.27 g of the target crystal form. Its X-ray powder diffraction spectrum is shown in Figure 6; its infrared absorption spectrum is shown in Figure 13; its differential scanning calorimetry analysis spectrum is shown in Figure 20; and its thermogravimetric analysis spectrum is shown in Figure 27.

Example 53: Preparation of Form (VI) of AD-35

Take 6.0 g of AD-35 form (III) and spread it on a watch glass, heat it at 120°C for 8 h to obtain 5.18 g of the target form.

Example 54: Preparation of Form (VI) of AD-35

Add 2.0 g of the compound represented by formula A to 10 ml of ethanol, heat in a 50°C water bath with stirring until the solid is completely dissolved, slowly add 0.29 g of phosphoric acid (85%), solid begins to precipitate after 3 minutes, add 40 ml of ethyl acetate dropwise, continue stirring for 3 hours, cool to 5°C, filter, and obtain 1.20 g of the target crystal form, the solid is needle-shaped and flocculent.

Example 55: Preparation of Form (VI) of AD-35

Add 2.0 g of the compound represented by formula A to 8 ml of ethanol, heat in a water bath at 70°C with stirring until the solid is completely dissolved, slowly add 0.29 g of phosphoric acid (85%), solid begins to precipitate after 3 minutes, add 40 ml of ethyl acetate dropwise, continue stirring for 3 hours, cool to 20°C, filter, and obtain 1.30 g of the target crystal form.

The X-ray powder diffraction patterns of the crystalline form (VI) of AD-35 obtained in Examples 53-55 are consistent with the X-ray powder diffraction patterns of the crystalline form (VI) of AD-35 in Example 52.

Example 56: Preparation of Amorphous Form (VII) of AD-35

At room temperature, 2.0 g AD-35 was completely dissolved in 20 ml water, and the solution was vacuum dried at 40 ° C for 72 hours to obtain 2.01 g of the target crystal form. Its X-ray powder diffraction spectrum is shown in Figure 7; the infrared absorption spectrum is shown in Figure 14; the differential scanning calorimetry analysis spectrum is shown in Figure 21; and the thermogravimetric analysis spectrum is shown in Figure 28.

Preparation Example 1: Preparation of AD-35 according to patent WO2014005421A1

Add 2 g (0.049 mol) of compound A and 40 ml of ethanol to a reaction flask, heat and stir at 60°C until completely dissolved, add 0.57 g (0.049 mol) of 85% phosphoric acid, stir to precipitate a colloidal solid, add 40 ml of ethyl acetate dropwise, cool to room temperature, stir for 1 hour, filter, wash the filter cake with a small amount of ethyl acetate, and dry to obtain 2.1 g of compound AD-35, whose X-ray powder diffraction pattern is shown in Figure 29, which is different from AD-35 crystal forms I to VI.

Preparation Example 2: Preparation of AD-35 according to patent WO2017177816A1

To a 50 mL reaction bottle, add 2 g (4.9 mmol) of compound A and 40 mL of ethanol, heat at 60°C to dissolve, add 0.57 g (4.9 mmol) of 85% phosphoric acid while stirring, precipitate a colloidal solid, add 40 ml of ethyl acetate dropwise, cool to room temperature, stir for 1 hour, filter, wash the filter cake with a small amount of ethyl acetate, and dry to obtain 2.3 g of an off-white colloidal solid. Its X-ray powder diffraction pattern is shown in Figure 30, which is different from Preparation Example 1 and AD-35 Forms I to VI.

Finally, the present invention provides residual solvent analysis of some AD-35 crystal forms, as well as stability and hygroscopicity studies of AD-35 crystal forms. The results are as follows:

(1) Residual solvent analysis

(Measurement method and conditions)

Take the crystalline form III prepared in Example 32 and the crystalline form IV prepared in Example 35, measure the residual amount of methanol and dichloromethane in each sample under the following conditions, and calculate the average value of the two results.

result:

It can be clearly seen from the above results that the residual solvent of the crystal form (III) is mainly dichloromethane, and the residual solvent of the crystal form (IV) is mainly methanol. Combined with the results of thermogravimetric analysis and differential scanning calorimetry analysis, the crystal form (III) is a dichloromethane solvate, and the crystal form (IV) is a methanol solvate.

(2) Stability determination

The crystal form I prepared in Example 1, the crystal form II prepared in Example 29, the crystal form III prepared in Example 32, the crystal form IV prepared in Example 35, the crystal form V prepared in Example 48, the crystal form VI prepared in Example 52, the sample obtained in Preparation Example 1, and the sample obtained in Preparation Example 2 were subjected to a stability test at 60°C for 10 days. The HPLC purity and the maximum single impurity content of the compound before and after placement were detected, and the crystal form after 60°C and 10 days was detected. The results are shown in the following table:

(Measurement method and conditions)

Accurately weigh 50 mg of each crystal form sample at each temperature into a 50 ml brown volumetric flask and dilute to scale with diluent. Measure the impurity content of each sample under the following conditions.

result:

From the stability data of 10 days at 60°C in the above table, it can be seen that after 10 days, the HPLC purity and maximum single impurity content of crystal forms I, II, III, IV, V and VI have small changes, and the chemical stability of the crystal forms is better; while the HPLC purity change of the solids obtained in Preparation Examples 1 and 2 is greater than the HPLC purity change of crystal forms I to VI, and the change value of the HPLC purity of the solids obtained in Preparation Examples 1 and 2 is the largest, so the chemical stability of crystal forms I to VI is better than that of the solids obtained in Preparation Examples 1 and 2. After 10 days at 60°C, crystal forms I, II and VI are stable, while crystal forms III, IV, V and the solids obtained in Preparation Examples 1 and 2 have a phenomenon of crystal form change.

(3) Hygroscopicity measurement

Take a dry stoppered glass weighing bottle and place it in a suitable 25℃±1℃ constant temperature sealed container (place a saturated sodium chloride solution at the bottom with a relative humidity of 75%±2%; or a saturated ammonium sulfate solution at a relative humidity of 80%±2%; or a saturated potassium nitrate solution at a relative humidity of 92.5%±2%) one day before the experiment, and accurately weigh the weight (M ₁ ).

Take an appropriate amount of the sample and spread it evenly in the above weighing bottle. The thickness of the sample is generally about 1 mm. Accurately weigh the weight (M ₂ ).

The weighing bottle is opened and placed under the above-mentioned constant temperature and humidity conditions with the bottle cap on for 24 hours; the weighing bottle is covered with the cap and the weight is accurately determined (M ₃ ).

Calculation formula:

result:


Note: When the hygroscopicity of Form III is tested, dichloromethane evaporates and the mass decreases, so the hygroscopicity of Form III is measured by the following method.

Additional experiments:

1) Take 0.1 g of the test sample of Form III and determine the water content (%) in the sample by Karl Fischer volumetric water determination method. Each sample is measured twice on average and the average value W ₁ is calculated.

2) Take 0.1 g of each Form III sample obtained at three different humidity levels (75%±2%, 80%±2% and 92.5%±2%) in the above hygroscopicity experiment, and determine the water content (%) in the sample by Karl Fischer volumetric water determination method. Determine each sample twice on average and calculate the average value W ₂ .

3) Weight gain percentage (%) = W ₂ - _{W 1} .

result:

It can be seen from the results that under the relative humidity of 75% ± 2% and 80% ± 2%, AD-35 crystal form I, crystal form II, crystal form III, and crystal form VI are almost non-hygroscopic (almost non-hygroscopic < 0.2%); under the relative humidity of 92.5% ± 2%, AD-35 crystal form I, crystal form II, and crystal form III are slightly hygroscopic (0.2% ≤ hygroscopic < 2%). Since crystal form III is a dichloromethane solvate, it loses dichloromethane under the above humidity conditions, resulting in a decrease in mass. Crystal form IV is almost non-hygroscopic under the relative humidity of 75% ± 2%, but is slightly hygroscopic under the relative humidity of 80% ± 2%, and is hygroscopic under the relative humidity of 92.5% ± 2%. Regardless of the relative humidity of 75% ± 2% and 80% ± 2%, or the relative humidity of 92.5% ± 2%, the solids obtained from Form V and Preparation Examples 1 and 2 are hygroscopic (2% ≤ hygroscopic < 15%), but the hygroscopicity of Form V is lower than that of the solids obtained from Preparation Examples 1 and 2. The hygroscopicity of the solids obtained from Forms I to VI of AD-35, Preparation Examples 1 and 2 increases with the increase of humidity, and the hygroscopicity of Forms I to VI of AD-35 is significantly better than that of the solids obtained from Preparation Examples 1 and 2.

Claims (26)

The crystalline form (I) of 6-[2-[1-(2-pyridylmethyl)-4-piperidinyl]ethyl]spiro[[1,3]dioxol[4,5-f]isoindole-7,1'-cyclopropane]-5-one phosphate (AD-35) having the following structure,
It is characterized in that its X-ray powder diffraction pattern has characteristic peaks at the following diffraction angles 2θ: 7.2±0.2°, 7.8±0.2°, 14.2±0.2°, 16.1±0.2°, 16.5±0.2°, 21.0±0.2°, and 23.5±0.2°. The AD-35 crystalline form (I) according to claim 1, characterized in that its X-ray powder diffraction pattern further has characteristic peaks at the following diffraction angles 2θ: 12.8±0.2°, 16.7±0.2°, 17.6±0.2°, 18.7±0.2°, 19.3±0.2°, 20.0±0.2°, 21.7±0.2°, 24.1±0.2°, and 26.6±0.2°. The AD-35 crystal form (I) according to claim 1 or 2, characterized in that the crystal form (I) has an X-ray powder diffraction pattern as shown in Figure 1. The crystalline form (II) of AD-35 is characterized in that its X-ray powder diffraction pattern has characteristic peaks at the following diffraction angles 2θ: 6.8±0.2°, 12.7±0.2°, 16.6±0.2°, 20.2±0.2°, 20.8±0.2°, and 22.6±0.2°. The AD-35 crystalline form (II) according to claim 4 is characterized in that its X-ray powder diffraction pattern further has characteristic peaks at the following diffraction angles 2θ: 13.8±0.2°, 19.6±0.2°, 20.0±0.2°, 24.7±0.2°, and 28.0±0.2°. The AD-35 crystal form (II) according to claim 4 or 5, characterized in that the crystal form (II) has an X-ray powder diffraction pattern as shown in Figure 2. The crystalline form (III) of AD-35 is characterized in that its X-ray powder diffraction pattern has characteristic peaks at the following diffraction angles 2θ: 9.2±0.2°, 18.2±0.2°, 18.5±0.2°, 20.4±0.2°, and 23.9±0.2°. The AD-35 form (III) according to claim 7 is characterized in that its X-ray powder diffraction pattern further has characteristic peaks at the following diffraction angles 2θ: 11.5±0.2°, 15.4±0.2°, 19.0±0.2°, 22.1±0.2°, 25.9±0.2°, and 26.8±0.2°. The AD-35 crystal form (III) according to claim 7 or 8, characterized in that the crystal form (III) has an X-ray powder diffraction pattern as shown in Figure 3. The crystalline form (IV) of AD-35 is characterized in that its X-ray powder diffraction pattern has characteristic peaks at the following diffraction angles 2θ: 6.5±0.2°, 9.8±0.2°, 14.4±0.2°, 19.1±0.2°, 20.3±0.2°, and 21.4±0.2°. The AD-35 crystalline form (IV) according to claim 10 is characterized in that its X-ray powder diffraction pattern further has characteristic peaks at the following diffraction angles 2θ: 17.7±0.2°, 21.9±0.2°, 23.4±0.2°, 25.9±0.2°, and 27.6±0.2°. The AD-35 crystal form (IV) according to claim 10 or 11, characterized in that the crystal form (IV) has an X-ray powder diffraction pattern as shown in Figure 4. The crystalline form (V) of AD-35 is characterized in that its X-ray powder diffraction pattern has characteristic peaks at the following diffraction angles 2θ: 7.0±0.2°, 12.7±0.2°, 15.8±0.2°, 20.5±0.2°, 20.6±0.2°, and 22.1±0.2°. The AD-35 crystalline form (V) according to claim 13 is characterized in that its X-ray powder diffraction pattern further has characteristic peaks at the following diffraction angles 2θ: 9.8±0.2°, 19.5±0.2°, 21.1±0.2°, 24.6±0.2°, and 25.7±0.2°. The AD-35 crystal form (V) according to claim 13 or 14, characterized in that the crystal form (V) has an X-ray powder diffraction pattern as shown in Figure 5. The crystalline form (VI) of AD-35 is characterized in that its X-ray powder diffraction pattern has characteristic peaks at the following diffraction angles 2θ: 6.0±0.2°, 8.8±0.2°, 14.4±0.2°, 18.5±0.2°, 19.0±0.2°, 19.5±0.2°, and 23.9±0.2°. The AD-35 crystalline form (VI) according to claim 16 is characterized in that its X-ray powder diffraction pattern further has characteristic peaks at the following diffraction angles 2θ: 10.4±0.2°, 10.9±0.2°, 11.9±0.2°, 15.2±0.2°, and 22.3±0.2°. The AD-35 crystal form (VI) according to claim 16 or 17, characterized in that the crystal form (VI) has an X-ray powder diffraction pattern as shown in Figure 6. A method for preparing the AD-35 crystalline form (I) according to any one of claims 1 to 3, wherein the method is selected from any one of the following methods: The method (1) comprises the following steps: 1) dissolving the compound represented by formula A in an organic solvent a; the dissolving temperature is 30 to 130° C., preferably 40 to 90° C.; the organic solvent a is selected from one or more of dichloromethane, tetrahydrofuran, acetonitrile, toluene, ethanol, ethyl acetate, N,N-dimethylformamide, methanol, chloroform, and acetone; the volume mass ratio (ml/g) of the organic solvent a to the compound represented by formula A is 8 to 100:1, preferably 10 to 50:1;
2) adding phosphoric acid in an organic solvent b dropwise; the molar ratio of the phosphoric acid to the compound of formula A is 0.95-1.05:1, and the organic solvent b is selected from one or more of ethanol, tetrahydrofuran, acetonitrile, methanol, N,N-dimethylformamide, and acetone; the volume mass ratio (ml/g) of the organic solvent b to the compound of formula A is 2-20:1; 3) stirring and crystallizing; the stirring rate is 60 to 1500 rpm, preferably 120 to 1000 rpm; the crystallization temperature is -25 to 30°C; 4) filtering to obtain the crystalline form (I) of AD-35; Method (2), comprising the following steps: 1) Add AD-35 to a mixed solvent of an organic solvent and water, and heat under reflux to dissolve; the mass volume ratio (g/ml) of the AD-35 to the mixed solvent is 1:10.4-66; the volume ratio of the organic solvent to water is 5-30:1; the organic solvent is selected from one or more of ethanol, isopropanol, tetrahydrofuran, acetone, n-pentanol, ethyl acetate, n-butanol, N,N-dimethylformamide, dichloromethane, acetonitrile, and dimethyl sulfoxide; 2) standing or stirring at -25 to 30°C for crystallization; or, adding an organic solvent dropwise at -25 to 30°C for crystallization; the organic solvent is selected from one or more of methyl tert-butyl ether, isopropanol, tetrahydrofuran, and ethyl acetate; the volume ratio (ml/g) of the organic solvent to the mixed solvent in step (1) is 0.5 to 6:1; 3) filtering to obtain the crystalline form (I) of AD-35; Method (3), comprising the following steps: The AD-35 crystal form (IV) according to any one of claims 10 to 12, or the AD-35 crystal form (V) according to any one of claims 13 to 15, or the AD-35 amorphous form (VII) is stirred in ethanol at 40 to 80° C. for 4 h to 48 h, cooled to room temperature, and filtered to obtain the AD-35 crystal form (I); the mass volume ratio (g/ml) of the AD-35 to ethanol is 1:20 to 50; Method (4), comprising the following steps: The AD-35 crystal form (IV) described in any one of claims 10 to 12, or the AD-35 crystal form (V) described in any one of claims 13 to 15 is heated at high temperature for 3h to 7h to obtain the AD-35 crystal form (I), wherein the high temperature heating temperature is 120°C to 200°C. A method for preparing the AD-35 crystal form (II) according to any one of claims 4 to 6, characterized in that the method comprises:
(1) dissolving the compound represented by formula A in an alcohol solvent; the dissolution temperature is 50-70°C; the mass volume ratio (g/ml) of the compound A to the alcohol solvent is 1:4-6; the alcohol solvent is a C ₂ -C ₄ alcohol, preferably ethanol and isopropanol; (2) adding phosphoric acid under stirring; the molar ratio of the phosphoric acid to the compound of formula A is 0.4 to 0.85:1; the stirring rate is 10 to 180 rpm; (3) adding ethyl acetate dropwise; the volume ratio (ml/g) of the alcohol solvent to ethyl acetate in step (1) is 1:1-2; (4) Filtration to obtain the crystal form (II) of AD-35. A method for preparing the AD-35 crystal form (III) according to any one of claims 7 to 9, characterized in that the method comprises: (1) Adding AD-35 to a mixed solvent of methanol and dichloromethane, heating and refluxing to dissolve, wherein the mass volume ratio (g/ml) of AD-35 to the mixed solvent is 1:8-18; the volume ratio (ml/g) of methanol to dichloromethane is 1:3-8; (2) adding dichloromethane at -25 to 25°C or optionally further adding the seed crystals of the AD-35 crystal form (III) according to any one of claims 7 to 9 or adding dichloromethane in which the seed crystals of the AD-35 crystal form (III) according to any one of claims 7 to 9 are suspended, and standing for 48 to 96 hours for crystallization; the volume ratio (ml/ml) of the dichloromethane to the methanol in step (1) is 1:20 to 40; (3) Filtration to obtain the crystalline form (III) of AD-35. A method for preparing the AD-35 crystalline form (IV) according to any one of claims 10 to 12, wherein the method is selected from any one of the following methods: The method (1) comprises the following steps: 1) dissolving the compound represented by formula A in methanol or a mixed solvent of methanol and dichloromethane at room temperature; the mass volume ratio (g/ml) of the compound represented by formula A to methanol or a mixed solvent of methanol and dichloromethane is 1:5-9; the volume ratio (ml/ml) of methanol to dichloromethane is 1:4-8;
2) adding phosphoric acid or a methanol solution of phosphoric acid; the molar ratio of the phosphoric acid to the compound of formula A is 1:1; the volume mass ratio (ml/g) of the methanol to the compound of formula A in step (1) is 1-2:1; 3) adding a poor solvent dropwise for crystallization; the poor solvent is selected from one or more of ethyl acetate, dichloromethane, ether, and acetone; the volume mass ratio (ml/g) of the poor solvent to the compound represented by formula A in step (1) is 30 to 50:1; (4) filtering to obtain the crystalline form (IV) of AD-35; Method (2), comprising the following steps: (1) dissolving AD-35 in a mixed solvent of methanol and dichloromethane, wherein the volume ratio (ml/ml) of methanol to dichloromethane is 1:4; or dissolving AD-35 in a mixed solvent of methanol, water and dichloromethane, wherein the volume ratio (ml/ml) of methanol, water and dichloromethane is 10:1:80; or dissolving AD-35 in a mixed solvent of methanol and water, wherein the volume ratio (ml/ml) of methanol to water is 6:1; the dissolution temperature is 20 to 40°C; the mass volume ratio of AD-35 to the mixed solvent is 1:18.2 to 35; (2) adding a poor solvent for crystallization; the poor solvent is selected from one or more of n-heptane, dichloromethane, ethyl acetate, and isopropyl ether; the volume mass ratio (ml/g) of the poor solvent to the AD-35 in step (1) is 40 to 100:1; (3) filtering to obtain the crystalline form (IV) of AD-35; Method (3), comprising the following steps: (1) Recrystallizing AD-35 by reflux stirring in methanol; the volume mass ratio (ml/g) of methanol to AD-35 is 10 to 30; Alternatively, AD-35 is refluxed and stirred in a mixed solvent of methanol and water for recrystallization; the volume mass ratio (ml/g) of methanol to AD-35 is 10 to 30, and the volume mass ratio (ml/g) of water to AD-35 is 0.5 to 1.5; Alternatively, AD-35 is refluxed and stirred in a mixed solvent of methanol and dichloromethane for recrystallization; the volume mass ratio (ml/g) of methanol to AD-35 is 1 to 2, and the volume mass ratio (ml/g) of dichloromethane to AD-35 is 1 to 6; (2) Cool to room temperature and filter to obtain the crystalline form (IV) of AD-35. A method for preparing the AD-35 crystalline form (V) according to any one of claims 13 to 15, characterized in that the method comprises: (1) Add AD-35 to an organic solvent selected from the group consisting of n-propanol, isopropanol, acetone, acetonitrile, and toluene, wherein the mass volume ratio (g/ml) of AD-35 to the organic solvent is 1:32 to 40; add water to dissolve the AD-35; wherein the mass volume ratio (g/ml) of AD-35 to water is 1:2 to 4.5; (2) Stirring at 0-5°C for 24-48 hours; Alternatively, adding the AD-35 crystal form (V) seed crystals according to any one of claims 13 to 15 and stirring for 4 to 8 hours at 0 to 5°C; (3) Filtration to obtain the crystalline form (V) of AD-35. A method for preparing the AD-35 crystalline form (VI) according to any one of claims 16 to 18, wherein the method is selected from any one of the following methods: The method (1) comprises the following steps: High temperature heating of the crystalline form (III) of AD-35 according to any one of claims 7 to 9; the temperature of the high temperature heating is 120 to 150° C., and the time of the high temperature heating is 4 to 8 hours; Method (2), comprising the following steps: 1) dissolving the compound represented by formula A in ethanol; the dissolving temperature is 50-70° C.; the mass volume ratio (g/ml) of the compound represented by formula A to ethanol is 1:4-5;
2) Add 0.5 equivalent of phosphoric acid; 3) adding ethyl acetate dropwise and stirring to crystallize; the volume ratio of the ethyl acetate to the ethanol in step (1) is 4 to 5:1; 4) Cool to 5-20°C and filter to obtain the crystalline form (VI) of AD-35. A pharmaceutical composition comprising an effective amount of the crystalline form (I) of AD-35 described in any one of claims 1 to 3, the crystalline form (II) of AD-35 described in any one of claims 4 to 6, the crystalline form (III) of AD-35 described in any one of claims 7 to 9, the crystalline form (IV) of AD-35 described in any one of claims 10 to 12, the crystalline form (V) of AD-35 described in any one of claims 13 to 15, or the crystalline form (VI) of AD-35 described in any one of claims 16 to 18. Use of the crystalline form (I) of AD-35 according to any one of claims 1 to 3, the crystalline form (II) of AD-35 according to any one of claims 4 to 6, the crystalline form (III) of AD-35 according to any one of claims 7 to 9, the crystalline form (IV) of AD-35 according to any one of claims 10 to 12, the crystalline form (V) of AD-35 according to any one of claims 13 to 15, the crystalline form (VI) of AD-35 according to any one of claims 16 to 18, or the pharmaceutical composition according to claim 25 in the preparation of a medicament for treating Alzheimer's disease.