AD-35 polymorphic substance as well as preparation method and application thereof

Abstract

The present invention provides crystalline forms of 6-[2-[1-(2-pyridylmethyl)-4-piperidinyl] ethyl] spiro [[1, 3] dioxo [4, 5-f] isoindole-7, 1 '-cyclopropane]-5-one phosphate (AD-35) and processes for their preparation. The invention also provides an application of the crystal form substance of AD-35 in preparation of a medicine for treating Alzheimer's disease. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to polymorphs of AD-35 and methods for their preparation, specifically to polymorphs of 6-[2-[1-(2-pyridinylmethyl)-4-piperidinyl]ethyl]spiro[[1,3]dioxoleno[4,5-f]isoindole-7,1'-cyclopropane]-5-one phosphate (AD-35) and corresponding preparation methods. Background Art

[0002] WO2014005421 reported a new class of benzodioxolene compounds, which have the activity of inhibiting acetylcholinesterase and can be used for the treatment of Alzheimer's disease. Among these compounds, the compound AD-35 is particularly remarkable. Its chemical name is: 6-[2-[1-(2-pyridinylmethyl)-4-piperidinyl]ethyl]spiro[[1,3]dioxoleno[4,5-f]isoindole-7,1'-cyclopropane]-5-one phosphate, and its chemical structure is as follows:

[0003]

[0004] Why is AD-35 particularly remarkable? Because compared with donepezil, it is a relatively weak acetylcholinesterase inhibitor, and its in vitro activity of inhibiting acetylcholinesterase is about one-tenth of that of donepezil. However, this compound shows equivalent pharmacodynamic effects to donepezil in the Morris water maze experiment, that is, the effects of improving memory and learning ability are equivalent to those of donepezil. Further studies have found that in addition to having the activity of inhibiting acetylcholinesterase, AD-35 can significantly inhibit the production and release of pro-inflammatory cytokines TNF-α and IL-1β induced by Aβ 25-35 induced, thereby greatly reducing the toxicity of Aβ 25-35 to nerve cells and effectively protecting nerve cells. In vitro experiments also found that AD-35 has a certain ability to chelate transition metal ions such as Cu 2+ and can inhibit the polymerization of Aβ induced by Cu 2+ and the depolymerization of Aβ polymers in the presence of Cu 2+ Thus, it can be seen that AD-35 is a multi-mechanism and multi-functional compound (Li et al. Journal of Alzheimer’s Disease 2017, 56(4), 1403), and it protects nerve cells through multiple mechanisms.

[0005] In addition, the safety of AD-35 is also very remarkable. The completed first-phase clinical single-dose escalation tolerance test (SAD) showed that no adverse reactions occurred when subjects took 90 mg of AD-35 once; the multiple-dose escalation tolerance test (MAD) further showed that no adverse reactions occurred when subjects took 120 mg of AD-35 once a day for two consecutive weeks.

[0006] In summary, AD-35 has great promise to become a new drug for treating Alzheimer's disease with few side effects. Its multiple action mechanisms are likely to enable this compound not only to relieve the symptoms of Alzheimer's disease patients, but also to delay the progression of this disease.

[0007] For drugs, different crystal forms of drugs result in different physicochemical properties of polymorphic drugs, such as melting point, apparent solubility, dissolution rate, optical and mechanical properties, crystallinity, crystal habit, particle size and particle size distribution, aggregation state of particles, density, filtration and grinding, fragmentation, powder preparation, etc., which in turn affect the characteristics of dosage forms, such as fluidity, dissolution rate, bioavailability and stability. These physicochemical 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 the active pharmaceutical ingredient and the preparation. Therefore, it is necessary to study the crystal forms of AD-35 and the properties of each crystal form to meet the actual application of AD-35. Summary of the Invention

[0008] The present invention relates to stable polymorphs of 6-[2-[1-(2-pyridinylmethyl)-4-piperidinyl]ethyl]spiro[[1,3]dioxoleno[4,5-f]isoindole-7,1'-cyclopropane]-5-one phosphate (AD-35), namely crystal form (I), crystal form (II), crystal form (III), crystal form (IV), crystal form (V), crystal form (VI), and amorphous form (VII), and also provides a preparation method for the polymorphs of AD-35.

[0009]

[0010] In one aspect of the present invention, there is provided crystal form (I) of AD-35, whose X-ray powder diffraction (XRPD) 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°, 23.5±0.2°.

[0011] Furthermore, 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°. More specifically, preferably, the X-ray powder diffraction spectrum of the AD-35 crystal form (I) of the present invention has the 2θ, d value, and relative intensity data shown in Table 1 below:

[0012] Table 1

[0013]

[0014]

[0015] Without limitation, the AD-35 crystal form (I) of the present invention has an X-ray powder diffraction spectrum as shown in Figure 1 shown below.

[0016] In addition, the infrared absorption spectrum of the AD-35 crystal form (I) of the present invention in potassium bromide has absorption peaks at approximately 454.4 cm -1 , 504.8 cm -1 , 535.8 cm -1 , 568.1 cm -1 , 757.3 cm -1 , 779.5 cm -1 , 861.4 cm -1 , 874.8 cm -1 , 925.6 cm -1 , 951.0 cm -1 , 1027.9 cm -1 , 1073.2 cm -1 , 1127.9 cm -1 , 1165.3 cm -1 , 1247.6 cm -1 , 1282.0 cm -1 , 1368.2 cm -1 , 1411.0 cm -1 , 1475.2 cm -1 , 1590.1 cm -1 , 1620.7 cm -1 , 1671.9 cm -1 , 2859.6 cm -1 , 2918.1 cm -1 , 3047.8 cm -1 , 3440.8 cm -1 .

[0017] Non-limitingly, the polymorph (I) of AD-35 of the present invention has an infrared spectrum as Figure 8 shown.

[0018] The differential scanning calorimetry (DSC) spectrum of the polymorph (I) of AD-35 of the present invention has a maximum endothermic peak at 223 ± 5 °C.

[0019] Non-limitingly, the polymorph (I) of AD-35 of the present invention has a DSC spectrum as Figure 15 shown.

[0020] Non-limitingly, the polymorph (I) of AD-35 of the present invention has a TGA spectrum as Figure 22 shown.

[0021] Another object of the present invention is also to provide a method for preparing the polymorph (I) of AD-35, which is selected from any one of the following methods:

[0022] The compound of formula A with the following structure is the free base of AD-35, namely 6-[2-[1-(2-pyridinylmethyl)-4-piperidinyl]ethyl]spiro[[1,3]dioxoleno[4,5-f]isoindole-7,1'-cyclopropane]-5-one.

[0023]

[0024] Method (1), which comprises the following steps:

[0025] 1) Dissolve the compound shown in formula A in organic solvent a; the temperature of the dissolution is 30 - 130 °C, preferably 40 - 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, acetone; the volume-mass ratio (ml / g) of the organic solvent a to the compound of formula A is 8 - 100:1, preferably 10 - 50:1;

[0026] 2) Dropwise add phosphoric acid in organic solvent b; the molar ratio of the phosphoric acid to the compound of formula A is 0.95 - 1.05:1, the organic solvent b is selected from one or more of ethanol, tetrahydrofuran, acetonitrile, methanol, N,N-dimethylformamide, acetone; the volume-mass ratio (ml / g) of the organic solvent b to the compound shown in formula A is 2 - 20:1;

[0027] 3) Stir for crystallization; the stirring rate is 60 - 1500 rpm, preferably 120 - 1000 rpm; the crystallization temperature is -25 - 30 °C;

[0028] 4) Filter to obtain the polymorph (I) of AD-35.

[0029] Method (2), which comprises the following steps:

[0030] 1) Add AD-35 to a mixed solvent of an organic solvent and water, and heat under reflux for dissolution; the mass-volume ratio (g / ml) of 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, dimethyl sulfoxide;

[0031] 2) Stand or stir for crystallization at -25 to 30 °C; or, add an organic solvent dropwise for crystallization at -25 to 30 °C; the organic solvent is selected from one or more of methyl tert-butyl ether, isopropanol, tetrahydrofuran, ethyl acetate; the volume ratio (ml / g) of the organic solvent to the mixed solvent in step (1) is 0.5 - 6:1;

[0032] 3) Filter to obtain the crystal form (I) of AD-35.

[0033] Method (3), which comprises the following steps:

[0034] Stir the crystal form (IV) of AD-35, or the crystal form (V) of AD-35, or the amorphous form (VII) of AD-35 in ethanol at 40 - 80 °C for 4 h - 48 h, cool to room temperature, and filter to obtain the crystal form (I) of AD-35; the mass-volume ratio (g / ml) of AD-35 to ethanol is 1:20 - 50.

[0035] Method (4), which comprises the following steps:

[0036] Heat the crystal form (IV) of AD-35, or the crystal form (V) of AD-35 at a high temperature for 3 h - 7 h to obtain the crystal form (I) of AD-35, wherein the high temperature for heating is 120 °C - 200 °C.

[0037] On the other hand, the present invention provides a crystal form (II) of AD-35, whose X-ray powder diffraction (XRPD) 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 °, 22.6 ± 0.2 °.

[0038] 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°. Even further, preferably, the X-ray powder diffraction spectrum of the AD-35 crystal form (II) of the present invention has the 2θ, d and relative intensity data as shown in Table 2 below:

[0039] Table 2

[0040]

[0041]

[0042] Non-limitingly, the AD-35 crystal form (II) of the present invention has an X-ray powder diffraction spectrum as shown in Figure 2 shown.

[0043] In addition, the infrared absorption spectrum of the AD-35 crystal form (II) of the present invention in potassium bromide has absorption peaks at approximately 529.1 cm -1 , 762.6 cm -1 , 777.1 cm -1 , 866.4 cm -1 , 934.5 cm -1 , 955.6 cm -1 , 1029.3 cm -1 , 1128.2 cm -1 , 1163.9 cm -1 , 1245.9 cm -1 , 1288.1 cm -1 , 1352.0 cm -1 , 1369.9 cm -1 , 1413.2 cm -1 , 1474.2 cm -1 , 1600.4 cm -1 , 1618.1 cm -1 , 1677.7 cm -1 , 2841.1 cm -1 , 2923.9 cm -1 , 3424.7 cm -1 .

[0044] Non-limitingly, the AD-35 crystal form (II) of the present invention has an infrared spectrum as shown in Figure 9 shown.

[0045] The differential scanning calorimetry (DSC) spectrum of the AD-35 crystal form (II) of the present invention has a maximum endothermic peak at 224±5 °C.

[0046] Non - restrictively, the polymorph (II) of AD - 35 of the present invention has a DSC pattern as Figure 16 shown.

[0047] Non - restrictively, the polymorph (II) of AD - 35 of the present invention has a TGA pattern as Figure 23 shown.

[0048] Another object of the present invention is also to provide a method for preparing the polymorph (II) of AD - 35, the method comprising:

[0049]

[0050] (1) Dissolving the compound shown by formula A in an alcohol solvent; the dissolving 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 C2 - C4 alcohol, preferably ethanol and isopropanol;

[0051] (2) Adding phosphoric acid under stirring; the molar ratio of the phosphoric acid to the compound of formula A is 0.4 - 0.85:1; the stirring rate is 10 - 180 rpm;

[0052] (3) Drop - adding ethyl acetate; the volume (ml / g) ratio of the alcohol solvent in step (1) to ethyl acetate is 1:1 - 2;

[0053] (4) Filtering to obtain the polymorph (II) of AD - 35.

[0054] On the other hand, the present invention provides a polymorph (III) of AD - 35, 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 °, 23.9 ± 0.2 °.

[0055] Furthermore, the X - ray powder diffraction pattern of the polymorph (III) of AD - 35 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 °, 26.8 ± 0.2 °.

[0056] Even further, preferably, the X - ray powder diffraction spectrum of the polymorph (III) of AD - 35 of the present invention has 2θ, d and relative intensity data as shown in Table 3 below:

[0057] Table 3 XRPD data of the polymorph (III) of AD - 35

[0058]

[0059] Without limitation, the polymorph (III) of AD-35 according to the present invention has an X-ray powder diffraction pattern as follows: Figure 3 shown.

[0060] In addition, the infrared absorption spectrum of the polymorph (III) of AD-35 in potassium bromide has absorption peaks at approximately 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 , 3045.8 cm -1 , 3420.2 cm -1 .

[0061] Without limitation, the polymorph (III) of AD-35 according to the present invention has an infrared spectrum as follows: Figure 10 shown.

[0062] The differential scanning calorimetry (DSC) curve of the polymorph (III) of AD-35 according to the present invention has endothermic peaks at 122 ± 5 °C and 213 ± 5 °C.

[0063] Without limitation, the polymorph (III) of AD-35 according to the present invention has a DSC curve as follows: Figure 17 shown.

[0064] The TGA step weight loss of the polymorph (III) of AD-35 according to the present invention is 10.8699%. 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 a dichloromethane solvate and contains 0.5 molecules of dichloromethane.

[0065] Non-limitingly, the crystalline form (III) of AD-35 of the present invention has a TGA spectrum as shown in Figure 24 shown.

[0066] Another object of the present invention also lies in providing a preparation method of the crystalline form (III) of AD-35, and the method includes:

[0067] (1) Adding AD-35 into a mixed solvent of methanol and dichloromethane, heating to reflux for dissolution, and the mass-volume ratio (g / ml) of the AD-35 to the mixed solvent is 1:8 to 18; the volume ratio (ml / g) of the methanol to the dichloromethane is 1:3 to 8;

[0068] (2) Adding dichloromethane at -25 to 25 °C, or optionally further adding seeds of the crystalline form (III) of AD-35 or adding dichloromethane in which seeds of the crystalline form (III) of AD-35 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;

[0069] (3) Filtering to obtain the crystalline form (III) of AD-35.

[0070] On the other hand, the present invention provides a crystalline form (IV) of AD-35, and its 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°, 21.4 ± 0.2°.

[0071] Furthermore, the X-ray powder diffraction pattern of the crystalline form (IV) of AD-35 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°, 27.6 ± 0.2°.

[0072] Furthermore, preferably, the X-ray powder diffraction spectrum of the crystalline form (IV) of AD-35 of the present invention has 2θ, d, and relative intensity data as shown in Table 4 below:

[0073] Table 4

[0074]

[0075]

[0076] Non-limitingly, the crystalline form (IV) of AD-35 of the present invention has an X-ray powder diffraction spectrum as shown in Figure 4 shown.

[0077] In addition, the infrared absorption spectrum of the polymorph (IV) of AD-35 of the present invention in potassium bromide has absorption peaks at approximately 449.3 cm -1 , 506.7 cm -1 , 533.1 cm -1 , 766.1 cm -1 , 778.1 cm -1 , 856.7 cm -1 , 870.2 cm -1 , 920.0 cm -1 , 936.4 cm -1 , 1029.4 cm -1 , 1052.3 cm -1 , 1149.5 cm -1 , 1162.0 cm -1 , 1228.2 cm -1 , 1250.7 cm -1 , 1280.0 cm -1 , 1320.5 cm -1 , 1352.9 cm -1 , 1370.2 cm -1 , 1414.0 cm -1 , 1477.1 cm -1 , 1599.5 cm -1 , 1620.4 cm -1 , 1667.9 cm -1 , 2811.2 cm -1 , 2864.9 cm -1 , 2930.1 cm -1 , 3002.8 cm -1 , 3054.9 cm -1 , 3218.9 cm -1 , 3419.3 cm -1 .

[0078] Without limitation, the polymorph (IV) of AD-35 of the present invention has an infrared spectrum as Figure 11 shown.

[0079] The differential scanning calorimetry (DSC) spectrum of the polymorph (IV) of AD-35 of the present invention has endothermic peaks at 143 ± 5 °C, 169 ± °C, and 223 ± 5 °C.

[0080] Without limitation, the polymorph (IV) of AD-35 of the present invention has a DSC spectrum as Figure 18 shown.

[0081] The TGA spectrum of the crystalline form (IV) of AD-35 according to the present invention shows two steps, with a total weight loss of 4.7402%. The gas phase results indicate that the main residual solvent is methanol (4.8840%), and the moisture content is 0.81%, indicating that it exists in the form of a methanol solvate and contains 0.75 methanol molecules.

[0082] Without limitation, the crystalline form (IV) of AD-35 of the present invention has a TGA spectrum as shown in Figure 25 Figure.

[0083] Another object of the present invention is to provide a method for preparing the crystalline form (IV) of AD-35, which is selected from any one of the following methods:

[0084] Method (1), which comprises the following steps:

[0085] 1) At room temperature, dissolve the compound shown in formula A in methanol or a mixed solvent of methanol and dichloromethane; the mass-volume ratio (g / ml) of the compound shown in formula A to methanol or the mixed solvent of methanol and dichloromethane is 1:5 to 9; the volume ratio (ml / ml) of methanol to dichloromethane is 1:4 to 8;

[0086]

[0087] 2) Add phosphoric acid or a methanol solution of phosphoric acid; the molar ratio of phosphoric acid to the compound shown in formula A is 1:1; the volume-mass ratio (ml / g) of methanol to the compound shown in formula A in step (1) is 1 to 2:1;

[0088] 3) Dropwise add a poor solvent 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 shown in formula A in step (1) is 30 to 50:1;

[0089] (4) Filter to obtain the crystalline form (IV) of AD-35.

[0090] Method (2), which comprises the following steps:

[0091] (1) Dissolve AD-35 in a mixed solvent of methanol and dichloromethane, where the volume ratio (ml / ml) of methanol to dichloromethane is 1:4; or dissolve it in a mixed solvent of methanol, water, and dichloromethane, where the volume ratio (ml / ml) of methanol, water, and dichloromethane is 10:1:80; or dissolve it in a mixed solvent of methanol and water, where 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;

[0092] (2) Crystallize by adding a poor solvent; 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 AD - 35 in step (1) is 40 - 100:1;

[0093] (3) Filter to obtain the crystal form (IV) of AD - 35.

[0094] Method (3) includes the following steps:

[0095] (1) Recrystallize AD - 35 by refluxing and stirring in methanol; the volume - mass ratio (ml / g) of methanol to AD - 35 is 10 - 30;

[0096] Or recrystallize AD - 35 by refluxing and stirring in a mixed solvent of methanol and water; the volume - mass ratio (ml / g) of methanol to AD - 35 is 10 - 30, and the volume - mass ratio (ml / g) of water to AD - 35 is 0.5 - 1.5;

[0097] Or recrystallize AD - 35 by refluxing and stirring in a mixed solvent of methanol and dichloromethane; the volume - mass ratio (ml / g) of methanol to AD - 35 is 1 - 2, and the volume - mass ratio (ml / g) of dichloromethane to AD - 35 is 1 - 6;

[0098] (2) Cool to room temperature and filter to obtain the crystal form (IV) of AD - 35.

[0099] On the other hand, the present invention provides a crystal form (V) of AD - 35, whose X - ray powder diffraction (XRPD) 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°, 22.1 ± 0.2°.

[0100] Furthermore, the X - ray powder diffraction pattern of the crystal form (V) of AD - 35 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°, 25.7 ± 0.2°.

[0101] Even further, preferably, the X - ray powder diffraction spectrum of the crystal form (V) of AD - 35 in the present invention has 2θ, d, and relative intensity data as shown in Table 5 below:

[0102] Table 5

[0103]

[0104] Non - restrictively, the crystal form (V) of AD - 35 in the present invention has as Figure 5The X-ray powder diffraction pattern shown

[0105] In addition, the infrared absorption spectrum of polymorph (V) of AD-35 of the present invention in potassium bromide has absorption peaks at approximately 454.5 cm -1 , 503.8 cm -1 , 526.7 cm -1 , 754.8 cm -1 , 767.8 cm -1 , 778.7 cm -1 , 860.5 cm -1 , 926.8 cm -1 , 1034.9 cm -1 , 1072.5 cm -1 , 1131.8 cm -1 , 1165.6 cm -1 , 1250.2 cm -1 , 1271.0 cm -1 , 1285.2 cm -1 , 1417.5 cm -1 , 1474.4 cm -1 , 1598.5 cm -1 , 1617.8 cm -1 , 1653.5 cm -1 , 2937.2 cm -1 , 3002.3 cm -1 , 3396.3 cm -1 .

[0106] Without limitation, polymorph (V) of AD-35 of the present invention has an infrared spectrum as shown Figure 12 in the figure

[0107] The differential scanning calorimetry (DSC) pattern of polymorph (V) of AD-35 of the present invention has endothermic peaks at 123 ± 5 °C and 225 ± 5 °C

[0108] Without limitation, polymorph (V) of AD-35 of the present invention has a DSC pattern as shown Figure 19 in the figure

[0109] The TGA step weight loss of polymorph (V) of AD-35 of 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 molecules

[0110] Without limitation, polymorph (V) of AD-35 of the present invention has a TGA pattern as shown Figure 26 in the figure

[0111] Another object of the present invention is also to provide a method for preparing the AD-35 crystal form (V), the method comprising:

[0112] (1) Add AD-35 to an organic solvent which is one or a combination of several of n-propanol, isopropanol, acetone, acetonitrile, and toluene; the mass-volume ratio (g / ml) of AD-35 to the organic solvent is 1:32 to 40; add water to dissolve; the mass-volume ratio (g / ml) of AD-35 to water is 1:2 to 4.5;

[0113] (2) Stir at 0 to 5 °C for 24 to 48 h;

[0114] Alternatively, add seeds of the AD-35 crystal form (V) and stir at 0 to 5 °C for 4 to 8 h;

[0115] (3) Filter to obtain the AD-35 crystal form (V).

[0116] On the other hand, the present invention provides the AD-35 crystal form (VI), whose X-ray powder diffraction (XRPD) 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°, 23.9 ± 0.2°.

[0117] Furthermore, the X-ray powder diffraction pattern of the AD-35 crystal 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°, 22.3 ± 0.2°.

[0118] Even further, preferably, the X-ray powder diffraction spectrum of the AD-35 crystal form (VI) of the present invention has the 2θ, d, and relative intensity data as shown in Table 6 below:

[0119] Table 6

[0120]

[0121]

[0122] Without limitation, the AD-35 crystal form (VI) of the present invention has an X-ray powder diffraction spectrum as Figure 6 shown.

[0123] In addition, the infrared absorption spectrum of the AD-35 crystal form (VI) of the present invention in potassium bromide has absorption at about 506.3 cm -1 , 566.3 cm -1 , 765.7 cm -1 , 777.8 cm -1, 857.4 cm -1 , 873.3 cm -1 , 927.1 cm -1 , 952.1 cm -1 , 1038.5 cm -1 , 1068.8 cm -1 , 1131.7 cm -1 , 1163.9 cm -1 , 1254.2 cm -1 , 1277.6 cm -1 , 1290.9 cm -1 , 1368.3 cm -1 , 1411.0 cm -1 , 1472.9 cm -1 , 1677.1 cm -1 , 2926.5 cm -1 , 3443.6 cm -1 。

[0124] Without limitation, the polymorph (VI) of AD-35 of the present invention has an infrared spectrum as Figure 13 shown.

[0125] The differential scanning calorimetry (DSC) spectrum of the polymorph (VI) of AD-35 of the present invention has a maximum endothermic peak at 215 ± 5 °C.

[0126] Without limitation, the polymorph (VI) of AD-35 of the present invention has a DSC spectrum as Figure 20 shown.

[0127] Without limitation, the polymorph (VI) of AD-35 of the present invention has a TGA spectrum as Figure 27 shown.

[0128] Another object of the present invention is also to provide a method for preparing the polymorph (VI) of AD-35, which is any one selected from the following methods:

[0129] Method (1), which includes the following steps:

[0130] Heat the polymorph (III) of AD-35 at a high temperature; the high temperature is 120 - 150 °C, and the heating time is 4 - 8 h.

[0131] Method (2), which includes the following steps:

[0132] 1) Dissolve the compound shown in formula A in ethanol; the dissolution temperature is 50 - 70 °C; the mass-volume ratio (g / ml) of the compound shown in formula A to ethanol is 1:4 - 5;

[0133]

[0134] 2) Add 0.5 equivalent of phosphoric acid;

[0135] 3) Dropwise add ethyl acetate and stir for crystallization; the volume ratio of the ethyl acetate to the ethanol in step (1) is 4-5:1;

[0136] 4) Cool to 5-20 °C, filter to obtain the crystalline form (VI) of AD-35.

[0137] On the other hand, the present invention provides an amorphous form (VII) of AD-35, which has an X-ray powder diffraction (XRPD) pattern diffraction peak as Figure 7 shown.

[0138] In addition, the infrared absorption spectrum of the amorphous form (VII) of AD-35 according to the present invention in potassium bromide has absorption peaks 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 .

[0139] Without limitation, the amorphous form (VII) of AD-35 of the present invention has an infrared spectrum as Figure 14 shown.

[0140] Without limitation, the amorphous form (VII) of AD-35 of the present invention has a DSC pattern as Figure 21 shown.

[0141] Without limitation, the amorphous form (VII) of AD-35 of the present invention has a TGA pattern as Figure 28 shown.

[0142] Another object of the present invention is also to provide a method for preparing amorphous (VII) of AD-35, the method comprising:

[0143] Dissolve AD-35 in water, and then vacuum-dry the solution at 40°C and -0.09 Mpa.

[0144] In this application, for the dissolution and crystallization steps involved in all the above methods, unless otherwise specified, stirring is generally required, and the stirring can be carried out in a known manner, such as magnetic stirring, mechanical stirring, etc.

[0145] In this application, the so-called normal temperature or room temperature refers to the temperature range of 20°C to 25°C.

[0146] The present invention provides a pharmaceutical composition, which contains an effective amount of crystalline form (I) or crystalline form (II) or crystalline form (III) or crystalline form (IV) or crystalline form (V) or crystalline form (VI) or amorphous (VII) of the said 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.

[0147] The pharmaceutical composition of the present invention may further contain a pharmaceutically acceptable carrier or excipient. The dosage form and the pharmaceutical composition can be prepared with commonly used pharmaceutically acceptable excipients and additives and common techniques. The pharmaceutically acceptable excipients and additives include non-toxic compatible fillers, binders, disintegrants, buffers, preservatives, antioxidants, lubricants, flavoring agents, thickening agents, coloring agents, emulsifying agents, etc.

[0148] The present invention provides the use of crystalline form (I) or crystalline form (II) or crystalline form (III) or crystalline form (IV) or crystalline form (V) or crystalline form (VI) or amorphous (VII) of AD-35 or the said pharmaceutical composition in the preparation of a drug for treating Alzheimer's disease.

[0149] Advantages of the present invention: The chemical stabilities of crystalline forms I, II, III, IV, V and VI are better than those of the solids obtained in Preparation Example 1 and Preparation Example 2 at 60°C, among which crystalline form I is the most stable, and the preparation method of crystalline form III has a good impurity removal effect and can be used to solve the problem of impurities that are difficult to remove; moreover, the hygroscopicity of the six crystalline forms is also small, which provides great convenience for the later transportation, storage or formulation process of the product. Description of the Drawings

[0150] Figure 1 Powder X-ray diffraction pattern of crystalline form (I) obtained in Example 1.

[0151] Figure 2Powder X-ray diffraction pattern of crystalline form (II) obtained in Example 29.

[0152] Figure 3 Powder X-ray diffraction pattern of crystalline form (III) obtained in Example 32.

[0153] Figure 4 Powder X-ray diffraction pattern of crystalline form (IV) obtained in Example 35.

[0154] Figure 5 Powder X-ray diffraction pattern of crystalline form (V) obtained in Example 48.

[0155] Figure 6 Powder X-ray diffraction pattern of crystalline form (VI) obtained in Example 52.

[0156] Figure 7 Powder X-ray diffraction pattern of amorphous (VII) obtained in Example 56.

[0157] Figure 8 Infrared absorption spectrum of crystalline form (I) obtained in Example 1 in potassium bromide.

[0158] Figure 9 Infrared absorption spectrum of crystalline form (II) obtained in Example 29 in potassium bromide.

[0159] Figure 10 Infrared absorption spectrum of crystalline form (III) obtained in Example 32 in potassium bromide.

[0160] Figure 11 Infrared absorption spectrum of crystalline form (IV) obtained in Example 35 in potassium bromide.

[0161] Figure 12 Infrared absorption spectrum of crystalline form (V) obtained in Example 48 in potassium bromide.

[0162] Figure 13 Infrared absorption spectrum of crystalline form (VI) obtained in Example 52 in potassium bromide.

[0163] Figure 14 Infrared absorption spectrum of amorphous (VII) obtained in Example 56 in potassium bromide.

[0164] Figure 15 Differential scanning calorimetry analysis pattern of crystalline form (I) obtained in Example 1.

[0165] Figure 16 Differential scanning calorimetry analysis pattern of crystalline form (II) obtained in Example 29.

[0166] Figure 17 Differential scanning calorimetry analysis pattern of crystalline form (III) obtained in Example 32.

[0167] Figure 18 DSC analysis pattern of crystalline form (IV) obtained in Example 35.

[0168] Figure 19 DSC analysis pattern of crystalline form (V) obtained in Example 48.

[0169] Figure 20 DSC analysis pattern of crystalline form (VI) obtained in Example 52.

[0170] Figure 21 DSC analysis pattern of amorphous (VII) obtained in Example 56.

[0171] Figure 22 TGA analysis pattern of crystalline form (I) obtained in Example 1.

[0172] Figure 23 TGA analysis pattern of crystalline form (II) obtained in Example 29.

[0173] Figure 24 TGA analysis pattern of crystalline form (III) obtained in Example 32.

[0174] Figure 25 TGA analysis pattern of crystalline form (IV) obtained in Example 35.

[0175] Figure 26 TGA analysis pattern of crystalline form (V) obtained in Example 48.

[0176] Figure 27 TGA analysis pattern of crystalline form (VI) obtained in Example 52.

[0177] Figure 28 TGA analysis pattern of amorphous (VII) obtained in Example 56.

[0178] Figure 29 Powder X-ray diffraction pattern of AD-35 obtained in Preparation Example 1.

[0179] Figure 30 Powder X-ray diffraction pattern of AD-35 obtained in Preparation Example 2. Detailed implementation manners

[0180] The following examples further explain the present invention, however, they do not constitute a limitation or restriction on the scope of the present invention.

[0181] The compound shown in Formula A and the compound AD-35 used in the method of the present invention are both prepared according to the preparation methods disclosed in WO2017177816A1.

[0182] There are no special restrictions on the solvents used in the present invention, and commercially available conventional solvents can be adopted.

[0183] The X-ray powder diffraction instrument and test conditions involved in the present invention are as follows: the model of the X-ray diffraction instrument is Rigaku D / max-2200, with a Cu target. Operating method: scanning temperature is 25°C, scanning speed is 4° / min, and scanning step width is 0.01°.

[0184] The infrared spectrophotometer and test conditions involved in the present invention are as follows: the model of the infrared spectrophotometer is BRWKERVECTOR 22; operating method: using the KBr tablet pressing method, with a scanning range of 400 - 4000 cm-1.

[0185] The DSC test conditions involved in the present invention are as follows: the model of the DSC detector is NETZSCH DSC 200F3; operating method: heating rate is 10°C / min, and temperature range is 20 - 250°C.

[0186] The TGA test conditions involved in the present invention are as follows: the model of the TGA detector is PerkinElmer TGA4000; operating method: heating rate is 10°C / min, and temperature range is 30 - 250°C.

[0187] The moisture test conditions involved in the present invention are as follows: the model of the moisture detector is Metrohm 852Titrando + 803TiStand; operating method: Karl Fischer volumetric method for moisture determination.

[0188] It should be emphasized that for the numerical values or numerical endpoints involved in the technical solution of the present invention, their meanings or intended protection scopes are not limited to the numbers themselves. Those skilled in the art can understand that they include the allowable error ranges widely accepted in the art, such as experimental errors, measurement errors, statistical errors, and random errors, etc., and these error ranges are all included within the scope of the present invention.

[0189] Example 1: Preparation of polymorph (I) of AD-35

[0190] Add 1.0 g of the compound shown in formula A to 15 ml of dichloromethane, heat and dissolve at 30°C, add dropwise a 5 ml ethanol solution containing 0.29 g of phosphoric acid (85%), stir at 0°C for 1 h, with a stirring rate of 120 rmp, filter, and obtain 0.71 g of the target polymorph. The solid is in the form of blocky particles and has good fluidity. Its X-ray powder diffraction pattern is as Figure 1 shown; the infrared absorption spectrum is as Figure 8 shown; the differential scanning calorimetry analysis pattern is as Figure 15 shown; the thermogravimetric analysis pattern is as Figure 22 shown.

[0191] Example 2: Preparation of Polymorph (I) of AD-35

[0192] Add 1.0 g of the compound shown in Formula A to 20 ml of tetrahydrofuran, heat and dissolve at 50 °C, add dropwise a 5 ml tetrahydrofuran solution containing 0.27 g of phosphoric acid (85%), stir at 5 °C for 1 h, the stirring rate is 1000 rmp, filter to obtain 0.80 g of the target polymorph.

[0193] Example 3: Preparation of Polymorph (I) of AD-35

[0194] Add 1.0 g of the compound shown in Formula A to 20 ml of acetonitrile, heat and dissolve at 60 °C, add dropwise a 5 ml acetonitrile solution containing 0.29 g of phosphoric acid (85%), stir at 0 °C for 2 h, the stirring rate is 60 rmp, filter to obtain 1.11 g of the target polymorph.

[0195] Example 4: Preparation of Polymorph (I) of AD-35

[0196] Add 1.0 g of the compound shown in Formula A to 50 ml of toluene, heat and dissolve at 70 °C, add dropwise a 10 ml ethanol solution containing 0.29 g of phosphoric acid (85%), stir at -10 °C for 1 h, the stirring rate is 1500 rmp, filter to obtain 0.89 g of the target polymorph.

[0197] Example 5: Preparation of Polymorph (I) of AD-35

[0198] Add 40 g of the compound shown in Formula A to 600 ml of ethanol, heat and dissolve at 70 °C, add dropwise an 80 ml methanol solution containing 11.6 g of phosphoric acid (85%), continue to stir for 1 h, stir at -5 °C for 1 h, the stirring rate is 300 rmp, filter to obtain 47.7 g of the target polymorph.

[0199] Example 6: Preparation of Polymorph (I) of AD-35

[0200] Add 1.0 g of the compound shown in Formula A to 10 ml of ethyl acetate, heat and dissolve at 70 °C, add dropwise a 5 ml ethanol solution containing 0.30 g of phosphoric acid (85%), stir at 30 °C for 1 h, the stirring rate is 500 rmp, filter to obtain 0.82 g of the target polymorph.

[0201] Example 7: Preparation of Polymorph (I) of AD-35

[0202] Add 1.0 g of the compound shown in Formula A to 100 ml of N,N-dimethylformamide, heat and dissolve at 130 °C, add dropwise a 20 ml N,N-dimethylformamide solution containing 0.29 g of phosphoric acid (85%), stir at -25 °C for 3 h, the stirring rate is 800 rmp, filter to obtain 0.98 g of the target polymorph.

[0203] Example 8: Preparation of Polymorph (I) of AD-35

[0204] 1.0 g of the compound shown in Formula A was added to 20 ml of methanol and dissolved by heating at 50 °C. A 3-ml methanol solution containing 0.29 g of phosphoric acid (85%) was added dropwise, and the mixture was stirred at 0 °C for 1 hour at a stirring rate of 100 rmp. After filtration, 0.99 g of the target polymorph was obtained.

[0205] Example 9: Preparation of Polymorph (I) of AD-35

[0206] 1.0 g of the compound shown in Formula A was added to 8 ml of chloroform and dissolved by heating at 50 °C. A 3-ml ethanol solution containing 0.29 g of phosphoric acid (85%) was added dropwise, and the mixture was stirred at 10 °C for 2 h at a stirring rate of 200 rmp. After filtration, 0.99 g of the target polymorph was obtained.

[0207] Example 10: Preparation of Polymorph (I) of AD-35

[0208] 1.0 g of the compound shown in Formula A was added to 30 ml of acetone and dissolved by heating at 50 °C. A 2-ml 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 rmp. After filtration, 0.94 g of the target polymorph was obtained.

[0209] Example 11: Preparation of Polymorph (I) of AD-35

[0210] 1.0 g of the compound shown in Formula A was added to a mixed solvent of 20 ml of ethanol, 20 ml of ethyl acetate and 10 ml of N,N-dimethylformamide and dissolved by heating at 60 °C. A 15-ml ethanol solution containing 0.29 g of phosphoric acid (85%) was added dropwise, and the mixture was stirred at 0 °C for 1 h at a stirring rate of 800 rmp. After filtration, 0.82 g of the target polymorph was obtained.

[0211] Example 12: Preparation of Polymorph (I) of AD-35

[0212] 0.5 g of AD-35 was added to a mixed solvent of 10 ml of ethanol and 0.9 ml of water and dissolved by heating under reflux. The mixture was allowed to stand at 25 °C for crystallization for 48 h, and then filtered to obtain 0.42 g of the target polymorph.

[0213] Example 13: Preparation of Polymorph (I) of AD-35

[0214] 0.5 g of AD-35 was added to a mixed solvent of 10 ml of isopropanol and 1.25 ml of water and dissolved by heating under reflux. The mixture was allowed to stand at 30 °C for crystallization for 48 h, and then filtered to obtain 0.43 g of the target polymorph.

[0215] Example 14: Preparation of Polymorph (I) of AD-35

[0216] 0.5 g of AD-35 was added to a mixed solvent of 3 ml of ethanol, 15 ml of tetrahydrofuran and 3 ml of water, and the mixture was heated under reflux for dissolution. Then it was allowed to stand for crystallization at 20 °C for 48 h, and filtered to obtain 0.31 g of the target crystal form.

[0217] Example 15: Preparation of Crystal Form (I) of AD-35

[0218] 0.5 g of AD-35 was added to a mixed solvent of 10 ml of acetone and 2 ml of water, and the mixture was heated under reflux for dissolution. Then it was allowed to stand for crystallization at -25 °C for 48 h, and filtered to obtain 0.25 g of the target crystal form.

[0219] Example 16: Preparation of Crystal Form (I) of AD-35

[0220] 0.5 g of AD-35 was added to a mixed solvent of 10 ml of n-pentanol, 7 ml of acetone and 1 ml of water, and the mixture was heated under reflux for dissolution. Then it was allowed to stand for crystallization at 0 °C for 48 h, and filtered to obtain 0.44 g of the target crystal form.

[0221] Example 17: Preparation of Crystal Form (I) of AD-35

[0222] 0.5 g of AD-35 was added to a mixed solvent of 10 ml of n-pentanol, 5 ml of ethyl acetate, 5 ml of ethanol and 1.6 ml of water, and the mixture was heated under reflux for dissolution. Then it was stirred at 0 °C for 6 h, and filtered to obtain 0.38 g of the target crystal form.

[0223] Example 18: Preparation of Crystal Form (I) of AD-35

[0224] 0.5 g of AD-35 was added to a mixed solvent of 30 ml of n-butanol and 3 ml of water, and the mixture was heated under reflux for dissolution. Then it was stirred at 5 °C for 6 h to obtain 0.34 g of the target crystal form.

[0225] Example 19: Preparation of Crystal Form (I) of AD-35

[0226] 0.5 g of AD-35 was added to a mixed solvent of 10 ml of N,N-dimethylformamide and 0.5 ml of water, and the mixture was heated under reflux for dissolution. Then it was stirred at 30 °C for 48 h, and filtered to obtain 0.45 g of the target crystal form.

[0227] Example 20: Preparation of Crystal Form (I) of AD-35

[0228] 0.5 g of AD-35 was added to a mixed solvent of 20 ml of N,N-dimethylformamide and 3 ml of water, and the mixture was heated under reflux for dissolution. Then 20 ml of methyl tert-butyl ether was added dropwise for crystallization while stirring at 30 °C, and filtered to obtain 0.42 g of the target crystal form.

[0229] Example 21: Preparation of Crystal Form (I) of AD-35

[0230] 0.5 g of AD-35 was added to a mixed solvent of 1 ml of ethanol, 0.2 ml of water and 4 ml of dichloromethane, and the mixture was heated under reflux for dissolution. 31.2 ml of isopropanol was added dropwise with stirring at -25°C for crystallization. After filtration, 0.39 g of the target crystal form was obtained.

[0231] Example 22: Preparation of crystal form (I) of AD-35

[0232] 1.0 g of AD-35 was added to a mixed solvent of 20 ml of acetonitrile, 20 ml of N,N-dimethylformamide and 6 ml of water, and the mixture was heated under reflux for dissolution. 23 ml of tetrahydrofuran was added dropwise with stirring at 20°C for crystallization. After filtration, 0.78 g of the target crystal form was obtained.

[0233] Example 23: Preparation of crystal form (I) of AD-35

[0234] 0.5 g of AD-35 was added to a mixed solvent of 10 ml of dimethyl sulfoxide, 5 ml of ethanol and 0.5 ml of water, and the mixture was heated under reflux for dissolution. 20 ml of ethyl acetate was added dropwise with stirring at 0°C for crystallization. After filtration, 0.42 g of the target crystal form was obtained.

[0235] Example 24: Preparation of crystal form (I) of AD-35

[0236] 1.0 g of crystal form (IV) of AD-35 was added to 20 ml of ethanol, and the mixture was refluxed with stirring at 80°C for 4 h. After cooling to room temperature, filtration was carried out to obtain 0.92 g of the target crystal form.

[0237] Example 25: Preparation of crystal form (I) of AD-35

[0238] 1.0 g of crystal form (V) of AD-35 was added to 50 ml of ethanol, and the mixture was stirred at 40°C for 48 h. After cooling to room temperature, filtration was carried out to obtain 0.86 g of the target crystal form.

[0239] Example 26: Preparation of crystal form (I) of AD-35

[0240] 1.0 g of amorphous form (VII) of AD-35 was added to 20 ml of ethanol, and the mixture was stirred at 60°C for 12 h. After cooling to room temperature, filtration was carried out to obtain 0.85 g of the target crystal form.

[0241] Example 27: Preparation of crystal form (I) of AD-35

[0242] 0.5 g of crystal form (IV) of AD-35 was spread out on a watch glass and heated at 120°C for 7 h to obtain 0.47 g of the target crystal form.

[0243] Example 28: Preparation of crystal form (I) of AD-35

[0244] Spread 0.5 g of the crystal form (V) of AD-35 on a watch glass and heat it at 200 °C for 3 h to obtain 0.44 g of the target crystal form.

[0245] The X-ray powder diffraction pattern of the crystal form (I) of AD-35 obtained in Example 2-28 is consistent with the X-ray powder diffraction pattern of the crystal form (I) of AD-35 in Example 1.

[0246] Example 29: Preparation of the crystal form (II) of AD-35

[0247] Add 17.4 g of the compound shown in Formula A to 87 ml of ethanol, heat and dissolve it at 70 °C, add 4.2 g of phosphoric acid (85%) at a rotation speed of 180 rpm, dropwise add 87 ml of ethyl acetate, cool to room temperature, filter to obtain 18.4 g of the target crystal form, and the solid particles agglomerate. Its X-ray powder diffraction pattern is as Figure 2 shown; the infrared absorption spectrum is as Figure 9 shown; the differential scanning calorimetry pattern is as Figure 16 shown; the thermogravimetric analysis pattern is as Figure 23 shown.

[0248] Example 30: Preparation of the crystal form (II) of AD-35

[0249] Add 5.0 g of the compound shown in Formula A to 20 ml of isopropanol, heat and dissolve it at 65 °C, add 0.57 g of phosphoric acid (85%) at a rotation speed of 100 rpm, dropwise add 40 ml of ethyl acetate, cool to room temperature, filter to obtain 2.18 g of the target crystal form.

[0250] Example 31: Preparation of the crystal form (II) of AD-35

[0251] Add 5.0 g of the compound shown in Formula A to 30 ml of n-butanol, heat and dissolve it at 50 °C, add 0.57 g of phosphoric acid (85%) at a rotation speed of 10 rpm, dropwise add 50 ml of ethyl acetate, cool to room temperature, filter to obtain 2.01 g of the target crystal form.

[0252] The X-ray powder diffraction patterns of the crystal form (II) of AD-35 obtained in Examples 30 and 31 are consistent with the X-ray powder diffraction pattern of the crystal form (II) of AD-35 in Example 29.

[0253] Example 32: Preparation of the crystal form (III) of AD-35

[0254] Add 2.0 g of AD-35 to a mixed solvent of 4 ml of methanol and 32 ml of dichloromethane, heat under reflux to dissolve, add 160 ml of dichloromethane at -25 °C, and crystallize at -25 °C for 48 h, filter to obtain 1.91 g of the target crystal form, and the solid is needle-shaped and flocculent. Its X-ray powder diffraction pattern is as Figure 3as shown; the infrared absorption spectrum is as Figure 10 shown; the differential scanning calorimetry spectrum is as Figure 17 shown; the thermogravimetric analysis spectrum is as Figure 24 shown.

[0255] Example 33: Preparation of Polymorph (III) of AD-35

[0256] 5.0 g of AD-35 was added to a mixed solvent of 15 ml of methanol and 45 ml of dichloromethane, heated under reflux to dissolve, 450 ml of dichloromethane was added at 0 °C, a small amount of polymorph III seed crystal was added, and the mixture was allowed to stand for 72 h, then filtered to obtain 4.83 g of the target polymorph.

[0257] Example 34: Preparation of Polymorph (III) of AD-35

[0258] 20.0 g of AD-35 was added to a mixed solvent of 40 ml of methanol and 120 ml of dichloromethane, heated under reflux to dissolve, 800 ml of dichloromethane in which a small amount of polymorph III seed crystal was suspended was added at 25 °C, and the mixture was allowed to crystallize at 25 °C for 96 h, then filtered to obtain 20.7 g of the target polymorph.

[0259] The X-ray powder diffraction pattern of the polymorph (III) of AD-35 obtained in Examples 33 and 34 is consistent with the X-ray powder diffraction pattern of the polymorph (III) of AD-35 in Example 32.

[0260] Example 35: Preparation of Polymorph (IV) of AD-35

[0261] At room temperature, 1.0 g of the compound shown in Formula A was dissolved in 8 ml of methanol, 0.29 g of phosphoric acid (85%) was added, and 40 ml of ethyl acetate was added dropwise to crystallize, then filtered to obtain 0.82 g of the target polymorph. The solid was large blocky particles. Its X-ray powder diffraction pattern is as Figure 4 shown; the infrared absorption spectrum is as Figure 11 shown; the differential scanning calorimetry spectrum is as Figure 18 shown; the thermogravimetric analysis spectrum is as Figure 25 shown.

[0262] Example 36: Preparation of Polymorph (IV) of AD-35

[0263] At room temperature, 1.0 g of the compound shown in Formula A was dissolved in a mixed solvent of 1 ml of methanol and 8 ml of dichloromethane, a 1 ml methanol solution containing 0.29 g of phosphoric acid (85%) was added, and 30 ml of dichloromethane was added dropwise to crystallize, then filtered to obtain 0.94 g of the target polymorph.

[0264] Example 37: Preparation of Polymorph (IV) of AD-35

[0265] At room temperature, 1.0 g of the compound shown in Formula A was dissolved in a mixed solvent of 1 ml of methanol and 4 ml of dichloromethane. A 2-ml methanol solution containing 0.29 g of phosphoric acid (85%) was added, and a mixed solution of 30 ml of diethyl ether and 20 ml of acetone was added dropwise for crystallization. After filtration, 1.12 g of the target crystal form was obtained.

[0266] Example 38: Preparation of Crystal Form (IV) of AD-35

[0267] 0.5 g of AD-35 was added to a mixed solvent of 1 ml of methanol, 0.1 ml of water and 8 ml of dichloromethane, and stirred and dissolved at 30 °C. 40 ml of n-heptane was added dropwise at 30 °C for crystallization. After filtration, 0.45 g of the target crystal form was obtained.

[0268] Example 39: Preparation of Crystal Form (IV) of AD-35

[0269] 0.5 g of AD-35 was added to a mixed solvent of 1 ml of methanol, 0.1 ml of water and 8 ml of dichloromethane, and stirred and dissolved at 25 °C. 40 ml of dichloromethane was added dropwise, and after filtration, 0.49 g of the target crystal form was obtained.

[0270] Example 40: Preparation of Crystal Form (IV) of AD-35

[0271] 0.5 g of AD-35 was added to a mixed solvent of 2 ml of methanol and 8 ml of dichloromethane, and stirred and dissolved at 20 °C. 50 ml of ethyl acetate was added dropwise for crystallization. After filtration, 0.45 g of the target crystal form was obtained.

[0272] Example 41: Preparation of Crystal Form (IV) of AD-35

[0273] 1.0 g of AD-35 was added to a mixed solvent of 30 ml of methanol and 5 ml of water, heated and dissolved at 40 °C. 40 ml of isopropyl ether was added dropwise for crystallization. After filtration, 0.98 g of the target crystal form was obtained.

[0274] Example 42: Preparation of Crystal Form (IV) of AD-35

[0275] 1.0 g of AD-35 was added to 10 ml of methanol, refluxed and stirred for 2 h, cooled to room temperature, and filtered to obtain 0.70 g of the target crystal form.

[0276] Example 43: Preparation of Crystal Form (IV) of AD-35

[0277] 1.0 g of AD-35 was added to 30 ml of methanol, refluxed and stirred for 1.5 h, cooled to room temperature, and filtered to obtain 0.50 g of the target crystal form.

[0278] Example 44: Preparation of Crystal Form (IV) of AD-35

[0279] 1.0 g of AD-35 was added to a mixed solvent of 10 ml of methanol and 0.5 ml of water, refluxed and stirred for 2 h, cooled to room temperature, filtered, and 0.38 g of the target crystal form was obtained.

[0280] Example 45: Preparation of Crystal Form (IV) of AD-35

[0281] 1.0 g of AD-35 was added to a mixed solvent of 30 ml of methanol and 1.5 ml of water, refluxed and stirred for 2 h, cooled to room temperature, filtered, and 0.24 g of the target crystal form was obtained.

[0282] Example 46: Preparation of Crystal Form (IV) of AD-35

[0283] 10.0 g of AD-35 was added to a mixed solvent of 10 ml of methanol and 60 ml of dichloromethane, dissolved by refluxing and then stirred for 1 h, cooled to room temperature, filtered, and 3.8 g of the target crystal form was obtained.

[0284] Example 47: Preparation of Crystal Form (IV) of AD-35

[0285] 10.0 g of AD-35 was added to a mixed solvent of 20 ml of methanol and 10 ml of dichloromethane, refluxed and stirred for 2 h, cooled to room temperature, filtered, and 4.1 g of the target crystal form was obtained.

[0286] The X-ray powder diffraction pattern of the crystal form (IV) of AD-35 obtained in Examples 36 - 47 was consistent with the X-ray powder diffraction pattern of the crystal form (IV) of AD-35 in Example 35.

[0287] Example 48: Preparation of Crystal Form (V) of AD-35

[0288] 0.5 g of AD-35 was added to a mixed solvent of 10 ml of n-propanol and 10 ml of toluene, 1 ml of water was added for dissolution, and crystallization was carried out by stirring at 0 °C for 24 h, then filtered, and 0.41 g of the target crystal form was obtained. The solid was in the form of blocky particles. Its X-ray powder diffraction pattern is as Figure 5 shown; the infrared absorption spectrum is as Figure 12 shown; the differential scanning calorimetry pattern is as Figure 19 shown; the thermogravimetric analysis pattern is as Figure 26 shown.

[0289] Example 49: Preparation of Crystal Form (V) of AD-35

[0290] 4.0 g of AD-35 was added to a mixed solvent of 80 ml of n-propanol and 80 ml of toluene, 8 ml of water was added for dissolution, and crystal seed of crystal form V (crystal form V prepared in Example 48) was added at 0 °C and stirred for 8 h, then filtered, and 3.1 g of the target crystal form was obtained.

[0291] Example 50: Preparation of Polymorph (V) of AD-35

[0292] Add 1.0 g of AD-35 to a mixed solvent of 20 ml of isopropanol and 20 ml of toluene, add 3 ml of water to dissolve, add the polymorph V seed crystal (polymorph V prepared in Example 48) at 5 °C, stir for 6 h, filter, and obtain 0.74 g of the target polymorph.

[0293] Example 51: Preparation of Polymorph (V) of AD-35

[0294] Add 1.0 g of AD-35 to a mixed solvent of 2 ml of acetone and 30 ml of acetonitrile, add 4.5 ml of water to dissolve, add the polymorph V seed crystal (polymorph V prepared in Example 48) at 0 °C, stir for 4 h, filter, and obtain 0.56 g of the target polymorph.

[0295] The X-ray powder diffraction pattern of the polymorph (V) of AD-35 obtained in Examples 49 - 51 is consistent with the X-ray powder diffraction pattern of the polymorph (V) of AD-35 in Example 48.

[0296] Example 52: Preparation of Polymorph (VI) of AD-35

[0297] Take 6.0 g of the polymorph (III) of AD-35 and spread it flat on a watch glass, heat at 150 °C for 4 h to obtain 5.27 g of the target polymorph. Its X-ray powder diffraction pattern is as Figure 6 shown; the infrared absorption spectrum is as Figure 13 shown; the differential scanning calorimetry pattern is as Figure 20 shown; the thermogravimetric analysis pattern is as Figure 27 shown.

[0298] Example 53: Preparation of Polymorph (VI) of AD-35

[0299] Take 6.0 g of the polymorph (III) of AD-35 and spread it flat on a watch glass, heat at 120 °C for 8 h to obtain 5.18 g of the target polymorph.

[0300] Example 54: Preparation of Polymorph (VI) of AD-35

[0301] Add 2.0 g of the compound shown in Formula A to 10 ml of ethanol, heat and stir in a water bath at 50 °C until the solid is completely dissolved, slowly add 0.29 g of phosphoric acid (85%), start to precipitate solids after 3 min, add 40 ml of ethyl acetate dropwise, continue to stir for 3 h, cool to 5 °C, filter, and obtain 1.20 g of the target polymorph. The solid is needle-shaped and flocculent.

[0302] Example 55: Preparation of Polymorph (VI) of AD-35

[0303] 2.0 g of the compound shown in Formula A was added to 8 ml of ethanol, and the mixture was heated with stirring in a water bath at 70 °C until the solid was completely dissolved. 0.29 g of phosphoric acid (85%) was slowly added. After 3 min, a solid began to precipitate. 40 ml of ethyl acetate was added dropwise, and stirring was continued for 3 h. The mixture was cooled to 20 °C and filtered to obtain 1.30 g of the target crystal form.

[0304] The X-ray powder diffraction pattern of the crystal form (VI) of AD-35 obtained in Examples 53-55 was consistent with the X-ray powder diffraction pattern of the crystal form (VI) of AD-35 in Example 52.

[0305] Example 56: Preparation of amorphous (VII) of AD-35

[0306] At room temperature, 2.0 g of AD-35 was completely dissolved in 20 ml of water. The solution was dried in vacuo at 40 °C for 72 h to obtain 2.01 g of the target crystal form. Its X-ray powder diffraction pattern is as Figure 7 shown; the infrared absorption spectrum is as Figure 14 shown; the differential scanning calorimetry pattern is as Figure 21 shown; the thermogravimetric analysis pattern is as Figure 28 shown.

[0307] Preparation Example 1: Preparation of AD-35 according to Patent WO2014005421A1

[0308] 2 grams (0.049 mol) of the compound of Formula A and 40 ml of ethanol were added to a reaction flask. The mixture was heated with stirring at 60 °C until completely dissolved. 0.57 grams (0.049 mol) of 85% phosphoric acid was added, and a colloidal solid precipitated out upon stirring. 40 ml of ethyl acetate was added dropwise, and the mixture was cooled to room temperature and stirred for 1 h. The mixture was filtered, and the filter cake was washed with a small amount of ethyl acetate and dried to obtain 2.1 g of compound AD-35. Its X-ray powder diffraction pattern is as Figure 29 shown, which is different from crystal forms I-VI of AD-35.

[0309] Preparation Example 2: Preparation of AD-35 according to Patent WO2017177816A1

[0310] 2 grams (4.9 mmol) of the compound of Formula A and 40 ml of ethanol were added to a 50 mL reaction flask. The mixture was heated to dissolve at 60 °C, and 0.57 grams of 85% (4.9 mmol) phosphoric acid was added with stirring. A colloidal solid precipitated out. 40 ml of ethyl acetate was added dropwise, and the mixture was cooled to room temperature and stirred for 1 h. The mixture was filtered, and the filter cake was washed with a small amount of ethyl acetate and dried to obtain 2.3 g of a white colloidal solid. Its X-ray powder diffraction pattern is as Figure 30 shown, which is different from Preparation Example 1 and crystal forms I-VI of AD-35.

[0311] Finally, the present invention provides an analysis of residual solvents in partial crystal forms of AD-35, as well as studies on the stability and hygroscopicity of the crystal forms of AD-35. The results are as follows:

[0312] (1) Residual solvent analysis

[0313] (Measurement method and conditions)

[0314] Take the crystal form III prepared in Example 32 and the crystal form IV prepared in Example 35, and measure the residual amounts of methanol and dichloromethane in each sample under the following conditions, and calculate the average value of the two results.

[0315]

[0316] Results:

[0317]

[0318]

[0319] It can be clearly seen from the above results that the main residual solvent in crystal form (III) is dichloromethane, and the main residual solvent in crystal form (IV) is methanol. Combining the results of its thermogravimetric analysis and differential scanning calorimetry, crystal form (III) is a dichloromethane solvate, and crystal form (IV) is a methanol solvate.

[0320] (2) Stability determination

[0321] Take 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 samples obtained in Preparation Example 1 and the samples obtained in Preparation Example 2, and conduct a stability experiment at 60 °C for 10 days. Detect the HPLC purity and the maximum single impurity content of the compound before and after storage, and detect the crystal form at 60 °C after 10 days. The results are shown in the following table:

[0322] (Measurement method and conditions)

[0323] Precisely weigh 50 mg of each crystal form sample at each temperature into a 50 ml brown volumetric flask, and dilute it to the mark with a diluent. Measure the impurity content of each sample under the following conditions.

[0324]

[0325] Results:

[0326]

[0327]

[0328] From the stability data of the above table placed at 60°C for 10 days, it can be seen that after 10 days, the changes in HPLC purity and the maximum single impurity content of crystal forms I, II, III, IV, V, and VI are all relatively small, indicating relatively good chemical stability of the crystal forms; while the change in HPLC purity of the solids obtained in Preparation Example 1 and Preparation Example 2 is greater than that of crystal forms I-VI, and the change value of the HPLC purity of the solids obtained in Preparation Example 1 and Preparation Example 2 is the largest. Therefore, the chemical stability of crystal forms I-VI is better than that of the solids obtained in Preparation Example 1 and Preparation Example 2. After being placed at 60°C for 10 days, crystal forms I, II, and VI are stable, while crystal forms III, IV, V, and the solids obtained in Preparation Example 1 and Preparation Example 2 show the phenomenon of crystal form change.

[0329] (3) Hygroscopicity determination

[0330] Take a dry stoppered glass weighing bottle and place it in a suitable constant temperature and closed container at 25°C ± 1°C one day before the experiment (sodium chloride saturated solution is placed at the bottom, relative humidity is 75% ± 2%; or ammonium sulfate saturated solution is placed, relative humidity is 80% ± 2%; or potassium nitrate saturated solution is placed, relative humidity is 92.5% ± 2%), and accurately weigh the weight (M1).

[0331] Take an appropriate amount of the test sample and spread it evenly in the above-mentioned weighing bottle. The thickness of the test sample is generally about 1 mm, and accurately weigh the weight (M2).

[0332] Open the weighing bottle and place the bottle cap in the above-mentioned constant temperature and humidity conditions for 24 hours; cover the weighing bottle cap and accurately weigh the weight (M3).

[0333] Calculation formula:

[0334]

[0335] Result:

[0336]

[0337]

[0338] Note: During the hygroscopicity test of crystal form III, dichloromethane volatilizes and the mass decreases. Therefore, the hygroscopicity of crystal form III is determined by the following method.

[0339] Supplementary experiment:

[0340] 1) Take 0.1 g of the test sample of crystal form III and determine the water content (%) in the sample by the Karl Fischer volumetric method for water determination. Each sample is measured twice on average, and the average value W1 is obtained.

[0341] 2) Weigh 0.1 g of the crystalline form III samples obtained under the three different humidities (75% ± 2%, 80% ± 2% and 92.5% ± 2%) in the above hygroscopicity experiment respectively, and determine the moisture content (%) in the samples according to the volumetric Karl Fischer method. Each sample is measured twice on average, and the average value W2 is calculated.

[0342] 3) Percentage of weight gain (%) = W2 - W1.

[0343] Results:

[0344]

[0345] It can be seen from the results that under the conditions of relative humidity of 75% ± 2% and 80% ± 2%, the crystalline forms I, II, III and VI of AD-35 have almost no hygroscopicity (almost no hygroscopicity < 0.2%); under the condition of relative humidity of 92.5% ± 2%, the crystalline forms I, II and III of AD-35 have slightly hygroscopicity (0.2% ≤ hygroscopicity < 2%). Since the crystalline form III is a dichloromethane solvate, dichloromethane is lost under the above humidity conditions, resulting in a decrease in mass. The crystalline form IV has almost no hygroscopicity under the condition of relative humidity of 75% ± 2%, slightly hygroscopicity under the condition of relative humidity of 80% ± 2%, and hygroscopicity under the condition of 92.5% ± 2%. Whether under the conditions of relative humidity of 75% ± 2% and 80% ± 2% or under the condition of relative humidity of 92.5% ± 2%, the crystalline form V and the solids obtained in Preparation Example 1 and Preparation Example 2 are hygroscopic (2% ≤ hygroscopicity < 15%), but the hygroscopicity of the crystalline form V is lower than that of the solids obtained in Preparation Example 1 and Preparation Example 2. The hygroscopicity of the crystalline forms I-VI of AD-35, the solids obtained in Preparation Example 1 and Preparation Example 2 increases with the increase of humidity, and the hygroscopicity effect of the crystalline forms I-VI of AD-35 is significantly better than that of the solids obtained in Preparation Example 1 and Preparation Example 2.

Claims

1. Polymorph (I) of 6-[2-[1-(2-pyridylmethyl)-4-piperidyl]ethyl]spiro[[1,3]dioxolano[4,5-f]isoindole-7,1'-cyclopropane]-5-one phosphate (AD-35) with the following structure, which 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°, 23.5 ± 0.2°.

2. The polymorph (I) of AD-35 according to claim 1, which is 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°, 26.6 ± 0.2°.

3. The polymorph (I) of AD-35 according to claim 1 or 2, which is characterized in that, The crystal form (I) has an X-ray powder diffraction pattern as shown in Figure 1.

4. Polymorph (II) of AD-35, which 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°, 22.6 ± 0.2°.

5. The polymorph (II) of AD-35 according to claim 4, which 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°, 28.0 ± 0.2°.

6. The polymorph (II) of AD-35 according to claim 4 or 5, which is characterized in that, The crystal form (II) has an X-ray powder diffraction pattern as shown in Figure 2.

7. Polymorph (III) of AD-35, which 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°, 23.9 ± 0.2°.

8. The polymorph (III) of AD-35 according to claim 7, which 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°, 26.8 ± 0.2°.

9. The polymorph (III) of AD-35 according to claim 7 or 8, which is characterized in that, The crystal form (III) has an X-ray powder diffraction pattern as shown in Figure 3.

10. Polymorph (IV) of AD-35, which 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°, 21.4 ± 0.2°.

11. The polymorph (IV) of AD-35 according to claim 10, which 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°, 27.6 ± 0.2°.

12. The polymorph (IV) of AD-35 according to claim 10 or 11, which is characterized in that, The crystal form (IV) has an X-ray powder diffraction pattern as shown in Figure 4.

13. Polymorph (V) of AD-35, which 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°, 22.1 ± 0.2°.

14. The polymorph (V) of AD-35 according to claim 13, which 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°, 25.7 ± 0.2°.

15. The polymorph (V) of AD-35 according to claim 13 or 14, which is characterized in that, The crystal form (V) has an X-ray powder diffraction pattern as shown in Figure 5.

16. Polymorph (VI) of AD-35, which 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°, 23.9 ± 0.2°.

17. The AD-35 polymorph (VI) according to claim 16, 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°, 22.3 ± 0.2°.

18. The AD-35 polymorph (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.

19. A method for preparing the AD-35 polymorph (I) according to any one of claims 1 to 3, wherein the method is selected from any one of the following methods: Method (1), which comprises the following steps: 1) Dissolve the compound shown by formula A in organic solvent a; the temperature of the dissolution is 30 - 130°C, preferably 40 - 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, acetone; the volume-mass ratio (ml / g) of the organic solvent a to the compound of formula A is 8 - 100:1, preferably 10 - 50:1; 2) Dropwise add organic solvent b of phosphoric acid; the molar ratio of the phosphoric acid to the compound of formula A is 0.95 - 1.05:1, the organic solvent b is selected from one or more of ethanol, tetrahydrofuran, acetonitrile, methanol, N,N-dimethylformamide, acetone; the volume-mass ratio (ml / g) of the organic solvent b to the compound shown by formula A is 2 - 20:1; 3) Stir for crystallization; the rate of the stirring is 60 - 1500 rpm, preferably 120 - 1000 rpm; the temperature of the crystallization is -25 - 30°C; 4) Filter to obtain the crystal form (I) of AD-35; Method (2), which includes the following steps: 1) Add AD-35 to a mixed solvent of an organic solvent and water, and heat under reflux for dissolution; the mass-volume ratio (g / ml) of 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, dimethyl sulfoxide; 2) Stand or stir for crystallization at -25 - 30°C; or, dropwise add an organic solvent for crystallization at -25 - 30°C; the organic solvent is selected from one or more of methyl tert-butyl ether, isopropanol, tetrahydrofuran, ethyl acetate; the volume ratio (ml / g) of the organic solvent to the mixed solvent in step (1) is 0.5 - 6:1; 3) Filter to obtain the crystal form (I) of AD-35; Method (3), which includes the following steps: Stir the AD-35 crystal form (IV) described in any one of claims 10 - 12, or the AD-35 crystal form (V) described in any one of claims 13 - 15, or the AD-35 amorphous form (VII) in ethanol at 40 - 80°C for 4 h - 48 h, cool to room temperature, filter to obtain the crystal form (I) of AD-35; the mass-volume ratio (g / ml) of AD-35 to ethanol is 1:20 - 50; Method (4), comprising the following steps: Subjecting the AD-35 polymorph (IV) according to any one of claims 10 to 12, or the AD-35 polymorph (V) according to any one of claims 13 to 15 to high-temperature heating for 3 h to 7 h to obtain the polymorph (I) of AD-35, wherein the temperature of the high-temperature heating is 120°C to 200°C.

20. A method for preparing the AD-35 polymorph (II) according to any one of claims 4 to 6, characterized in that, The method comprises: (1) Dissolving the compound shown by formula A in an alcohol solvent; the dissolving temperature is 50 to 70°C; the mass-volume ratio (g / ml) of the compound A to the alcohol solvent is 1:4 to 6; the alcohol solvent is C2-C4 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) Dropwise adding ethyl acetate; the volume (ml / g) ratio of the alcohol solvent in step (1) to ethyl acetate is 1:1 to 2; (4) Filtering to obtain the polymorph (II) of AD-35.

21. A method for preparing the AD-35 polymorph (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 to reflux for dissolution, the mass-volume ratio (g / ml) of the AD-35 to the mixed solvent is 1:8 to 18; the volume ratio (ml / g) of methanol to dichloromethane is 1:3 to 8; (2) Adding dichloromethane at -25 to 25°C or optionally further adding seeds of the AD-35 polymorph (III) according to any one of claims 7 to 9 or adding dichloromethane suspended with seeds of the AD-35 polymorph (III) according to any one of claims 7 to 9, and standing for 48 to 96 h for crystallization; the volume ratio (ml / ml) of the dichloromethane to the methanol in step (1) is 1:20 to 40; (3) Filtering to obtain the polymorph (III) of AD-35.

22. A method for preparing the AD-35 polymorph (IV) according to any one of claims 10 to 12, wherein the method is selected from any one of the following methods: Method (1), which comprises the following steps: 1) At room temperature, dissolving the compound shown by formula A in methanol or a mixed solvent of methanol and dichloromethane; the mass-volume ratio (g / ml) of the compound shown by formula A to methanol or the mixed solvent of methanol and dichloromethane is 1:5 to 9; the volume ratio (ml / ml) of methanol to dichloromethane is 1:4 to 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 methanol to the compound shown by formula A in step (1) is 1 to 2:1; 3) Dropwise adding a poor solvent 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 shown by formula A in step (1) is 30 to 50:1; (4) Filtering to obtain the polymorph (IV) of AD-35; Method (2), comprising the following steps: (1) Dissolve AD-35 in a mixed solvent of methanol and dichloromethane, where the volume ratio (ml / ml) of methanol to dichloromethane is 1:4; or dissolve it in a mixed solvent of methanol, water and dichloromethane, where the volume ratio (ml / ml) of methanol, water and dichloromethane is 10:1:80; or dissolve it in a mixed solvent of methanol and water, where the volume ratio (ml / ml) of methanol to water is 6:1; the dissolution temperature is 20-40 °C; the mass-volume ratio of AD-35 to the mixed solvent is 1:18.2-35; (2) Add a poor solvent for crystallization; the poor solvent is selected from one or more of n-heptane, dichloromethane, ethyl acetate, isopropyl ether; the volume-mass ratio (ml / g) of the poor solvent to AD-35 in step (1) is 40-100:1; (3) Filter to obtain the crystal form (IV) of AD-35; Method (3), which includes the following steps: (1) Reflux and stir AD-35 for recrystallization in methanol; the volume-mass ratio (ml / g) of methanol to AD-35 is 10-30; Or reflux and stir AD-35 for recrystallization in a mixed solvent of methanol and water; the volume-mass ratio (ml / g) of methanol to AD-35 is 10-30, and the volume-mass ratio (ml / g) of water to AD-35 is 0.5-1.5; Or reflux and stir AD-35 for recrystallization in a mixed solvent of methanol and dichloromethane; the volume-mass ratio (ml / g) of methanol to AD-35 is 1-2, and the volume-mass ratio (ml / g) of dichloromethane to AD-35 is 1-6; (2) Cool to room temperature and filter to obtain the crystal form (IV) of AD-35.

23. A method for preparing the AD-35 polymorph (V) according to any one of claims 13 to 15, characterized in that, The method includes: (1) Add AD-35 to an organic solvent which is a combination of one or more of n-propanol, isopropanol, acetone, acetonitrile, toluene; the mass-volume ratio (g / ml) of AD-35 to the organic solvent is 1:32-40; add water for dissolution; the mass-volume ratio (g / ml) of AD-35 to water is 1:2-4.5; (2) Stir at 0-5 °C for 24-48 h; Or, add the crystal seed of the crystal form (V) of AD-35 described in any one of claims 13-15 and stir at 0-5 °C for 4-8 h; (3) Filter to obtain the crystal form (V) of AD-35.

24. A method for preparing the AD-35 polymorph (VI) according to any one of claims 16 to 18, said method being selected from any one of the following methods: Method (1), which comprises the following steps: Heat the crystal form (III) of AD-35 described in any one of claims 7-9 at a high temperature; the high temperature heating temperature is 120-150 °C, and the high temperature heating time is 4-8 h; Method (2), which includes the following steps: 1) Dissolve the compound shown in formula A in ethanol; the dissolution temperature is 50-70 °C; the mass-volume ratio (g / ml) of the compound shown in formula A to ethanol is 1:4-5; 2) Add 0.5 equivalent of phosphoric acid; 3) Dropwise add ethyl acetate and stir for crystallization; the volume ratio of ethyl acetate to ethanol in step (1) is 4-5:1; 4) Cool to 5-20 °C and filter to obtain the crystal form (VI) of AD-35.

25. A pharmaceutical composition, said composition containing an effective amount of the polymorph (I) of AD-35 according to any one of claims 1 to 3 or the polymorph (II) of AD-35 according to any one of claims 4 to 6 or the polymorph (III) of AD-35 according to any one of claims 7 to 9 or the polymorph (IV) of AD-35 according to any one of claims 10 to 12 or the polymorph (V) of AD-35 according to any one of claims 13 to 15 or the polymorph (VI) of AD-35 according to any one of claims 16 to 18.

26. Use of the crystalline form (I) of AD-35 according to any one of claims 1 to 3, or the crystalline form (II) of AD-35 according to any one of claims 4 to 6, or the crystalline form (III) of AD-35 according to any one of claims 7 to 9, or the crystalline form (IV) of AD-35 according to any one of claims 10 to 12, or the crystalline form (V) of AD-35 according to any one of claims 13 to 15, or 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 the treatment of Alzheimer's disease.

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