# Patent

## Title
Crystal of tetracyclic compound

## Abstract

The present invention relates to type II and type III crystals of 9-ethyl-6,6-dimethyl-8-(4-morpholin-4-yl-piperidin-1-yl)-11-oxo-6,11-dihydro-5H-benzo[b]carbazole-3-carbonitrile that is a pharmaceutically useful novel crystal.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a National Stage application of PCT/JP2015/062516, filed Apr. 24, 2015, which claims priority from Japanese application JP 2014-092102, filed Apr. 25, 2014.
TECHNICAL FIELD
The present invention relates to a novel crystal of a tetracyclic compound, or a salt or hydrate thereof.
BACKGROUND ART
Anaplastic Lymphoma Kinase (ALK) is one of the receptor tyrosine kinases belonging to the insulin receptor family (Non Patent Literature 1 and. Non Patent Literature 2). It is reported that genetic abnormalities of ALK cause production of abnormal kinases fused with other genes.
As diseases accompanied by the abnormalities of ALK, cancer and cancer metastasis (Non Patent Literature 1 and Patent Literature 1), depression, and cognitive dysfunction (Non Patent Literature 2), for example, are known, and effective therapeutic and preventive medicines these diseases are provided by providing an ALK inhibitor.
As a compound having an ALK inhibitory effect, a compound represented by formula (I) (compound name: 9-ethyl-6,6-dimethyl-8-(4-morpholin-4-yl-piperidin-1-yl)-11-oxo-6,11-dihydro-5H-benzo[b]carbazole-3-carbonitrile) and the like are known (Patent Literature 3, Patent Literature 4, and Patent Literature 5).




However, the crystal form of formula (I) has not been reported so far.
CITATION LIST
Patent Literatures


    Patent Literature 1: Japanese Patent Laid-Open No. 2009-100783
    Patent Literature 2: Japanese Patent Laid-Open No. 2008-280352
    Patent Literature 3: Japanese Patent. No. 4588121
    Patent Literature 4: Japanese Patent No, 4918630
    Patent Literature 5: Japanese Patent Laid-Open No. 2012-126711


Non Patent Literatures


    Non Patent Literature 1: Nature, vol. 448, p.p. 561-566, 2007
    Non Patent Literature 2: Neuropsychopharmacology, vol. 33, p.p. 685-700, 2008


SUMMARY OF INVENTION
Technical Problem
As described above, the compound represented by formula (I) is known to have an ALK inhibitory activity, but a novel crystal that can be pharmaceutically useful has been desired.
Solution to Problem
As a result of diligent studies, the present inventors have found novel crystal forms (type II crystal and type III crystal) of the compound represented by formula (I).
That is, according to one aspect of the present invention, the following crystals (1) to (5) are provided:

    (1) A crystal of a monohydrochloride of a compound represented by formula (I), having peaks at diffraction angles (2θ) of 9.2°±0.2°, 10.2°±0.2°, 16.2°±0.2°, 20.5°±0.2°, and 21.6°±0.2° in a powder X-ray diffraction pattern:






    (2) The crystal according to (1), having peaks at diffraction angles (2θ) of 9.2°±0.2°, 10.2°±0.2°, 16.2°±0.2°, 17.5°±0.2°, 19.5°±0.2°, 20.5°±0.2°, 21.6°±0.2°, and 22.8°±0.2° in a powder X-ray diffraction pattern;
    (3) The crystal according to (1) or (2), being a monohydrate crystal;
    (4) A crystal of a monohydrochloride of a compound represented by formula (I), having peaks at diffraction angles (2θ) of 12.7°±0.2°, 143°±0.2°, 15.0°±0.2°, 18.5°+0.2°, and 25.7°±0.2° in a powder X-ray diffraction pattern; and
    (5) The crystal according to (4), having peaks at diffraction angles (2θ) of 7.5°±0.2°, 12.7°±0.2°, 14.3°±0.2°, 15.0°±0.2°, 18.5°±0.2°, 20.3°±0.2°, 21.0°±0.2° and 25.7°±0.2° in a powder X-ray diffraction pattern.


Advantageous Effect of Invention
A novel crystal according to the present invention can be pharmaceutically useful.



BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a graph of measurement results of powder X-ray diffraction for a type II crystal.
FIG. 2 is a graph of measurement results of powder X-ray diffraction for a type III crystal.
FIG. 3 is a graph of measurement results of powder X-ray diffraction for a type I crystal.
FIG. 4 is a graph of measurement results of powder X-ray diffraction for the type II crystal after being stored at low humidity.
FIG. 5 is a graph of measurement results of powder X-ray diffraction for the type II crystal after being stored at a relative humidity of 70% RH.
FIG. 6 is a graph of measurement results of weight change rate (%) for the type II crystal in a temperature environment at a relative humidity ranging from 0% RH to 90% RH.



DESCRIPTION OF EMBODIMENTS
A type II crystal of a monohydrochloride of the compound of formula (I) according to the present invention can be obtained by drying a type III crystal, which will be described below, at about 40° C. under reduced pressure.
The type II crystal is characterized by having peaks at diffraction angles (2θ) of 9.2°, 10.2°, 16.2°, 20.5°, and 21.6°, more specifically, at diffraction angles (2θ) of 9.2°, 10.2°, 16.2°, 17.5°, 19.5°, 20.5°, 21.6°, and 22.8° in a powder X-ray diffraction pattern. An example of the measurement results of powder X-ray diffraction for the type II crystal is shown in FIG. 1, and an example of the peaks in the powder X-ray diffraction pattern is shown in Table 1.







TABLE 1





Diffraction angle (2θ)

















3.6
19.5
29.2


6.6
20.0
29.6


8.9
20.5
30.3


9.2
20.8
31.0


10.2
21.6
31.3


11.1
22.2
32.6


11.3
22.8
32.9


12.0
23.2
33.6


12.1
23.8
34.0


13.3
24.2
34.8


14.6
24.6
35.5


16.0
24.8
36.2


16.2
25.6
37.7


17.3
26.2
38.3


17.5
26.9
38.8


18.0
27.5
39.4


18.2
27.8
39.9


18.5
28.4


18.8
28.9









In one aspect of the present invention, the type II crystal is a monohydrate. Note that, the monohydrate is not specifically limited as long as it is a crystal that stably holds about one equivalent of water in an environment (such as temperature and relative humidity) in which pharmaceutical products are generally stored and used.
The type III crystal of the monohydrochloride of the compound of formula (I) according to the present invention can be obtained by adding dropwise a solution containing the compound of formula (I) to a mixture of ethanol and hydrochloric acid (containing one equivalent or more of hydrochloric acid with respect to the compound of formula (1)) while maintaining the temperature of the mixture at about 15° C.
The type III crystal is characterized by having peaks in the powder X-ray diffraction pattern at diffraction angles (2θ) of 12.7°, 14.3°, 15.0°, 18.5° and 25.7°, more specifically, at diffraction angles (2θ) of 7.5°, 12.7°, 14.3°, 15.0°, 18.5°, 20.3°, 21.0° and 25.7°, An example of the measurement results of powder X-ray diffraction for the type III crystal is shown in FIG. 2, and an example of the peaks in the powder X-ray diffraction pattern is shown in Table 2.







TABLE 2





Diffraction angle (2θ)

















3.5
19.9
29.5


7.0
20.3
29.6


7.5
21.0
29.9


8.5
22.1
30.3


9.0
22.5
30.5


10.8
22.8
30.9


11.3
23.1
31.4


11.4
23.7
32.1


12.7
24.0
32.8


13.3
24.5
34.0


14.1
24.9
34.4


14.3
25.2
34.8


15.0
25.7
35.3


15.7
26.0
36.2


16.0
26.7
36.3


16.4
26.9
36.7


16.8
27.2
36.9


17.1
27.5
37.6


17.9
27.7
38.2


18.2
28.5


18.5
28.8


19.6
29.1









In the present invention, an analysis by the powder X-ray diffraction can be performed, for example, in accordance with a conventional method such as “powder X-ray diffraction measurement method” described in the Japanese Pharmacopoeia (15th revision) Further, according to the Japanese Pharmacopoeia, the same crystal forms usually have the same diffraction angles 2θ within the range of ±0.2 degree. Accordingly, the present invention includes not only crystals having diffraction angles of the peaks in the powder X-ray diffraction that completely agree with each other but also crystals having diffraction angles of the peaks that agree with each other within a margin of error of about ±0.2 degree.
An example of the measurement conditions in the powder X-ray diffraction analysis is shown below.

    
    
        Measuring apparatus: X'Pert-Pro MPD (manufactured by PANalytical BV)
        Anticathode: Cu
        Tube voltage: 45 kV
        Tube current: 40 mA
        Step width: 0.02
        Scan axis: 2θ
        Sampling time per step: 43 seconds
        Scan range: 3 to 40°
    
    


The water content in crystals can be measured by a conventional method, such as using a dynamic vapor sorption isotherm instrument or the Karl Fischer's method.
An example of the measurement conditions when using the dynamic vapor sorption isotherm instrument is shown below.
Dynamic vapor sorption isotherm instrument: DVS-1
(Surface Measurement Systems)
Temperature: Constant temperature of about 25° C.
Atmospheric gas: Dry nitrogen
Flow rate of atmospheric gas: 200 sccm (ml/min)
Minimum waiting time: 10 min
Maximum waiting time: 1200 min
An example of the measurement conditions in the method for measuring the water content using a Karl Fischer Analyzer is shown below.

    
    
        Analysis method: Coulometric titration
        KF analyzer: Trace moisture analyzer, type KF-100 (manufactured by Mitsubishi Chemical Corporation)
        Anode liquid: AQUAMICRON AX (manufactured by Mitsubishi Chemical Corporation)
        Cathode liquid: AQUAMICRON CXU (manufactured by Mitsubshi Chemical Corporation)
    
    


The present inventors have further specified a crystal of the above-described compound of formula (I) (hereinafter, referred to as type I crystal) that is different from the type II crystal and the type III crystal. The type I crystal can be obtained by adding dropwise a solution containing the compound of formula (I) to a mixture of ethanol and hydrochloric acid. (containing one molar equivalent or more of hydrochloric acid with respect to the compound of formula (I)) while maintaining the temperature of the mixture at about 35° C. or more. The type I crystal is characterized by having peaks in the powder X-ray diffraction pattern at diffraction angles (2θ) of 8.4°, 14.0°, 16.7°, 18.8°, and 23.3°. An example of the measurement results of powder X-ray diffraction for the type I crystal is shown in FIG. 3, and an example of the peaks in the powder X-ray diffraction pattern is shown in Table 3.







TABLE 3





Diffraction angle (2θ)

















3.5
20.2
28.8


8.0
20.5
29.5


8.4
21.0
29.9


8.7
21.5
30.8


11.0
21.8
31.3


11.9
22.1
31.8


12.1
22.3
31.9


14.0
22.6
32.6


15.1
22.9
33.1


15.6
23.3
33.2


16.1
24.1
33.8


16.4
24.8
34.7


16.7
25.4
35.3


17.1
25.7
35.5


17.5
26.1
36.4


18.2
26.9
36.6


18.8
27.7
37.5


19.0
27.9
38.8


19.1
28.2
39.4









The compound represented by formula (I) and its hydrochloride can be produced in accordance with the methods described in Patent Literatures 3 to 5, but not limited to them.
EXAMPLES
Hereinafter, suitable examples of the present invention will be described further in detail. However, the present invention is not limited to these examples.
Example 1
Type I crystal of monohydrochloride of 9-ethyl-6,6-dimethyl-8-(4-morpholin-4-yl-piperidin-1-yl)-11-oxo-6,11-dihydro-5H-benzo[b]carbazole-3-carbonitrile
400 g of 9-ethyl-6,6-dimethyl-8-(4-morpholin-4-yl-piperidin-1-yl)-11-oxo-6,11-dihydro-5H-benzo[b]carbazole-3-carbonitrile was dissolved in a mixture of 4.8 L of methyl ethyl ketone, 1.44 L of acetic acid, and 1.68 L of distilled water at room temperature, and this solution was added dropwise to a mixture of 12 L of ethanol and 0.8 L of 2 N hydrochloric acid at 60° C. A precipitated solid was collected by filtration and was washed with 2 L of ethanol followed by drying, to obtain 357 g of the type I crystal of the monohydrochloride of the titled compound.
Example 2
Type III crystal of monohydrochloride of 9-ethyl-6,6-dimethyl-8-(4-morpholin-4-yl-piperidin-1-yl)-11-oxo-6,11-dihydro-5H-benzo[b]carbazole-3-carbonitrile
9-Ethyl-6,6-dimethyl-8-(4-morpholin-4-yl-piperidin-1-yl)-11-oxo-6,11-dihydro-5H-benzo[b]carbazole-3-carbonitrile (9.00 g) was dissolved in a mixture of methyl ethyl ketone (90 ml), distilled water (31.5 ml), and acetic acid (27.0 ml). This solution was added dropwise to a mixture of ethanol (90 ml) and 2N hydrochloric acid (18.00 ml) that was stirred at 15° C. while maintaining the temperature of the mixture at 15° C. Subsequently, after washing with a mixture of methyl, ethyl ketone (18.00 ml), distilled water (6.30 ml), and acetic acid (5.40 ml), the mixture was stirred at 15° C. A precipitated solid, was collected by filtration, to obtain the type III crystal of the monohydrochloride of the titled compound.
Example 3
Type II crystal of monohydrochloride of 9-ethyl-6,6-dimethyl-8-(4-morpholin-4-yl-piperidin-1-yl)-11-oxo-6,11-dihydro-5H-benzo[b]carbazole-3-carbonitrile
The III crystal obtained in Example 2 was washed with ethanol (90 ml), followed by drying at 40° C. for about 16 hours under reduced pressure, to obtain the type II crystal of the monohydrochloride of the titled compound.
Example 4
Type II crystal of monohydrochloride of 9-ethyl-6,6-dimethyl-8-(4-morpholin-4-yl-piperidin-1-yl)-11-oxo-6,11-dihydro-5H-benzo[b]carbazole-3-carbonitrile
9-ethyl-6,6-dimethyl-8-(4-morpholin-4-yl-piperidin-1-yl)-11-oxo-6,11-dihydro-5H-benzo[b]carbazole-3-carbonitrile (4.00 g) was added to a mixture of methyl ethyl ketone (40 ml), distilled water (14 ml), and acetic acid (12 ml) to be dissolved therein at 35° C. This solution was added dropwise to a mixture of ethanol (40 ml) and 2N hydrochloric acid (8.00 ml) (stirred at 15° C.) while maintaining the temperature of the mixture at 15° C. To this mixture, a mixture of methyl ethyl ketone (8.00 ml), distilled water (2.80 ml), and acetic acid (2.40 ml) was further added dropwise while maintaining the temperature of the mixture at 15° C. Subsequently, the mixture was stirred at 15° C. A precipitated solid was collected by filtration and was washed with ethanol (40 ml), followed by drying at 40° C. under reduced pressure, to obtain the type II crystal of the monohydrochioride of the titled compound (2.4805 g).
Example 5
Type III crystal of monohydrochloride of 9-ethyl-6,6-dimethyl-8-(4-morpholin-4-yl-piperidin-1-yl)-11-oxo-6,11-dihydro-5H-benzo[b]carbazole-3-carbonitrile
9-ethyl-6,6-dimethyl-8-(4-morpholin-4-yl-piperidin-1-yl)-11-oxo-6,11-dihydro-5H-benzo[b]carbazole-3-carbonitril (4.00 g) was added to a mixture of methyl ethyl ketone (40 ml), distilled water (14 ml), and acetic acid (12 ml) to be dissolved therein at 35° C. This solution was added dropwise to a mixture of ethanol (40 ml) and 2N hydrochloric acid (8.00 ml) (stirred at 15° C.) while maintaining the temperature of the mixture at 15° C. A mixture of methyl ethyl ketone (8.00 ml), distilled water (2.80 ml), and acetic acid (2.40 ml) was added dropwise thereto while maintaining the temperature of the mixture at 15° C. Subsequently, the mixture was stirred at 15° C. A precipitated solid was collected by filtration, to obtain the type III crystal of the monohydrochloride of the titled compound (7.8435 g).
[Experimental Example 1] Powder X-Ray Diffraction Analysis
For the type I, type II, and type III crystals of a monohydrochloride of 9-ethyl-6,6-dimethyl-8-(4-morpholin-4-yl-piperidin-1-yl)-11-oxo-6,11-dihydro-5H-benzo[b]carbazole-3-carbonitrile, the powder X-ray diffraction was measured under the following conditions. The measurement results for the type II crystal, the type III crystal, and the type I crystal are shown in FIGS. 1, 2, and 3.

    
    
        Measuring apparatus: X'Pert-Pro MPD (manufactured by PANalytical HV)
        Anticathode: Cu
        Tube voltage: 45 kV
        Tube current: 40 mA
        Step width: 0.02
        Scan axis: 20
        Sampling time per: 43 seconds
        Scan range: 3 to 40°
    
    


[Experimental Example 2] Investigation on Transformation of Crystal form of Type II Crystal Due to Humidity
In order to investigate the transformation of the crystal form of the type II crystal of the monohydrochloride of 9-ethyl-6,6-dimethyl-8-(4-morpholin-4-yl-piperidin-1-yl)-11-oxo-6,11-dihydro-5H-benzo[b]carbazole-3-carbonitrile due to humidity, samples were placed in the following humidity conditions, and changes in crystal form were investigated using the powder X-ray diffraction.
Test Conditions 1 (Investigation on Transformation of Crystal form of Type II Crystal at Low Humidity)


    
    
        Amount of sample: About 17 mq
        Temperature: Constant temperature of about 25° C.
        Atmospheric gas: Dry nitrogen
        Flow rate of atmospheric gas: 200 sccm (ml/min)
        Mass change rate: 0.002 dm/dt
        Relative humidity: Samples were placed at a relative humidity of 0% RH
        Minimum waiting time: 10 min
        Maximum waiting time: 1200 min.

Test Conditions 2 (Iinvestigation on Transformation of Crystal Form of Type II Crystal at High Humidity)

        Amount of sample: About 16 mg
        Temperature: Constant temperature of about 25° C.
        Atmospheric s: Dry nitrogen
        Flow rate of atmospheric gas: 200 sccm (ml/min)
        Mass change rate: 0.002 dm/dt (%/min)
        Relative humidity: Samples were placed at a relative humidity of 70% RH
        Minimum waiting time: 10 min
        Maximum waiting time: 1200 min
    
    


From the results of the powder X-ray diffraction, it was revealed that transformation into another crystal form was caused when the type II crystal was stored at low humidity (FIG. 4). When the type II crystal was allowed to stand in the air, the crystal form of the type II crystal rapidly returned to the original crystal form within one hour. It is inferred from this that the type II crystal dehydrates to be a anhydrate in low humidity environment (at a relative humidity of 15% RH or less). Further, it was revealed that the type II crystal contained water of crystallization.
When stored at 70% RH, the type II crystal showed a powder X-ray diffraction pattern (FIG. 5) different from the powder X-ray diffraction pattern of the type II crystal. It was revealed from this that transformation into another crystal form was caused when the type II crystal was stored at high humidity. As the crystal was allowed to stand in the air, and the powder X-ray diffraction was measured over time, the crystal form returned to the original form, type II crystal, in the measurement after 4 hours. It is inferred from this that the type II crystal absorbs moisture in high humidity environment (at a relative humidity of 65 RH or more), to transform into another crystal form containing water of crystallization.
[Experimental Example 3] Measurement of Vapor Sorption Isotherm of Type II Crystal
For the type II crystal of the monohydrochloride of 9-ethyl-6,6-dimethyl-8-(4-morpholin-4-yl-piperidin-1-yl)-11-oxo-6,11-dihydro-5H-benzo[b]carbazole-3-carbonitrile (about 5 mg), the vapor sorption isotherm was measured using a dynamic vapor sorption isotherm instrument: DVS-1 (Surface Measurement Systems) under the following conditions.
Test Conditions


    
    
        Temperature: Constant temperature of about 25° C.
        Atmospheric gas: Dry nitrogen
        Flow rate of atmospheric gas: 200 sccm (ml/min)
        Minimum waiting time: 10 min
        Maximum waiting time: 1200 min
        Mass change rate: 0.002 dm/dt (% min), where the mass change rate was 0.001 dm/dt (% min) at 5, 10, 15, 55, 60, and 65% RH.
    
    


Relative humidity: Relative humidity was varied to 0, 5, 10, 15, 20, 30, 40, 50, 55, 60, 65, 70, 80, 90, 80, 70, 65, 60, 55, 50, 40, 30, 20, 15, 10, 5, and 0% RR in this order. Such variation was regarded as one cycle, and three cycles were carried out. The measurement results are shown in FIG. 6. The weight change rate (%) of the type II crystal, when the temperature environment was varied from a relative humidity of 0% RH to 90% RH at about 25° C., was 3.7% in the range of a relative humidity from 0% RH to 15% RH, 0.05% in the range of a relative humidity from 15% RH to 55% RH, 11% in the range of a relative humidity from 55% RH to 65% RH, and 0.04% in the range of a relative humidity from 65% RH to 90% RH.
Assuming that the type II crystal was a monohydrochloride monohydrate of the compound of formula (I), the molecular weight would be 537.0928. From the molecular weight and mass change rate (%), it is inferred that the type II crystal is a monohydrochloride monohydrate and is dehydrated when it is stored in an atmosphere of 0% RH, so as to be transformed into a monohydrochloride. Further, it is inferred that the type II crystal absorbs moisture in high humidity environment with a humidity of 65% RH or more and is transformed into a monohydrochloride tetrahydrate.

## Claims

1. A crystal of a monohydrochloride of a compound represented by formula (I), having peaks at diffraction angles (2θ) of 9.2°±0.2°, 10.2°±0.2°, 16.2°±0.2°, 20.5°±0.2°, and 21.6°±0.2° in a powder X-ray diffraction pattern:

2. The crystal according to claim 1, having peaks at diffraction angles (2θ) of 9.2°±0.2°, 10.2°±0.2°, 16.2°±0.2°, 17.5°±0.2°, 19.5°±0.2°, 20.5°±0.2°, 21.6°±0.2°, and 22.8°±0.2° in a powder X-ray diffraction pattern.

3. The crystal according to claim 1, being a monohydrate crystal.

4. A crystal of a monohydrochloride of a compound represented by formula (I), having peaks at diffraction angles (2θ) of 12.7°±0.2°, 14.3°±0.2°, 15.0°±0.2°, 18.5°±0.2°, and 25.7°±0.2° in a powder X-ray diffraction pattern

5. The crystal according to claim 4, having peaks at diffraction angles (2θ) of 7.5°±0.2°, 12.7°±0.2°, 14.3°±0.2°, 15.0°±0.2°, 18.5°±0.2°, 20.3°±0.2°, 21.0°±0.2°, and 25.7°±0.2° in a powder X-ray diffraction pattern.

6. The crystal according to claim 2, being a monohydrate crystal.