2-{4-[N-(5,6-DIPHENYLPYRAZIN-2-YL)-N-ISOPROPYLAMINO]BUTYLOXY}ACETIC ACID FORM II CRYSTAL, PHARMACEUTICAL COMPOSITION, PGI2 RECEPTOR AGONIST COMPOSITION AND THERAPEUTIC COMPOSITION

Abstract

A crystal of 2-{4-[N-(5,6-diphenylpyrazin-2-yl)-N-isopropylamino]butyloxy}acetate (compound B). A crystal of form I of compound B, showing peaks at diffraction angles (2θ) of 6.4°, 8.1°, 9.5°, 10.9°, 13.2°, 15.7°, 17.0°, 19.5°, 20.3°, 21.0° and 22.8° in an X-ray powder diffraction spectrum obtained using Cu-Ka radiation (λ = 1.54 Å). A crystal of form II of compound B, showing peaks at diffraction angles (2q) of 9.6º, 11.4º, 11.7º, 16.3º, 17.5º, 18.5º, 18.7º, 19.9º, 20.1º, 21.0º and 24.6º in an X-ray powder diffraction spectrum obtained using Cu-Ka radiation (l = 1.54 Å).

Description

147393 [DESCRIPTION] [Title of the invention] CRYSTAL [Technical field]

[0001] The present invention relates to a novel crystal of 2-{4-[N-(5,6-diphenylpyrazin-2-yl)-isopropylamino]butyloxy}acetate (hereinafter referred to as compound B). [Chem. 1] H3C CH3 [Previous Art]

[0002] A pharmaceutical product needs to maintain its quality over a long period, even under varying distribution and storage conditions. Therefore, it requires a compound serving as an active ingredient that possesses physicochemical stability. Consequently, a crystalline structure is generally adopted as the active ingredient in a pharmaceutical product. IF-2018-49906246-APN-ANP#INPI Page 1 of 29, which can be expected to have high stability. In a process to control the crystal structure of an active pharmaceutical ingredient, it is not only difficult to find optimal conditions for obtaining the crystal, but even if the crystal is obtained, the existence of polymorphism is often problematic. This problem arises because there is a difference in physicochemical stability depending on the crystalline form. Furthermore, if the crystalline form to be used as an active ingredient in a pharmaceutical product is incorrectly selected, a reduction in purity, transformation of the crystalline form, or similar changes may occur depending on the external environment during storage. This makes it difficult to maintain consistent compound quality and, depending on the crystalline form, can lead to unexpected events such as reduced pharmacological efficacy or adverse effects. Therefore, when a crystal of a compound is successfully obtained to serve as an active ingredient in a pharmaceutical product, a rigorous evaluation and examination of the physicochemical stability of the polymorphism is necessary.

[0003] However, it is impossible to predict the existence or non-existence of polymorphism or a crystalline form. IF-2018-49906246-APN-ANP#INPI Page 2 of 29 stable from the structure of a compound and, moreover, there is a compound that cannot be crystallized in some cases and it is necessary to study in a varied way the conditions to form a crystal for each compound.

[0004] On the other hand, compound B is known for its excellent PGI2 receptor agonist effect and exhibits several medicinal effects, including platelet aggregation inhibition, vasodilation, bronchial smooth muscle dilation, lipid deposition inhibition, and leukocyte activation inhibition (see, for example, PTL 1 to PTL 6). However, the current situation is that it is unknown whether a crystal can form, let alone whether polymorphism exists, and obtaining an optimal crystal for its development as a pharmaceutical product is a significant objective. [Reference Listing] [Patent Literature]

[0005] [PTL 1] WO 2002 / 088084 [PTL 2] WO 2009 / 157396 [PTL 3] WO 2009 / 107736 [PTL 4] WO 2009 / 154246 [PTL 5] WO 2009 / 157397 IF-2018-49906246-APN-ANP#INPI Página 3 de 29 [PTL 6] WO 2009 / 157398 [PTL 7] US 2014 / 0221397 [PTL 8] US 2011 / 0178103 [PTL 9] US 2011 / 0015211 [PTL 10] US 2011 / 0118254 [PTL 11] US 2011 / 0105518 [No literatura de patentes]

[0006] [NPL 1] Hepatology, 2007, Vol. 45, No. 1, pp. 159169 [NPL 2] PubMed: Nihon Yakurigaku Zasshi, 2001, Feb, 117(2), pp. 123-130, Abstract [NPL 3] International Angiology, 29, Supl. 1 a No. 2, pp. 49-54, 2010 [NPL 4] Japanese Journal of Clinical Immunology, Vol. 16, No. 5, pp. 409-414, 1993 [NPL 5 ] Japanese Journal of Thrombosis and Hemostasis , Vol. 1, No. 2, pp. 94-105, 1990, Abstract [NPL 6] The Journal of Rheumatology, Vol. 36, no. 10, pp. 2244-2249, 2009 [NPL 7] The Japanese Journal of Pharmacology, Vol. 43, no. 1, pp. 81-90, 1987 [NPL 8] British Heart Journal, Vol. 53, no. 2, pp. 173-179, 1985 [NPL 9] The Lancet, 1, 4880, pt 1, pp. 569-572, 1981 IF-2018-49906246-APN-ANP#INPI Page 4 of 29 [NPL 10] European Journal of Pharmacology, 449, pp. 167-176, 2002 [NPL 11] The Journal of Clinical Investigation, 117, pp. 464-72, 2007 [NPL 12 ] American Journal of Physiology Lung Cellular and Molecular Physiology, 296: L648-L656 2009 [Synthesis of the invention] [Technical problem]

[0007] An object of the present invention is to provide a crystal of compound B that has excellent physicochemical stability and also to provide a pharmaceutical composition containing the crystal as an active ingredient. [Solution to the problem]

[0008] A method for producing compound B is disclosed in Example 42 of PTL 1. However, in Example 42 of PTL 1, it is not specified what form of compound B was obtained. Accordingly, when the present inventor attempted to produce compound B according to the same procedure as the method disclosed in Example 42 of PTL 1, it was found that the form is a crystal (hereafter referred to as a crystal of the form IF-2018-49906246-APN-ANP#INPI Page 5 of 29 III) (see Reference Example 1 mentioned below). The results of the X-ray powder diffraction measurement, IR measurement, and DSC measurement of the crystal of form III are shown in FIG. 1, FIG. 2, and FIG. 3, respectively. However, as shown in the Test Example mentioned below, the crystal of form III was found to be thermodynamically unstable, and therefore the present inventor made intensive studies in order to achieve the above object and, as a result, it was found that there is a crystal of form I and a crystal of form II, each of which is thermodynamically more stable, and thus the present invention was completed.

[0009] The present invention may include, for example, the following points (1) to (7). (1) A crystal of form I of compound B (hereafter referred to as crystal of form I of the present invention), exhibiting diffraction peaks at diffraction angles (2θ) of 6.4°, 8.1°, 9.5°, 10.9°, 13.2°, 15.7°, 17.0°, 19.5°, 20.3°, 21.0° and 22.8° in an X-ray powder diffraction spectrum obtained using Cu-Kα radiation (λ=1.54 Å). (2) A crystal of form I of the present invention, exhibiting absorption peaks with wavenumber of 2874 IF-2018-49906246-APN-ANP#INPI Page 6 of 29 cm-1, 1736 cm-1, 1558 cm1, 1375 cm'1, 1126 cm-1 and 696 cirr1 in an infrared absorption spectrum. ( 3 ) A crystal of form I of the present invention, having an endothermic peak at 127 °C in differential scanning calorimetry. (4) A crystal of form II of compound B (hereafter referred to as the crystal of form II of the present invention), exhibiting diffraction peaks at diffraction angles (2Θ) of 9.6°, 11.4°, 11.7°, 16.3°, 17.5°, 18.5°, 18.7°, 19.9°, 20.1°, 21.0° and 24.6° in an X-ray powder diffraction spectrum obtained using Cu-Kα radiation (λ=1.54 Å). (5) A crystal of form II of the present invention, exhibiting absorption peaks with wavenumbers of 2867 cm1, 174 9 cm-1, 156 8 cm-1, 13 82 cm'1, 1131 cm-1 and 701 cm-1 in an infrared absorption spectrum. ( 6 ) A crystal of form II of the present invention, having an endothermic peak at 147 °C in differential scanning calorimetry. (7) A pharmaceutical composition containing the crystal according to any of points (1) to (6) as an active ingredient (hereinafter referred to as the pharmaceutical composition of the present invention).

[0010] IF-2018-49906246-APN-ANP#INPI Page 7 of 29 When a diffraction angle (2Θ) is specified for a diffraction peak in the Examples and claims of the present invention, it is understood that a value obtained is within the range of ±0.2°, preferably within the range of ±0.1°. Furthermore, when an absorption peak in an infrared absorption spectrum (hereafter referred to as the IR spectrum) is specified in the Examples and claims of the present invention, it is understood that a value obtained is within the range of ± 2 cm-1, preferably within the range of ± 1 cm-1. Furthermore, when an endothermic peak by differential scanning calorimetry (hereinafter referred to as DSC) is specified in the Examples and claims of the present invention, it is understood that a value obtained is within the range of ± 3 °C, preferably within the range of ± 2 °C. [Brief description of the drawings]

[0011] [FIG. 1] FIG. 1 shows a graph of the powder X-ray diffraction spectrum of a crystal of form III. The vertical axis represents peak intensity (cps) IF-2018-49906246-APN-ANP#INPI Page 8 of 29 and the horizontal axis represents a diffraction angle (2Θ [°])· [FIG. 2] FIG. 2 shows a graph of the IR spectrum of the crystal of form III. The vertical axis represents a transmittance (%) and the horizontal axis represents a wavenumber (cm-1). [FIG. 3] FIG. 3 shows a DSC measurement graph when the temperature of the Form III crystal was increased by 10 °C per minute. The vertical axis in the drawing represents an exothermic quantity (mW) (in the case of a negative value, the value represents an endothermic quantity) and the horizontal axis represents temperature (°C). [FIG. 4] FIG. 4 shows a graph of the powder X-ray diffraction spectrum of the crystal of form I of the present invention. The vertical axis represents a peak intensity (cps) and the horizontal axis represents a diffraction angle (20 [°] ). [FIG. 5] FIG. 5 shows a graph of the powder X-ray diffraction spectrum of the crystal of form II of the present invention. The vertical axis represents a peak intensity (cps) and the horizontal axis represents a diffraction angle (20 [°]). [FIG. 6] FIG. 6 shows a graph of the IR spectrum of the crystal of form I of the present invention. The axis IF-2018-49906246-APN-ANP#INPI Page 9 of 29 The vertical axis represents a transmittance (%) and the horizontal axis represents a wavenumber (cm-1). [FIG. 7] FIG. 7 shows a graph of the IR spectrum of the crystal of form II of the present invention. The vertical axis represents a transmittance (%) and the horizontal axis represents a wavenumber (cm-1). [FIG. 8] FIG. 8 shows a DSC measurement graph when the temperature of the crystal of form I of the present invention was increased by 10 °C per minute. The vertical axis represents an exothermic quantity (mW) per second (in the case of a negative value, the value represents an endothermic quantity) and the horizontal axis represents temperature (°C). [FIG. 9] FIG. 9 shows a DSC measurement graph when the temperature of the crystal of form II of the present invention was increased by 10 °C per minute. The vertical axis in the drawing represents an exothermic quantity (mW) (in the case of a negative value, the value represents an endothermic quantity) and the horizontal axis represents temperature (°C). [Description of the forms of realization] [0012 ] A. Crystal of form I of the present invention The crystal of form I of the present invention is IF-2018-49906246-APN-ANP#INPI Page 10 of 29 is characterized by showing diffraction peaks at diffraction angles (2Θ) of 6.4°, 8.1°, 9.5°, 10.9°, 13.2°, 15.7°, 17.0°, 19.5°, 20.3°, 21.0° and 22.8° in an X-ray powder diffraction spectrum obtained using Cu-Kcx radiation (λ=1.54 A). Furthermore, it is characterized, in preference, by showing diffraction peaks at 15.8°, 17.2°, 21.9°, 23.7°, 24.5°, 25.5°, 25.8°, 28.9° and 32.0° in addition to the diffraction peaks mentioned above. Furthermore, the crystal of form I of the present invention is characterized in that it shows absorption peaks with wavenumbers of 2 87 4 cm-1, 17 36 cm-1, 155 8 cm-1, 137 5 cm-1, 1126 cm-1 and 696 cm-1 in an IR spectrum (KBr method). Furthermore, the crystal of form I of the present invention is characterized in that it has an endothermic peak at 127 °C in differential scanning calorimetry. The crystal of form I of the present invention can be obtained, for example, by the method described in Example 1 below.

[0013] B. Crystal of form II of the present invention The crystal of form II of the present invention is characterized in that it exhibits diffraction peaks at diffraction angles (2Θ) of 9.6°, 11.4°, 11.7°, 16.3°, 17.5°, 18.5°, 18.7°, 19.9°, 20.1°, 21.0° and 24.6° in an X-ray powder diffraction spectrum obtained using a IF-2018-49906246-APN-ANP#INPI Page 11 of 29 Cu-Kα radiation (λ=1.54 A). Furthermore, it is characterized, in preference, by showing diffraction peaks at 19.4°, 20.6°, 21.1°, 21.7°, 22.7°, 26.6°, 26.7°, 28.8 and 30.8° in addition to the diffraction peaks mentioned above. Furthermore, the crystal of form II of the present invention is characterized in that it shows absorption peaks with wavenumbers of 2867 cm-1, 174 9 cm-1, 1568 cm-1, 13 82 cm-1, 1131 cm-1 and 701 cm-1 in an IR spectrum (KBr method). Furthermore, the crystal of form II of the present invention is characterized in that it has an endothermic peak at 147 °C in differential scanning calorimetry. The crystal of form II of the present invention can be obtained, for example, by the method described in Example 2 below.

[0014] C. Medical application · pharmaceutical composition of the present invention Compound B according to the present invention has an excellent PGI2 receptor agonist effect and exhibits several medicinal effects, such as an inhibitory effect on platelet aggregation, a vasodilatory effect, a bronchial smooth muscle dilating effect, an inhibitory effect on lipid deposition, and an effect IF-2018-49906246-APN-ANP#INPI Page 12 of 29 inhibitor of leukocyte activation (see, for example, PTL 1).

[0015] Accordingly, the crystal of form I of the present invention, the crystal of form II of the present invention (hereinafter collectively referred to as the crystal of the present invention), or the pharmaceutical composition of the present invention is useful as a preventive or therapeutic agent for transient ischemic attack (TIA), diabetic neuropathy (see, for example, NPL 1), diabetic gangrene (see, for example, NPL 1), a peripheral circulatory disorder [for example, chronic arterial occlusion (see, for example, NPL 2), intermittent claudication (see, for example, NPL 3), peripheral embolism, vibration syndrome, or Raynaud's disease] (see, for example, NPL 4 and NPL 5), a connective tissue disease [for example, systemic lupus erythematosus, scleroderma (see, for example, PTL 7 and NPL 6), a mixed conjunctival disease, or a vasculitic syndrome],Reocclusion / restenosis after percutaneous transluminal coronary angioplasty (PTCA), arteriosclerosis, thrombosis (e.g., acute cerebral thrombosis or pulmonary embolism) (see, for example, NPL 5 and NPL 7), hypertension, pulmonary hypertension, an ischemic disease [e.g., myocardial infarction, IF-2018-49906246-APN-ANP#INPI Page 13 of 29 cerebral or myocardial infarction (see, for example, NPL 8) ], angina pectoris (for example, stable angina pectoris or unstable angina pectoris) (see, for example, NPL 9), glomerulonephritis (see, for example, NPL 10), diabetic nephropathy (see, for example, NPL 1), chronic renal failure (see, for example, PTL 8), allergy, bronchial asthma (see, for example, NPL 11), ulcer, pressure ulcer (ulcer), restenosis after coronary intervention such as atherectomy or stent implantation, dialysis thrombocytopenia, a disease in which fibrogenesis is involved in an organ or tissue [for example, a kidney disease {for example, tubulointerstitial nephritis (see, for example, PTL 9)}, a respiratory disease {for example, interstitial pneumonia (for example, fibrosis pulmonary) (see, for example, PTL 9), a chronic obstructive pulmonary disease (see, for example, NPL 12)}, a digestive disease (for example, hepatocirrhosis, viral hepatitis,chronic pancreatitis or cirrhotic gastric cancer), a cardiovascular disease (e.g., myocardial fibrosis), a bone or joint disease (e.g., bone marrow fibrosis or rheumatoid arthritis), a skin disease (e.g., postoperative scar, burn scar, keloid or hypertrophic scar), an obstetric disease (e.g., uterine fibroid), a urinary disease (e.g., IF-2018-49906246-APN-ANP#INPI Page 14 of 29 prostatic hypertrophy), other diseases (e.g., Alzheimer's disease, sclerosing peritonitis, type I diabetes, and postoperative organ adhesion)], erectile dysfunction (e.g., diabetic erectile dysfunction, psychogenic erectile dysfunction, psychotic erectile dysfunction, erectile dysfunction due to chronic renal failure, erectile dysfunction following pelvic surgery for prostate resection, or vascular erectile dysfunction associated with aging or arteriosclerosis), an inflamed bowel disease (e.g., ulcerative colitis, Crohn's disease, intestinal tuberculosis, ischemic colitis, or intestinal ulcer associated with Behcet's disease) (see, e.g., PTL 10), gastritis, gastric ulcer, an ischemic eye disease (e.g., retinal artery occlusion, retinal vein occlusion, or ischemic optic neuropathy), sudden hearing loss, avascular bone necrosis,intestinal damage caused by administration of a non-steroidal anti-inflammatory drug (NSAID) (e.g., diclofenac, meloxicam, oxaprozin, nabumetone, indomethacin, ibuprofen, ketoprofen, naproxen or celecoxib) (there is no particular limitation as long as damage occurs, for example, in the duodenum, small intestine or large intestine; however, for example, mucosal damage such as erosion or ulceration that is, IF-2018-49906246-APN-ANP#INPI Page 15 of 29 occurs in the duodenum, small intestine or large intestine) or symptoms (e.g., paralysis, dulling of sensory perception, pain, numbness or a reduction in the ability to walk) associated with spinal canal stenosis (e.g., spinal canal stenosis, thoracic spinal canal stenosis, lumbar spinal canal stenosis, coexisting cervical and lumbar spinal stenosis or sacral spinal stenosis) (see PTL 11). Furthermore, the crystal of the present invention or the pharmaceutical composition of the present invention is also useful as an accelerating agent for gene therapy or angiogenic therapy such as autologous bone marrow transplantation or an accelerating agent for angiogenesis in peripheral artery restoration or angiogenic therapy. [0016 ] When the crystal of the present invention is administered as a pharmaceutical product, the crystal is administered as such or is contained in a pharmaceutically acceptable, non-toxic, inert carrier in an amount within the range, for example, from 0.1% to 99.5%, preferably within the range of 0.5% to 90%. Examples of carriers include solid, semi-solid, or liquid diluents, fillers, and other agents IF-2018-49906246-APN-ANP#INPI Page 16 of 29 pharmaceutical formulation auxiliaries. Among them, one type, two, or more types can be used.

[0017] The pharmaceutical composition of the present invention may be in any form of oral preparations such as a powder, capsule, tablet, sugar-coated tablet, granule, powdered preparation, suspension, liquid, syrup, elixir, and tablet, and parenteral preparations such as an injection and a suppository in a solid or liquid dose unit. It may be in the form of a sustained-release preparation. Among these, oral preparations such as a tablet are particularly preferred. The powder can be produced by grinding the glass of the present invention to an appropriate fineness. The powdered preparation can be produced by grinding the crystal of the present invention to a suitable fineness and then by mixing the ground crystal with a similarly ground pharmaceutical carrier, for example, an edible carbohydrate such as starch or mannitol. A flavoring, preservative, dispersant, coloring, perfume, or the like can also be added arbitrarily. The capsule can be produced by first filling a IF-2018-49906246-APN-ANP#INPI Page 17 of 29. The capsule may consist of a powder or a powdered preparation formed into a powder form as previously described, or a granulated material as will be described in the section on the tablet, for example, in a capsule shell such as a gelatin capsule. Alternatively, the capsule may be produced by mixing a lubricant or a fluidizing agent such as colloidal silica, talc, magnesium stearate, calcium stearate, or solid polyethylene glycol with a powder or a powdered preparation formed into a powder form, followed by a filling operation. The efficacy of the pharmaceutical product when the capsule is taken may be improved by adding a disintegrating agent or a solubilizing agent such as carboxymethylcellulose, calcium carboxymethylcellulose, low-substituted hydroxypropylcellulose, croscarmellose sodium, sodium starch glycolate, calcium carbonate, or sodium carbonate. On the other hand, it is also possible to form a soft capsule by suspending and dispersing the fine crystal powder of the present invention in a vegetable oil, polyethylene glycol, glycerin or a surfactant and by wrapping the resulting material with a gelatin sheet. The tablet can be produced by adding an excipient to the powdered crystal of the present invention IF-2018-49906246-APN-ANP#INPI Page 18 of 29 to prepare a powder mixture, granulation or slagging of the powder mixture and then addition of a disintegrating agent or lubricant, followed by tablet formation. The powder mixture can be prepared by mixing the suitably powdered crystal of the present invention with a diluent or a base. If necessary, a binder (e.g., sodium carboxymethylcellulose, methylcellulose, hydroxypropyl methylcellulose, gelatin, polyvinylpyrrolidone, or polyvinyl alcohol), a dissolution retarder (e.g., paraffin), a reabsorbing agent (e.g., a quaternary salt), an adsorbent (e.g., bentonite or kaolin), or the like may be added. The granule can be produced by first moistening the powder mixture with a binder, for example, a syrup, starch paste, gum arabic, a cellulose solution, or a polymer solution, stirring and mixing the wet mixture, and then drying and chopping it. Instead of granulating the powder in this way, it is also possible to form the granule by first passing the powder through a tableting machine and then partially chopping the resulting slag. Adding stearic acid, a stearate salt, talc, mineral oil, or similar substances as a lubricant to the granule thus produced... IF-2018-49906246-APN-ANP#INPI Page 19 of 29 shows how to prevent the granules from sticking together. Furthermore, the tablet can also be produced by mixing the crystal of the present invention with an inert fluid carrier and, thereafter, by direct formation of the resulting mixture without undergoing a granulation or slagging stage as previously described. The tablet thus produced can be film-coated or sugar-coated. Alternatively, a transparent or semi-transparent protective coating film can be used, made from a shellac sealing film, a coating film made of sugar or a polymeric material, or a polished coating film made of wax. Another oral preparation, for example a liquid, syrup, tablet, or elixir, can also be formulated in a unit dose form such that its predetermined quantity contains a predetermined amount of the crystal of the present invention. The syrup can be produced by dissolving the crystal of the present invention in a suitable aqueous flavoring solution. The elixir can be produced using a non-toxic alcoholic carrier. The suspension can be produced by dispersing the IF-2018-49906246-APN-ANP#INPI Page 20 of 29. The crystal of the present invention is placed in a non-toxic carrier. If necessary, a solubilizing agent or an emulsifier (for example, an ethoxylated isostearyl alcohol or a polyoxyethyl sorbitol ester), a preservative, a flavoring agent (for example, peppermint oil or saccharin), or the like may be added. If necessary, the unit-dose formulation for oral administration can be microencapsulated. It is also possible to extend the duration of action or achieve sustained release by coating the formulation or incorporating it into a polymer, wax, or similar material. The parenteral preparation may be in the form of a liquid unit dose for intramuscular or intravenous injection, for example, as a solution or suspension. The parenteral preparation may be produced by suspending or dissolving a predetermined amount of the crystal of the present invention in a non-toxic liquid carrier suitable for injection, for example, an aqueous or oily medium, and then sterilizing the suspension or solution. It is also possible to add a stabilizing agent, a preservative, an emulsifier, or the like. The suppository can be produced by dissolving or suspending the crystal of the present invention in a IF-2018-49906246-APN-ANP#INPI Page 21 of 29 solid having a low melting point and being soluble or insoluble in water, for example, polyethylene glycol, cocoa butter, a semi-synthetic oil or fat [for example, Witepsol (registered trademark)], a higher ester (for example, myristyl palmitate ester) or a mixture thereof.

[0018] The dosage varies according to a patient's condition such as body weight or age, the route of administration, the nature and degree of a disease, or similar factors; however, the dosage, as the amount of the crystal of the present invention per day for an adult, is appropriately within the range of 0.001 mg to 100 mg, preferably within the range of 0.01 mg to 10 mg. In some cases, a dose no higher than the above range may be sufficient, or conversely, a dose no lower than the above range may be necessary. Furthermore, the preparation may be administered once or several times daily, or at intervals of one to several days. [Examples]

[0019] From now on, the present invention will be described in greater detail with reference to the Examples and Test Examples; however, the present invention is not limited by any means to them. IF-2018-49906246-APN-ANP#INPI Page 22 of 29

[0020] An X-ray powder diffraction spectrum was measured using SmartLab (manufactured by Rigaku Corporation) (optical system: focusing method, voltage: 45 kV, current: 200 mA, wavelength: Cu-Kα, sun slit: 5.0°, scan range: 4 to 40°, scan speed: 47.3° / min, sample rotation: 60° / min). An IR spectrum was measured using IR Affinity-1 (manufactured by Shimadzu Corporation) (measurement mode: % transmittance, cumulative number: 16 times, resolution: 2.0, wavenumber range: 400 to 4000 cm~ Ό. A DSC was measured using a DSC-50 (manufactured by Shimadzu Corporation) (cell: alumina (open), gas: nitrogen (20.0 mL / min), heating rate: 10 °C / min, holding temperature: 250 °C, holding time: 0 min).

[0021] Reference Example 1: Production of Form III Crystal After dissolving tert-butyl 2-{4-[N-(5,6-diphenylpyrazin-2-yl)-N-isopropylamino]butyloxy}acetate (see, for example, PTL 1) (13.15 g) in methanol (179.7 mL), a 1 N aqueous solution of sodium hydroxide (41.47 mL) was added. After heating the resulting mixture under reflux IF-2018-49906246-APN-ANP#INPI Page 23 of 29. For 1 hour, the solvent was distilled under reduced pressure, and water was added to the residue to dissolve it. After washing with diethyl ether, the resulting aqueous layer was neutralized with 1 N hydrochloric acid (44 mL), and extraction was carried out with ethyl acetate. The resulting ethyl acetate layer was dried over anhydrous magnesium sulfate, and the solvent was distilled under reduced pressure. Diisopropyl ether was then added to the residue to effect crystallization. The resulting crystal was filtered and washed with an appropriate amount of diisopropyl ether. The crystal was dried at 40 °C under reduced pressure, yielding a crystal of form III (9.88 g). The results of the X-ray powder diffraction measurement, IR measurement, and DSC measurement of the crystal of form III are shown in FIG. 1, FIG. 2, and FIG. 3, respectively. Diffraction angles (20): 8.4°, 12.6°, 13.4°, 14.3°, 14.6°, 15.9°, 16.9°, 18.0°, 18.8°, 19.4°, 20.3°, 20.6°, 21.6°, 21.7°, 22.3°, 22.5°, 23.3°, 23.7°, 23.9°, 27.0°, 29.6° and 30.8° IR absorption peak: 2867 cm-1, 1747 cm-1, 1558 cm-1, 1380 cm-1, 1131 cm-1 and 701 cm-1 DSC endothermic peak: 118 °C

[0022] Reference example 2: production of compound BA a suspension of 2-{4-[N-(5,6-diphenylpyrazin-2IF-2018-49906246-APN-ANP#INPI Page 24 of 29 100 g of 12 ... The deposited material was dried at 65 °C under reduced pressure, obtaining a target compound (208.3 g).

[0023] Example 1; Production of crystal of form I of the present invention The compound B (63 g) produced in Reference Example 2 was dissolved in acetonitrile (315 mL) at 90 °C and stirred at the same temperature for 30 minutes. The solution was filtered, washed with 5 mL of acetonitrile, and stirred again with heating. As a stimulation, a small amount of the compound B produced in Reference Example 2 was added, followed by gradual cooling and further heating. IF-2018-49906246-APN-ANP#INPI Page 25 of 29. The stirring was carried out at 10 °C or lower for 1 hour, and then the glass was filtered and washed with an appropriate amount of acetonitrile. The glass was dried at 65 °C under reduced pressure, obtaining the glass of form I of the present invention (59.5 g). The results of the X-ray powder diffraction measurement, IR measurement, and DSC measurement of the crystal of form I of the present invention are shown in FIG. 4, FIG. 6, and FIG. 8, respectively. Diffraction angles (2Θ): 6.4°, 8.1°, 9.5°, 10.9°, 13.2°, 15.7°, 15.8°, 17.0°, 17.2°, 19.5°, 20.3°, 21.0°, 21.9°, 22.8°, 23.7°, 24.5°, 25.5°, 25.8°, 28.9° and 32.0° IR absorption peak: 2874 cm-1, 1736 cm-1, 1558 cm-1, 1375 cm-1, 1126 cm-1 and 696 cm-1 DSC endothermic peak: 127 °C

[0024] Example 2: Production of the crystal of form II of the present invention Compound B (0.5 g) produced in Reference Example 2 was dissolved in isopropyl alcohol (2.5 mL) and an 8% aqueous solution of sodium hydroxide (1.5 mL) at 80 °C, and stirring was carried out at the same temperature for 30 minutes. The solution was gradually cooled to room temperature, and the pH of the solution was adjusted to 5–6 with a 4 N aqueous solution of hydrochloric acid. IF-2018-49906246-APN-ANP#INPI Page 26 of 29 at room temperature and then, stirring was carried out at 10 °C or less for 1 hour. After that, the glass was filtered and washed with an appropriate amount of water. The glass was dried at 65 °C under reduced pressure, obtaining the glass of form II of the present invention (0.45 g). The results of the X-ray powder diffraction measurement, IR measurement, and DSC measurement of the crystal of form II of the present invention are shown in FIG. 5, FIG. 7, and FIG. 9, respectively. Diffraction angles (2Θ): 9.6°, 11.4°, 11.7°, 16.3°, 17.5°, 18.5°, 18.7°, 19.4°, 19.9°, 20.1°, 20.6°, 21.0°, 21.1°, 21.7°, 22.7°, 24.6°, 26.6°, 26.7°, 28.8° and 30.8° IR absorption peak: 2867 cm-1, 1749 cm-1, 1568 cm-1, 1382 cm-1, 1131 cm-1 and 701 cm-1 DSC endothermic peak: 147 °C

[0025] Example test 1: stability test Several crystalline forms of compound B were placed in glass bottles, which were then hermetically sealed and stored at 90 °C. Samples were taken after 1 day, 5 days, and 14 days and dissolved in methanol at a concentration of 1 mg / mL. The analogues were measured by HPLC, and the crystalline form was confirmed for the crystals after 14 days. The results are shown. IF-2018-49906246-APN-ANP#INPI Page 27 of 29 in Table 1.

[0026] [Table 1] Storage Conditions Form I Form II Form III Appearance HPLC Surface (%) Appearance HPLC Surface (%) Appearance HPLC Surface (%) Before storage white crystal 99.8 yellow crystal 100 yellow crystal 99.9 90 °C, after 1 day No change 99.8 No change 100 No change 99.9 90 °C, after 5 days No change 99.8 No change 100 No change 99.9 90 °C, after 14 days No change 99.6 No change 99.9 No change 99.7 Crystal after 14 days Form I + Form II Form II Form II From the previous results, it was revealed that 'in any of the crystalline forms, the chemical stability is very high; however, form I and form III gradually transform into form II, which is thermodynamically stable.

[0027] Example of test 2: solvent suspension test of the crystal of form I of the present invention in various solvents The crystal of form I of the present invention was mixed with various solvents and stirred at room temperature for 30 minutes. The resulting crystals were obtained by filtration and their crystal forms were confirmed. The results are shown in Table 2. IF-2018-49906246-APN-ANP#INPI Page 28 of 29

[0028] [Table 2] Solvent Crystalline form after 30 minutes at room temperature cyclohexane Form I + Form II (1:1) water Form I + Form II (10:1) 2—Propanol Form I + Form II (1:10) toluene Form I + Form II (10:1) As previously described, the crystal of form I of the present invention partially transformed into the crystal of form II of the present invention when suspended in all solvents. From these results, it was revealed that the crystal of form II of the present invention is thermodynamically stable when suspended in various solvents at room temperature. IF-2018-49906246-APN-ANP#INPI Page 29 of 29 Argentine Republic - National Executive Branch 2018 - Year of the Centenary of the University Reform Additional Signature Sheet Graphic Report Number: IF-2018-49906246-APN-ANP#INPI CITY OF BUENOS AIRES Friday, October 5, 2018 Reference: 20180102776 The document was imported by the GEDO system with a total of 29 page(s). Digitally signed by GESTION DOCUMENTAL ELECTRONICA - GDE DN: cn=ELECTRONIC DOCUMENTARY MANAGEMENT - GDE, c=AR, o=MINISTRY OF MODERNIZATION, ou=SECRETARY OF ADMINISTRATIVE MODERNIZATION, serialNumber=CUIT 30715117564 Date: 2018.10.05 14:32:54 -03'00' Darío Julio Martin Mayares Administrative Advisor National Patent Administration National Institute of Industrial Property Digitally signed by GESTION DOCUMENTAL ELECTRONICA GDE DN: cn=GEST10N ELECTRONIC DOCUMENTARY - GDE, c=AR, o=MINISTRY OF MODERNIZATION, ou=SECRETARY OF ADMINISTRATIVE MODERNIZATION, serialNumber=CUIT 30715117564 Date: 2018.10.05 14:32:55 -03'00'

Claims

1. A crystal of form II of 2-{4-[N-(5,6-diphenylpyrazin-2-yl)-N-isopropylamino]butyloxy}acetic acid, characterized in that it exhibits diffraction peaks at diffraction angles (2θ) of 9.6°, 11.4°, 11.7°, 16.3°, 17.5°, 18.5°, 18.7°, 19.9°, 20.1°, 21.0°, and 24.6° in an X-ray powder diffraction spectrum obtained using Cu-Kα radiation (λ = 1.54 Å). Eight claims follow.