JPH0374664B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention provides YM-
The present invention relates to a dextrorotary optical isomer of diastereomer A of 09730 or a pharmacologically acceptable acid addition salt thereof, a method for producing the compound, and a drug containing the compound as an active ingredient. (Background of the invention) YM-09730 has a chemical name of 2,6-dimethyl-
It is called 4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid-3-(1-benzylpyrrolidin-3-yl) ester-5-methyl ester, and is shown by the following chemical structural formula. It is a dihydropyridine-3,5-dicarboxylic acid ester derivative. YM-09730 is a compound that was first synthesized by researchers at the applicant company of this application, and it has been reported that it has vasodilatory and blood pressure lowering effects, and that these effects are long-lasting (patented). No. 1137506,
Special Publication No. 57-30111). YM-09730 has two asymmetric carbon atoms, and it is presumed from a stereochemical standpoint that isomers based on these asymmetric carbon atoms exist, but the above patent publication does not contain any information regarding these. There is nothing written and it is unconfirmed. The present inventors previously separated diastereomer A and diastereomer B of YM-09730, and found that diastereomer A was significantly superior to diastereomer B and a mixture of both diastereomers. He discovered that it had a unique pharmacological effect and filed a patent application (Japanese Patent Application No. 75,998/1983). (Means for Solving the Problem) This time, we further separated the dextrorotatory optical isomer of diastereomer A, and found that this has even better pharmacological effects than the levorotatory optical isomer and their mixtures. This was confirmed and the present invention was completed. Here, diastereomer A is a compound whose hydrochloride salt has a melting point of 200 to 206°C, and can be clearly distinguished from diastereomer B, which has a melting point of 180 to 185°C. The target compound of the present invention is specified by the melting point of the above-mentioned hydrochloride (the melting point in this case means that the melting point of the compound of the present invention is within the indicated temperature range). The dextrorotatory optical isomer of diastereomer A or its pharmacologically acceptable acid addition salt is targeted. Here, typical pharmacologically acceptable acid addition salts are:
L-(-)-malate or hydrochloride. As shown in the results of the pharmacological experiments described later, the dextrorotary optical isomer (d
The rate of increase in coronary blood flow when directly administered into the coronary artery is approximately 0.4 times that of the levorotatory optical isomer (l-isomer), and the pharmacologically acceptable acid addition salt thereof is approximately 0.4 times that of the levorotatory optical isomer (l-isomer), and the rate of increase in coronary blood flow when administered directly into the coronary artery is approximately 0.4 times that of the levorotatory optical isomer (l-isomer). It shows an area ratio of 2.5 times that of the dl body), and also shows that it has a high affinity for coronary arteries. This means that the pharmacological action of YM-09730 does not appear as a mere average value of the physical mixing ratios of the dextrorotatory and levorotatory isomers. Furthermore, the fact that the compound has high affinity for coronary arteries is a new pharmacological finding discovered by the present inventors, and increases the possibility of using the present compound as a medicine. (Specific description of the manufacturing method) Next, the manufacturing method of the dextrorotary optical isomer of diastereomer A or its pharmacologically acceptable acid addition salt of the present invention will be described. As mentioned above, in Special Publication No. 57-30111,
There is no description of isomers of YM-09730, and there are no reports of the production of isomers in later literature. A pair of diastereomers A generally differs from optical antipodes in that they have different absolute values of optical rotation and also differ in all physical and chemical properties.
Therefore, since its nature is not clear,
It is not possible to produce each diastereomer based on the difference in their properties, and therefore it is not possible to separate the optical isomers of each diastereomer. The present inventors synthesized YM-09730 by the method described in Reference Examples below, and the YM obtained therein
-09730 was found to be an equal mixture of diastereomers A and B. Based on this, we first investigated various methods of obtaining diastereomer A from a mixture. As a result, we subjected the mixture of each isomer to column chromatography using silica gel as a carrier and a mixture of ethyl acetate and acetic acid as the eluent. By doing so, diastereomer A is produced from the first eluate and diastereomer B is produced from the later eluate, and then the dextrorotary optical isomer is separated by racemic resolution of diastereomer A. These series of isomers belong to novel compounds first revealed by the present inventors. The silica gel used as a carrier in the method for separating diastereomer A is not particularly limited as long as it is commonly used in column chromatography. There is no particular restriction on the mixing ratio of ethyl acetate and acetic acid in the mixed solvent used as the eluent. Usually, ethyl acetate is used as the main ingredient, mixed with a small amount of acetic acid. The mixing ratio is approximately 30-50V/V of ethyl acetate to 1-10% of acetic acid.
It is about 10V/V, and as the amount of acetic acid is decreased, the elution time of the target compound becomes longer. Appropriate conditions can be adopted for the elution rate and treatment temperature. In addition, as a manufacturing method different from the above manufacturing method,
The present inventors succeeded in producing an acid addition salt of diastereomer A by converting a mixture of diastereomers into a specific acid addition salt and fractionally recrystallizing this. The acid addition salts used in this production method include:
Examples include malonate, paranitrobenzoate, and maleate. These acid addition salts are crystalline and diastereomers A and B have different solubilities in organic solvents, so they can be used in a method for producing diastereomer A by fractional recrystallization. A particularly preferred acid addition salt is malonate. This salt can be recrystallized once to obtain crystals with an extremely high content of diastereomer A. Examples of solvents that can be used in this production method include methanol, ethanol, acetone, and acetonitrile. The acid addition salt of diastereomer A of YM-09730 obtained by each of the above production methods is first converted into a free form, and then treated with L-(-)-malic acid to separate the racemates. YM−
The dextrorotary optical isomer of diastereomer A of 09730 is obtained. Note that the dextrorotary optical isomer is obtained by using the free base of YM-09730 obtained in the reference example below instead of diastereomer A of YM-09730, and adding L-
It can also be obtained by racemic separation under the action of (-)-malic acid. (Effects of the Invention) Next, the pharmacological effects, acute toxicity, and pharmaceutical dosage of the dextrorotary optical isomer of diastereomer A of YM-09730 will be explained. (1) Coronary blood flow increasing effect Measurement method: Pentobarbital sodium 30mg/Kgi.
The dog was anesthetized with V. and the dog's chest was opened. Blood was led from the left carotid artery using a pump (Harvard Apparatus,
1215D), the left circumflex coronary artery was perfused at a constant pressure, and coronary blood flow was measured using an electromagnetic flowmeter (MF-25, Nihon Kohden). The perfusion pressure is always set at 120 using the blood flow pump controller (SCS-21, data graph).
The pump was driven so that mmHg was maintained (Tsukada Norimasa et al.: Journal of the Japanese Pharmacological Society 74 59P, 1978). In order to examine the direct effect of the test drug on the coronary artery, the drug was administered directly into the coronary artery. Drug evaluation was performed based on the area of the rate of increase in coronary blood flow during 120 minutes after administration of the test drug (post-administration coronary blood flow - pre-administration coronary blood flow / pre-administration coronary blood flow x 100). Measurement result;

【table】

[Table] Comparing the coronary blood flow increasing effect at a dose that increases coronary blood flow by 50% (ED ₅₀ %), all isomers had approximately the same efficacy. On the other hand, when comparing the area of increase in coronary blood flow when 1 μg is directly administered into the coronary artery, diastereomer A (d-form) hydrochloride shows that
2.5 than diastereomer A (dl form) hydrochloride
twice as much as diastereomer A (l-form) hydrochloride
The coronary blood flow increasing effect of diastereomer A (d-form) hydrochloride is 38 times higher than that of diastereomer A (dl).
(isomer) hydrochloride and (l-isomer) hydrochloride. In this experiment, the test drug was administered directly into the coronary artery, so diastereomer A (d-form) hydrochloride was treated as diastereomer A (dl-form) hydrochloride and diastereomer A (l-form) hydrochloride. It has been shown to have a high affinity for coronary artery vascular beds compared to Having such a high affinity for coronary arteries means that it is highly useful for coronary artery diseases such as angina pectoris. (2) Acute toxicity Male ICR mice, 6 weeks old and weighing 27 to 29 g, were orally administered diastereomer A dextrorotatory optical isomer hydrochloride as a 0.5% methylcellulose suspension and observed for 7 days. The acute toxicity value (LD ₅₀ ) of the hydrochloride was calculated using the Litchfield & Wilcoxon method (Journal of Pharmacology).
Pharmacol.), Vol. 96, pp. 99-113, 1949), and the value was 190 (158-228) mg/kgp.o. (3) Dosage Varies depending on body weight and symptoms, but usually administered intravenously
0.1 to 2 mg, orally 5 to 20 mg per day, once or twice a day. (Example) Next, the target compound of the present invention, its manufacturing method, and medicament will be further explained with reference to Examples and Prescription Examples. In addition, YM used as a raw material in each example
A manufacturing example of -09730 will be explained as a reference example. Reference example 1.51 g (0.01 mol) of 3-nitrobenzaldehyde, 2.61 g (0.01 mol) of 1-benzyl-3-acetoacetyloxypyrrolidine, and 1.15 g (0.01 mol) of 3-aminocrotonic acid methyl ester are dissolved in 5 ml of isopropanol. Heat under reflux for 8 hours. The solvent was distilled off under reduced pressure, the resulting residue was dissolved in chloroform, washed sequentially with dilute hydrochloric acid, water, and saturated aqueous sodium bicarbonate solution, dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure to obtain crude 2, 6
-dimethyl-4-(3-nitrophenyl)-1,4
-dihydropyridine-3,5-dicarboxylic acid-3
4.91 g of -(1-benzylpyrrolidin-3-yl)ester-5-methyl ester was obtained in the form of caramel. When the crude base obtained here was analyzed for diastereomer production ratio by high performance liquid chromatography under the conditions shown below, it was found that diastereomer A
(Retention time 28 minutes): Diastereomer B (Retention time
The ratio was 1:1 (29 minutes). Column: Nucleosil 5C ₁₈ , 4.6mmφ×300
mm, column temperature: 30℃, mobile phase: containing tetra-n-pentylammonium bromide (3mM)
0.05M potassium dihydrogen phosphate (PH3)-acetonitrile (80:20V/V), flow rate: 0.9ml/min, UV detector (λ254nm). Note that diastereomers A and B are YM-
Differences are observed in the signals of methylene nuclear magnetic resonance spectra in the N-benzyl group of 09730. When measured in deuterated methanol _d4 , diastereomer A shows a singlet signal at 4.40 ppm, and diastereomer B shows a singlet signal at 4.30 ppm, each corresponding to two hydrogen atoms. Example 1 4.91 g of the crude free base obtained in the above reference example and 1.04 g of malonic acid were dissolved in 15 ml of acetonitrile.
After standing overnight at 5°C, the precipitated crystals were collected by filtration (2.03 g) and recrystallized twice from 25 times the volume of methanol to obtain YM-, which does not contain diastereomer B.
Malonate of diastereomer A of 09730 1.27
I got g. Melting point 181.5-182.5℃ (decomposition). 1.27 g of this malonate was suspended in 5 ml of chloroform, and 2.5 ml each of saturated sodium bicarbonate aqueous solution was added.
2 times with 2.5 ml of water and 2.5 ml each of 10% hydrochloric acid aqueous solution.
The aqueous chloroform solution washed several times was dried over anhydrous magnesium sulfate and evaporated to dryness under reduced pressure.
The hydrochloride of diastereomer A of YM-09730 is precipitated by dissolving the residue in 2 ml of acetone and leaving it to stand.
1.09g was obtained. Hydrochloride of diastereomer A of YM-09730
4.35 g of its free base obtained by treating 4.67 g with saturated aqueous sodium bicarbonate solution and L-(-)-
Dissolve 1.18 g of malic acid in 28 ml of ethanol by heating and leave it at 0 to 5°C overnight. The precipitated crystals are collected by filtration and dried to obtain diastereomer A of YM-09730.
L-(-)-malate of the dextrorotary enantiomer of
2.43g was obtained. This was recrystallized from 85 ml of ethanol to obtain 2.21 g of L-(-)-malate. Specific optical rotation [α] ²⁰ _D +82.2° (C = 0.5, methanol). Even if this is recrystallized again from ethanol, no change in [α] ²⁰ _D is observed. Elemental analysis value (as C ₂₇ H ₂₉ N ₃ O ₆・C ₄ H ₆ O ₅ ) C (%) H (%) N (%) Experimental value 59.72 5.80 6.73 Theoretical value 59.51 5.64 6.72 Example 2 Obtained in reference example Crude free base of YM-09730
4.91g and 1.34g of L-(-)-malic acid in acetone 25g
ml, stir at 0-5℃ for 48 hours, filter out the precipitated crystals, wash with a small amount of cold acetone,
0.57 g of L-(-)-malate of the dextrorotatory optical isomer of diastereomer A of -09730 was obtained. Specific optical rotation [α] ²⁰ _D +78.3° (C=0.5, methanol). this
Crystal 0.44 obtained by recrystallizing from 50 times the volume of ethanol
The specific optical rotation of g was [α] ²⁰ _D +82.2° (C=0.5, methanol). Example 3 2.21 g of L-(-)-malate of diastereomer A of YM-09730 obtained in Example 1 was suspended in 8 ml of chloroform, twice with 4.3 ml each of a saturated aqueous sodium bicarbonate solution, and 4.3 ml of water. ml and 4.3 ml of 10% hydrochloric acid twice. The chloroform solution is dried over anhydrous magnesium sulfate, filtered and evaporated to dryness under reduced pressure. The residue was dissolved in 3.5 ml of acetone and left to stand to precipitate 1.64 g of the dextrorotatory hydrochloride of diastereomer A of YM-09730. Specific optical rotation [α] ²⁰ _D +116.5° (C=0.5, methanol)
. Melting point 223-225℃ (decomposed) Elemental analysis value (as C ₂₇ H ₂₉ N ₃ O ₆・HCl) C (%) H (%) N (%) Cl (%) Experimental value 61.35 5.55 8.01 6.96 Theoretical value 61.42 5.73 7.96 6.71 Example 4 1.25 g of L-(-)-malate of the dextrorotary optical isomer of diastereomer A of YM-09730 was suspended in 5 ml of chloroform, and suspended twice with 3 ml of saturated aqueous sodium bicarbonate solution each time. , and washed twice with 3 ml of water. After drying this chloroform solution over anhydrous magnesium sulfate, the solvent was distilled off under reduced pressure. 6 ml of ethanol was added to the resulting residue and allowed to stand overnight at 5°C to obtain the free base of the dextrorotatory optical isomer of diastereomer A of YM-09730 in crystal form. Yield 0.84
g. Melting point 138-140℃ Elemental analysis value (as C ₂₇ H ₂₉ N ₃ O ₆ ) C (%) H (%) N (%) Theoretical value 65.98 5.95 8.55 Experimental value 66.04 5.96 8.51 NMR (in CDCl ₃ , TMS internal standard , δppm) 1.40~3.0 (6H, m, C ₂ ′, ₄ ′, ₅ ′−H ₂ ) 2.34, 2.36 (6H, s, C ₂ , ₆ ′−CH ₃ ) 3.65 (5H, s, −COOCH ₃ and −CH ₂ φ) 5.10 (1H, s, C ₄ -H) 5.12 (1H, m, C ₃ '-H) 5.78 (1H, broad s, NH) 7.16-8.24 (9H, m, H in benzene ring) Prescription example 1 (tablet)

[Table] 50 g of the above isomer hydrochloride, 502 g of lactose, and 126.5 g of corn starch are mixed uniformly, and 150 g of a 10% hydroxypropyl cellulose aqueous solution is added and kneaded to produce granules. After drying, add 3.5g of magnesium stearate and mix evenly to make 1 tablet 140mg.
tablets. Prescription example 2 (capsules)

[Table] Mix the above ingredients uniformly and fill 200 mg into gelatin capsules to make capsules. Prescription example 3 (Injection) YM-09730 Diastereomer A dextrorotary optical isomer hydrochloride 1mg D-sorbitol 100mg Dissolve the above ingredients in distilled water for injection, add hydrochloric acid to adjust the pH to 4, and then inject. Add distilled water to bring the total volume to 2 ml.

Claims (1)

[Scope of Claims] 1. 2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid-3- whose hydrochloride has a melting point of 223 to 230°C.
(1-benzylpyrrolidin-3-yl)ester-5-methyl ester (hereinafter referred to as YM-09730)
A dextrorotary optical isomer of diastereomer A or a pharmacologically acceptable acid addition salt thereof. 2. Claim 1, wherein the acid addition salt is L-(-)-malate or hydrochloride.
Compounds described in Section. 3. The compound according to claim 1, which is a dextrorotatory optical isomer hydrochloride of diastereomer A of YM-09730. 4 2,6 dimethyl-4-(3-nitrophenyl)
-1,4-dihydropyridin-3,5-dicarboxylic acid-3-(1-benzylpyrrolidin-3-yl)
Ester-5-methyl ester (hereinafter referred to as YM-
09730) using silica gel as a carrier,
The acetate of diastereomer A was separated from the eluate by column chromatography using a mixture of ethyl acetate and acetic acid as an eluent, and then treated with a base, followed by reaction with L-(-)-malic acid. L-(-)- of the dextrorotary optical isomer of diastereomer A
A diastereomer of YM-09730 whose hydrochloride has a melting point of 223 to 230°C, characterized in that the malate is precipitated and optionally treated with a base or a pharmacologically acceptable acid. A method for producing a dextrorotatory optical isomer of A or a pharmacologically acceptable acid addition salt thereof. 5 2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid-3-(1-benzylpyrrolidine-3-
yl) ester-5-methyl ester (YM
The malonate of a mixture of diastereomer A and diastereomer B (referred to as -09730) was fractionally recrystallized to obtain the malonate of diastereomer A, which was then treated with a base, and then L-(-) - reacting malic acid to precipitate the dextrorotary enantiomer L-(-)-malate of diastereomer A, optionally treated with a base or further with a pharmacologically acceptable acid; A method for producing a dextrorotatory optical isomer of diastereomer A of YM-09730 or a pharmacologically acceptable acid addition salt thereof, the hydrochloride having a melting point of 223 to 230°C. 6. The manufacturing method according to claim 5, wherein the acid addition salt is L-(-)-malate or hydrochloride. 7 2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid-3- whose hydrochloride has a melting point of 223 to 230°C
A vasodilator containing a dextrorotatory optical isomer of diastereomer A of (1-benzylpyrrolidin-3-yl)ester-5-methyl ester or a pharmacologically acceptable acid addition salt thereof as an active ingredient.