KR100435906B1 - Prodrugs of γ-vinyl-γ-aminobutyric acid, manufacturing process thereof and antiepileptic composition containing them - Google Patents

Abstract

The present invention relates to prodrugs of gamma-vinyl-gamma-aminobutyric acid represented by the following formula (1), a preparation method thereof, and an antiepileptic agent containing the same.

In the above formula, A is a radical represented by the following formula (2), (3), (4) or (5).

(Wherein R ₁ represents hydrogen, methyl or ethyl group)

Description

Prodrugs of γ-vinyl-γ-aminobutyric acid, manufacturing process about and antiepileptic composition containing them}

The present invention relates to prodrugs of gamma-vinyl-gamma-aminobutyric acid, methods for their preparation and therapeutic agents for epilepsy containing the same.

Epilepsy, a convulsive disease, is a condition that places many restrictions on normal social activities. The number of patients ranges from one to two percent of the entire population and ranks second in the psychiatric sector, with 40 to 60 percent of patients taking anticonvulsants. Most of the epilepsy depends on drug treatment, but clinically various various seizure symptoms are complex, so there is a limitation in the spectrum of clinical application. Therefore, several anticonvulsants are combined in drug therapy. , Side effects are serious. In addition, analogs of gamma-aminobutyric acid (Gaba) (Gaba agonists, Gaba reuptake inhibitors, Gaba aminotransferase inhibitors, etc.) are essential for exhibiting anticonvulsive activity. Since it is limited by the efficacy, as well as disadvantages such as increased side effects due to the use of excessive drug.

To overcome these problems with conventional anticonvulsants, four to five new anticonvulsants have been introduced as new drugs, but these drugs are also known to not effectively suppress various convulsions.

Therefore, there is a need for the development of anticonvulsants that can more effectively suppress various convulsions and control all of a wide range of convulsion symptoms, that is, have excellent efficacy and exhibit a wide range of activities and thus have a wide range of clinical applications and reduce side effects.

It is an object of the present invention to provide a novel concept of epilepsy therapeutics which can control all of a wide range of seizure symptoms while showing excellent efficacy by increasing the transition to the central nervous system.

The present invention relates to prodrugs of gamma-vinyl-gamma-aminobutyric acid represented by the following formula (1), a preparation method thereof, and an antiepileptic agent containing the same.

The first aspect of the present invention relates to a prodrug of gamma-vinyl-gamma-aminobutyric acid represented by the following formula (1).

In the above formula, A is a radical represented by the following formula (2), (3), (4) or (5),

(Wherein R ₁ represents hydrogen, methyl or ethyl group)

The second aspect of the present invention relates to a method for preparing the compounds represented by the formula (1). Compounds of formula (1) according to the invention can be prepared according to the following reaction scheme 1.

Referring to the reaction scheme 1 is as follows.

Step 1: Using a known compound (6) (gamma-vinyl-gamma-aminobutyric acid) as a starting material and triethylamine (TEA) as a base, a box temperature (BOC) in an aqueous solution containing dioxane -ON) to synthesize compound (7) (tibox gamma-vinyl-gamma-aminobutyric acid) in which the amine group was protected with Tbok, and

Step 2: Compound 7 was coupled with AH using 1-hydroxybenzotriazole (HOBt) and 1- [3- (dimethylamino) propyl] -3-ethylcarbodiimide (EDCI) Gain 8,

Step 3: Deprotection of compound (8) with methylene chloride solution containing 33% trifluoroacetic acid (TFA) and 5% dimethyl sulfide (DMS) to prepare a compound in the form of trifluoroacetate Is neutralized with diisopropylethylamine (DIEA) to synthesize a compound of formula (1) as a target compound.

The gamma-vinyl-gamma-aminobutyric acid prodrug according to the present invention is currently used clinically or has anti-convulsive activity using gamma-vinyl-gamma-aminobutyric acid (gamma-vinylgaba) as the basic structure of the prodrug. As a substance, it is linked to amide bonds with drugs (Gaba agonists, Gaba reuptake inhibitors, Gaba aminotransferase inhibitors, etc.) which act by different mechanisms and exhibit excellent anticonvulsive activity. That is, by synthesizing a dual acting prodrug in which two drugs are connected in one structure, the lipid affinity, which is a problem of the existing drugs, is improved to increase lipid solubility, thereby facilitating the passage of the cerebrovascular barrier. In addition, two drugs with different mechanisms of action are hydrolyzed by metabolic-related enzymes in the brain, each of which is a parent material, and exhibits anti-convulsive activity in different mechanisms. Anticonvulsant active substance made of the original substance in the brain increases the water solubility, so it is not easy to pass through the cerebrovascular barrier outside the brain, so the blood drug concentration in the brain is higher than other methods to increase the lipid solubility of the drug.

Therefore, the gamma-vinyl-gamma-aminobutyric acid prodrug of the present invention is more active than conventional anticonvulsants, thereby reducing the dosage, thereby reducing side effects, increasing the application spectrum, and exhibiting rapid efficacy expression time. .

After all, the third aspect of the present invention relates to a therapeutic agent for epilepsy comprising the compound represented by the formula (1). At this time, the effective amount of the compound of the formula (1) is 0.1 ~ 1.0 mmol / kg to adults. The method of administering an antiepileptic agent containing the compound of formula (1) of the present invention as a main component may be a conventional method of administration such as tablets, injections, capsules, and the like.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

Example 1 Synthesis of 1- (4-amino-hex-5-enoyl) -piperidine-3-carboxylic acid methyl ester

1) First step: A mixed solution of distilled water (14 mL) and dioxane (1,4-dioxane, 14 mL) was added to a 250 mL round bottom flask, and gamma-vinyl-gamma-aminobutyric acid (γ-vinyl GABA, 3g, 23.23 mmole) was dissolved, triethylamine (TEA, 4.9 mL, 35.31 mmole) was added, followed by addition of temperature (BOC-ON, 6.4 g, 25.89 mmole), followed by stirring at room temperature for 3 hours. Distilled water (50 mL) and ethyl acetate (50 mL) were added to the reaction solution, the water layer was separated, impurities were removed with ethyl acetate (50 mL × 3), and acidified to pH 2-3 with 5% aqueous citric acid solution. It was. The aqueous layer was extracted with ethyl acetate (100 mL × 2), washed with 5% aqueous citric acid solution (70 mL × 3), saturated brine (70 mL × 2), dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure. 4.6 g (20.39 mmole) of vinyl-gamma-aminobutyric acid were obtained as a white solid compound. (87.8%)

mp 88.7 ~ 91.2 ℃

Mass (FAB) 230 (MH ⁺ )

¹ H-NMR (300 MHz, CDCl ₃ )

5.75 (m, 1H), 5.15 (dd, 2H), 4.57 (br, 1H), 4.14 (m, 1H), 2.43 (t, 2H),

1.86 (m, 2 H) 1.45 (s, 9 H)

2) second step: In an 250 mL round bottom flask, anhydrous dimethylformamide was added, dissolve Tbok-gamma-vinyl-gamma-aminobutyric acid (1.06 g, 4.61 mmole) and 1-hydroxybenzotriazole (HOBt, 0.654 g, 4.84 mmole) was added and then 1- [3- (dimethylamino) propyl] -3-ethylcarbodiimide (EDCI, 0.93 g, 4.84 mmole) was added at 0 ° C. and stirred for 40 minutes to form an active ester. Nifecotic acid methyl ester (0.99 g, 6.91 mmole) and triethylamine (1.03 mL, 7.38 mmole) were dissolved in anhydrous dimethylformamide (10 mL) and added to the reaction solution where the active ester was formed, followed by stirring for 24 hours. Distilled water (10 mL) was added to the reaction mixture to stop the reaction. The mixture was diluted and extracted with ethyl acetate (50 × 4 mL), and the organic layer was diluted with 5% aqueous citric acid solution (70 mL × 3) and 5% aqueous sodium bicarbonate solution (70 mL × 3). ) And washed with saturated brine (70 mL × 2). After drying over anhydrous magnesium sulfate, filtration and concentration under reduced pressure, the residue was purified by column chromatography (ethyl acetate: hexane = 1: 2, volume: volume) to remove impurities and pigments. Sherie-butoxycarbonylamino-hex-5-enoyl) -piperidine-3-carboxylic acid methyl ester (1.19 g, 3.36 mmole) was obtained. (72.8%)

Mass (FAB) 355 (MH ⁺ )

¹ H-NMR (300 MHz, CDCl ₃ )

5.74 (m, 1H), 5.10 (dd, 2H), 4.72 (br, 1H), 4.60 (m, 1H), 4.08 (m, 1H),

3.70 (d, 3H) 3.36 (m, 1H), 3.00 (m, 1H) 2.81 (m, 1H), 2.42 (m, 2H),

2.01 (m, 1H), 1.79 (m, 1H). 1.40 (s, 9H)

3) Step 3: Into a 100 mL round bottom flask, anhydrous methylene chloride (CH ₂ Cl ₂ , 5.55 mL) was added and 1- (4-tertary-butoxycarbonylamino-hex-5-enoyl) -piperi Dissolve dine-3-carboxylic acid methyl ester (0.79 g, 2.23 mmole), add dimethylsulfide (0.45 ml, 5% of the total volume of solution), and after 10 minutes, trifluoroacetic acid (3 ml, total solution). 33% of the volume) was added dropwise and stirred at room temperature for 2 hours. The reaction mixture was concentrated under reduced pressure, 5 ml of methylene chloride was added to the residue, and the residue was dissolved. After neutralization by addition of 0.5 ml of diisopropylethylamine (DIEA), the residue was concentrated under reduced pressure, followed by column chromatography (methylene chloride: methanol = 13). (1, volume: volume) to give a highly viscous colorless transparent oily compound 1- (4-amino-hex-5-enoyl) -piperidine-3-carboxylic acid methyl ester. (94%)

Mass (FAB) 255 (MH ⁺ )

¹ H-NMR (300 MHz, CDCl ₃ )

5.82 (m, 1H), 5.38 (dd, 1H), 5.34 (dd, 1H), 3.87 (m, 1H), 3.71 (dt, 1H),

3.69 (s, 3H), 3.45 (dt, 1H), 3.11 (m, 1H), 2.95 (dt, 1H), 2.51 (m, 1H),

2.43 (m, 2H), 2.11-1.47 (m, 6H)

¹³ C-NMR (75 MHz, CDCl ₃ )

173.23, 171.69, 132.84, 120.89, 54.31, 51.98, 47.22, 46.29, 44.00,

42.68, 29.39, 27.92, 26.74

Example 2 Synthesis of 1- (4-Amino-hex-5-enoyl) -piperidine-4-carboxylic acid methyl ester

The target compound was synthesize | combined by the method similar to the method of Example 1 except having used isonifecotic acid methyl ester instead of nifecotic acid methyl ester in Example 1-2.

Mass (FAB) 255 (MH ⁺ )

¹ H-NMR (300 MHz, CDCl ₃ )

5.75 (q, 1H), 5.39 (dd, 2H) 4.22 (d, 1H), 3.76 (m, 2H), 3.65 (s, 3H),

3.14 (t, 1H), 2.81 (t, 1H), 2.47 (t, 2H), 1.70 (m, 4H), 1.50-1.60 (m, 2H)

¹³ C-NMR (75 MHz, CDCl ₃ )

174.42, 171.07, 132.85, 120.94, 54.34, 54.18, 51.97, 45.00, 41.50,

40.34, 29.26, 27.89, 27.51

Example 3: Synthesis of 4- (4-amino-hex-5-enoylamino) -butyric acid methyl ester

A target compound was synthesized in the same manner as in Example 1, except that gamma-aminobutyric acid methyl ester was used instead of nifecotic acid methyl ester in Example 1).

Mass (FAB) 229 (MH ⁺ )

¹ H-NMR (250 MHz, CDCl ₃ )

5.80 (m, 1H), 5.15 (t, 2H), 4.29 (q, 1H), 3.65 (s, 3H), 2.95 (t, 2H),

2.38 (m, 4H), 1.92 (m, 2H), 1.80 (q, 2H)

¹³ C-NMR (75 MHz, DMSO- d ₆ )

176.83, 174.73, 137.40, 115.61, 52.59, 51.56, 39.21, 32.90, 29.8,

23.43, 23.43

Example 4 Preparation of 4- (4-Amino-hex-5-enoylamino) -hex-5-enoic Acid Methyl Ester

A target compound was synthesized in the same manner as in Example 1 except that gamma-vinyl-gamma-aminobutyric acid methyl ester was used instead of nifecotic acid methyl ester in Example 1-2.

Mass (FAB) 255 (MH ⁺ )

¹ H-NMR (250 MHz, D ₂ O)

5.77 (m, 2H), 5.40 (m, 2H), 5.13 (m, 2H), 4.28 (m, 1H), 3.70 (m, 1H),

3.64 (s, 3H), 2.35 (m, 4H), 1.88 (m, 1H)

¹³ C-NMR (62.5 MHz, DMSO- d ₆ )

176.81, 174.49, 137.32, 132.58, 122.42, 115.69, 54.00, 52.60, 51.58,

31.84, 30.79, 29.08, 28.20

Preparation Examples 1-4 of the Formulation: Tablets

30.0 mmol of the compound of Examples 1-4

Lactose BP 150.0 mg

Starch BP 30.0 mg

Pregelatinized Corn Starch BP 15.0 mg

1.0 mg magnesium stearate

The compounds of Examples 1-4 were sieved and mixed with lactose, starch and pregelatinized corn starch, then a suitable volume of purified water was added and granulated into a powder. The granules were dried and then mixed with magnesium stearate and compressed to obtain tablets.

Preparation Example 2 Preparation of Capsule

30.0 mmol of the compound of Examples 1-4

Starch 1500 100.0 mg

Magnesium Stearate BP 1.0 mg

The compounds of Examples 1-4 were sieved and mixed with excipients and then filled into gelatin capsules to obtain capsules.

Experimental Example 1: anticonvulsant effect experiment

Experimental animals used in the present invention were used to seizure-induced icr male rats (ICR) male and four were group 1. In this case, 25, 50, 75, and 100 mg / kg of the compound of Examples 1 to 4 dissolved in polyethylene glycol 400 in the fasted rats were administered intraperitoneally, respectively, to induce cramping after 30 minutes. The anticonvulsant effect of the compounds of 1-4 was measured. Artificially induced convulsions may be induced by electric shock spasm, pentylenetetrazole spasm, bicuculine spasm and picrotoxin spasm, depending on the materials and methods used. It was.

Electroshock convulsion induction (MES) is a method of inducing convulsions by applying 50 mA, 60-cycle, alternating current for 0.2 seconds by placing the electrode in the rat's eye after moistening the rat's eye with 0.9% physiological saline. Anticonvulsant activity was measured to the extent that hind limb tonic seizures caused by compound 4 were lost.

Pentylenetetrazole (PTZ) seizure-induced experiments were carried out for 30 minutes after 80 mg / kg (CD ₉₇ ) of pentylenetetrazole was administered in a 0.5% aqueous solution. Measured.

A bikyu kyulrin (BIC) and peak toxin (PIC) induced convulsions test in Examples 1 to 4 after the administration of the compound after 6 hours bikyu kyulrin 3.2mg / kg (CD _97), and a peak toxin 5mg / kg (CD ₉₇ ) Was administered in a 0.5% aqueous solution and observed for 30 minutes to determine anticonvulsant activity with or without convulsions lasting at least 5 seconds.

ED ₅₀ values were obtained by quantitative anticonvulsant activity assessment based on dose-response data. The ANOVA test was used as a significance test and the Newman-Keuls test was used as a post hoc test. The experimental results are shown in Table 1.

Anticonvulsant Activity of the Compounds of Examples 1-4 compound ED ₅₀ (mmol / kg) MES PTZ BIC PIC Example 1 > 0.54 0.15 0.14 0.10 Example 2 > 0.54 0.32 0.15 0.26 Example 3 0.64 0.58 0.47 0.47 Example 4 > 0.54 > 0.54 0.40 0.33 Gamma-vinyl-gamma-aminobutyric acid No effect No effect 0.22 0.21

As shown in Table 1, for the reference drug gamma-vinyl-gamma-aminobutyric acid, ED ₅₀ was found to be "ineffective" as ">10.00" or more for electroshock cramping and pentylenetetrazole induced cramping. The compounds of the present invention all exhibit excellent anticonvulsive efficacy against electroshock cramps, pentylenetetrazole-induced cramps, bicuculin-induced cramps, and picrotoxin-induced cramps, evenly regardless of the cause or drug. In other words, it was confirmed that the spectrum is wide.

Experimental Example 2: Anticonvulsant activity expression time test of the compound of Example 1-2

The anticonvulsant activity expression time test was done about the compound of Example 1-2. In other words, the anticonvulsant activity was measured to the maximum value by measuring the anticonvulsant activity according to time after administering the compounds of Examples 1 to 2 at a dose of 100 mg / kg to rats inducing cramping with picrotoxin (PCR). Expression time was measured and the results are shown in Table 2.

Anticonvulsant activity expression time test of the compound of Examples 1-2 compound Dosage Time (hours) Convulsion-induced rats Example 1 100 mg / kg 3 2/4 6 0/4 9 0/4 18 0/4 Example 2 100 mg / kg 3 2/4 6 2/4 9 0/4 18 0/4 Gamma-vinyl-gamma-aminobutyric acid 100 mg / kg 3 4/4 6 4/4 9 3/4 18 0/4

As shown in Table 2, in the case of the control drug gamma-vinyl-gamma-aminobutyric acid, the time when the anticonvulsant effect was shown in all four rats was 18 hours after the administration of the drug. While the time was very long, the compounds of the present invention showed anticonvulsive activity only 3 hours after administration, so that no cramps were induced in two of the four mice tested and showed maximum activity within 6 hours after administration. Therefore, the compounds of the present invention, compared with the reference drug gamma-vinyl-gamma-aminobutyric acid showed a shorter action expression time required to exhibit the maximum anticonvulsant activity and excellent anticonvulsant effect.

In the present invention, the prodrug of gamma-vinyl-gamma-aminobutyric acid is more active than conventional anticonvulsants, and thus the dosage can be reduced, so that side effects are reduced, the spectrum of application is increased, and rapid efficacy expression time is shown. It can be used as a preferable epilepsy treatment.

Claims (3)

The compound of formula (1) Wherein A is a radical represented by the following formula (2), (3), (4) or (5) Wherein R ₁ represents hydrogen, methyl or ethyl group.) Compound (7) is synthesized by reacting compound (6) with a double temperature (BOC-ON), After coupling this with AH to give compound (8), The compound (8) is subjected to deprotection reaction, characterized by the above-mentioned formula (1). A therapeutic agent for epilepsy comprising the compound of claim 1.