HK1163077B - Benzazepine derivatives useful as vasopressin antagonists - Google Patents

Abstract

The present invention provides a benzazepine compound that can maintain for a long period of time the blood level of tolvaptan enabling to provide the desired pharmaceutical effects. The benzazepine compound of the present invention is represented by general formula (1) wherein R1 represents a substituted alkyl group or an optionally substituted acyl group.

Description

The present invention relates to a novel benzazepine compound and a pharmaceutical preparation.

BACKGROUND ART

Tolvaptan represented by the following formula (2) is a known compound, and is disclosed, for example, in U.S. Patent No. 5,258,510 (Example 1199).

Tolvaptan is known to be useful as a vasopressin antagonist having aquaretic efficacy (Circulation, 107, pp. 2690-2696 (2003)). However, because of its low water solubility, tolvaptan has problems in that it is poorly absorbed from the gastrointestinal tract, and its dosage form and administration route are limited. From the viewpoint of medical treatment, the development of a new drug that can maintain for a long period of time the blood level of tolvaptan enabling to provide the desired pharmaceutical effects has been desired. US 5,622,947 A relates to vasopressin and oxytocin antagonists which contain, as the active ingredient, a benzoheterocyclic compound represented by the following general formula:

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide a novel benzazepine compound that has excellent properties, such as the maintenance of the blood level of tolvaptan for a long period of time enabling to provide the desired pharmaceutical effects.

The present inventors carried out extensive research to overcome the above problem, and as a result found that benzazepine compounds represented by general formula (1) have excellent properties, such as the maintenance of pharmaceutical effects of the active ingredient tolvaptan for a long period of time in the body. The present invention has been accomplished based on the above findings.

The present invention provides the following benzazepine compounds, and pharmaceutical preparations containing the compounds shown in Items 1 to 3 below.

• Item 1. A benzazepine compound represented by general formula (1) wherein R1 is a group of (1-5):(1-5) a -CO-R8 group (wherein R8 is (8-1) an alkyl group optionally substituted with a halogen atom, a lower alkanoyloxy group, or a phenyl group (substituted with a dihydroxy phosphoryloxy group in which the hydroxy groups are optionally substituted with benzyl groups, and a lower alkyl group), (8-2) a lower alkoxy group substituted with a halogen atom, a lower alkanoyloxy group, or a dihydroxyphosphoryloxy group, (8-3) a pyridyl group, or (8-4) a lower alkoxyphenyl group;
• Item 2. The compound according to Item 1, wherein, in formula (1), R1 is a -CO-R8 group wherein R8 is an alkyl group; or a salt thereof.
• Item 3. A pharmaceutical preparation comprising the benzazepine compound of Item 1 or a pharmacologically acceptable salt thereof, and a pharmacologically acceptable diluent and/or carrier. Item 4. The pharmaceutical preparation according to Item 3 which is used as a vasodilator, hypotensive drug, aquaretic agent, or platelet aggregation inhibitor.

Specific examples of the groups in general formula (1) are as follows.

In this specification, the term "lower" refers to *C_1-6", unless otherwise specified.

Examples of lower alkanoyloxy groups include straight or branched C_2-6 alkanoyloxy groups, such as acetyloxy, n-propionyloxy, n-butyryloxy, isobutyryloxy, n-pentanoyloxy, tert-butylcarbonyloxy, and n-hexanoyloxy group.

Examples of lower alkoxy groups include straight or branched C_1-6 alkoxy groups, such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, sec-butoxy, n-pentyloxy, isopentyloxy, neopentyloxy, n-hexyloxy, isohexyloxy, and 3-methylpentyloxy.

Examples of lower alkyl groups include straight or branched C_1-6 alkyl groups, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl, and 3-methylpentyl.

Examples of halogen atoms include fluorine, chlorine, bromine, and iodine.

Examples of lower alkoxy phenyl groups include alkoxyphenyl groups in which the alkoxy moiety is a straight or branched C_1-6 alkoxy group, such as methoxyphenyl, ethoxyphenyl, n-propoxyphenyl, isopropoxyphenyl, n-butoxyphenyl, isobutoxyphenyl, tert-butoxyphenyl, sec-butoxyphenyl, n-pentyloxyphenyl, isopentyloxyphenyl, neopentyloxyphenyl, n-hexyloxyphenyl, isohexyloxyphenyl, and 3-methylpentyloxyphenyl.

The benzazepine compounds represented by general formula (1) can be prepared by various methods; for example, by the processes according to the following Reaction Schemes.

Among the benzazepine compounds represented by general formula (1) or salts thereof, Compound (1a) wherein R¹ is a group of (1-5) above can be prepared from tolvaptan of formula (2) according to Reaction Scheme-1, 2, or 3. wherein R is -R⁸ (wherein R⁸ is as defined above).

According to the process shown in Reaction Scheme-1, Compound (1a) is prepared by reacting Compound (2) with an acid anhydride (3) in the presence or absence of a basic compound in a suitable solvent.

The amount of acid anhydride (3) is usually about 1 mole to a large excess, and preferably about 1 to about 10 moles, per mole of Compound (2).

The solvent may be any known solvent that does not adversely affect the reaction. Examples of such solvents include ethers such as diethyl ether, dioxane, tetrahydrofuran, monoglyme, and diglyme; halogenated hydrocarbons such as methylene chloride, chloroform, 1,2-dichloroethane, and carbon tetrachloride; esters such as ethyl acetate; aromatic hydrocarbons such as benzene, toluene, and xylene; aprotic polar solvents such as acetonitrile, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and N-methylpyrrolidone (NMP); and mixed solvents thereof.

Examples of basic compounds include triethylamine, pyridine, and the like. The amount of basic compound is usually at least about 1 mole, and preferably about 1 to about 10 moles, per mole of Compound (2). Such a basic compound can also be used as the solvent.

When a catalyst such as 4-dimethylaminopyridine is present in the reaction,system in the above reaction, the reaction can be promoted.

The reaction temperature of the above reaction is usually room temperature to 150°C, and preferably room temperature to 100°C. The reaction time is usually 15 minutes to 24 hours, preferably 30 minutes to 6 hours, and more preferably 1 to 3 hours. wherein R is as defined above, and X¹ is a halogen atom.

According to the process shown in Reaction Scheme-2, Compound (2) is reacted with an acid halide (4) in the presence of a basic compound in a suitable solvent to prepare Compound (1a).

The amount of acid halide (4) is usually about 1 mole to a large excess, and preferably about 1 to about 10 moles, per mole of Compound (2).

The solvent may be any known solvent that does not adversely affect the reaction. Examples of such solvents include ethers such as diethyl ether, dioxane, tetrahydrofuran, monoglyme, and diglyme; halogenated hydrocarbons such as methylene chloride, chloroform, 1,2-dichloroethane, and carbon tetrachloride; esters such as ethyl acetate; aromatic hydrocarbons such as benzene, toluene, and xylene; aprotic polar solvents such as acetonitrile, DMF, DMSO, and NMP; and mixed solvents thereof.

Examples of basic compounds include carbonates such as sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, and cesium carbonate; phosphates such as potassium phosphate, and sodium phosphate; organic bases such as pyridine, imidazole, N-ethyldiisopropylamine, dimethylaminopyridine, triethylamine, trimethylamine, dimethylaniline, N-methylmorpholine, 1,5-diazabicyclo[4.3.0]nonene-5 (DBN), 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), and 1,4-diazabicyclo [2.2.2]octane (DABCO); and mixtures thereof.

The amount of basic compound is usually at least about 1 mole, and preferably about 1 to about 10 moles, per mole of Compound (2). Such an organic base can also be used as the solvent.

When a catalyst such as 4-dimethylaminopyridine is present in the reaction system in the above reaction, the reaction can be promoted.

The reaction temperature of the above reaction is usually -10°C to 100°C, and preferably 0°C to 50°C, and more preferably 0°C to room temperature. The reaction time is usually 15 minutes to 24 hours, preferably 30 minutes to 6 hours, and more preferably 1 to 3 hours. wherein R is as defined above.

According to the process shown in Reaction Scheme-3, Compound (2) is condensed with a carboxylic acid (5) in the presence of an activator to prepare Compound (1a).

The amount of carboxylic acid (5) is usually about 1 to about 10 moles, and preferably about 1 to about 5 moles, per mole of Compound (2).

Examples of activators include dicyclohexylcarbodiimide, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (WSC), carbonyldiimidazole, and the like. Such activators can be used singly or in a combination of two or more.

The amount of activator is usually at least about 1 mole, and preferable about 1 mole to about 5 moles, per mole of Compound (2).

The condensation reaction is usually carried out in a suitable solvent in the presence or absence of a basic compound. Examples of solvents that can be used include ethers such as diethyl ether, dioxane, tetrahydrofuran, monoglyme, and diglyme; halogenated hydrocarbons such as methylene chloride, chloroform, 1,2-dichloroothane, and carbon tetrachloride; esters such as ethyl acetate; aromatic hydrocarbons such as benzene, toluene, and xylene; aprotic polar solvents such as acetonitrile, DMF, DMSO, and NMP; and mixed solvents thereof.

Examples of basic compounds include triethylamine, pyridine, and the like. The amount of basic compound is usually at least about 1 mole, and preferably about 1 to about 10 moles, per mole of Compound (2). Such a basic compound can also be used as the solvent.

When a catalyst such as 4-dimethylaminopyridine is present in the reaction system, the reaction can be promoted.

The reaction is usually carried out at about -20°C to about 100°C, and preferably at 0°C to room temperature. The reaction usually completes in about 5 minutes to about 90 hours.

Compounds represented by general formula (1) of the present invention and salts thereof include stereoisomers, optical isomers, and solvates (hydrates, ethanolates, etc.) thereof.

Among the benzazepine compounds represented by general formula (1) of the invention, compounds having a basic group can be easily converted into acid addition salts by reacting the compounds with pharmaceutically acceptable acids. Examples of such salts include inorganic acid salts such as hydrochloride, sulphate, phosphate, hydrobromate, hydriodate, and nitrate; organic acid salts such as acetate, oxalate, succinate, maleate, fumarate, malate, tartrate, citrate, malonate, methanesulfonate, benzoate, trifluoroacetate, benzensuplhonate, formate, and toluenesulfonate; and amino acid salts (for example, arginate, aspartate, glutamate, etc.).

Among the benzazepine compounds represented by general formula (1) of the invention, compounds having an acidic group can be easily converted into salts with a base by reacting the compounds with pharmaceutically acceptable basic compounds. Examples of such salts include metal salts such as alkali metal salts (for example, sodium salts, potassium salts, etc.) and alkaline earth metal salts (for example, calcium salts, magnesium salts, etc.); ammonium salts; organic base salts (for example, trimethylamine salts, triethylamine salts, pyridine salts, picoline salts, dicyclohexylamine salts, N,N'-dibenzylethylenediamine salts, tris(hydroxymethyl)aminomethane salts, etc.); and the like. Examples of basic compounds include sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate, and the like.

These salts are included in the scope of the present invention.

Each of the object compounds obtained according to the above Reaction Schemes can be isolated and purified from the reaction mixture by, for example, after cooling, subjecting the reaction mixture to isolation procedures such as filtration, concentration, extraction, etc., to separate a crude reaction product followed by conventional purification procedures such as column chromatography, recrystallization, etc.

The compound of the present invention has, for example, vasopressin antagonism, vasodilatory activity, hypotensive activity, activity for inhibiting glucose release from the liver, mesangial cell growth inhibitory activity, aquaretic activity, and platelet aggregation inhibitory activity. The compound is useful as a vasodilator, hypotensor, aquaretic agent, and platelet aggregation inhibitor, and is effective in the prevention and treatment of hypertension, edema (e.g., cardiac edema, hepatic edema, renal edema, cerebral edema), abdominal dropsy, heart failure (e.g., severe heart failure), renal dysfunction, syndrome of inappropriate secretion of vasopressin (SIADH), liver cirrhosis, hyponatremia, hypokalemia, diabetes, circulatory insufficiency, polycystic kidney disease (PKD), and the like.

When administered to the human body as a medicine, the compound of the invention may be used simultaneously with or separately from other pharmaceutical drugs, such as vasopressin antagonists, ACE inhibitors, β-blocking agents, aquaretic agents, angiotensin II antagonists (ARB), and/or digoxin.

The compound of the invention can be used in the form of a general pharmaceutical composition. Such a pharmaceutical composition can be prepared by a conventional method using commonly used diluents and/or excipients, such as fillers, extending agents, binders, humectants, disintegrators, surfactants, and lubricants.

The form of the pharmaceutical composition containing the compound of the invention can be suitably selected depending on the purpose of the treatment. Examples thereof include tablets, pills, powders, solutions, suspensions, emulsions, granules, capsules, suppositories, injections (solutions, suspensions, etc.), ointments, and the like.

To form tablets, any of the various carriers conventionally known in this field can be widely used. Examples thereof include excipients such as lactose, white sugar, sodium chloride, glucose, urea, starch, calcium carbonate, kaolin, crystalline cellulose, and silicic acid; binders such as water, ethanol, propanol, simple syrup, glucose solutions, starch solutions, gelatin solutions, carboxymethylcellulose, shellac, methylcellulose, potassium phosphate, and polyvinylpyrrolidone; disintegrators such as dry starch, sodium alginate, agar powder, laminaran powder, sodium hydrogen carbonate, calcium carbonate, fatty acid esters of polyoxyethylene sorbitan; sodium lauryl sulfate, stearic acid monoglycerides, starch, and lactose; disintegration inhibitors such as white sugar, stearin, cacao butter, and hydrogenated oils; absorbing agents such as quaternary ammonium bases, and sodium lauryl sulfate; wetting agents such as glycerol, and starch; adsorbents such as starch, lactose, kaolin, bentonite, and colloidal silicic acid; lubricants such as purified talc, stearates, boric acid powder, and polyethylene glycol; and the like. Further, such tablets may be tablets provided with typical coating as required, for example, sugar-coated tablets, gelatin encapsulated tablets, enteric-coated tablets, film-coated tablets, double- or multi-layered tablets, etc.

To form pills, any of the various carriers conventionally known in this field can be widely used. Examples thereof include excipients such as glucose, lactose, starch, cacao butter, hydrogenated vegetable oils, kaolin, and talc; binders such as gum arabic powder, tragacanth powder, gelatin, and ethanol; disintegrators such as laminarin, and agar; and the like.

To form suppositories, any of the various carriers conventionally known in this field can be widely used. Examples thereof include polyethylene glycol, cacao butter, higher alcohols, esters of higher alcohols, gelatin, semi synthetic glycerides, and the like.

Capsules can be prepared according to a conventional method by mixing the active ingredient compound with various carriers as mentioned above and filling the mixture into a hard gelatin capsule, soft gelatin capsule, or the like.

To form injections, solutions, emulsions, and suspensions are preferably sterilized and isotonic to the blood. When injections are prepared in the form of solutions, emulsions and suspensions, any of the diluents commonly employed in this field can be used. Examples of such diluents include water, aqueous lactic acid solutions, ethyl alcohol, propylene glycol, ethoxylated isostearyl alcohol, polyoxylated isostearyl alcohol, polyoxyethylene sorbitan fatty acid esters, and the like. In this case, isotonizing agents such as sodium chloride, glucose, mannitol, and glycerol in an amount sufficient to prepare an isotonic solution may be incorporated into the pharmaceutical composition. Commonly used pH adjusters, solubilizers, buffers, smoothing agents, and the like may also be added.

Other additives such as coloring agents, preservatives, flavors, and sweetening agents, and other medicines can also be added, if necessary.

The amount of compound represented by general formula (1) or salt thereof in the pharmaceutical preparation of the invention is not particularly limited, and can be suitably selected from a wide range. In general, the proportion of the compound is preferably about 0.01 to about 70 wt.% of the pharmaceutical preparation.

The way of administration of the pharmaceutical preparation of the invention is not particularly limited, and can be administered by a method suitable to the form of the preparation, the patient's age, sex and other conditions, and the severity of the disease. For example, tablets, pills, solutions, suspensions, emulsions, granules, and capsules are administered orally. Injections are intravenously administered singly or as mixed with typical replacement fluid such as glucose solutions, amino acid solutions, or the like, or singly administered intramuscularly, intracutaneously, subcutaneously or intraperitoneally, as required.

The dosage of the pharmaceutical preparation of the invention is suitably selected according to the dosage regimen, the patient's age, sex and other conditions, and the severity of the disease. The dosage is usually such that the compound represented by general formula (1), which is an effective ingredient, is administered in an amount of 0.001 to 100 mg, and preferably 0.001 to 50 mg, per kg of body weight per day in one or more administrations.

The dosage varies with various conditions. A dosage smaller than the above range may be sufficient, while a dosage larger than the above range may be necessary.

The patents, patent applications, and documents cited herein are incorporated by reference.

EFFECT OF THE INVENTION

According to the present invention, a novel benzazepine compound that has excellent properties, such as the maintenance of the blood level of tolvaptan for a long period of time enabling to provide the desired pharmaceutical effects, can be provided.

When administered into the human body, Compound (1) of the invention or a salt thereof can be easily converted into tolvaptan, which is an active ingredient.

Further, Compound (1) of the invention or a salt thereof is readily crystallized and easy to handle. Furthermore, Compound (1) of the invention or a salt thereof has excellent chemical stability.

A composition that can provide pharmaceutical effects equivalent to that of a useful drug tolvaptan can be provided in various forms by using Compound (1) of the invention or a salt thereof.

BEST MODE FOR CARRYING OUT THE INVENTION

The following examples illustrate the present invention in further detail.

Example 10 {7-Chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-yl} hexadecanoate

Palmitoyl chloride (1.24 ml, 4.4 mmol) was added to a dichloromethane (20 ml) solution of tolvaptan (2.00 g, 4.4 mmol) and pyridine (0.40 ml, 5.0 mmol), and the mixture was stirred at room temperature over night. Water was added to the reaction mixture and the mixture was extracted with dichloromethane. The combined organic layer was washed with water and an aqueous saturated sodium chloride solution, and dried over magnesium sulfate. After filtration and concentration, the residue was purified by silica gel chromatography (n-hexane : ethyl acetate) to thereby obtain 2.25 g (74%) of (7-chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-yl} hexadecanoate as amorphous. ¹H-NMR (DMSO-d₆, 100°C) dppm :

• 0.85 (3H, t, J=6.8 Hz), 1.15-1.45 (24H, m), 1.55-1.70 (2H, m), 1.75-2.10 (4H, m), 2.37 (6H, s), 2.40-2.50 (2H, m), 3.05-3.55 (1H, m), 3.60-4.30 (1H, m), 5.90-6.00 (1H, m), 6.80-7.05 (2H, m), 7.10-7.45 (7H, m), 7.56 (1H, s), 9.81 (1H, br).

Example 11 {7-Chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-yl} chloroacetate

Tolvaptan (10 g, 22 mmol) and pyridine (2.7 ml, 33 mmol) were suspended in dichloromethane (100 ml), and chloroacetyl chloride (2.6 ml, 33 mmol) was added dropwise under cooling with ice. The obtained mixture was stirred at room temperature for 1 hour. 1N hydrochloric acid was added to the reaction mixture, and the mixture was extracted with dichloromethane. The organic layer was washed with 1N hydrochloric acid, dried over anhydrous sodium sulfate. After filtration and concentration under reduced pressure, the residue was purified by silica gel flash chromatography (n-hexane : ethyl acetate = 60 : 40 → 46 : 54). The purified product was concentrated under reduced pressure to obtain 12 g of (7-chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-yl} chloroacetate as white amorphous solid. ¹H-NMR (DMSO-d₆, 100°C) dppm :

• 1.7-2.2 (4H, m), 2.36 (6H, s), 2.6-4.3 (2H, m), 4.44 (2H, s), 5.9-6.0 (1H, m), 6.8-7.1 (2H, m), 7.1-7.3 (3H, m), 7.3-7.5 (4H, m), 7.57 (1H, s), 9.8 (1H, br).

Example 16 7-Chloro-1-(2-methyl-4-(2-methylbenzamido)benzoyl)-2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-yl 4-chlorobutyrate

Tolvaptan (10.0 g, 22.3 mmol) was dispersed in dichloromethane (100 ml). Pyridine (2.7 ml) was added thereto, and the mixture was stirred. 4-Chlorobutyric acid chloride (3.74 ml) was gradually added to the obtained mixture, and the mixture was stirred at room temperature over night. The reactant was then poured into water, and the mixture was extracted with dichloromethane, washed with a sodium hydrogen sulfate aqueous solution, dried over magnesium sulfate. After filtration and concentration under reduced pressure, the resulted residue was crystallized with diethyl ether. The resulted crystals were collected by filtration, and dried to obtain 10.7 g of 7-chloro-1-[2-methyl-4-(2-methylbenzamido)benzoyl]-2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-yl 4-chlorobutyrate as white powder. ¹H-NMR (CDCl₃) dppm :

• 1.50-2.92 (16H, m), 3.10-4.02 (2.4H, m), 4.70-5.13 (1H, m), 5.86-6.19 (1.2H, m), 6.48-6.68 (1H, m), 6.82-7.82 (8.8H, m).

Example 20 7-Chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-yl 3-[2-(bis-benzyloxy-phosphoryloxy)-4,6-dimethyl-phenyl]-3-methyl-butyrate

Tolvaptan (0.63 g), 3-[2-(bis-benzyloxy-phosphoryloxy)-4, 6-dimethyl-phenyl]-3-methyl-butyric acid (0.70 g), and 4-dimethylaminopyridine (DMAP) (24 mg, 0.22 mmol) were suspended in dichloromethane (10 ml). N ¹-((ethylimino)methylene)-N ³,N ³-dimethylpropane-1,3-diamine hydrochloride (WSC) (383 mg) was added thereto, and the mixture was stirred at room temperature for 3 hours. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate, dried over anhydrous sodium sulfate. After filtration and concentration under reduced pressure, the residue was purified by silica gel flash chromatography (n-hexane : ethyl acetate = 70 : 30 → 35 : 65). The purified product was concentrated under reduced pressure to obtain 0.92 g of 7-chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-yl 3-[2-(bis-benzyloxy-phosphoryloxy)-4,6-dimethyl-phenyl]-3-methyl-butyrate as white amorphous solid. ¹H-NMR (DMSO-d₆, 100°C) dppm :

• 1.5-1.9 (7H, m), 2.10 (3H, s), 2.32 (3H, s), 2.36 (3H, s), 2.6-4.3 (2H, m), 2.91 (2H, d, J=15.3 Hz), 3.13 (2H, d, J=15.3 Hz), 5.11 (2H, s), 5.14 (2H, s), 5.7-5.9 (1H, m), 6.74 (1H, s), 6.75-7.4 (20H, m), 7.54 (1H, s), 9.8 (1H, br).

Example 21 7-Chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-yl 3-(2,4-dimethyl-6-phosphonooxy-phenyl)-3-methyl-butyrate

A mixture of 7-chloro-1-[2-methyl-4-(2-methylbenzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-yl 3-[2-(bis-benzyloxy-phosphoryloxy)-4,6-dimethyl-phenyl]-3-methyl-butyrate (0.92 g) in ethyl acetate (10 ml) was hydrogenated over 5% platinum carbon (100 mg). The catalyst was removed by filtration through Celite layer, and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel flash chromatography (dichloromethane : methanol=90 : 10 → 50 : 50). The purified product was concentrated under reduced pressure, and the aqueous acetonitrile solution of the residue was freeze-dried to obtain 0.21 g of 7-chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-yl 3-(2,4-dimethyl-6-phosphonooxy-phenyl)-3-methyl-butyrate as white amorphous solid. ¹H-NMR (DMSO-d₆, 100 °C)dppm :

• 1.60 (3H, s), 1.61 (3H, s), 1.6-2.0 (4H, m), 2.10 (3H, s), 2.34 (3H, s), 2.37 (3H, s), 2.42 (3H, s), 2.3-4.2 (2H, m), 2.9-3.4 (2H, m), 5.8-5.9 (1H, m), 6.45 (1H, s), 6.8-6.9 (1H, m), 6.9-7.0 (1H, s), 7.0-7.4(7H, m), 7.43 (1H, d, J=7.4 Hz), 7.63 (s, 3H), 9.91 (1H, br).

Example 22 Chloromethyl {7-chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-yl} carbonate

Tolvaptan (5.0 g) and pyridine (1.1 ml) were suspended in dichloromethane (50 ml). Chloromethyl chloroformate (1.1 ml) was added thereto under cooling with ice, and the mixture was stirred at room temperature for 30 minutes. The reaction mixture was washed with water, dried over anhydrous sodium sulfate. After filtration and concentration under reduced pressure, the residue was purified by silica gel flash chromatography (n-hexane : ethyl acetate = 70 : 30 → 50 : 50). The purified product was concentrated under reduced pressure to obtain 6.1 g of chloromethyl {7-chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-yl} carbonate as white amorphous solid. ¹H-NMR (DMSO-d₆, 100 °C)dppm :

• 1.7-2.2 (4H, m), 2.36 (6H, s), 2.6-5.8 (2H, m), 5.9-6.0 (3H, m), 6.8-7.1 (2H, m), 7.1-7.5 (7H, m), 7.58 (1H, s), 9.8 (1H, br).

Example 23 {7-chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-yl} iodomethyl carbonate

Chloromethyl {7-chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-yl} carbonate (3.8 g) and sodium iodide (5.3 g) were added to acetone (27 ml), and then the mixture was heated under reflux for 3 hours. After cooling to room temperature, water was added thereto and the resulted precipitates were collected by filtration. The precipitates were washed with water, and dried to obtain 4.2 g of {7-chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-yl} iodomethyl carbonate as slightly yellow powder. ¹H-NMR (toluene-d₆, 100 °C)dppm :

• 1.3-1.8 (4H, m), 2.31 (3H, s), 2.42 (3H, s), 2.7-4.3 (2H, m), 5.48 (2H, d, J=5.1 Hz), 5.53 (2H, d, J=5.1, Hz), 5.5 (1H, m), 6.4-6.8 (3H, m), 6.8-7.2 (6 H, m), 7.2 (1H, m), 7.36 (1H, s).

Example 24 Acetoxymethyl {7-chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benzo[blazepin-5-yl} carbonate

Sodium acetate (300 mg) was added to an acetonitrile solution (5 ml) of {7-chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-yl} iodomethyl carbonate, and then the mixture was heated under reflux for 8 hours. The reaction mixture was cooled to room temperature and the insoluble substance was rempved by filtration. The filtrate was concentrated under reduced pressure and the residue was purified by silica gel flash chromatography (n-hexane : ethyl acetate = 71 : 29 → 30 : 70). The purified product was concentrated under reduced pressure. The aqueous acetonitrile solution of the residue was freeze-dried to obtain 6.1 g of acetoxymethyl {7-chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benzo[b]azepin-5-yl) carbonate as white amorphous solid. ¹H-NMR (Toluene-d₈, 100 °C) dppm : 1.3-1.8 (4H, m), 1.6 (3H, s), 2.3 (3 H, s), 2. 4 (3H, s), 2 . 7-4. 4 (2H, m), 5.6 (2H, dd, J=5.5Hz, 10.4Hz), 5.6-5.9 (1H, m), 6.5 (1H, d, J=8.4Hz), 6.6 (1H, br), 6.7 (1H, dd, J=2.3, 8.4Hz), 6.8-7.2 (5H, m), 7.3 (1H, d, J=2.1Hz), 7.4 (1H, 1.6Hz)

Example 27 5-Acetoxymethoxy-7-chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benzo[b]azepine

7-Chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-5-methylthiomethoxy-2,3,4,5-tetrahydro-1H-benzo[b]azepine (509 mg, 1.0 mmol) was dissolved in 1,2-dichloroethane (10 ml). Sulfuric chloride (0.12 ml, 1.5 mmol) was added thereto, and the mixture was stirred at room temperature for 15 minutes. The obtained mixture was concentrated under reduced pressure, and acetonitrile (10 ml), sodium acetate (246 mg, 2.0 mmol), and sodium iodide (450 mg, 3.0 mmol) were added to the residue, and then the mixture was heated under reflux for 1 hour. After cooling to room temperature, ethyl acetate was added thereto, and the insoluble subjexct was removed by filtration. The filtrate was concentrated under reduced pressure, and the residue was purified by silica gel flash chromatography (n-hexane : ethyl acetate = 65 : 35 → 50 : 50). The purified product was concentrated under reduced pressure, and the residue was dissolved in aqueous acetonitrile. After concentration at room temperature under reduced pressure, the resulted precipitates were collected by filtration, and dried to obtain 280 mg of 5-acetoxymethoxy-7-chloro-1-[2-methyl-4-(2-methyl-benzoylamino)-benzoyl]-2,3,4,5-tetrahydro-1H-benao[b]azepine as white powder. ¹H-NMR (toluene-d₈, 100 °C)dppm :

• 1.3-1.9 (7H, m), 2.32 (3H, s), 2.41 (3H, s), 2.8-4.1 (2H, m), 4.6-4.8 (1H, m), 5.17 (2H, s), 6.4-6.8 (3H, m), 6.8-7.3 (6H, m), 7.39 (1H, s).

Table 1 shows chemical formulae of the compounds obtained in Examples 10, 11, 16, 20 to 24 and 27. Table 1 Table 1

Example		Salt
10	-
11	-
16	-
20	-
21	-
22	-
23	-
24	-
27	-

Examples 40, 45 to 52, 68, 69, 92 and 93

The compounds of the following Examples 45, 46, 47, 48, 49, 50, 51, 52, 68, 92, 69, and 93 were prepared in the same manner as the above Example 10, using corresponding starting materials.

The compound of the following Example 40 was prepared in the same manner as the above Example 24, using corresponding starting material.

Table 2 shows chemical formulae and the physical properties, such as NMR and MS of the compounds obtained in Examples 40, 45 to 52, 68, 69, 92 and 93. Table 2 Table 2

Example		NMR	MS	Salt
40	1H-NMR(DMSO-d6) dppm:1.3-2.1 (4H, m), 2.2-2.4 (6H, m), 2.0-4.0 (2H, m), 5.3-5.6 (2H, m), 5.7-6.0 (1H, m), 6.4-7.7 (10H, m), 10.0(1H, br)	603	-
45	1H-NMR (CDCl3) dppm : 0.730.97 (3H, m), 1.11-259 (26.7H, m), 2.68-2.89 (1H, m), 2.98-3.97 (0.3H, m), 4.70-5.15 (1 H, m), 5.85-6.17 (12H, m), 6.46-6.67 (1H, m), 6.84-7.68(8.8H, m).	-	-
46	1H-NMR (CDCl3) dppm : 0.80-0.93 (3H, m), 1.13-262 (30.7H, m), 270-2.92 (1H, m), 2.99-3.95 (0.3H, m), 4.70-5.14 (1H, m), 5.84-6.16 (1.2H, m), 6.44-6.66 (1H, m), 6.85-7.78 (8.8H, m).	-	-
47	1H-NMR (CDCl3) dppm : 0.79-0.95 (3H, m), 1.10-2.63 (34.7H, m), 271-2.93 (1H, m), 2.98-4.03 (0.3H, m), 4.72-5.13 (1H, m), 5.88-6.16 (12H, m), 6.47-6.67 (1H, m), 6.86-7.74 (8.8H, m).	-	-
48	1H-NMR(CDCl3) dppm : 0.88 (3H, t, J = 6.6 Hz ), 1.15-1.50 (28H, m), 1.60-1.95 (4H, m), 2.05-2.60 (9H, m), 2.75-2.95 (1H, m), 4.75-5.10 (1H, m), 5.85-6.10 (1H, m), 6.50-6.65 (1H, m), 6.85-7.05 (3H, m), 7.15-7.75 (8H, m).	714	-
49	1H-NMR (CDCl3) dppm : 0.88 (3H, t, J = 6.7 Hz), 1.15-1.50 (32H, m), 1.60-2.00 (4H, m), 2.05-2.60 (9H, m), 2.75-2.95 (1H, m), 4.70-5.10 (1H, m), 5.85-6.10 (1H, m), 6.45-6.65 (1H, m), 6.85-7.10 (3H, m), 7.15-7.75 (8H, m).	742	-
50	1H-NMR (CDCl3) dppm: 1.03 (3H, t, J = 7.3 Hz), 1.6-1.8 (4H, m), 2.0-2.5 (4H, m), 2.43 (3H, s), 2.45 (3H, s), 2.81 (1H, t, J = 11.6Hz), 4.7-5.1 (1H, m), 5.9-6.1 (1H, m), 6.5-6.6 (1H, m), 6.9-7.9 (9H, m).	519	-
51	1H-NMR (CDCl3) dppm: 0.8-1.0 (3H, m), 1.2-1.4 (2H, m), 1.6-1.9 (4H, m), 2.1-2.6 (4H, m), 2.44 (3H, s), 2.46 (3H,s), 2.81 (1H, t, J = 11.5Hz), 4.7-5.1 (1H, m), 5.8-6.1 (1H, m), 6.4-6.6 (1H, m), 6.9-7.7 (9H, m).	547	-
52	1H-NMR (CDl3) dppm : 0.8-1.0 (3H, m), 1.2-1.5 (8H, m), 1.6-1.9 (4H, m), 2.0-2.5 (4H, m), 2.42 (3H, s), 244 (3H, s), 2.80 (1H, t, J = 11.5 Hz), 4.7-5.1 (1H, m), 5.9-6.1 (1H, m), 6.5-6.6 (1H, m), 6.9-8.0 (9H, m).	575	-
68	1H-NMR (CDCl3) dppm: 1.40-2-63 (19.6H, m), 2.68-2.93 (1H, m), 3.02-4.03 (0.4H, m), 4.71-5.13 (1H, m), 5.88-6.15 (1.2H, m), 6.45-6.68 (1H, m), 6.82-7.78 (8.8H, m).	576	-
69	1H-NMR (CDCl3) dppm: 1.63-1.96 (2H, m), 2.03-2.36 (2H, m), 2.25 (3H, s), 2.39-2.69 (6.6H, m), 2.72-2.96 (1H, m), 3.09-3.89 (0.4H, m), 4.70.5.16 (1 H, m), 5.84-6.18 (1.2H, m), 6.48-6.67 (1H, m), 6.83-7.76 (8.8H, m).	-	-
92	1H-NMR (DMSO-d6) dppm: 1.8-2.1 (4H, m), 236 (3H, s), 2.37 (3H,s), 2.8-4.3 (2H, m), 6.2-6.3 (1H, m) 6.8-7.1 (2H, m), 7.1-7.5 (7H, m), 7.58 (1H, s), 7.93 (2H, d, J=5.8Hz), 8.82 (2H, d, J=5.8Hz), 9.82 (1H, br).	554	Hydrochloride
93	1H-NMR (CDCl3) dppm : 1.77-2.00 (2H, m), 210-267 (6.6H, m), 2.78-3.00 (1H, m), 3.07-4.04 (3.4H, m), 4.75-5.24 (1H, m), 6.02-7.77 (12.6H, m), 7.97-8.24 (2.4H, m).	-	-

Test Example 1

The compounds obtained in Examples 50, and 52 were used as test compounds.

Each test compound, (examples 50, and 52) equivalent to 10 mg of tolvaptan, and hypromellose (125 mg) were suspended in 25 ml of water for injection in a porcelain mortar, to thereby obtain a suspension equivalent to 0.4 mg of tolvaptan per ml of suspension.

A spray-dried tolvaptan powder equivalent to 60 mg of tolvaptan, which was prepared in a similar manner to Example 3 of Japanese Unexamined Patent Publication No. 1999-21241 , was suspended in 50 ml of water for injection in a porcelain mortar. This suspension was diluted three-fold with water for injection, preparing a suspension of spray-dried powder equivalent to 0.4 mg of tolvaptan per ml of suspension.

The following tests were conducted to examine the oral absorption features of each suspension. Male rats (body weight: about 180 g) that had been deprived of food for about 18 hours were used as test animals. The above suspensions were each administered by forced oral administration using a sonde for oral administration at a dose of 2.5 ml/kg of body weight, producing 1 mg of tolvaptan per kg of body weight. The blood samples were collected from the jugular vein under light diethyl ether anesthesia at the time of 0.5 hour, 1 hour, 2 hours, 4 hours, 6 hours, and 8 hours later after dosing. The serum concentrations of tolvaptan (ng/ml) were determined by using UPLC-MS/MS (Waters).

The average pharmacokinetic parameters were calculated from the results. The results are shown in the following table. Table 3

Test Compound
Tolvaptan	80.9±28.5	26.4±12.9	1.50±0.58	2.95±0.35
Example 50	117.0±26,1	21.6±3.0	2.00±0.00	4.78±0.40
Example 52	78.8±41.7	11.6±11.1	2.67±1.15	9.10±7.98

Table 3

Mean±S.D. (n=3 or 4)

Table 3 reveals that, when administered in vivo, the test compounds indicate smaller Cmax than tolvaptan and the maximum drug concentration times (T_max) of the test compounds are delayed compared to tolvaptan. Consequently, the test compounds have prolonged effects.

Claims (4)

1. A benzazepine compound represented by general formula (1) wherein R¹ is a group of (1-5):

   (1-5) a -CO-R⁸ group (wherein R⁸ is (8-1) an alkyl group optionally substituted with a halogen atom, a C_2-6 alkanoyloxy group, or a phenyl group (substituted with a dihydroxy phosphoryloxy group in which the hydroxy groups are optionally substituted with benzyl groups, and a C_1-6 alkyl group), (8-2) a C_1-6 alkoxy group substituted with a halogen atom, a C_2-6 alkanoyloxy group, or a dihydroxyphosphoryloxy group, (8-3) a pyridyl group, or (8-4) a C_1-6 alkoxyphenyl group;

   or a salt thereof.
2. The compound according to claim 1, wherein, in formula (1), R¹ is a -CO-R⁸ group wherein R⁸ is an alkyl group, or a salt thereof.
3. A pharmaceutical preparation comprising the benzazepine compound of claim 1 or a pharmacologically acceptable salt thereof, and a pharmacologically acceptable diluent and/or carrier.
4. The pharmaceutical preparation according to claim 3 which is used as a vasodilator, hypotensive drug, aquaretic agent, or platelet aggregation inhibitor.