Hydropyridine derivative acid addition salts

The invention relates to acid addition salts of 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine with an acid, a medicament containing these salts as an active ingredient, the use of the salt addition salts, methods for the preparation of 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine acid addition salts, and a method for the preparation of 2-acetoxy-5 hydrochloride - (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine.

The acid addition salts of 2-acetoxy-5- (a-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine show excellent absorption after oral administration, metabolism to the active compound and activity inhibit platelet aggregation and are useful as therapeutic or prophylactic agents for diseases initiated by thrombus formation or embolization.

EP-542411 (Japanese Patent Application Publication No. H 6-411239) discloses that 2-acetoxy-5- (a-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine and its derivatives, which are antagonists of adenosine diphosphatase (hereinafter referred to as ADP) receptors, exhibit excellent platelet inhibitory activity and are useful as anticoagulants and anti-embolic agents.

For many years, the present inventors have studied the pharmacological activity of various hydropyridine derivatives in order to select compounds with an excellent activity of inhibiting platelets. The inventors have found that the acid addition salts of 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) 4,5,6,7-tetrahydrothieno [3,2-c] pyridine show excellent absorption after oral administration, metabolism to the compound active, platelet aggregation inhibiting activity, low toxicity and excellent storage and transport stability, and are useful as medicaments (preferably useful as therapeutic or prophylactic agents (preferably therapeutic agents) for diseases initiated by thrombus formation or embolization (preferably thrombosis or embolism).

The invention relates to two addition salts of 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine with an acid: hydrochloride or maleate. Preferred according to the invention are both 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine hydrochloride and 2-acetoxy-5- (a) maleate -cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine.

The invention also relates to a medicament containing one of the above-defined salts as an active ingredient, and the medicament is intended for the prevention or treatment of diseases initiated by thrombus formation or embolization in a warm-blooded animal, and in particular is intended for the prevention or treatment of thrombosis or embolism in humans, especially human thrombosis or embolism. it is intended to treat human thrombosis or embolism.

The invention also relates to the use of a salt as defined above for the manufacture of a medicament for the prevention or treatment of a disease initiated by thrombus formation or embolization in a warm-blooded animal, preferably the medicament for the prevention or treatment of thrombosis or embolism in a human, especially a medicament for the treatment of thrombosis or embolism. in a human.

The invention further relates to a process for the preparation of acid addition salts of 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine, characterized in that 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine is added to a solution of hydrochloric acid or maleic acid in an inert solvent, and if necessary with addition of seed crystals, and then the mixture is reacted. Preferably, in the process according to the invention, the acid is maleic acid and the inert solvent is acetone.

An alternative method of preparing 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine acid addition salts is the process characterized by -acetoxy-5- (a-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine in an inert solvent, hydrochloric acid or maleic acid are added dropwise, once or more than once if necessary with the addition of seed crystals, and the mixture is reacted. Preferably, in this process, the inert solvent is acetone and the acid is concentrated hydrochloric acid.

PL 208 386 B1

Another object of the invention is a process for the preparation of 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine hydrochloride, characterized in that half of the required the amount of concentrated hydrochloric acid to the solution of 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine in an inert solvent at elevated temperature, if necessary with addition of seed crystals, the remaining required amount of concentrated hydrochloric acid is then added dropwise at said temperature, and the mixture is reacted at this temperature. Preferably in this process the elevated temperature is in the range between 35 ° C and 60 ° C, more preferably between 40 ° C and 55 ° C, the dropwise time of half the required amount of concentrated hydrochloric acid being preferably in the range of 2 to 10 minutes.

In the method for producing the hydrochloride according to the invention, preferably, after the dropwise addition of half the required amount of concentrated hydrochloric acid, the mixture is allowed to stand under stirring for 30 minutes to 2 hours, and the required remaining amount of concentrated hydrochloric acid is preferably added dropwise for 30 minutes to 2 hours. hours. Preferably also, after the dropwise addition of the remaining amount of concentrated hydrochloric acid required, the mixture is allowed to stand under stirring for 1 hour to 3 hours.

2-Acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine hydrochloride has the following formula:

<img file="PL208386B1_D0001.tif" />

2-Acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine maleate has the following formula:

<img file="PL208386B1_D0002.tif" />

2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine acid addition salts have an asymmetric carbon in their molecule and each compound can exist in the form of two isomers in the R and S configuration. The present invention includes individual isomers and mixtures of these isomers in any proportion. The optical isomer of the acid addition salts of 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine of the present invention can be obtained by using an optically active starting material or can be isolated from a racemic mixture of the synthetically obtained 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine acid addition salts by conventional optical resolution .

In some cases, 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine acid addition salts that are allowed to contact atmospheric air , or which crystallize, can absorb water or can take up water to form a hydrate.

2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine acid addition salts are prepared with or without an inert solvent (preferably in an inert solvent) ) by adding 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine, which is synthesized by the method disclosed in EP-542411 (published Japanese application Patent Hei 6-41139), to acid (preferably hydrochloric acid, hydrogen chloride (gaseous) or maleic acid; more preferably concentrated hydrochloric acid or maleic acid; most preferably concentrated hydrochloric acid); or with or without obo4

By the dropwise addition or addition of acid (preferably hydrochloric acid, hydrogen chloride (gaseous) or maleic acid; more preferably concentrated hydrochloric acid or maleic acid; most preferably concentrated hydrochloric acid), one or more times , to 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine. In the course of this procedure, seed crystals of the said salt may be added, if necessary.

The solvent to be used in the above reaction is not particularly limited, provided that it does not adversely affect the reaction and can dissolve the starting material to some extent. Examples of such solvents include aliphatic hydrocarbons such as hexane, cyclohexane, heptane, ligroin, or petroleum ether; aromatic hydrocarbons such as benzene, toluene, or xylene; halogenated hydrocarbons such as dichloroethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, chlorobenzene or dichlorobenzene; ether derivatives such as diethyl ether, diisopropyl ether, tetrahydrofuran, dioxane, dimethoxyethane or diethylene glycol dimethyl ether; ketone derivatives such as acetone, methyl ethyl ketone or diethyl ketone; ester derivatives such as ethyl acetate, propyl acetate or butyl acetate; carboxylic acids such as acetic acid or propionic acid; or nitrile derivatives such as acetonitrile or propionitrile. For the preparation of the hydrochloride, the preferred solvents are ether derivatives, ketone derivatives, ester derivatives, carboxylic acids or nitrile derivatives; more preferred solvents are tetrahydrofuran, dioxane, acetone, methyl ethyl ketone, ethyl acetate, acetic acid or acetonitrile; even more preferred solvents are tetrahydrofuran, dioxane, acetic acid or acetone. Acetone is most preferred. On the other hand, for the preparation of the maleate, the preferred solvents are ether derivatives, ketone derivatives, ester derivatives or nitrile derivatives; more preferred solvents are tetrahydrofuran, dioxane, acetone, methyl ethyl ketone, ethyl acetate or acetonitrile; even more preferred solvents are tetrahydrofuran, dioxane or acetone. Acetone is most preferred.

The reaction temperature depends on the reagent, solvent and the like, and is usually from -20 ° C to 100 ° C, preferably from 0 ° C to 70 ° C. In the case of the hydrochloride, the reaction temperature is preferably from 30 ° C to 60 ° C, more preferably from 40 ° C to 55 ° C.

The reaction time depends on the reagent, solvent, reaction temperature and the like, and is usually 5 minutes to 10 hours, preferably 10 minutes to 5 hours.

In the case of the maleate preparation, the reaction is preferably carried out by adding 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine to a solution of maleic acid in acetone. between 0 ° C and 70 ° C, and then left at said temperature for 1 hour to 3 hours.

In the case of the hydrochloride preparation, the reaction is preferably carried out by adding or dropwise the required amount of concentrated hydrochloric acid (usually equimolar to the thienopyridine derivative) to the 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6 solution. 7-tetrahydrothieno [3,2-c] pyridine in acetone between 0 ° C and 70 ° C (preferably between 35 ° C and 60 ° C) and then left at said temperature for 30 minutes to 3 hours.

More preferably the reaction is carried out by dropping half the required amount of concentrated hydrochloric acid (usually equimolar to the thienopyridine derivative) to a solution of the thienopyridine derivative in acetone between 35 ° C and 60 ° C (preferably between 40 ° C and 55 ° C) over a period of 2 minutes. up to 10 minutes, adding seeding crystals of said salt if necessary, then leaving at said temperature for 30 minutes to 2 hours; and then the remaining required amount of concentrated hydrochloric acid is further added dropwise to the reaction mixture over 30 minutes to 2 hours, and left at said temperature for 1 hour to 3 hours.

After reaction, the 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine acid addition salt can be isolated from the reaction mixture by conventional methods. For example, after the reaction, the obtained crystals are isolated by filtration to yield the expected product, or the solvent from the reaction mixture is evaporated to yield the expected product. The product, if necessary, can be purified by crystallization, dissolution and precipitation or by chromatography.

The 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine acid addition salts of the present invention show excellent absorption after oral administration, metabolism to the compound active, and the activity of inhibiting platelet aggregation, low toxicity and excellent stability during storage and transport, and therefore useful

As therapeutic or prophylactic agents (preferably as therapeutic agents) for diseases initiated by thrombus formation or by embolization; more preferably as prophylactic or therapeutic agents (preferably therapeutic agents) for thrombosis or embolism. The medicaments mentioned above are preferably intended for warm-blooded animals, more preferably for humans.

Industrial use

When the 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine acid addition salts of the present invention are used as therapeutic or prophylactic agents for disease mentioned above, they can be administered individually or as mixtures with pharmaceutically acceptable excipients, diluents or the like, in various dosage forms such as tablets, capsules, granules, powders, syrups or the like for oral administration; and injections, suppositories or the like for parenteral administration.

Each of the above formulations can be prepared by generally known methods using formulation additives such as excipients, lubricants, binders, disintegrants, emulsifiers, stabilizers, correctors and diluents.

Examples of excipients include organic excipients, for example sugar derivatives such as lactose, sucrose, glucose, mannitol or sorbitol; starch derivatives such as corn starch, potato starch, α-starch or dextrin; cellulose derivatives such as crystalline cellulose; acacia gum; dextran; pullulan; and inorganic excipients, for example silicate derivatives such as light silicic acid anhydride, synthetic aluminosilicate, calcium silicate or magnesium metaaluminosilicate; phosphate derivatives such as calcium hydrogen phosphate; carbonate derivatives such as calcium carbonate; sulfate derivatives such as calcium sulfate or the like.

Examples of lubricants include stearic acid; metal stearates such as calcium stearate or magnesium stearate; talc; waxes such as beeswax and ginger wax; boric acid; adipic acid; sulfate derivatives such as sodium sulfate; glycol; fumaric acid; sodium benzoate; DL-leucine; lauryl sulfate derivatives such as sodium lauryl sulfate or magnesium lauryl sulfate; silicic acid derivatives such as silicic anhydride or silicic acid hydrate; and the starch derivatives mentioned above in relation to excipients.

Examples of binders include hydroxypropyl cellulose, hydroxypropyl methylcellulose, polyvinylpyrrolidone, Macrogol (trade name) or excipients mentioned among the excipients above.

Examples of disintegrants include cellulose derivatives such as low-substituted hydroxypropyl cellulose, carboxymethyl cellulose, calcium carboxymethyl cellulose or internally cross-linked sodium carboxymethyl cellulose; chemically modified starch or cellulose derivatives such as carboxymethyl starch or sodium carboxymethyl starch; cross-linked polyvinylpyrrolidone; and the starch derivatives mentioned above.

Examples of emulsifiers include colloidal clay such as bentonite or veegum; metal hydroxides such as magnesium hydroxide or aluminum hydroxide; anionic surfactants such as sodium lauryl sulfate or calcium stearate; cationic surfactants such as benzalkonium chloride; nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene sorbitan fatty acid esters or sucrose fatty acid esters.

Examples of the stabilizing agent include ester derivatives of parahydroxybenzoic acid such as methylparaben or propylparaben; alcohols such as chlorobutanol, benzyl alcohol, or phenethyl alcohol; benzalkonium chloride; phenolic derivatives such as phenol or cresol; timerozal; dehydroacetic acid or sorbic acid.

Examples of correcting agents include sweeteners, acidulants, flavors or the like which are commonly used.

The specific dose of the compound of the present invention will be modified depending on the severity of the patient's symptoms, age, and the like. For oral administration, the amount of the active ingredient per unit dose may range from 0.1 mg (preferably 1 mg) to 1000 mg (preferably 500 mg). A unit dose for intravenous administration may range from 0.01 mg (preferably 0.1 mg) to 500 mg (preferably 250 mg) of a compound of the invention.

The unit dose may be administered to an adult human from 1 to 7 times daily for a period of 1 to 7 days depending on the severity of the patient's symptoms.

The most advantageous way of carrying out the invention

The following Reference Examples, Test Examples and Preparation Examples are intended to further illustrate the present invention and should not be considered as limiting the scope of the invention.

PL 208 386 B1

Example 1

2-Acetoxy-5- (a-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothien- [3,2-c] pyridine hydrochloride (crystal A)

To a solution of 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine (10 g), obtained in Reference Example 1, in acetone ( 150 ml) was added dropwise concentrated hydrochloric acid (36%, 2.71 g) while stirring at room temperature (25 ° C). A small amount of crystals of the expected product (crystal A obtained by another procedure) were added to the solution, and the mixture was stirred for 90 minutes at the same temperature. The obtained crystals were separated by filtration, and the crystals were washed with a small amount of acetone and dried at 50 ° C under reduced pressure for 4 hours to give the title compound as a white crystal (8.1 g, 74% yield) (crystal A).

Mp: 133-136 ° C;

¹H NMR (CDCl3) δ ppm: 0.92-0.99 (1H, m), 1.05-1.16 (2H, m), 1.23-1.34 (1H, m), 1.84 -1.95 (1H, m), 2.26 (3H, s), 3.07-3.23 (2H, m), 3.57-4.39 (4H, m), 6.04 (1H , s), 6.45 (1H, br s), 7.37-7.57 (3H, m), 7.66-7.75 (1H, m);

Mass spectrum (Cl, m / z): 374 (M⁺+1);

IR (KBr) vmax cm^-1: 1762, 1720.

Example 2

2-Acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine maleate

2-Acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine was added to a solution of maleic acid (4.43 g) in acetone (60 ml). (15.0 g), obtained in Reference Example 1, then the mixture was stirred at room temperature (25 ° C) for 2 hours. The resulting crystals were separated by filtration, washed with a small amount of acetone and dried at 50 ° C under reduced pressure for 4 hours to give the title compound as white crystals (17.1 g, 92% yield).

Mp: 171-172 ° C;

¹H NMR (CD3OD) δ ppm: 0.89-0.97 (1H, m), 1.02-1.09 (2H, m), 1.14-1.23 (1H, m), 1.94 -2.03 (1H, m), 2.25 (3H, s), 3.00-3.09 (2H, m), 3.33-3.50 (2H, m), 3.88 (1H , d, J = 14.9Hz), 4.05 (1H, d, J = 14.9Hz), 5.70 (1H, s), 6.25 (2H, s), 6.40 (1H, s ), 7.30-7.42 (2H, m), 7.45-7.52 (1H, m), 7.56-7.66 (1H, m);

Mass spectrum (Cl, m / z): 374 (M⁺+1); lR (KBr) vmax cm^-1: 1782, 1713.

Example 3

2-Acetoxy-5- (a-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothien- [3,2-c] pyridine hydrochloride (B1 crystal)

To a solution of 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine (10 g), obtained in Reference Example 1, in acetone ( 100 ml) was added by dropwise addition of concentrated hydrochloric acid (36%, 2.71 g) over 1 minute while stirring at 40 ° C. The reaction mixture was stirred at the same temperature for 60 minutes (crystals began to precipitate 10 minutes after the addition of concentrated hydrochloric acid). The obtained crystals were separated by filtration and washed with acetone (20 ml) and then dried at 60 ° C under reduced pressure for 2 hours to give the title compound as white crystals (9.72 g, 89% yield) (crystal B1) which showed greater storage stability than crystal A.

Mp: 166-174 ° C;

Mass spectrum (Cl, m / z): 374 (M⁺+1);

IR (KBr) vmax cm^-1: 1758, 1690.

Example 4

2-Acetoxy-5- (a-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno- [3,2-c] pyridine hydrochloride (crystal B2)

To a solution of 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothien- [3,2-c] pyridine (50 g), obtained in Reference Example 1, in acetone (750 ml) concentrated hydrochloric acid (36%, 6.78 g) was added dropwise over 5 minutes while stirring at 40 ° C. The crystals B1 (0.1 g) obtained in Example 3 were added to the reaction mixture as seeding crystals, and the obtained mixture was stirred at the same temperature for 60 minutes. Then concentrated hydrochloric acid (36%, 6.10 g) was added dropwise to the resulting mixture over 60 minutes, and the mixture was stirred at the same temperature for 120 minutes. The obtained crystals were separated by filtration, and then the crystals

The mixture was washed with acetone (100 ml) and dried at 70 ° C under reduced pressure for 3 hours to give the title compound as white crystals (47.8 g, 92% yield) (B2 crystal), which showed a higher storage stability than crystal B1 obtained in example 3.

Mp: 165-178 ° C;

Mass spectrum (Cl, m / z): 374 (M⁺+1);

IR (KBr) Vmax cm^-1: 1758, 1690.

Example 5

2-Acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine maleate

To a solution of maleic acid (932 g) in acetone (15 L) heated to 40 ° C was added 2-acetoxy-5- (a-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2- c] pyridine (3000 g) obtained in Reference Example 1. The mixture was stirred at room temperature for 2 hours. The obtained crystals were separated by filtration and washed with acetone (4 L), then dried at 60 ° C under reduced pressure for 8 hours to give the title compound as white crystals (3538 g, 90% yield).

Mp: 172-173 ° C;

Mass spectrum (Cl, m / z): 374 (M⁺+1);

IR (KBr) vmax cm^-1: 1782, 1713.

Example 6

2-Acetoxy-5- (a-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno- [3,2-c] pyridine hydrochloride (crystal B2)

To a solution of 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine (50 g), obtained in Reference Example 1, in acetone (750 ml) was added by dropwise addition of concentrated hydrochloric acid (36%, 6.78 g) over 5 minutes while stirring at 55 ° C. Crystals B1 (0.1 g) obtained in Example 3 as mother crystals were added to the reaction mixture, and the resulting mixture was stirred at the same temperature for 60 minutes. To the resulting mixture was added concentrated hydrochloric acid (36%, 6.08 g) dropwise over 60 minutes, and the mixture was stirred at the same temperature for 120 minutes. After the obtained crystals were separated by filtration, the crystals were washed with acetone (100 ml) and dried at 70 ° C under reduced pressure for 3 hours to give the title compound as a white crystal (46.2 g, 89% yield) (crystal B2).

Mp: 164-178 ° C;

Mass spectrum (Cl, m / z): 374 (M⁺+1);

IR (KBr) vmax cm^-1: 1758, 1690.

Reference example 1

2-Acetoxy-5- (a-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine (a) 2-fluorobenzyl-cyclopropyl ketone

To a suspension of magnesium powder (7.2 g) in anhydrous diethyl ether (60 ml) was added a solution of 2-fluorobenzyl bromide (30 ml) in diethyl ether (30 ml), and the mixture was stirred at room temperature for 1 hour. The reaction mixture was added dropwise to a solution of cyclopropyl cyanide (18.2 ml) in diethyl ether (120 ml) over 100 minutes. After stirring for 30 minutes at room temperature, the stirred mixture was refluxed for 1 hour. After completion of the reaction, the reaction mixture was partitioned between ethyl acetate and saturated aqueous sodium chloride solution. The ethyl acetate layer was washed successively with water, a saturated aqueous sodium bicarbonate solution and a saturated aqueous sodium chloride solution, then dried over anhydrous sodium sulfate and evaporated under reduced pressure. The residue was purified by column chromatography on silica gel using toluene as the eluent to give the expected compound (23 g, containing a solvent) in the form of a yellow liquid.

¹H NMR (CDCl3) δ ppm: 0.82-0.98 (2H, m), 1.03-1.17 (2H, m), 1.92-2.06 (1H, m), 3.86 (2H, s), 7.10-7.30 (4H, m);

Mass spectrum (Cl, m / z): 179 (M⁺+1).

(b) 5- (a-Cyclopropylcarbonyl-2-fluorobenzyl) -2-oxo-2,4,5,6,7,7a-hexahydrothieno [3,2-c] pyridine

N-bromosuccinimide (9.6 g) and benzoyl peroxide (0.5 g) were added to a solution of 2-fluorobenzylcyclopropyl ketone (8.7 g) obtained in Reference Example 1 (a) in carbon tetrachloride (80 ml), the mixture was refluxed for 6 hours. After completion of the reaction, toluene was added to the reaction mixture, and the resulting solid was filtered off. The filtrate was concentrated under reduced pressure

Under high pressure. The residue was purified by silica gel column chromatography using toluene as eluent to give α-cyclopropylcarbonyl-2-fluorobenzyl bromide (8.5 g) as a yellow oil.

To a solution of α-cyclopropylcarbonyl-2-fluorobenzyl bromide (6.0 g), obtained above, in dimethylformamide (20 ml) was added 2-oxo-2,4,5,6,7,7α-hexahydrothieno [3,2- c] pyridine (4.8 g), which was prepared according to the method described in EP 192535 (Japanese Patent Application Publication No. 61-246186) and potassium hydrogen carbonate (7.0 g). After stirring for 2 hours at room temperature, the reaction mixture was partitioned between ethyl acetate and water. The ethyl acetate layer was washed with a saturated aqueous sodium chloride solution, then dried over anhydrous magnesium sulfate and evaporated under reduced pressure. After purification of the residue by column chromatography on silica gel using toluene / ethyl acetate = 3/1 as eluent, the product was crystallized from diisopropyl ether to give the expected product (2.6 g, 35% yield) in the form of pale brown crystals.

Mp: 123-125 ° C;

¹H NMR (CDCl3) δ ppm: 0.75-0.96 (2H, m), 2.01 (1H, m), 2.02-2.17 (1H, m), 2.25-2.45 and 2.47-2.62 (2H total, each m), 2.85 and 3.10 (2H total, each d, J = 12.0Hz), 3.88-4.01 and 4.03- 4.16 (total of 2H, each m), 4.85 and 4.89 (total of 1H, each s), 6.03 and 6.06 (total of 1H, each s), 7.10-7.45 (4H , m);

Mass spectrum (Cl, m / z): 332 (M⁺+1), 262;

Analysis calcd for C18H18FNO2S: C, 65.23; H, 5.48; N, 4.23.

Found C, 65.09; H, 5.55; N, 4.20.

(c) 2-Acetoxy-5- (a-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine

To the solution of 5- (a-cyclopropylcarbonyl-2-fluorobenzyl) -2-oxo-2,4,5,6,7,7a-hexahydrothieno [3,2-c] pyridine (2.6 g) obtained in the reference example 1 (b), in a mixture of dimethylformamide (10 ml) and acetic anhydride (5 ml) cooled in an ice bath, sodium hydride (60% dispersion in mineral oil, 0.35 g) was added, and the mixture was stirred in the same temperature for 30 minutes and then at room temperature for 3 hours. After completion of the reaction, the mixture was extracted with ethyl acetate, and the extract was washed with a saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. After purification of the residue by column chromatography on silica gel using toluene / ethyl acetate 3/1 as eluent, the product was crystallized from diisopropyl ether to give the title compound (1.88 g, 65% yield) as white crystals.

Mp: 120-122 ° C;

¹H NMR (CDCl3) δ ppm: 0.80-0.95 (2H, m), 0.99-1.16 (2H, m), 2.27 (3H, s), 2.21-2.34 (1H, m), 2.70-2.95 (4H, m), 3.47 (1H, d, J = 15.0Hz), 3.57 (1H, d, J = 15.0Hz), 4 M. 83 (IH, s), 6.27 (IH, s), 7.10-7.55 (4H, m).

IR (KBr) v_hasks cm^-1: 1758, 1704.

Mass spectrum (Cl, m / z): 374 (M⁺+1), 304.

Analysis calcd for C 20 H 20 FNO 3 S: C, 64.32; H, 5.40; N, 3.75.

Found C, 64.46; H, 5.39; N, 3.73.

TEST EXAMPLE 1

Plasma concentration of the metabolite in dogs

After oral administration of the test compound to male beagle dogs (weighing approximately 10 kg, purchased from Kasho Co., Ltd. and Nippon No-san Kogyo KK), the blood plasma concentration of the metabolite was measured. The reference metabolite used was (2Z) - [1- [α-cyclopropylcarbonyl-2-fluorobenzyl] -4-methylthio-3-piperidinylidene] acetic acid (hereinafter referred to as the S-methyl form). This S-methyl form is the major metabolite of 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine in human, dog or rat plasma. It has been reported that the S-methyl form can be an indicator of the amount of the active metabolite 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine, as it is formed on by further metabolism of the active metabolite [Annu. Rep. San-kyo Res. Lab., 51, 1 (1999)].

Thirty minutes after feeding, each dog was orally dosed with each test compound (10 mg / kg) contained in a gelatin capsule. Three ml blood samples were taken with a heparinized syringe from each dog's saphenous vein at 15, 30, 45, 60, 90, and 120 minutes after administration. Immediately after sampling, whole blood was centrifuged to obtain plasma. Plasma samples were stored at -30 ° C until analysis. To 0.5 ml of thawed plasma was added 0.25 ml of 2-hydroxyacetophenone (1 μg / ml, as substance - internal standard), 0.25 ml of 10 mM potassium phosphate buffer (pH 4.5) and 0 , 5 ml of methanol). The mixture was stirred at 20 ± 3 ° C.

After adding 8 ml of an isopropyl alcohol / chloroform mixture (1/9), the mixture was shaken to extract the S-methyl form and internal standard material into the solvent phase. The extract was separated into a water phase and a solvent phase using a low speed centrifuge (1500 xg for 15 minutes). An appropriate aliquot of the lower solvent phase was dried dry with a nitrogen stream and redissolved in 0.25 ml of the HPLC mobile phase. Separately, a known amount of the S-methyl form was added to the control dog plasma, followed by similar extraction. A calibration curve was prepared by plotting the area ratio of the S-methyl form peak and internal standard on the Y axis to the corresponding concentration of the S-methyl form on the X axis. The concentration of S-methyl in the sample was calculated from the calibration curve.

HPLC conditions:

column: YMC A302 (4.6 x 150 mm);

mobile phase: acetonitrile / isopropyl alcohol / water / trifluoroacetic acid (10/12/78 / 0.01); flow rate: 1.0 ml / min .; detection: UV 220 nm; injected amount: 30 g

The results are shown in Table 1. In this table, the area under the plasma concentration time curve, which is an indication of the amount produced in vivo, and the maximum plasma concentration, which are pharmacokinetic parameters, are abbreviated as AUC and Cmax, respectively. In the table, the term hydrochloride means 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine hydrochloride as obtained in Example 1, while "the free form is 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine.

Table 1

Pharmacokinetic parameters (mean ± standard deviation) of S-methyl in plasma after oral administration to dogs

<td>Tested compound</td><td>n</td><td>AUC (gmin / ml)</td><td>Cmax ^{(gg / ml)}</td>

<td>Hydrochloride</td><td> 4</td><td> 74,1 ± 25,8</td><td> 1,09 ± 0,26</td>

<td>Free character</td><td> 3</td><td> 36,4 ± 8,2</td><td> 0,615 ± 0,141</td>

The results indicate that both AUC and Cmax increased upon conversion of 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine to its hydrochloride salt.

Test practice 2

Platelet aggregation inhibitory effect (after feeding)

Male beagles (weighing approximately 10 kg, purchased from Kasho Co., Ltd. and Nippon Nosan Kogyo KK) were used for this test. One group consisted of 5 or 6 dogs. Platelet aggregation was measured with an automated platelet aggregation meter (PAM-6C, trade name; a product of Mebanix Corporation) according to the method of Born, et al. (J. Physiol., 168, 178 (1963)) with partial modification.

Each time at 2.5 and 4.5 hours after feeding, 5.4 ml of knA / were withdrawn from each dog's head vein using sodium citrate (0.6 ml, 3.8% (w / v)) as an agent. anticoagulant. The citrated blood was centrifuged (240 g, 20 minutes) to separate platelet rich plasma (hereinafter referred to as PRP) and platelet poor plasma (hereinafter referred to as PPP). After counting the number of platelets in PRP with an automated hematology analyzer (K-1000, trade name; a product of Sysmex Corporation), PPP was added to adjust the number of platelets to 3 x 10⁸/ ml. The PRP (240 µl) introduced into the cuvette was placed in an automatic platelet aggregation meter. After preheating (at 37 ° C) for 1 minute, 10 g of ADP (final concentration of 20 gM) was added to induce platelet aggregation. Platelet aggregation was measured for 10 minutes and the maximum aggregation was determined as the pre-administration value.

The next day, 30 minutes after feeding, the dogs were orally administered each of the test compounds in a gelatin capsule. Blood was drawn each time 2 and 4 hours after administration. Platelet aggregation of PRP was measured, determining the maximum aggregation. The inhibition (%) of platelet aggregation by the test compound was calculated by comparison with the pre-administration value. The results are presented in Tables 2 and 3.

In these tables, the term "hydrochloride" means 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine hydrochloride prepared in Example 1,

PL 208 386 B1 free is 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine and "maleate is 2-acetoxy-5-maleate). - (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine obtained in example 2.

Table 2

Inhibition of platelet aggregation (mean ± standard deviation) after oral administration to dogs

<td rowspan="2">Tested relationship</td><td rowspan="2">Dose (mg / kg)</td><td rowspan="2">n</td><td colspan="2">Inhibition of platelet aggregation (%)</td>

<td>2 hours</td><td>4 hours</td>

<td>Hydrochloride</td><td> 0,3</td><td> 5</td><td> 49,0 ± 18,7</td><td> 48,5 ± 18,3</td>

<td>Free character</td><td> 0,3</td><td> 5</td><td> 25,8 ± 10,9</td><td> 28,6 ± 14,2</td>

Table 3

Inhibition of platelet aggregation (mean ± standard deviation) after oral administration to dogs

<td rowspan="2">Tested relationship</td><td rowspan="2">Dose (mg / kg)</td><td rowspan="2">n</td><td colspan="2">Inhibition of platelet aggregation (%)</td>

<td>2 hours</td><td>4 hours</td>

<td>Maleate</td><td> 0,3</td><td> 6</td><td> 50,9 ± 14,5</td><td> 58,6 ± 15,7</td>

<td>Free character</td><td> 0,3</td><td> 6</td><td> 21,7 ± 9,8</td><td> 23,8 ± 12,6</td>

TEST EXAMPLE 3

Platelet aggregation inhibitory effect (fasting)

Male beagles (weighing approximately 10 kg, purchased from Kasho Co., Ltd. and Nippon Nosan Kogyo KK) were used for this test. One group consisted of 3 dogs. Platelet aggregation was measured with an automated platelet aggregation meter (PAM-6C, trade name; a product of Mebanix Corporation) according to the method of Born, et al. (J. Physiol., 168, 178 (1963)) with partial modification.

5.4 mL of blood was drawn from the head vein of each overnight fasting dog using sodium citrate (0.6 mL, 3.8% (w / v)) as an anticoagulant. The citrated blood was centrifuged (240 g, 20 minutes) to separate platelet rich plasma (hereinafter referred to as PRP) and platelet poor plasma (hereinafter referred to as PPP). After the number of platelets in PRP was counted with an automated hematology analyzer (K-1000, trade name; a product of Sysmex Corporation), PPP was added to adjust the number of platelets to 3 x 10⁸/ ml. PRP (240 μL loaded into the cuvette was placed in an automatic platelet aggregation meter. After pre-heating (at 37 ° C) for 1 minute, 10 μL ADP (final concentration 20 μM) was added to induce platelet aggregation. Platelet aggregation was measured for 10 minutes and the maximum aggregation is determined as the pre-administration value.

The next day, the dogs were orally administered each test compound in a gelatin capsule. Blood was drawn each time 2 and 4 hours after administration. Platelet aggregation of PRP was measured, determining the maximum aggregation. The inhibition (%) of platelet aggregation by the test compound was calculated by comparison with the pre-administration value. The results are presented in Table 4.

In this table, "maleate means 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine maleate obtained in Example 2, while" the free form is 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine.

Table 4

Inhibition of platelet aggregation (mean ± standard deviation) after oral administration to dogs

<td rowspan="2">Tested relationship</td><td rowspan="2">Dose (mg / kg)</td><td rowspan="2">n</td><td colspan="2">Inhibition of platelet aggregation (%)</td>

<td>2 hours</td><td>4 hours</td>

<td>Maleate</td><td> 1,0</td><td> 3</td><td> 63,4 ± 22,9</td><td> 88,5 ± 5,7</td>

<td>Free character</td><td> 1,0</td><td> 3</td><td> 27,9 ± 24,8</td><td> 28,7 ± 24,4</td>

PL 208 386 B1

Test results 2 and 3 show that the inhibitory effect of 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine hydrochloride and maleate on ADP induced platelet aggregation is stronger than 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine, and that both 2-acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine hydrochloride and maleate show significantly better pharmacological activity than 2-acetoxy- 5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine.

Preparation example 1

2-Acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine hydrochloride powder (50 mg), lactose (128.7 mg) is combined, cellulose (70 mg) and magnesium stearate (1.3 mg), passed through a screen (60 mesh) and filled into hard gelatin capsules (No. 3, 250 mg).

Preparation example 2

2-Acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine hydrochloride powder (50 mg), lactose (124 mg), cellulose ( 25 mg) and magnesium stearate (1 mg), and compressed on a tableting machine to provide a tablet weighing 200 mg which, if required, may be coated.

Preparation example 3

2-Acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine maleate powder (50 mg), lactose (128.7 mg) is combined, cellulose (70 mg) and magnesium stearate (1.3 mg), passed through a screen (60 mesh) and filled into hard gelatin capsules (No. 3, 250 mg).

Preparation example 4

2-Acetoxy-5- (α-cyclopropylcarbonyl-2-fluorobenzyl) -4,5,6,7-tetrahydrothieno [3,2-c] pyridine maleate powder (50 mg), lactose (124 mg), cellulose ( 25 mg) and magnesium stearate (1 mg), and compressed on a tableting machine to yield a tablet weighing 200 mg, which, if required, may be coated.