Substituted phenylamidines medicaments containing said compounds and method for production thereof

Abstract

The present invention relates to phenylamidines of general formula 1

Description

[0001] The scope of protection of WO 96/33970 covers phenylamidines of general formula 2

[0002] wherein R1 denotes inter alia a C1-4-alkyloxycarbonyl group, an aryl-C1-3-alkyloxycarbonyl group or a group of formula 3

[0003] wherein

[0004] Ra denotes a hydrogen atom or an alkyl group and

[0005] Rb denotes an alkyl group or a 3- to 7-membered cycloalkyl group, even though no such compound is specifically described in this published application.

[0006] It has now been found that the phenylamidines of general formula 4

[0007] wherein

[0008] R6 denotes a hydroxy, C1-18-alkyloxycarbonyl, arylcarbonyl or aryl-C1-4-alkyloxycarbonyl group,

[0009] R7 denotes a hydrogen atom, a C1-8-alkyl, C4-7-cycloalkyl, phenyl-C1-4-alkyl or R8—CO—OCHR9-group wherein

[0010] R8 denotes a C1-4-alkyl, C1-4-alkoxy, C3-7-cycloalkyl or C4-7-cycloalkoxy group and

[0011] R9 denotes a hydrogen atom or a C1-4-alkyl group,

[0012] the tautomers, the stereoisomers and the salts thereof, particularly the physiologically acceptable salts thereof with inorganic or organic acids or bases, also have valuable pharmacological properties, preferably antithrombotic effects.

[0013] The term aryl moieties mentioned in the definition of the abovementioned groups refers to a phenyl group which may in each case be monosubstituted by R10, mono-, di- or trisubstituted by R11 or monosubstituted by R10 and additionally mono- or disubstituted by R11, while the substituents may be identical or different and

[0014] R10 denotes a cyano, carboxy, C1-4-alkoxycarbonyl, aminocarbonyl, C1-4-alkylaminocarbonyl, di-(C1-4-alkyl)-aminocarbonyl, C1-4-alkylsulphenyl, C1-4-alkylsulphinyl, C1-4-alkylsulphonyl, hydroxy, C1-4-alkylsulphonyloxy, trifluoromethyloxy, nitro, amino, C1-4-alkylamino, di-(C1-4-alkyl)-amino, C1-4-alkyl-carbonylamino, N-(C1-4-alkyl)-C1-4-alkylcarbonylamino, C1-4-alkylsulphonylamino, N-(C1-4-alkyl)-C1-4-alkylsulphonyl-amino, aminosulphonyl, C1-4-alkylaminosulphonyl or di-(C1-4-alkyl)-aminosulphonyl group or a carbonyl group which is substituted by a 5- to 7-membered alkyleneimino group, while in the abovementioned 6- to 7-membered alkyleneimino groups a methylene group in the 4 position may in each case be replaced by an oxygen or sulphur atom or by a sulphinyl, sulphonyl, imino or N-(C1-4-alkyl)-imino group, and

[0015] R11 denotes a fluorine, chlorine, bromine or iodine atom or a C1-4-alkyl, trifluoromethyl or C1-4-alkoxy group or

[0016] two groups R11, if they are bound to adjacent carbon atoms, together denote a C3-5-alkylene, methylenedioxy or 1,3-butadien-1,4-ylene group.

[0017] The present invention relates to the compounds of the above general formula I, the tautomers, the stereoisomers and the salts thereof, particularly the physiologically acceptable salts thereof with inorganic or organic acids or bases, pharmaceutical compositions containing these compounds and processes for the preparation thereof.

[0018] Preferred compounds of the above general formula I are those wherein

[0019] the substituted amidino group is in the 4 position, particularly those compounds wherein

[0020] R6 denotes a hydroxy, C1-18-alkyloxycarbonyl, phenylcarbonyl or phenyl-C1-4-alkyloxycarbonyl group and

[0021] R7 denotes a hydrogen atom, a C1-8-alkyl, C5-7-cycloalkyl or phenyl-C1-4-alkyl group,

[0022] while the abovementioned phenyl moieties may in each case be mono- or disubstituted by R11, the substituents being identical or different, and

[0023] R11 denotes a fluorine, chlorine or bromine atom, a C1-2-alkyl, trifluoromethyl or C1-2-alkoxy group,

[0024] the tautomers, the stereoisomers and the salts thereof.

[0025] Particularly preferred compounds of the above general formula I are those wherein

[0026] R6 denotes a hydroxy, C1-12-alkyloxycarbonyl, phenylcarbonyl or phenyl-C1-2-alkyloxycarbonyl group and

[0027] R7 denotes a C1-8-alkyl or C5-7-cycloalkyl group,

[0028] the tautomers, the stereoisomers and the salts thereof.

[0029] Most preferred compounds of the above general formula I are those wherein

[0030] R6 denotes a hydroxy, C5-12-alkyloxycarbonyl, phenylcarbonyl or benzyloxycarbonyl group and

[0031] R7 denotes a C1-4-alkyl or C5-6-cycloalkyl group,

[0032] the tautomers, the stereoisomers and the salts thereof.

[0033] The following are mentioned as examples of preferred compounds:

[0034] (1) 4-[2-[[4-(octyloxycarbonylamidino)phenyl]aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine,

[0035] (2) 4-[2-[[4-(hexyloxycarbonylamidino)phenyl]aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine,

[0036] (3) 4-[2-[[4-(methyloxycarbonylamidino)phenyl]aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine,

[0037] (4) 4-[2-[[4-(benzoylamidino)phenyl]aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine and

[0038] (5) 4-[2-[[4-(hydroxyamidino)phenyl]aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine

[0039] and the salts thereof.

[0040] The new compounds of general formula I may be obtained, for example, by the following method:

[0041] a. In order to prepare a compound of general formula I wherein R6 has the meanings given hereinbefore, with the exception of the hydroxy group:

[0042] acylating a compound of general formula 5

[0043] wherein

[0044] R7 is as hereinbefore defined,

[0045] with a compound of general formula

Z1—R6′  (III),

[0046] wherein

[0047] R6′ has the meanings given for R6 hereinbefore, with the exception of the hydroxy group, and

[0048] Z1 denotes a nucleofugic leaving group such as a halogen atom, e.g. a chlorine atom, or, if R6′ denotes an arylcarbonyl group, Z1 may also denote a hydroxy group.

[0049] The reaction is preferably carried out in a solvent such as acetone, methylene chloride, tetrahydrofuran, toluene, dioxane or acetonitrile, optionally in the presence of an inorganic or a tertiary organic base, preferably at temperatures between −20° C. and the boiling temperature of the solvent used.

[0050] The reaction with a compound of general formula III wherein Z1 denotes a nucleofugic leaving group is preferably carried out in a solvent such as methylene chloride, acetonitrile, tetrahydrofuran, toluene, acetone or acetone/water, optionally in the presence of a base such as potassium carbonate or N-ethyl-diisopropylamine at temperatures between −10 and 60° C., and

[0051] the reaction with a carboxylic acid of general formula III is preferably carried out in the presence of a dehydrating or acid-activating agent, e.g. in the presence of isobutyl chloroformate, thionyl chloride, trimethylchlorosilane, phosphorus trichloride, N,N′-dicyclohexylcarbodiimide, N,N′-dicyclohexylcarbodiimide/N-hydroxysuccinimide, N,N′-carbonyldiimidazole or N,N′-thionyldiimidazole, triphenylphosphine/carbon tetrachloride or triphenylphosphine/diethyl azodicarboxylate, optionally in the presence of a base such as potassium carbonate, N-ethyl-diisopropylamine or N,N-dimethylamino-pyridine at temperatures between −10 and 60° C.

[0052] b. In order to prepare a compound of general formula I wherein R6 denotes a hydroxy group:

[0053] reacting a nitrile of general formula 6

[0054] wherein

[0055] R7 is as hereinbefore defined, with hydroxylamine or the salts thereof.

[0056] The reaction is expediently carried out in a solvent such as methanol, ethanol, n-propanol, water, methanol/water, tetrahydrofuran, tetrahydrofuran/water, dioxane or dioxane/water, optionally in the presence of a tertiary organic base such as triethylamine, at temperatures between 0 and 150° C., e.g. at the boiling temperature of the reaction mixture, but preferably at temperatures between 50 and 100° C.

[0057] Moreover, the compounds of general formula I obtained may be resolved into their enantiomers and/or diastereomers and the compounds of general formula I obtained with a double bond may be resolved into their cis/trans isomers. Thus, for example, cis/trans mixtures may be resolved into their cis and trans isomers, and compounds with at least one optically active carbon atom may be resolved into their enantiomers.

[0058] Thus, for example, the cis/trans mixtures obtained may be resolved by chromatography into their cis and trans isomers, the compounds of general formula I obtained which occur as racemates may be separated into their optical enantiomers by methods known per se (cf. Allinger N. L. and Eliel E. L. in “Topics in Stereochemistry”, Vol. 6, Wiley Interscience, 1971) and compounds of general formula I with at least 2 asymmetric carbon atoms may be resolved into their diastereomers on the basis of their physical-chemical differences using methods known per se, e.g. by chromatography and/or fractional crystallisation, and, if these compounds are obtained in racemic form, they may subsequently be resolved into the enantiomers as mentioned above.

[0059] The enantiomers are preferably separated by column separation on chiral phases or by recrystallisation from an optically active solvent or by reacting with an optically active substance which forms salts or derivatives such as e.g. esters or amides with the racemic compound, particularly acids and the activated derivatives or alcohols thereof, and separating the diastereomeric mixture of salts or derivatives thus obtained, e.g. on the basis of their differences in solubility, whilst the free antipodes may be released from the pure diastereomeric salts or derivatives by the action of suitable agents. Optically active acids in common use are e.g. the D- and L-forms of tartaric acid or dibenzoyltartaric acid, di-O-p-tolyltartaric acid, malic acid, mandelic acid, camphorsulphonic acid, glutamic acid, aspartic acid or quinic acid. An optically active alcohol may be, for example, (+) or (−)-menthol and an optically active acyl group in amides, for example, may be a (+)- or (−)-menthyloxycarbonyl.

[0060] Furthermore, the compounds of formula I may be converted into the salts thereof, particularly for pharmaceutical use into the physiologically acceptable salts with inorganic or organic acids. Acids which may be used for this purpose include for example hydrochloric acid, hydrobromic acid, sulphuric acid, methanesulphonic acid, phosphoric acid, fumaric acid, succinic acid, lactic acid, citric acid, tartaric acid or maleic acid.

[0061] Moreover, if the new compounds of formula I contain a carboxy group, they may subsequently, if desired, be converted into the salts thereof with inorganic or organic bases, particularly for pharmaceutical use into the physiologically acceptable salts thereof. Suitable bases for this purpose include for example sodium hydroxide, potassium hydroxide, arginine, cyclohexylamine, ethanolamine, diethanolamine and triethanolamine.

[0062] The compounds used as starting materials are known from the literature in some cases or may be obtained by methods known from the literature (see Examples).

[0063] As already mentioned, the new phenylamidines of general formula I and their salts, particularly their physiologically acceptable salts with inorganic or organic acids or bases, have valuable properties. Thus, the new phenylamidines of general formula I and their salts have valuable pharmacological properties, not only an anti-inflammatory activity and an inhibiting effect on bone degradation but also, in particular, antithrombotic and antiaggregatory effects and an inhibiting effect on tumours and metastases.

[0064] In view of their biological properties the new compounds of general formula I according to the invention and the physiologically acceptable salts thereof are suitable for treating or preventing diseases in which smaller or greater aggregations of cells occur or cell-matrix interactions play a part, e.g. in combating or preventing venous and arterial thromboses, cerebrovascular diseases, pulmonary embolism, cardiac infarct, arteriosclerosis, osteoporosis and the metastasis of tumours, and for treating genetically caused or acquired disorders of the interactions of cells with one another or with solid structures. They are also suitable as an accompanying therapy in thrombolysis using fibrinolytics or vascular interventions such as transluminal angioplasty or in the treatment of shock, psoriasis, diabetes and inflammation.

[0065] The compounds of general formula I include in particular new prodrugs of the compound

[0066] A=4-[2-[(4-amidinophenyl)aminocarbonyl]ethyl]-1-carboxymethyl-piperazine (Example 1(2) of WO 96/33970).

[0067] The biological properties of the new compounds were investigated as follows, for example:

[0068] The concentration of compound A was measured in the plasma after oral administration of the compound

[0069] B=4-[2-[[4-(hexyloxycarbonylamidino)phenyl]aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine (Example 1(1) of the present application).

[0070] After oral administration of 1 mg/kg of compound B to Rhesus monkeys the concentration of compound A in the plasma was measured 2, 4, 8 and 24 hours after administration of the substance. For this purpose the Rhesus plasma was incubated with a suspension of human thrombocytes in plasma and the compound (3S,5S)-5-[(4′-amidino-4-biphenylyl)-oxymethyl]-3-carboxymethyl-pyrrolidin-2-one-[3-3H-4-biphenylyl] (3H-BIBU 52, described in DE-A-4,214,245) as ligand. The free and bound ligand were separated by centrifugation and quantitatively determined by scintillation counting. The concentration of compound A was calculated from the amount of bound ligand using a calibration curve.

[0071] For this purpose, donor blood is taken from an anticubital vein and anticoagulated with trisodium citrate (final concentration: 13 mmol/l). The blood is centrifuged for 10 minutes at 170×g and the supernatant platelet-rich plasma (PRP) is removed. The remaining blood is sharply centrifuged off again at 3200×g and the supernatant platelet-depleted plasma (PDP) is removed.

[0072] For the calibration curve for calculating the concentration, 5 μl of a solution of compound A are added to 995 μl of PDP (final concentration 5000 nmol/l). Further plasma samples from this sample are diluted with PDP to give a final concentration of 2.5 nmol/l.

[0073] 10 μl of 3H-BIBU 52 (final concentration 10 nmol/l), 10 μl of 14C-sucrose (370 Bq) and 80 μl of PRP are added to 150 μl of plasma sample from the Rhesus monkey or calibration curve plasma and the preparations are incubated for 20 minutes at ambient temperature. Then the samples are centrifuged for 5 minutes at 2000×g and the supernatant is drawn off. 100 μl of the supernatant are combined with 100 μl of NaOH 0.2 mol/l, 15 μl of HCl 5 mol/l and 2 ml of scintillator and the 3H- and 14C-radioactivity are measured quantitatively. The pellet is dissolved in 200 μl of NaOH 0.2 mol/l. 180 μl thereof are combined with 15 μl of HCl 5 mol/l and 2 ml of scintillator and the 3H- and 14C-radioactivity are measured. The residual plasma remaining in the pellet is determined from the 14C content and removed. The quantity of bound ligand is determined from the 3H content. The quantity of bound ligand is plotted against the concentration of the calibration curve plasma. The concentration of compound A in the Rhesus plasma is calculated from the quantity of bound ligand in the relevant plasma sample compared with the calibration curve.

[0074] The following Table contains the values found:

	conc. of A	conc. of A	conc. of A	conc. of A
compound	in [nM], 2 h	in [nM], 4 h	in [nM], 8 h	in [nM], 24 h
B	413	316	145	0

[0075] As the results show, after oral administration of 1 mg/kg of compound B to Rhesus monkeys, high plasma levels of the anti-thrombotically active compound A are maintained for a period of at least 8 hours.

[0076] For combating or preventing the illnesses mentioned above, the dose is between 0.1 μg and 30 mg/kg of body weight, preferably 1 μg to 15 mg/kg of body weight, administered up to 4 times a day. For this, the compounds of formula I prepared according to the invention may be formulated, optionally together with other active substances such as thromboxane-receptor antagonists and thromboxane synthesis inhibitors or combinations thereof, ADP receptor antagonists, clopidogrel, ticlopidine, serotonin antagonists, α-receptor antagonists, alkylnitrates such as glycerol trinitrate, phosphodiesterase inhibitors, prostacycline and their analogues, fibrinolytics such as tPA, prourokinase, urokinase, streptokinase, or anticoagulants such as heparin, dermatane sulphate, activated Protein C, vitamin K antagonists, hirudine, inhibitors of thrombin or other activated clotting factors, together with one or more inert conventional carriers and/or diluents, e.g. with corn starch, lactose, glucose, microcrystalline cellulose, magnesium stearate, polyvinylpyrrolidone, citric acid, tartaric acid, water, water/ethanol, water/glycerol, water/sorbitol, water/polyethyleneglycol, propyleneglycol, stearylalcohol, carboxymethylcellulose or fatty substances such as hard fat or suitable mixtures thereof, to produce conventional galenic preparations such as plain or coated tablets, capsules, powders, suspensions, solutions, sprays or suppositories.

[0077] The Examples that follow are intended to illustrate the invention:

Preparation of the Starting Compounds:

EXAMPLE I

[0078] N-(4-cyanophenyl)-acrylamide

[0079] Prepared by reacting 4-amino-benzonitrile with acrylic acid chloride in methylene chloride in the presence of triethylamine.

[0080] Melting point: 192-194° C. Rf value: 0.43 (silica gel; methylene chloride/methanol=20:1)

EXAMPLE II

[0081] 4-[2-[(4-cyanophenyl)aminocarbonyl]ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine

[0082] Prepared by reacting N-(4-cyanophenyl)-acrylamide and 1-[(ethoxycarbonyl)methyl]-piperazine in toluene at reflux temperature.

[0083] Rf value: 0.80 (silica gel; methylene chloride/methanol/conc. aqueous ammonia=9:1:0.1) Mass spectrum: (M+H)+=345

EXAMPLE III

[0084] 4-[2-[(4-amidinophenyl)aminocarbonyl]ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine-triacetate

[0085] Prepared by catalytic hydrogenation of 4-[2-[[4-(hydroxyamidino)phenyl]-aminocarbonyl]ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine in glacial acetic acid at 60° C. in the presence of palladium/charcoal.

[0086] Rf value: 0.27 (silica gel; methylene chloride/methanol/conc. aqueous ammonia=4:1:0.1) Mass spectrum: (M+H)+=362

Preparation of the End Products:

EXAMPLE 1

[0087] 4-[2-[[4-(octyloxycarbonylamidino)phenyl]aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine

[0088] 6.9 g of potassium carbonate are added to 5.4 g of 4-[2-[(4-amidinophenyl)aminocarbonyl]ethyl]-1-[(ethoxycarbonyl)methyl-piperazine-triacetate in 150 ml of acetone and 50 ml of water at 0° C. To this mixture 2.9 ml of octyl chloroformate in 10 ml of acetone are added dropwise, with stirring, at a temperature below 7° C. After stirring overnight at ambient temperature the mixture is diluted with water and the acetone is drawn off in vacuo. The residue is extracted with ethyl acetate, washed with saline solution, dried and evaporated down. The residue is purified by chromatography over a silica gel column with methylene chloride/methanol, to which some concentrated aqueous ammonia has been added.

[0089] Yield: 2.3 g (45% of theory), Melting point: 136-138° C. Rf value: 0.27 (silica gel; methylene chloride/methanol/conc. aqueous ammonia=9:1:0.1)

[0090] The following compounds are obtained analogously to Example 1:

[0091] (1) 4-[2-[[4-(hexyloxycarbonylamidino)phenyl]aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine

[0092] Melting point: 131-134° C. Mass spectrum: (M+H)+=490

[0093] (2) 4-[2-[[4-(methoxycarbonylamidino)phenyl]aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine

[0094] Melting point: 155-156° C. Mass spectrum: (M+H)+=420

[0095] (3) 4-[2-[[4-(benzoylamidino)phenyl]aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine

[0096] Melting point: 189° C. Mass spectrum: (M+H)+=466

EXAMPLE 2

[0097] 4-[2-[[4-(hydroxyamidino)phenyl]aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine

[0098] To a solution of 6 g of 4-[2-[(4-cyanophenyl)aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine in 50 ml of ethanol are added 2.4 g of hydroxylamine-hydrochloride and 4.8 ml of triethylamine and the mixture is refluxed for 3 hours. It is cooled, the precipitate is suction filtered, washed with ethanol and dried.

[0099] Yield: 5.1 g (77% of theory), Melting point: 182-183° C. Mass spectrum: (M+H)+=378

EXAMPLE 3

[0100] Tablet Containing 50 mg of Active Substance

[0101] Composition:

	(1)	Active substance	50.0 mg
	(2)	Lactose	98.0 mg
	(3)	Maize starch	50.0 mg
	(4)	Polyvinylpyrrolidone	15.0 mg
	(5)	Magnesium stearate	2.0 mg
			215.0 mg

[0102] Preparation:

[0103] (1), (2) and (3) are mixed together and granulated with an aqueous solution of (4). (5) is added to the dried granulated material. From this mixture tablets are pressed, biplanar, faceted on both sides and with a dividing notch on one side. Diameter of the tablets: 9 mm.

EXAMPLE 4

[0104] Tablet Containing 350 mg of Active Substance

[0105] Preparation:

	(1)	Active substance	350.0 mg
	(2)	Lactose	136.0 mg
	(3)	Maize starch	80.0 mg
	(4)	Polyvinylpyrrolidone	30.0 mg
	(5)	Magnesium stearate	4.0 mg
			600.0 mg

[0106] (1), (2) and (3) are mixed together and granulated with an aqueous solution of (4). (5) is added to the dried granulated material. From this mixture tablets are pressed, biplanar, faceted on both sides and with a dividing notch on one side. Diameter of the tablets: 12 mm.

EXAMPLE 5

[0107] Capsules Containing 50 mg of Active Substance Composition:

	(1)	Active substance	50.0 mg
	(2)	Dried maize starch	58.0 mg
	(3)	Powdered lactose	50.0 mg
	(4)	Magnesium stearate	2.0 mg
			160.0 mg

[0108] Preparation:

[0109] (1) is triturated with (3). This trituration is added to the mixture of (2) and (4) with vigorous mixing.

[0110] This powder mixture is packed into size 3 hard gelatine capsules in a capsule filling machine.

EXAMPLE 6

[0111] Capsules Containing 350 mg of Active Substance

[0112] Composition:

	(1)	Active substance	350.0 mg
	(2)	Dried maize starch	46.0 mg
	(3)	Powdered lactose	30.0 mg
	(4)	Magnesium stearate	4.0 mg
			430.0 mg

[0113] Preparation:

[0114] (1) is triturated with (3). This trituration is added to the mixture of (2) and (4) with vigorous mixing.

[0115] This powder mixture is packed into size 0 hard gelatin capsules in a capsule filling machine.

Claims

1. Phenylamidines of general formula

2. Phenylamidines of general formula I according to claim 1, wherein the substituted amidino group is in the 4 position, the tautomers, the stereoisomers and the salts thereof.

3. Phenylamidines of general formula I according to claim 2, wherein R6 denotes a hydroxy, C1-18-alkyloxycarbonyl, phenylcarbonyl or phenyl-C1-4-alkyloxycarbonyl group and R7 denotes a hydrogen atom, a C1-8-alkyl, C5-7-cycloalkyl or phenyl-C1-4-alkyl group, while the abovementioned phenyl moieties may in each case be mono- or disubstituted by R11, the substituents being identical or different, and R11 denotes a fluorine, chlorine or bromine atom, a C1-2-alkyl, trifluoromethyl or C1-2-alkoxy group, the tautomers, the stereoisomers and the salts thereof.

4. Phenylamidines of general formula I according to claim 2, wherein R6 denotes a hydroxy, C1-12-alkyloxycarbonyl, phenylcarbonyl or phenyl-C1-2-alkyloxycarbonyl group and R7 denotes a C1-8-alkyl or C5-7-cycloalkyl group, the tautomers, the stereoisomers and the salts thereof.

5. Phenylamidines of general formula I according to claim 2, wherein R6 denotes a hydroxy, C5-12-alkyloxycarbonyl, phenylcarbonyl or benzyloxycarbonyl group and R7 denotes a C1-4-alkyl or C5-6-cycloalkyl group, the tautomers, the stereoisomers and the salts thereof.

6. The following compounds according to claim 2:(1) 4-[2-[[4-(octyloxycarbonylamidino)phenyl]aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine, (2) 4-[2-[[4-(hexyloxycarbonylamidino)phenyl]aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine, (3) 4-[2-[[4-(methyloxycarbonylamidino)phenyl]aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine, (4) 4-[2-[[4-(benzoylamidino)phenyl]aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine and (5) 4-[2-[[4-(hydroxyamidino)phenyl]aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine and the salts thereof.

7. 4-[2-[[4-(octyloxycarbonylamidino)phenyl]aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine and the salts thereof.

8. 4-[2-[[4-(hexyloxycarbonylamidino)phenyl]aminocarbonyl]-ethyl]-1-[(ethoxycarbonyl)methyl]-piperazine and the salts thereof.

9. Physiologically acceptable salts of the compounds according to at least one of claims 1 to 8 with inorganic or organic acids or bases.

10. Pharmaceutical compositions containing a compound according to at least one of claims 1 to 8 or a physiologically acceptable salt according to claim 9 optionally together with one or more inert carriers and/or diluents.

11. Use of a compound according to at least one of claims 1 to 9 for preparing a pharmaceutical composition which is suitable for combating or preventing diseases in which smaller or larger aggregations of cells occur or cell-matrix interactions play a part.

12. Process for preparing a pharmaceutical composition according to claim 10, characterised in that by a non-chemical method a compound according to at least one of claims 1 to 9 is incorporated in one or more inert carriers and/or diluents.

13. Process for preparing the compounds of general formula I according to claims 1 to 9, characterised in that a. in order to prepare a compound of general formula I wherein R6 has the meanings given in claims 1 to 8 with the exception of the hydroxy group, a compound of general formula 8wherein R7 is defined as in claims 1 to 8, is acylated with a compound of general formulaZ1—R6′  (III),wherein R6′ has the meanings given for R6 in claims 1 to 8 with the exception of the hydroxy group and Z1 denotes a nucleofugic leaving group or, if R6′ denotes an arylcarbonyl group, Z1 may also denote a hydroxy group, or b. in order to prepare a compound of general formula I wherein R6 denotes a hydroxy group, a nitrile of general formula 9wherein R7 is defined as in claims 1 to 8, is reacted with hydroxylamine or the salts thereof and if necessary any protecting group using during the reactions is cleaved, and/or subsequently, if desired, a compound of general formula I thus obtained is separated into its stereoisomers and/or a compound of general formula I thus obtained is converted into the salts thereof, particularly, for pharmaceutical use, into the physiologically acceptable salts thereof.