Amidine derivatives, the preparation and use thereof as medicaments with LTB4 antagonistic effect

Abstract

Compounds of the formula 1

Description

[0001] The invention relates to new amidine derivatives, the preparation thereof using conventional methods and their use in pharmaceutical compositions.

[0002] The new amidine derivatives correspond to the formula 2

[0003] wherein

[0004] R1 and R2, which may be identical or different, denote CF3, halogen, R5, OR5, COR6, SR6, SOR6, SO2R6, SO2NR5R7, C(OH)R5R7 or together may also denote the double-bonded groups —CR8═CR9—CH═CH—, —CH═CR8—C9═CH—, —CR8═CH—CR9═CH—, —O—CHR10—CH2—, —O—CH2—O—, —O—CH2—CH2—O—, —(CH2)3-4—, —NH—CO—O—, —NH—CO—CH2—O—, —CO—CH2—O— or —CO—CH2CH2—O—, linked with adjacent carbon atoms of the benzene ring, whilst these groups nay in turn be substituted by C1-4-alkyl,

[0005] R3 denotes halogen, OH, CF3, R5, OR6, COR6, CONH5R7, CH2OH, CH2—O—(C1-4-alkyl), SR6, SOR6, SO2R6, SO2NR5R7, NH—CO—(C1-4-alkyl), NH—SO2—(C1-4-alkyl), NR5R7 or C(OH)R5R7 (whilst if R3 is the same as R5, R5 can only denote H if at least one of the substituents R1 and R2 does not denote H), a heterocyclic 5-membered ring having 1 to 3 heteroatoms and of the formula 3

[0006] (wherein D, E and G, which may be identical or different, denote CH, N, C—(C1-4-alkyl) or C-phenyl and L denotes O or S),

[0007] R4 denotes halogen, NH2, NH—(C1-4-alkyl), N(C1-4-alkyl)2, OH, C1-4-alkoxy,

[0008] R5 denotes H, C1-12-alkyl, phenyl, phenyl optionally substituted by halogen, C1-4-alkyl, C1-4-alkoxy or C2-5-acyl, or phenyl—(C1-4-alkyl),

[0009] R6 denotes C1-12-alkyl, phenyl, or phenyl optionally substituted by halogen, C1-4-alkyl, C1-4-alkoxy or C2-C5-acyl,

[0010] R7 denotes H or C1-12-alkyl,

[0011] R8, R9 (which may be identical or different) denote H, OH, C1-4-alkyl, C1-4-alkoxy or C2-5-acyl,

[0012] R10 denotes H or C1-4-alkyl,

[0013] R11, R12, which may be identical or different, denote H, OH, halogen, CF3, C1-4-alkyl or C1-4-alkoxy,

[0014] A denotes one of the groups

X1-A1-X2  (II)

X2-A2-X3  (III)

X4-A2-X2  (IV)

(CH2)1-2—NH—CO—(CH2)1-3—X2  (V)

—CH═CH-A2-X2  (VI)

[0015] 4

[0016] B

[0017] A1 denotes C2-4-alkylene, cis- or trans-CH2—CH═CH—CH2, CH2—C≡C—CH2 or 5

[0018] A2 denotes C1-5-alkylene,

[0019] X1 denotes O, NH, S, SO, SO2, CO, CH2 or 6

[0020] X2 denotes O, NH, S or —O— 7

[0021] X3 denotes NH—CO, CO—NH, SO2—NH or 8

[0022] X4 denotes NH—CO, CO—NH, NH—SO2, SO2—NH or NH—CO—NH, and (if they contain one or more chiral centres), may occur in the form of racemates, in enantiomerically pure or concentrated form, possibly as pairs of diastereomers and (if a double bond is present) in cis- or trans-form and as free bases or as salts, preferably with physiologically acceptable acids.

[0023] Within the scope of the above definitions, the preferred compounds are the compounds of formula 9

[0024] wherein

[0025] R1, R2, which may be identical or different, denote R7, OR7, COR6, halogen or together denote the double bonded groups —CR8═R9—CH═CH—, —CH═CR8—CR9═CH—, —O—CHR10—CH2— or —CO—CH2—CH2—O—, linked with adjacent carbon atoms of the benzene ring,

[0026] R3 denotes halogen, CF3, R7, OR7, CO—(C1-4-alkyl), NH—CO—(C1-4-alkyl), NHSO2—(C1-4-alkyl) or N(R10)2 (whilst R7 can only denote H if at least one of the substituents R1 and R2 does not denote H) or a heterocyclic five-membered ring such as 10

[0027] R6 and R7 are as hereinbefore defined, and

[0028] A denotes the group II.

[0029] The following may be particularly mentioned as examples of the group of formula —C6H2R1R2R3: 11

[0030] Of the definitions of A particular mention may be made of: 12

[0031] Special mention should also be made of the compounds of formula 13

[0032] wherein

[0033] a denotes 0 or 1,

[0034] b denotes 1 or 2,

[0035] R denotes C1-4-alkyl, and if a=0 or 1 and b=1, and if a=1 and b=2, R may also denote hydrogen, and

[0036] R preferably denotes CH3, C2H5 or H, and for a=1, b is preferably 1.

[0037] In the above definitions, the term halogen denotes F, Cl, Br or I, preferably F, Cl. If the groups listed are alkyl chains or contain alkyl chains, these may be straight-chained or branched. The alkyl chains in R5, R6 and R7 preferably contain up to 6 carbon atoms, more particularly 1 to 4 carbon atoms. In particular, as a constituent of COR6, R6 denoting alkyl may also be mono- or poly-fluorine-substituted. Particular examples of substituents of ring systems are alkyls such as methyl, ethyl and the propyl. A preferred acyl group is COCH3, a preferred alkoxy group is CH3O. The bridge A preferably contains 4 to 6 members. The group is arranged between the two ring systems in formula I and in corresponding formulae so as to correspond to the written form of formulae II to VI, whereas the groups which are valid for both R1 and R2 are not listed in the proper orientation. If R1 and R2 together denote a double bonded group, R3 preferably denotes H or C2-5-acyl, e.g. acetyl. The groups R1, R2 and R3 should not all simultaneously denote CF3, COR6, SR6, SOR6, SO2R6, SO2NR5R7 or C(OH)R5R7, but rather these groups as well as OR5, with the definition phenoxy or substituted phenoxy, preferably occur only once or possibly twice, whilst alkyl, acyl and halogen, in particular, may occur as further substituents. The bonds or CH2 groups in IX/IXa/IXb are generally in the α-position to one another. Typical groups for A are, for example, O—(CH2)2—O, O—(CH2)4—O, whilst one of the O-atoms may be replaced by S, NH or Co, as well as groups such as CH2—CH2—CONH, CH2—CH2—NH—CO, CO—NH—CH2—CH2 or NH—CO—CH2—CH2. The amidino group is usually in the para-position relative to the carbon atom to which A is linked.

[0038] The new compounds are prepared by conventional methods.

[0039] 1. Reaction of imidoesters of the formula 14

[0040] wherein R1 to R4, A and B are as hereinbefore defined and R preferably represents a C1-6-alkyl group or benzyl (but if desired the man skilled in the art can also use derivatives of other alcohols), and ammonia. The reaction is preferably carried out in an organic solvent at temperatures between about 0° C. and the boiling temperature of the reaction mixture, preferably between ambient temperature and about 100° C. or the boiling temperature, if this is lower. Suitable solvents are polar solvents such as methanol, ethanol and propanol.

[0041] If the starting materials are sufficiently acid-resistant the reaction may be carried out via the corresponding acid imide chlorides instead of the imidoesters.

[0042] 2. In order to prepare compounds of formula I wherein A is linked via O or S to at least one of the ring systems:

[0043] reaction

[0044] (a) of a phenol or thiophenol of formula 15

[0045]  wherein Z denotes OH or SH and R1, R2 and R3 are as hereinbefore defined, with a compound of the formula 16

[0046]  wherein A1, A2, B, R4, X2 and X3 are as hereinbefore defined and L represents a nucleofugic leaving group, or

[0047] (b) of a phenol or thiophenol of the formula 17

[0048]  wherein B, R4 and Z are as hereinbefore defined, with a compound of the formula 18

[0049]  wherein A1, A2, R1, R2, R3 and Z are as hereinbefore defined.

[0050] The reaction is carried out in aprotic solvents such as dimethylsulphoxide, dimethylformamide, acetonitrile or alcohols such as methanol, ethanol or propanol with the addition of a base (metal carbonates, metal hydroxides, metal hydrides) at temperatures between about 0 and 140° C. or the boiling temperature of the reaction mixture.

[0051] The phenols or thiophenols may also be used in the form of salts, e.g. alkali metal salts. Examples of suitable nucleofugic leaving groups include halogens such as Br and Cl.

[0052] 3. Reduction of an amidoxime of the formula 19

[0053] wherein A, B and R1 to R4 are as hereinbefore defined.

[0054] For the reduction of XIX it is appropriate to use catalytic hydrogenation, particularly with Raney nickel in a lower alcohol such as methanol. Conveniently, the amidoxime of formula XIX is dissolved in methanol, with the addition of the calculated amount of the particular acid the salt of which is the desired end product, and hydrogenated at ambient temperature under gentle pressure, e.g. up to 5 bar, until the uptake of hydrogen has ended.

[0055] The starting materials may be obtained from known compounds by conventional methods.

[0056] Thus, the starting materials for process 1 may be obtained from the corresponding nitriles by reacting them with HCl via the step of the imide chlorides or directly by reacting them with, for example, C1-6-alcohols or benzyl alcohol in the presence of an acid such as HCl. The reaction of the nitrites with H2S in solvents such as pyridine or dimethylformamide in the presence of a base such as triethylamine and subsequent alkylation or benzylation result in compounds of formula X. Starting from carboxylic acid amides, which moreover correspond to the compounds of formula X, compounds of formula X may also be obtained by reaction with a trialkyloxonium salt such as triethyloxonium tetrafluoroborate, in a solvent such as dichloromethane, tetrahydrofuran or dioxane at temperatures between 0 and 50° C., preferably at ambient temperature.

[0057] The starting materials XIX may also be obtained by reacting corresponding amidoximes instead of amidine analogously to method 1 or 2; by analogous reaction of corresponding nitrites from which the starting materials XIX are finally obtained by the addition of hydroxylamine.

[0058] The compounds according to the invention are therapeutically useful, particularly in the light of their LTB4-antagonistic activity. They are therefore suitable for use, particularly, in those diseases in which inflammatory and/or allergic processes are involved, such as asthma, ulcerative colitis, psoriasis and also for treating gastropathy induced by non-steroidal antiphlogistics. The new compounds may also be used in conjunction with other active substances, e.g. antiallergics, secretolytics, β2-adrenergics, steroids for inhalation, antihistamines and/or PAF-antagonists. They may be administered by topical, oral, transdermal, nasal or parenteral route or by inhalation.

[0059] The therapeutic or prophylactic dose is dependent on the nature and gravity of the disease, as well as the potency of the individual compounds and the body weight of the patient. For oral administration the dose is between 10 and 250 mg, preferably between 20 and 200 mg. For inhalation, the patient takes between about 2 and 20 mg of active substance. The new compounds may be administered in conventional preparations such as or coated tablets, capsules, lozenges, powders, granules, solutions, emulsions, syrups, aerosols for inhalation, ointments and suppositories.

[0060] The Examples which follow illustrate some possible formulations for the preparations.

FORMULATION EXAMPLES

[0061]

1. Tablets
Composition:
Active substance according to 20 parts by weight
the invention
Stearic acid                  6 parts by weight
Dextrose                      474 parts by weight

[0062] The constituents are processed in the usual way to form tablets weighing 500 mg. If desired, the content of active substance may be increased or reduced and the quantity of dextrose reduced or increased accordingly.

2. Suppositories
Composition:
Active substance according to 100 parts by weight
the invention
Powdered lactose              45 parts by weight
Cocoa butter                  1555 parts by weight

[0063] The ingredients are processed in the usual way to form suppositories weighing 1.7 g.

[0064] 3. Powder for inhalation

[0065] Micronised powdered active substance (compound of formula I; particle size about 0.5 to 7 μm) is packed into hard gelatine capsules in a quantity of 5 mg, optionally with the addition of micronised lactose. The powder is inhaled using conventional inhalation devices, e.g. according to DE-A 3 345 722.

[0066] The compounds according to the invention were tested inter alia for their activity in the tests described below.

[0067] a) U937—Receptor Binding Test/LTB4

[0068] The binding of 3H-LTB4 (3 nM) to vital U937 cells (differentiated human monocytary cell line with naturally expressed LTB4 receptors) is inhibited, in dosage dependent manner, by an increasing concentration of the test substance (incubation 2 hours at 0° C.). After the unbound 3H-LTB4 has been separated off by membrane filtration, the radioactivity of the bound LTB4 receptor/3H-LTB4 g complex is quantified by scintillation measurement. The affinity (inhibition constant Kl) was determined by repeated adaptation of a displacement curve to the measurements (program: “coupled mass equilibria” on Wang computer).

[0069] b) Aggregation of Neutrophilic Granulocytes in the Guinea-Pig

[0070] Indicated by LTB4 in vitro (increase in light transmission in the aggregometer, recorded in mm; each experiment repeated twice): inhibition 2 minutes after incubation with test substance in polydiol/DMSO.

[0071] c) Leukotrien-B4-Indicated Accumulation of Neutrophiles in the Mouse Ear

[0072] Evaluation of the neutrophilic influx by photometric measurement (mOD/min) of the myeloperoxidase activity (Bradley et al.: J. Invest. Dermatol. 78, 206, 1982) in the skin of the ear. Increase 6 hours after topical treatment of the left ear with LTB4 (250 ng on each side) compared with the right ear (2×5 μl acetone as solvent).

[0073] Substance administered by oral route in 1% tylose 300, 30 minutes before the LTB4 stimularion.

4. Results
	a)*	b)**	c)***
20	12.0	1.9	0.8
21	3.8  6.3	0.06 0.31	1.2 0.9
R = H
R = CH3
22	1.7 15.0	0.02 0.32	3.8 2.3
R = H
R = CH3
*Receptor binding U937-8 Ki [nM] (1)
**LTB4-induced neutroph. Aggr. EC50 [μM] (2)
***LTB4-induced neutroph. Accum. p.o. ED50 [mg/kg]

[0074] The 3H-LTB4-receptor binding to guinea-pig spleen cells, in the presence of 10% blood plasma yielded Kl-values of, in some cases, far less than 1 μM, more particularly between 0.2 and 0.02. Inhibition of the LTB4-induced aggregation of neutrophiles resulted in EC50-values between about 0.5 and 0.05 μM.

[0075] Particular mention should be made of the compounds according to Examples 1 and 5 and Nos. 10, 11, 13, 19, 20, 22 and 23 from Table I, No. 1 from Table II, No. 2 from Table III.

[0076] The Examples which follow illustrate the possible methods of preparing the-compounds according to the invention.

[0077] Process 1:

Example 1

[0078] 23

[0079] To a solution of 2.0 g of 7-[4-(4-cyano-phenoxy)-E-but(2 )-enyloxy)]-8-propyl-4H-1-benzopyran-4-one in 50 ml of chloroform and 1.5 ml of ethanol are added 5 ml of a solution of hydrogen chloride in diethylether (17%). The mixture is left to stand for 14 days at ambient temperature and the product is precipitated with diethylether. 1.15 g of 7-[4-(4-imidacarboxyethyl-phenoxy)-E-but (2)-enyloxy]-8-propyl-4H-1-benzopyran-4-one-hydrochloride are obtained. The imidoester is mixed with 50 ml of ethanolic ammonia solution (5 M) and heated for 3 hours to 70° C. The mixture is evaporated down and the residue is chromatographed (chloroform/methanol 7:3, silica gel). After recrystallisation from dichloromethane/diethylether, 0.6 g of 7-[4-(4-amidino-phenoxy)-E-but(2)-enyloxy]-8-propyl-4H-1-benzopyran-4-one-hydrochloride are obtained (m.p. 144-148° C.).

Example 2

[0080] To a solution of 2.5 g of 4-[4-(2-propyl-3-methoxy-phenoxy)-butyloxyl-benzonitrile, prepared from 2-propyl-3-methoxy-phenol and 4-bromobutoxybenzonitrile- in 40 ml of ethanol, hydrogen chloride is introduced at −20° C. with stirring for 1 hour and the mixture is left to stand at ambient temperature for 16 hours.

[0081] The solvent is distilled off in vacuo and the residue is taken up in 50 ml of ethanol. A mixture of 14 ml of ethanolic ammonia solution and 50 ml of ethanol is added dropwise thereto and the mixture is left to stand for 24 hours at ambient temperature. The solvent is evaporated off and the residue is chromatographed (chloroform/methanol 8:2; silica gel 60). 1.8 g of 4-[4-(2-propyl-3-methoxy-phenoxy)-butyloxy]-benzamidine-hydrochloride-hemihydrate are obtained. (M.p. 117-121° C.).

Example 3

[0082] 24

[0083] Hydrogen chloride is introduced at −20° C. into a solution of 32.0 g of 4-((4-acetyl-2-isopropyl-5-methyl-phenoxy)-butyloxy]-benzonitrile in 350 ml of ethanol and the resulting mixture is stirred for 48 hours. The crystals precipitated are suction filtered and washed with diethylether. 41.0 g of 4-[4-(4-acetyl-2-isopropyl-5-methyl-phenoxy)-butyloxy]-benzimidoethylester-hydrochloride are obtained (m.p. 100-102° C. decomp.). 15.0 g of the imidoester are added at ambient temperature in several batches to 33 ml of ethanolic ammonia solution (5 M) and 100 ml of ethanol. The mixture is stirred for 36 hours at ambient temperature, evaporated down and the residue is stirred with 50 ml of water. The residue is suction filtered, recrystallised from 30 ml of ethanol and washed with diethylether. 11.5 g of 4-[4-(4-acetyl-2-isopropyl-5-methyl-phenoxy)-butyloxy]-benzamidine-hydrochloride are obtained (m.p. 182-183° C. decomp.).

Example 4

[0084] 25

[0085] Hydrogen chloride is introduced at −20° C. into a solution of 3.0 g of 4-[4-(4-cyano-phenoxy)-butylamino]-acetophenone in 40 ml of ethanol, with stirring, for 4 hours and the mixture is left to stand at ambient temperature for 16 hours. The solvent is distilled off in vacuo and the residue is taken up in 50 ml of ethanol. A mixture of 14 ml of ethanolic ammonia solution and 50 ml of ethanol is added dropwise thereto and the mixture is left to stand for 24 hours at ambient temperature. The solvent is evaporated off and the residue is chromatographed (chloroform/methanol 7:3, silica gel 60). 0.3 g of 4-[4-(4-amidino-phenoxy)butylamino]-acetophenone are obtained (m.p. 200-202° C.).

[0086] Process 2:

Example 6

[0087] 26

[0088] 8.2 g of 4-acetyl-3-methoxy-2-propyl-phenol are dissolved in 80 ml of dimethylformamide and 1.1 g of sodium hydride is added in batches to the solution (as an 80% dispersion in white oil). The mixture is heated to 80° C. for 30 minutes and combined with a solution of 5.75 g oft 4-(4-bronopropylthio)-benzamidine (prepared from dibromobutane and 4-cyanobenzothiol by means of 4-(4-bromobutyl-thio)-benzonitrile) in 40 ml of dimethylformamide. After 5 hours at 80° C. the mixture is allowed to cool, acidified with ethereal hydrochloric acid and the solvents are distilled off in vacuo. The residue is taken up in ethanol and filtered. The filtrate is concentrated by evaporation. The process is repeated with chloroform and acetonitrile. The residue is stirred with diethylether. After decanting, 5.65 g of a brownish-yellow oil are left. The product is chromatographed (chloroform/methanol 7:3, silica gel). 2.4 g of an oil are obtained which is crystallised from toluene. The product is dissolved in acetonitrile, acidified with ethereal hydrochloric acid. The crystals are suction filtered, washed with cold acetonitrile, dissolved in water and crystallised once more after the addition of 2 N hydrochloric acid. 0.8 g of 4-[4-4-acetyl-3-methoxy-2-propylphenoxy)-butylthio]-benzamidine-hydrochloride are obtained (m.p. 120-122° C.).

[0089] Process 3:

Example 7

[0090] a) 4-[4-(4-Acetylphenoxy-butoxy]-benzamidoxime

[0091] 45.6 g (0.3 mol) of 4-hydroxybenzamidoxime and 81.3 g (0.3 mol). of 4-bromo-butoxy-acetophenone are dissolved in 300 ml of dimethylformamide. After the addition of 55.2 g (0.4 mol) of anhydrous potassium carbonate the mixture is heated to 80° C. for 2 hours. The inorganic salts are suction filtered, evaporated down in vacuo and recrystallised from acetonitrile.

[0092] Yield: 47.8 g

[0093] M.p.: 164.5-165.5° C.

[0094] b) 3-[4-(4-Acetylphenoxy)butoxy]-benzamidine-methanesulphonate

[0095] 47.8 g of the compound synthesised according to a) are dissolved in 10 times the quantity of methanol with the addition of the calculated amount of methanesulphonic acid. After the addition of Raney nickel, the mixture is hydrogenated at 5 bar until the uptake of hydrogen has ended. The mixture is suction filtered, the solvent is distilled off in vacuo and the residue is recrystallised from ethanol.

[0096] Yield: 45.2 g

[0097] M.p.: 204-204.5° C.

[0098] The-other-compounds of formula I can be obtained according to the processes described above. “Ac” hereinafter denotes CH3CO—.

TABLE I
Compounds of formula
27
			M.p.[° C.]
			(Hydro-
No.	Ra	b	chloride)
1	28	2	240
2	29	2	209-10
3	30	4
4	31	4	143
5	32	4	124
6	33	4	190
7	34	4	199-4
8	35	4	189
9	36	4	125-31
10	37	4	148-50
11	38	4	132-40
12	39	4	160-3
13	40	4	160-5
14	41	4	228-31
15	42	4	140-6
16	43	4
17	44	4	170-2
18	45	4	149-50
19	46	4	167 (decomp.)
20	47	4	179
21	48	4	168-70
	CH3
22	49	4	187 (decomp.)
23	50	4	166-8
24	51	4
25	52	4
26	53	4
27	54	4
28	55	4
29	56	4	174-5
30	57	4	155-60
31	58	4	194-60
32	59	4	214-23
33	60	4
34	61	4
35	62	4	145-8
36	63	4	128-31
37	64	4
38	65	4
39	66	4
40	67	4	194
41	68	6	132
42	69	4
43	70	4
44	71	4

[0099]

TABLE II
Compounds of formula
72
					M.p.[° C.]
No.	B	R1	X1	X2	(Hydrochloride)
1	CH═CH	Ac	O	S
2	CH═CH	Ac	O	SO
3	CH═CH	Ac	O	SO2	160-2 (Base)
4	CH═CH	Ac	S	S
5	N═CH	Ac	O	S	152-60
6	CH═CH	Ac	O	NH	200-2
7	CH═CH	Ac	S	O	196-
8	CH═CH	Ac	SO	O
9	CH═CH	Ac	SO2	O	208

[0100]

TABLE III
Compounds of formula
73
				M.p.[° C.]
No.	A′	X′1	X′2	(Hydrochloride)
1	CH2—CH═CH—CH2	O	O	215-8
2	74	O	O	196-202
3	75	O	O	205-9
4	76	O	O	183

[0101]

TABLE IV
Compounds of formula
77
					M.p.[° C.]
No.	Rb	R1	R2	R4	(Hydrochloride)
1	78	H	H	H
2	79	H	H	H	174-6
3	80	n-C3H7	OCH3	2-OCH3	124-7
81
No.	R	a	b	M.p.[° C.]
1	H	0	1	178-80 (Hydrochloride)
2	H	1	1	248-51 (Hydrochloride)
3	H	1	2
4	CH3	0	1	176-8 (Hydrochloride)
5	CH3	1	1	236-40 (Methanesulphonate)
6	C2H5	0	1
7	C2H5	0	2
8	n-C3H7	0	2
9	n-C3H7
10	i-C3H7	1	1
11	n-C4H9	0	1	144-7 (Hydrochloride)
12	n-C4H9	0	2

Claims

1. Compounds of the formula

2. Compounds of the formula

3. Compounds according to claim 1 or 2, wherein R1/R2/R3 have the meanings C2-5-acyl/H/H; C6H5CO/H/H; C1-4-alkyl/OH/H; C2-5-acyl/C1-4-alkyl/H; C2-5-acyl/OH/C1-4-alkyl; OH/C2-5-acyl/C1-4-alkyl.

4. Compounds according to claim 1 or 2 characterised in that A denotes O—(CH2)2—O, O—(CH2)4—O or 92

5. compounds according to claim 1 or 2 characterised in that the group II is acetylphenyl.

6. Compounds according to claim 1 or 2 characterised in that the group

7. Compounds of the formula

8. Compounds according to claim 7, wherein a=0 or 1 and b=1 or a=0 and b=2 as free bases or as acid addition salts.

9. Compounds according to claim 8, wherein R denotes H, CH3, or C2H5, a denotes 0 or 1 and b denotes 1, as free bases or as acid addition salts.

10. Compounds according to claim 8, wherein a denotes 0, b denotes 2 and R denotes CH3, as free bases or as acid addition salts.

11. Pharmaceutical compositions, characterised in that they contain a compound according to claims 1, 2 or 7.

12. Use of compounds according to claims 1, 2 or 7 in the preparation of pharmaceutical compositions for the treatment of diseases in which inflammatory and/or allergic processes are involved, especially asthma, ulcerative colitis, psoriasis and for treating gastropathy induced by non-steroidal antiphlogistics.

13. Use of an effective dose of a compound according to claims 1, 2 or 7 for treating diseases in which LTB4-antagonistic compounds can be used.

14. Use of an effective dose of a compound according to claims 1, 2 or 7 for the treatment of diseases in which inflammatory and/or allergic processes are involved, particularly asthma, ulcerative colitis, psoriasis, and for treating gastropathy induced by non-steroidal antiphlogistics.

15. Process for preparing compounds according to claims 1, 2 or 7 characterised in that a) an imidoester of the formula 95 wherein R1 to R4, A and B are as hereinbefore defined and R preferably represents a C1-6-alkyl group or benzyl, is reacted with ammonia, or b1) a phenol or thiophenol of the formula 96 wherein Z denotes OH or SH and R1, R2 and R3 are as hereinbefore defined, is reacted with a compound of formula 97 wherein A1, A2, B, R4, X2 and X3 are as hereinbefore defined and L denotes a nucleofugic leaving group, or b2) a phenol or thiophenol of formula 98 wherein B, R4 and Z are as hereinbefore defined, is reacted with a compound of formula 99 wherein A1, A2, R1, R2, R3 and Z are as hereinbefore defined; or c) an amidoxime of the formula 100 wherein A, B and R1 to R4 are as hereinbefore defined, is reduced to form the corresponding amidine.