WO1997021725A1 - 3-aminoethyl-n-amidino-2,5-dihydropyrrole derivatives having arginine mimetic properties - Google Patents

Abstract

The present invention ocncerns new amidinopyrroline derivatives of formula (I) with the meanings of the symbols as given in the description as well as a process for their production and their use in pharmaceutical preparations.

Description

3-AMINOETHYL-N-AMIDINO-2,5-DIHYDROPYRROLE DERIVATIVES HAVING ARGININE MIMETIC PROPERTIES

The present invention concerns new amidinopyrroline derivatives, processes for their production and their use thereof in pharmaceutical preparations

It was found that compounds of the general formula (I) have the properties of an arginine mimetic. Arginine mimetics are pharmacophores which can replace arginine or an arginyl residue for example in inhibitors. Derivatives of (I) can replace arginine or already known arginine mimetics in biologically active substances and especially in therapeutically active substances. In particular they can be used in inhibitors for serine proteases such as thrombin or trypsin inhibitors. Inhibitors of thrombin inhibit the thrombin induced coagulation of fibrinogen in blood as well as the thrombin induced aggregation of blood platelets. Thus they prevent the formation of coagulation thrombi and platelet-rich thrombi and can be used to treat and prevent diseases such as thromboses, apoplexy, cardiac infarction, inflammations and arteriosclerosis

Thrombin the last enzyme of the coagulation cascade cleaves fibrinogen to fibrin which is cross-linked by factor XIII and becomes an insoluble gel which forms the matrix for a thrombus. Thrombin activates platelet aggregation by proteolysis of its receptor on the blood platelets and in this manner also contributes to thrombus formation. When blood vessels are damaged these processes are necessary to stop bleeding. Under normal circumstances no measurable thrombin concentrations in blood plasma are present. An increase of the thrombin concentration can lead to the formation of thrombi and thus to thromboembolic diseases which occur very frequently above all in industrial countries. Thrombin is kept ready in the plasma in the form of prothrombin and is released from this by factor Xa. Thrombin activates factors V, VIII and XI which then convert factor X into Xa. By this means thrombin catalyses its own release which is why very rapid increases in thrombin concentrations can occur. Thrombin inhibitors and factor Xa inhibitors can therefore inhibit the release of thrombin, and the platelet induced and plasmatic blood coagulation Trypsin is a digestive enzyme which is excreted by the pancreas when required. When the pancreas is damaged or inflamed the trypsin release which this causes can lead to tissue destruction. Trypsin inhibitors can reduce this threat and be used for instance to treat pancreatitis.

In addition such arginine mimetics can be incorporated into active substances which are able to inhibit the binding of ligands that bind to their receptor via sequences containing RGD. R.GD stands for the tripeptide Arg-Gly-Asp. Such ligands are for example fibrinogen, vitronectin or fibronectin. Such active substances can be used to treat diseases which are due to thrombo-embolic events such as stroke, myocardial infarction or arterial occlusive diseases as well as inflammations, osteoporosis or tumour diseases.

The invention concerns compounds which contain the structural element I as a pharmacophore as well as modifications known to a person skilled in the art which can be derived from the parent substance of structure I,

in which R 1 , R2 and Y can be the same or different and denote hydrogen or an organic residue. Preferred organic residues are such which result in a biological active compound of general formula I. Biological active means inter alia substances for plant protection and preferred pharmacological active compounds. Prodrugs of such biological active compounds are also included in the preferred structures of formula I. Prodrugs are substances which will be metabolized in vivo into the biological active compound. An example, but not a limitation for prodrugs are esters which will be converted to free acids by the organism e g by the liver metabolism.

Especially preferred are such derivates of compounds of the general formula I, wherein an arginine substructure or a known arginine mimetic substructure in a biological active sustance is substituted by the backbone structure of formula I' or I" .

wherein the jagged bonds represent in said bioiogical active compound the positions of the optional chemical bonds of the arginine or known arginine mimetic substructure which is substituted by the arginine mimetic structure (I') or (I") of the invention. A collection of pharmacological active compounds can be found in data bases for INNs (International Nonproprietary Names) which are hereby incorporated by reference.

In particular compounds of the general formula (I) are preferred

in which R 1 , R2 denote hydrogen, an amino acid, peptidyl, alkylsulfonyl or arylsulfonyl residue,

Y denotes hydrogen or a residue of the formula COX,

X denotes hydrogen or an OR3 or NR1 'R2' residue,

R3 denotes hydrogen or lower alkyl such as methyl, ethyl, propyl or butyl preferably ethyl and

R1', R2' can be the same or different and have the meanings of the residues R 1 and

R2.

Amino acid residue usually denotes the residue of a natural or unnatural amino acid. Unnatural amino acids are understood as α-, β-, γ- and ω-aminocarboxylic acids as well as derivatives thereof. Derivatives are in particular understood as compounds which are alkylated on the amino group or the carboxy group . Derivatives are also included which are either decarboxylated or deaminated. Examples of such amino acids and derivatives thereof are stated in the examples and preferred compounds In particular these are D-amino acids, citrulline, homocysteine, homoserine, hydroxyproline, hydroxylysine, ornithine, sarcosine, tranexamic acid , Adc [3-(2-aminoethyl)-2, 5 dihydropyrrol-1 -yl]-carbamidine], Ada [( 1 -amidino-2,5-dihydro- 1 H-pyrrol-3-yl)-alanine], Cha [cyclohexyl-alanine], Choi [2-carboxy-6-hydroxy-octahydroindol], norLeu(cyclo)-Gly [3-amino-2-oxo-hexahydro- 1 -azepineacetic acid], Pcs [4-piperidine carboxylic acid], Pip [pipecolic acid], Pla [phenyllactic acid], N-Me-Phe, HOOCCH2-Phe, HOOCCH2-Cha, 1 -carboxy-perhydroisoquinoline, N-cyclopentylglycine, EtSO2-Phe, N-(BuSO2-NorLeu(cyclo)-Gly.

A peptidyl residue is understood as a residue composed of any desired number of natural or unnatural identical of different amino acids. Peptidyl residues with 1 -50 amino acids are preferred and those with 1 , 2, 3 or 4 amino acids are particularly preferred .

Alkyl usually denotes a linear or branched alkyl residue with one to six carbon atoms. Aryl usually denotes a carbocycle with 6 to 14 C atoms or a 5- or 6-membered heterocycle with 1 , 2 or 3 heteroatoms selected from O, N or S. Unsubstituted or optionally substituted phenyl or naphthyl residues are preferred.

The arginine mimetic (I) in which R1 and R2 denote hydrogen is produced by well-known methods. Production from the precursor (II) is advantageous.

in which the primary amino group is protected preferably by reaction with phthalic acid anhydride to form the phthalimide, then the secondary amino group is amidated preferably by the methods described in Bannard et al., Can. J. Chem. 1958, 1 54 1 and subsequently the phthalimido group is cleaved preferably by hydrazine hydrate and subsequent treatment with hydrochloric acid. Compounds of the formula (I I ) in which Y denotes hydrogen can be produced by a) reducing the amide group of a compound of formula (III),

preferably with lithium aluminium hydride or lithium borohydride in the presence of trimethylchlorosilane or b) by rearranging the exocyclic double bond of a compound of the general formula (IV)

in which R5 denotes a protecting group for example a benzoyl group, an

alkvloxycarbonyl group or a benzyloxy-carbonyl group into the isomei with an endocyclic doubie bond and subsequently cleaving the protecting groups. The rearrangement of the exocyclic double bond to the endocyclic double bond is carried out in the presence of lyes preferably sodium hydroxide solution as described analogously in M. I. Labouta et al., Acta Chem. Scand. Ser. B. 1982, 669 - 674. This is followed by the cleavage of the protecting groups R5 and of the phthalimido group. c) to use the process as shown in scheme 1

To Scheme 1 a) NaBH₃CN/MeOH/RT

b) PhCOCI/Py/DMAP/RT;

c) DBU/toluene/RT/16h;

d) DIBAL-H/THF/-78 °C;

e) Ac₂O/Py/DMAP/0 °C;

f) Di-methyl-malonate/Pd(PPh₃)₄/THF/20h reflux;

g) DMF/NaCl/H₂O/ 1 50 °C/30 mm

h) LiOH/MeOH/H₂O/l N HCl

i) Diphenyl-phosphoryl-azide/THF/NEt₃/80 °C, 12 h, Cl₃CCH₂OH/THF/CuCl/2h reflux

j) 4 N H Cl/16 h; (23) (scheme 2)/EtN(i-Pr)₂

k) Zn/AcOH/RT

l) 4 N HCl in dioxane

Compounds of the general formula (II) in which Y denotes a carboxyl group can be produced according to the process outlined in schemes 2 or 3.

The compound (III) is produced from compounds of the general formula (XIV)

wherein R5 has the above-mentioned meanings with a reagent that activates the carboxyl group for example thionyl chloride or chloroformic acid isobutyl ester followed by aminonia. Subsequently the protecting group R5 is cleaved preferably with hydrochloric acid in dioxane or with trifluoroacetic acid or with hydroden bromide in glacial acetic acid. Compounds of the general formula (XIV) are known for example from M. I. Labouta et al., Acta Chem. Scand. Ser. B, 1982, 669 - 674 or can be produced by the processes described in this publication.

The compounds of the general formula (IV) are produced by reacting compounds of the general formula ( XV) with the compound (XVI) according to a Wittig reaction

wherein R denotes for a protecting group.

This Wittig reaction and the reagent (XVI ) are described in Ch. Sellier et al., Liebigs Ann Chem 1992, 3 1 7 - 324. The compounds (XV) are described in A. G. Schultz, Tetrahedron 1980, 1 757 - 1 761. Comments on scheme 2

╌ R3 and R5 have the above-mentioned meanings;

╌R6 denotes an alkyl or aryl residue such as a methyl, ethyl, trifluoromethyl, phenyl, tosyl or 4-nitro-phenyl residue, preferably a methyl or tosyl residue.

╌ L usually denotes a sulfonic acid residue such as a methanesulfonic acid, trifluoromethanesulfonic acid or p-toluenesulfinic acid residue, or a halogen such as chlorine, bromine, iodine or actate;

╌ MHal denotes a metal halogenide such as NaCl, NaBr, KI, MgCl2 or MgBr2, ╌ compounds of formula (V) are described in Timothy L. et al., J Org. Chem 48,

1129-1131 (1983),

╌ Conversion of an alcohol of formula (V) into a sulfonic or acetic acid ester of formula (VI) is achieved by standard methods of organic chemistry

╌ The conversion of an alcohol of formula (V) into a halogenide of formula (VI) by means of N-chloro-succinimide, N-bromosuccinimide or N-iodosuccinimide (NCS,

NBS, NIS) in the presence of triphenylphosphine (Ph3P) is carried out analogously to corresponding literature methods (e.g. Rozwadowska M. D, Tetrahedron Asym, 4, 1619-1624 (1993));

╌ A compound of formula (X) is converted into a compound of formula (II) by means of Claisen rearrangement analogously to methods which are described in Kazmaier U et al., Tetrahedron 52, 941-954 ( 1996),

╌ The epoxide opening of an epoxide of formula (XII) to form an allvl alcohol of formula (XI) is carried out under conditions which are described in Joshi V S et al. Tetrahedron, 24, 587-5830 (1968),

╌ Compounds of formula (XIII) are described in Grubbs H. etal., J. Am Chem Soc. , 114, 7324-7325 (1992);

╌ The decarboxylation of malonic esters by means of metal halogenides in

dimethylsulfoxide and at a high temperature is described in Krapcho A. P. et al., Tetrahedron Lett 957(1973).

To Scheme 3 a) 4 N HCl/ 1 6 h, (23)/EtN(i-Pr)₂

b) (24 )/HMDS/n-BuLi/- 78 °C

c) I N HCl/THF/RT/30 min

d) Boc₂O/EtN(i-Pr)₂/acetonitrile/ 16 h

e) LiOH/THF-MeOH-H₂O

f) 4 N HCl in dioxane

g) CI₃CCH₂OCOCl/DMAP/Py/RT/12 h

h) Zn/AcOH/RT

Some of the compounds of the general formula (I ) have one or several asymmetric centres. Hence optically active forms are also a subject matter of the invention as well as tautomers.

The invention also concerns all salts of compounds of the general formula ( I) Salts are primarily the acid addition salts. Physiologically acceptable salts come mainly into consideration for pharmaceutical purposes. Examples of salts of the compound of formula ( I ) which can be used physiologically are salts with physiologically tolerated mineral acids such as hydrochloric acid, sulfuric acid, sulfurous acid or phosphoric acid or with organic acids such as methane-sulfonic acid, p-toluenesulfonic acid, acetic acid, trifluoroacetic acid, citric acid, fumaric acid, maleic acid, tartaric acid, succinic acid or salicylic acid. For the production of pharmaceutical agents the substances of the general formula ( I ) and their salts are admixed with suitable pharmaceutical carrier substances, aromatics, flavourings and dyes and are for example formed as tablets or dragees or are suspended or dissolved in water or oil for example in olive oil with addition of appropriate auxiliary substances.

The substances of the general formula ( I ) and their salts can be administered enterallv or parenterally in a liquid or solid form. Water is preferably used as the injection medium which contains the usual additives in injection solutions such as stabilizing agents, solubilizers or buffers. Such additives are for example tartrate and citrate buffer, complexing agents (such as ethylenediamine tetraacetic acid and non-toxic salts thereof) and high molecular polymers such as liquid polyethylene oxide to regulate viscosity. Solid carriers are e.g. starch, lactose mannitol, methylcellulose talcum, highly-dispersed silicic acids, high molecular fatty acids (such as stearic acid) animal and vegetable fats and solid high molecular polymers (such as polyethylene glycols) Preparations which are suitable for oral administration can optionally contain flavourings and sweeteners.

The compounds are usually administered in amounts of 10- 1 500 mg per day with regard to 75 kg body weight. It is preferred to administer 1 -2 tablets with a content of active substance of 5-500 mg 2-3 times per day. The tablets can also be retarded in which case only 1 -2 tablets with 20-700 mg active substance have to be administered once per day. The active substance can also be applied by injection 1 -8 times per day or bv continuous infusion in which case 50-2000 mg per day are usually adequate.

Description of the figures

Fig I Spatial structui e of Adc from D-Pla-D-Phe-L-Choi- Adc (thick rods) in the enzyme trypsin (thin rods) from the X-ray structure of example 2. The spatial structure of the inhibitor DFPR in human thrombin is superimposed over this

(inhibitor: thin rods with spheres, thrombin thin lines). The sphere represents a water molecule.

The following abbrev iations are used in the examples:

Ac = acetyl

Ada = ( 1 -amidino-2,5-dihydro- 1 H-pyrrol-3-yl)-alanine

Adc = [3-(2-aminoethyl)-2,5-dihydropyrrol- 1 -yl]-carbamidine

Asp = aspartic acid

Bn = benzyl

Boc = tert butyloxvcarbonyl

Bu = butyl

Cbz = benzyloxycarbonvl

Cha = cyclohexylalanme

Choi = 2-carboxy-6-hydroxy-octahydromdole

DBU = 1 ,8-diazabicyclo[5.4.0]undec-7-ene

DIBAL-H = di-isobyle aluminum hydride

DMAP = 4-Dimethylaminopyridine DMF = dimethylformamide

eq = equivalent

Et = ethyl

Fmoc = 9-Fluorenylmethoxycarbonyl

Gly = glycine

HMDS = hexamethyldisilazane

i-Pr = iso-propyl

Me = methyl

NMM = N-methylmorpholine

norLeu(cyclo)-Gly = 3-amino-2-oxo-hexahydro- 1 -azepine-acetic acid

Pcs = 4-piperidine carboxylic acid

Ph = phenyl

Phe = phenylalanine

Pip = pipecolic acid

Pla = phenyllactic acid

Pmc = 2,2,5,7,8-pentamethylchroman-6-sulfonyl

Pro = proline

Py = pyridine

Ser = serine

t-Bu = tert -Butyl

TBTU = 2-( 1 H-benzotriazol- 1 -yl )- 1 ,1,3,3-tetramthyluronium letrafluorborate

TCP = Tritylchloride-polystyrene

TΗF = tetrahydrofuran

Troc = 2,2,2-Trichlorine-ethoxycarbonyl

Tyr = tyrosine

Trp = tryptophane

t_R = retention time

Val = valine The C,N,O-backbone of Ada and Adc are the backbone siiuctures w hich substitute the arginine or arginine mimetica structure in biological active substances of the invention, wherein OH-function of the carboxylic acid group of Ada may be replaced by another backbone atom, e.g. C, N or S. Apart from the compounds mentioned in the examples and compounds derived by combining all meanings of the substituents stated in the claims the following are preferred within the sense of the present invention: 1. N-Me-D-Phe-Cha-Adc

2. HOOCCH2-D-Phe-Pro-Adc

3. HOOCCH2-D-Cha-Pip-Adc

4. 1-Carboxy-perhydroisoquinolinyl-Pro-Adc

5. 1-Carboxy-perhydroisoquinolinyl-N-cyclopentyl-Gly-Adc

6. EtSO2-D-Phe-Pro-Adc

7. EtSO2-D-Phe-N-cyclopentyl-Gly-Adc

8. N-(BnSO2-norLeu(cyclo)-Gly-Adc

9. 3-({3-[2-(1-Amidino-2,5-dihydro-1H-pyrrol-3-yl)-ethyl]-2,4-dioxo-1,2,3,4-tetrahydro-quinazolin-6-carbonyl}-amino)-propionic acid

10. (4-{3-[2-(1-amidino-2,5-dihydro-1H-pyrrol-3-yl)-ethyl]-2-oxo-oxazolidin-5-ylmethoxy}-phenyl)-acetic acid

11.3-({1-[2-(1-Amidino-2,5-dihydro-1H-pyrrol-3-yl)-ethylcarbamoyl]-piperidin-3-carbonyl}-amino)-3-pyridin-2-yl-propionic acid

12. (4-{[2-(1-Amidino-2,5-dihydro-1H-pyrrol-3-yl)-ethylamino]-acetyl}-3-methoxycarbonylmethyl-ptperazin-1-yl)-acetic acid

13. [4-({[2-(1-Amidino-2,5-dihydro-1H-pyrrol-3-yl)-ethyl]-methylamino}-acetyl)-phenoxy]-acetic acid

14. {7-[2-(1-Amidino-25-dihydro-1H-pyrrol-3-yl)-ethylcarbamoyl]-3-oxo-4-phenethyl-2,3,4,5-tetrahydro-1H-benzo[e][1,4]diazepin-2-yl}-acetic acid

15.3-(4-{3-[2-(1-Amidino-2,5-dihydro-1H-pyrrol-3-y|)-ethyl]-2-oxo-imidazolidin-1-yl}-phenyl)-propionic acid

16.4-{3-[2-(1-Amidino-2,5-dihydro-1H-pyrrol-3-yl)-ethyl]-2-oxo-imidazolidin-1-yl}-cyclohexane carboxylic acid

17. [5-(4-{[2-(1-Amidino-2,5-dihydro-1H-pyrrol-3-yl)-ethylamino]-methyl}-pheno\ymethyl)-2-oxo-pyrrolidin-3-yl]-acetic acid

18. [5-({4-[2-(1-Amidino-2,5-dihydro-1H-pyrrol-3-yl)-ethylamino]-piperidin-1-yl}-acetyl)-2-carboxymethoxy-phenoxy]-acetic acid

19. (4-{[2-(1-Amidino-2,5-dihydro-1H-pyrrol-3-yl)-ethyl]-methyl-amino}-[1,4']bipiperidinyl-1'-yl)-acetic acid

20.3-{3-[2-(1-Amidino-2,5-dihydro-1H-pyrrol-3-yl)-ethylcarbamoyl]-propionylamino}-butyric acid 21.3-{3-[2-(1-Amidino-2,5-dihydro-1H-pyrrol-3-yl)-ethylcarbamoyl]-propionylamino}-3-phenyl-propionic acid

22.3-{3-[2-(1-Amidino-2,5-dihydro-1H-pyrrol-3-yl)-ethylcarbamoyl]-propionylamino}-3-pyridin-2-yl-propionic acid

23.3-{3-[2-(1-Amidino-2,5-dihydro-1H-pyrrol-3-yl)-ethylcarbamoyl]-propionylamino}-pent-4-ynone carboxylic acid

24.3-(2-{3-[2-(1-Amidino-2,5-dihydro-1H-pyrrol-3-yl)-ethyl]-ureido}-acetylamino)-N-(carboxy-phenyl-methyl)-succinic acid

25.3-(2-{3-[2-(1-Amidino-2,5-dihydro-1H-pyrrol-3-yl)-ethyl]-2-oxo-tetrahydropyrimidin-1-yl}-acetylamino)-propionic acid

26. {4-[2-(1-Amidino-2,5-dihydro-1H-pyrrol-3-yl)-ethylamino]-cyclohexyl}-acetic acid

27.3-(Butane-1-sulfonyl)-2-(4-{[2-(1-amidino-2.5-dihydio-1H-pyrrol-3-yl)-ethylamino]-methyl}-benzyl)-propionic acid

28.2-{2-[2-Amino-3-(1-amidino-2,5-dihydro-1H-pyrrol-3-yl)-propionylamino]-acetylamino]-succinic acid

29.1-{3-[2-(1-Amidino-2,5-dihydro-1H-pyrrol-3-yl)-ethyl]-2-oxo-oxazolidin-5-ylmethyl}-piperidin-4-carboxylic acid

30. Ada-Gly-Asp-Ser

31. Ada-Gly-Asp-Ser-NH2

32. Ada-Gly-Asp-Phe

33. Ada-Gly-Asp-Phe-NH2

34. Λda-Glv-Asp-Tyr

35. Ada-Glv-Asp-Tyr-NH2

36. Ada-Gly-Asp-Trp

37. Ada-Gly-Asp-Trp-NH2

38. Ada-Gly-Asp-Val

39. Ada-Gly-Asp-Val-NH2

40. Pla-Phe-Choi-Adc Example 1 : D-Pla-D-Phe-L-Choi-Adc

Production of the biomass

Three 20 1 glass cylinders with a pH regulator were filled with sterile filtered nutrient medium, each was inoculated with 50 ml preculture of Oscillatoria agardhn from the collection of algae cultures of the Institute of Plant Physiology of the University of Gottingen ( strain number B3 82) and incubated for ca 14 days at a constant pH of 8.5 a temperature of 20°C and an average irradiation of 30 Wm-2 under continuous gassing with sterile-filtered room air.

Nutrient medium

3.6 mg CaCI2 × 2 H2O, 20.3 mg Ca(NO3 )2 × 4 H2O, 2.7 mg KCI, 1.5 mg K2HPO4, 76.0 mg MgSO4 × 7 H2O, 84.0 mg NaHCO3, 1 ml trace element solution, 1000 ml deionized water. Trace element solution : 875 mg Na4EDTA, 9.7 mg Co(NO3)2 × 6 H2O, 284 mg FeCl2 × 6 H2O, 72.2 mg MnCl2 × 4 H2O, 25.2 mg Na2MoO4 × 2 H2O, 43.7 mg ZnSO4 × 7 H2O, 1000 ml deionized water (K. Zielinski, Dissertation, Univ Freiburg, 1988, p.23 ) Processing of the 3×20 1 cultures :

At the time of harvesting the three 20 1 cultures were combined and the cells and nutrient solution were separated by gentle centrifugation (5000 g, 10 min ). The biomass was frozen at -20°C and subsequently lyophilized.

The lyophilisate (ca 30 g) was extracted once with 1000 ml and twice with 500 ml methanol and the combined methanol phases were evaporated to dryness. The methanol extract (ca. 7 g) was taken up in 500 ml water and shaken out three times with 500 ml butanol each time. The butanol phases were combined and concentrated to dryness at 40°C on a rotary evaporator.

The butanol extracts were combined (ca.5 g), taken up in 150 ml methanol and absorbed onto ca. 25 g LiChroprep-CN phase (25-40 μm) and chromatographed over a LiChroprep-CN column (column: 52 × 356 mm; mobile phase gradient

water/acetonitrile/trifluoroacetic acid from ( 100:0:0:1 ) to (50:50:0. 1 ), total elution volume 5 1).

The fractions containing D-Pla-D-Phe-L-Choi-Adc which were identified with the aid of TLC or the thrombin time prolongation assay were pooled and evaporated to dryness at 40°C on a rotary evaporator.

The concentrate (ca. 1 g) was dissolved in 100 ml methanol, absorbed to ca. 5 g silica gel LiChroprep Si60 ( 1 5-25 μm) and chromatographed over a silica gel column (26 × 360 mm) with 1 500 ml chloroform/methanol/glacial acetic acid/water (65:25: 3.4) as the mobile solvent.

The pooled and concentrated fractions containing D-Pla-D-Phe-L-Choi-Adc (ca. 200 mg) were taken up in 3 ml methanol for the further purification and further separated by high pressure liquid chromatography on Nucleosil- 100 RP 18 ( 10 μm, column 20 × 250 mm) with water/acetonitrile/trifluoroacetic acid (70:30:0.1 ) as the mobile solvent

The concentrated fraction containing D-Pla-D-Phe-L-Choi-Adc (20 mg) was taken up in 1 ml methanol and subjected to a further high pressure liquid chromatography (column Nucleosil- 100 RP 18, 10 μm, 20 × 250 mm, mobile solvent 50 mM phosphate buffer pH 7.8/ acetonitrile (70: 30)). A fraction was obtained which only contained D-Pla-D-Phe-L-Choi-Adc. This was concentrated to ca 5 ml aqueous solution

In order to remove the buffer the aqueous concentrate was applied to a Nucleosil-100 RP 18 column (15 × 100 mm), whereby D-Pla-D-Phe-L-Choi-Adc was bound to the stationary phase. After washing with 100 ml water, the D-Pla-D-Phe-L-Choi-Adc was eluted with 200 ml water/methano! (10:90). The methanolic eluate was evaporated to dryness at 40°C on a rotary evaporator ca.3 mg pure D-Pla-D-Phe-L-Choi-Adc was obtained as a colourless phosphate salt.

Analytical data for D-Pla-D-Phe-L-Choi-Adc: a) Mass spectrometry The LSIMS spectrum of D-Pla-D-Phe-L-Choi-Adc yielded a pseudomolecule ion at MH+ 617 Da High resolution measurements in the positive LSIMS mode resulted in MH + 617345 Da which enabled C34H44N6O5 to be derived as the elemental composition of the neutral compound. The MS/MS spectrum of the molecular ion MH+ produced a series of daughter ions which confirmed the chemical structure derived for D-Pla-D-Phe-L-Choi-Adc.

Experimental conditions

The compound was measured at a resolution of ca 5000 in the LSIMS mode against PEG as the reference substance in the peak match mode.

Experimental data

LSIMS selected peaks (M/Z:rel.int.)

136:92, 154:100, 176: 9, 193: 6,239: 6,289: 14,307:19.331:3, 358:34, 381:2, 399:6.

469: 2.525:3, 593:7, 617:86, 647:8.667:3.713:6.

MS/MS of MH+ selected peaks (M/Z:rel.int.)

94:10, 120:64, 140:39, 153:3, 181:9, 209:16, 250:2, 268:7, 305:1.320:13, 149:1,

377:3, 453:2, 469:16, 540:3, 565:5 Assignment of the fragments (daughter ions):

(b) Gas chromatographic analysis of the acid total hydrolysate of D-Pla-D-Phe-L-Choi-Adc

The molecular components D-Pla and D-Phe could be detected in the acid total hydrolysate of D-Pla-D-Phe-L-Choi-Adc by gas chromatographic analysis on a chiral phase. Furthermore a peak was identified in the gas chromatogram by means of GC-MS coupling which could be assigned in the El mass spectrum to the molecular component Choi on the basis of the two typical masses of 4 1 9 Da (the molecular ion (M + ) of N,O-di-trifluoroacelyl-Choi-n-propyl ester ) and 332 Da (the fragment [M-C (O)OC3 H ]+ ).

Experimental conditions

The sample was hydrolyzed for 24 h with 6 N hydrochloric acid and derivatized after blowing off the hydrochloric acid. 0.5 ml 4 N hydrochloric acid in n-propanol was added to the dry hydrolysate for the detection of D-Phe and Choi and the reaction mixture was heated for 30 minutes to

1 10°C. The excess reagent was completely blown off. The subsequent acylation was carried out for 10 minutes at 150°C with trifluoroacetic acid anhydride. The reagent was again completely blown off and the sample was taken up in solvent.

For the detection of D-Pla 0 5 ml 4 N hydrochloric acid in methanol was added to the dry hydrolysate and the reaction mixture was heated for 10 minutes to 1 10°C. The excess reagent was completely blown off/ The subsequent aminoiysis was carried out at room temperature with n-propylamine. Afterwards it was silylated for 20 minutes at 70°C with hexamethyldisilazane.

The derivatized products of hydrolysis were analysed by capillary gas chromatography on a chiral phase. A 20 m capillary with an inside diameter of 0.28 mm and a film thickness of 0.25 μm was used which is covered with Chirasil Val . A flame-ionization detector was used for the detection. The peaks were assigned in the case of D-Phe and D-Pla by comparing the retention with those of reference substances. In the case of Choi a sector field mass spectrometer was used for the detection. ( c) NMR spectroscopy

The structure of the compound of example I was elucidated and confirmed by NMR spectroscopy (2D NMR, HMBC, HMQC, COSY (DQF-H, H-COSY , E .COSY ), TOCSY, ROESY ).

Example 2:

The compound of example 1 cocrystallizes with the bovine serine protease trypsin. It was possible to derive the connectivity of the inhibitor in the complex with bovine trypsin from the high resolution crystal structure of the serine protease inhibitor D-Pla-D-Phe-L-Choi-Adc. Comparison with an arginme-containing inhibitor showed that D-Pla-D-Phe-L-Choi-Adc contains an arginine mimetic.

The inhibitor D-Pla-D-Phe-L-Choi-Adc resembles the known thrombin inhibitor ( D)-Phe-Pro-Arg (DFPR) along the main chain. T here are differences at the N-terminus (an additional residue), at the proline analogue (a condensed ring with a hydroxy group) and at the C-terminus ( no carboxylate and a guamdino group partially integrated into a five-membered ring).

A comparison between the X-ray structure of D-Pla-D-Phe-L-Choi-Adc with trypsin and that of the trombin-DFPR complex (Bode, W., Mayr, I ., Baumann, U., Huber, R., Stone, S., & Hofsteenge, J. ( 1989) EMBO Journal 8, 3467-3475) clearly showed this similarity. If both X-ray structures are superimposed, the DFPR inhibitor lies within the electron density of D-Pla-D-Phe-L-Choi-Adc . Deviations only occur with respect to the differences in the side chain described above.

The Fo-Fc electron densities phased independently of the stated inhibitor structure confirmed the chemical structure of the molecular building block Adc. The five-membered ring is obvious. The spatial geometry of the electron density corresponds to a double bond in an equivalent position to the C of arginine. The planarity of the density is also consistent with a nitrogen atom in the N equivalent position. From this the guamdino group is deduced.

The refinement of the X-ray structure of the inhibitor D-Pla-D-Phe-L-Choi-Adc with the protein structure - at first with the appropriate geometric restraints, subsequently without any restraints - showed that the molecular building block Adc of D-Pla-D-Phe-L-Choi-Adc binds as an arginine analogue (Fig. 1 ). The additional ring atoms replace a water molecule. The other specific hydrogen bridges as well as the spatial position of the corresponding atoms remain almost identical. Description of the methods of X-ray structural analysis

Crystallization

Bovine ß-irypsin ( SIGMA) was repunfied (D. D. Schroeder , E. Shaw ( 1968) J Biol.

Chem. 243, 2943-2949) and lyophilized For crystallization preparations 3.5 mg of the lyophilisate (70 % w/w beta trypsin, 20 % benzamidine, 1 0 % CaCI2) was dissolved in 30 μl distilled H2O and mixed 1 : 1 with the precipitating solution ( 1.6 M

aminonium sulfate, 100 mM imidazole/H2SO4, pH 6, 0.02 % sodium azide). Crystals were produced by vapour diffusion (6 μl drops protein solution/4 ml precipitation solution). Benzamidine was replaced by D-Pla-D-Phe-L-Choi-Adc in the crystal by successive soaking: 1 ) twice for 2 hours in a pure harvest solution (2.5 M aminonium sulfate, TRIS/HCl pH 8, 10 mM CaCI2) in order to remove benzamidine and 2 ) overnight in inhibitor solution ( 1 .76 mg D-Pla-D-Phe-L-Choi-Adc dissolved in 176 μl harvest solution).

Data collection, evaluation

The crystal was oriented with a 4-circle goniometer from Siemens. The X-ray source was a copper rotating anode Rigaku Rotaflex-generator (45k V, 120 mA) equipped with a curved graphite monochromator. The diffracted reflexes were measured with a Siemens X1000 area counter. A total of 2464 recordings (width 0.1 degree) of four orientations were made corresponding to a theoretical completeness of 99 % for a resolution of 1.6 A (estimated with the program ASTRO (Siemens Industrial

Automation. Inc., Madison, WI., USA)). Automated indexing and data evaluation were carried out using SADI E and SAI NT (Siemens Industrial Automation, Ine., Madison. WI. ) ( see Table 1 ).

Electron density calculation, interpretation

The first electron density was phased with the 1.5 A resolved P2( 1 )2( 1 )2( 1 ) X-ray structure of trypsin (H. D. Bartunik, J. Summers, H. H. Bartsch, J. Mol. Bio. 2 10, 81 3, 1989) from the Brookhaven databank ( 1TLD, Abola, E.E. Bernstein, F. C., Bryant, S.H. Koetzle, T. F. & Weng, J. ( 1987) in Crystallographic databases - lnformation Content. Software Systems. Scientific Applications, Allen. F. H., Berghoff & G , Sievers, R. , eds., Data Commission of the International Commission of the

International Union of Crystllography (Bonn/ Cambridge/Chester, 1987), 107- 132) after structural and B factor refinement using XPLOR (Molecular Simulations

Incorporated MSI AG, Basel Switzerland). This density clearly showed the general orientation of the inhibitor Additional refinement cycles improved the densities and thus enabled the determination of the connectivities of the basic group in D-Pla-D- Phe-L-Choi-Adc. It was also possible to likewise determine all other positions of the inhibitor except the first phenyl ring of osciilarin which probably binds in a disordered manner.

Example 3:

(a) 4-Oxo-pyrrolidine-1,3-dicarboxylic acid 1-tert. butylester 3-ethylester

(J. Coopet etal. J. Chem. Soc. Perkin Trans.1, 1993, 1313-1318).

To a refluxing suspension of 1.58 g (66 mmol) sodium hydride in 100 ml THF was added dropwise a solution of 12.79 g (60 mmol) N-tert-butyloxycarbonyl-glycine ethyl ester and 7.15g (66 mmol) ethyl acrylate in 100 ml THF. After the addition was complete the mixture was heated to reflux for additional 2 h. The clear solution was cooled to room temperature, poured on 100 ml ether/100 ml water and acidified under vigorous stirring with 1N hydrochloric acid against methyl orange. The layers were separated and the aqueous layer was extracted three times with ether. The combined organic layers were washed with sat sodium bicarbonate and brine, dried over MgSO₄ and evaporated Short-path distillation of the residue gave 10.92 g (71%) 4-oxo-pyrrolidine-1,3-dicarboxylic acid 1-tert butylester 3-ethylester as a colorless oil, b p.119 - 122°C (0.2 mbar), which solidified on prolonged standing in the freezer.

GC/MS (HP 589011/HP 5972, column : HP 5, 30 m × 25 mm × 0.25 μm film thickness, carrier gas helium, temperature gradient 50°C, 3 mm, then with 20°C/minto250°C).

t_R = 9.68 mm

mlz [ %] - 185 (2), 130 (10), 112(18), 85 (6), 57 (100). b) 4-Hydroxy-pyrrolidine-1,3-dicarboxylic acid 1-tert.-butylester 3-ethylester To a solution of 5.15 g (20 mmol) 4-oxo-pyrrolidine-1,3-dicarboxylic acid 1-tert butylester 3-ethylester in 30 ml methanol was added 1.88 g (30 mmol) sodium cyanoborohydride and a small amount of methylorange. With stirring the pH was adjusted to 3 by dropwise addition of 1 N hydrochloric acid (color change from yellow to orange). After no more acid was consumed the mixture was stirred for one hour The solvent was evaporated in vacuo and the residue was partitioned between ethyl acetate and water. The organic layer was washed twice with water, then with brine. dried over magnesium sulfate and evaporated. The residual yellow oil was used in the next step without any further purification.

GC/MS (HP 5890 II/HP 5972, column: HP 5, 30 m × 25 mm × 0.25 μm film thickness carrier gas helium temperature gradient 50°C, 3 mm then with 20°C mm to 250 °C; ). t_R - 12.44 min (no separation of diastereomers).

m/z[%] = 259(M ,0.3), 241 (0.7), 202(5), 186(7) 158(10), 112 ( 14), 68 ( 31 ) 57

(100). c) 4-Benzoyloxy-pyrrolidine-1,3-dicarboxylic acid 1-tert.-butylester 3-ethylester

To an ice-cooled solution of the crude 4-hydroxy-pyrrolidine-13-dicarboxylic acid 1-tert-butylester 3-ethylester from the reduction described above and 244 mg (2 mmol) DMAP in 40 ml pyridine were added dropwise 3.51 g (25 mmol) benzoyl chloride. After the addition was complete, the ice bath was removed and the mixture was stirred at room temperature for 2 h. The mixture was diluted with ethyl acetate an poured on ice. The organic layer was separated, washed with water sat CuSO₄ water and brine, dried over MgSO₄ and evaporated. The lesidual yellow oil was used in the next step without further purification. GC7MS (HP 5890 II/HP 5972; column: HP 5, 30 m × 25 mm × 0.25 μm film thickness, carrier gas: helium, temperature gradient 50°C, 3 mm, then with 20°C/min to 250°C).

t_R = 1728 and 1738 min (1:1-mixture of cis/trans-isomers)

m/z[%] = 318(01), 290(5), 262(2), 241 (2), 185(29), 141 (10), 112(23), 105 (53), 77(27) 68(100), 57(97). d) 2,5-Dihydro-pyrrole-1,3-dicarboxylic acid 1 -tert.-butylester 3-ethyI ester

To a solution of the crude 4-benzoyloxy-pyrrolidine-1,3-dicarboxylic acid 1-tert-butylester 3-ethylester from the benzoylation described above in 75 ml dry toluene was added 4.11 g (27 mmol) DBU. The dark, heterogeneous mixture was stirred at room temperature for 16 h. After this time no starting material was delectable by FLC and GC analysis. The mixture was filtered through a short column of silica (elution with petrolether/ethyl acetate 1.1) and evaporated. Bulb-to-bulb distillation of the residual slightly yellow oii gave 4.46 g (86%) 25-dihydro-pyrrole-1,3-dicarboxylic acid 1-tert-butylester 3-ethyl ester as a colorless oil b. p.110°C 702 mbar, which slowly solidified to a waxy mass on standing in the freezer.

GC/MS (HP 5890 II/HP 5972, column: HP 5 30 m × 25 mm × 0.25 μm film thickness carrier gas: helium temperature gradient 50°C, 3 mm then with 20°C/min to 250°C).

t_R = 11.94 min. m/z[%] = 241 (M , 1.4), 196(0.4), 185(11), 168(11), 140(14), 112(17), 68(24), 57(100).

¹H-NMR (CDCl₃, 300 MHz)

δ = 127 (t, J = 71 Hz, 3H, OCH₂CH₃), 143, 1.44 [2s, 9H, C(CH₃)₃]*, 425 (d, J = 71 Hz, 2H, OCH₂CH₃), 415 - 427 (br m, 4H, 2-H, 5-H), 666 - 6.71 (m, 1 H, 4-H) ppm *Double set of signals due to hindered rotation.

¹³C-NMR (CDCI₃, 75 MHz)

δ = 1416, 1420 (q, -CH₂-CH3)^*, 28.45 [q, -C(CH₃)₃], 51.76, 51.99, 53.62, 53.84 (4t, C-2, C-5)^*, 60.69 (t, -CH₂-CH₃), 79.84 [s, -C(CH₃)₃], 132.29 (s, C-3), 13644. 136.55 (2d, C-4)^*, 153.86, 154.08 (2s, -NCOO-)^*, 162.75 (s, COOEt) ppm e) 3-Mydroxymethyl-2,5-dihydro-pyrrole-1-carboxylic acid tert.-butylester To a solution of 5.43 g (22.5 mmol) 2,5-dihydro-pyrrole-1,3-dicarboxy he acid 1-tert.-butylester 3-ethyl ester in 50 ml THF, cooled to - 78°C was dropwise added 50 ml of a 1N D1BAL-H solution in hexane. The mixture was allowed to warm to room temperature overnight. As TLC analysis indicated complete consumption of starting material, the mixture was cooled in an ice bath and 1.90 g water were cautiously added, followed by 1.90 g 15 % aqueous NaOH and 5.70 g water. The white precipitate was filtered off, washed thoroughly with ether and the combined filtrates were evaporated. Bulb-to-bulb distillation of the residual pale yellow oil gave 4.13 g (93 %) 3-hydroxvmethyl-2,5-dihydro-pyrrole-1-carboxylic acid tert.-butylester as a colorless oil, b. p.130°C (0.2 mbar).

GC/MS (HP 5890 II/HP 5972, column:: HP 5, 30 m × 25 mm × 025 μm film thickness, carrier gas helium, temperature gradient 50°C, 3 min, then with 20°C/min to 250°C)

t_R = 1134 min

m/z [%] = 199 (M , 1), 143(10), 142 (13), 126(13), I 12(12), 80(10), 68(45), 57(100)

¹H-NMR (CDCI₃, 300 MHz)

δ = 144 (s, 9H, t-Bu), 409 (br. m, 4H, 2-H, 4-H), 4.18 (br. s, 2H, CH₂OH), 5.63 (br d, 1H, 4-H) ppm. ¹³C-NMR(CDCI₃, 75 MHz)

δ = 28.5 [q, C(CH₃)₃], 52.8, 53.0, 5.2., 53.3 (4t, C-2, C-5) , 57.7, 59.8 (2d,

CH₂OH) Fehler! Textmarke nicht definiert., 79.5 [s, C(CH₃)₃], 120.0, 120.3 (2d, C-4) Fehler! Textmarke nicht definiert., 139.6 (s, C-3), 154.4 (s, COO/Bu) ppm ^*Double set of signals due to hindered rotation f) 3-Acetoxymethyl-2,5-dihydro-pyrrole-1-carboxylic acid tert.-butylester

To an ice-cooled solution of 4.13 g (20.7 mmol) 3-hydroxymethyl-2,5-dihydropyrrole-1-carboxylic acid tert.-butylester and 244 mg (2 mmol) DMAP in 50 ml pyridine was added 3.06 g (30 mmol) acetic anhydride. The mixture was stirred for 30 min at 0°C, then for additional 60 min at room temperature. The mixture was poured on ice and extracted twice with ether. The combined organic layers were evaporated in vacuo, dissolved in ether, washed with sat CuSO₄, water and brine and dried over MgSO₄. Evaporation and bulb-to-bulb distillation gave 4.82 g (97 %) 3-acetoxymethyl-2,5-dihydro-pyrrole-1-carboxylic acid ten.-butylester as a colorless oil, b. p. 105ºC(0.2 mbar).

GC/MS (HP 5890 II/HP 5972, column: HP 5, 30 m × 25 mm × 0.25 μm film thickness, carrier gas helium, temperature gradient 50°C, 3 min; then with 20°C/min to 250°C).

t_R = 11.87 min

m/z.[%] - 241 (M .0.2), 226(0.1), 185(5), 166(5).125 (18), 108(3), 81 (13), 80 (23), 57(100).

¹H-NMR (CDCl₃, 300 MHz)

δ = 1.43, 1.44 [2s, 9H, C(CH₃)₃]*, 2.04, 2.06 (2s, 3H, OOCCH₃)*, 4.05-4.12 (br m, 4H, 2-H, 5-H), 4.61 (br d, J = 5.7 Hz, 2H, CH₂O), 5.66 - 5.73 (br m, 1H, 4-H) ppm.

¹³C-NMR(CDCl₃, 75 MHz)

δ = 20.7 (q, OOCCH₃), 28.4 [q, C(CH₃)₃], 53.0.53.2.53.3 (3t, 2-C, 5-C) 60.8 (t,

*,

CH₂OAc), 79.5 [s, C(CH₃)₃], 123.4, 123.8 (2d, C-4)^*, 134.5, 134,6 (2s, C-3), 154.1 (s, NCOO), 170.5 (s, OOCCH,) ppm g) 2-(1-tert.-Butoxycarbonyl-2,5-dihydro-1H-pyrrol-3-yl-methyl)-malonic acid dimetylester

5.28 g (40 mmol) dimethyl malonate were cautiously added to an ice-cooled suspension of 864 mg (36 mmol) sodium hydride in 80 ml THF. The resulting clear solution was added to a solution of 4.82 g (20 mmol) 3-acetoxymethyl-2,5-dihydropyrrole-1-carboxylic acid tert.-butylester and 462 mg (04 mmol) Pd(PPh₃)₄ in 40 ml THF and the mixture was heated to reflux for 20 h. The reaction mixture was cooled to room temperature, diluted with ether and quenched with sat NH₄Cl. The organic layer was washed with sat NH₄Cl and brine, dried over MgSO₄ and evaporated. The residue was purified by flash chromatography (ethyl acetate/petrol ether 4: 1 to 2:1) and bulb-to-bulb distilled to yield 486 g (77 %) of 2-(1-tert.-butoxycarbonyl-2,5-dihydro-1H-pyrrol-3-yl-methyl)-malonic acid dimetylester as a colorless oil, b. p. 130°C/0.2 mbar. GC/MS (HP 5890 ll/HP 5972, column HP 5, 30 m × 25 mm × 0.25 μm film thickness, carrier gas helium, temperature gradient 50 °C, 3 min, then with 20°C/min to 250°C)

t_R = 14.07 min

m/z [%] = 313 (M , 0.1), 257(27), 240(5), 126(35), 82(59), 80(38), 57(100) ¹H-NMR (CDCl₃, 300 MHz)

δ = 1.43, 1.44 [2s, 9H, C(CH₃)₃]*, 2.68 (m, 2H, 3-CH₂), 3.57 [t, J = 66 Hz.1H, CH(COOCH₃)₂], 3.71, 3.72 [2s, 6H, CH(COOCH₃)₂], 3.97 - 4.10 (br m, 4H, 2-H, 5-H), 5.44 (br m, 1H, 4-H) ppm.

¹³C-NMR (CDCl₃, 75 MHz)

δ = 28.0, 28.1 (2t, 3-CH₂-)Fehler! Textmarke nicht definiert., 28.5 [q, C(CH₃)₃], 501 [d, CH(COOMe)₂] 52.7 (q, OCH₃), 53.1, 53.3, 54.5, 54.9 (4t, C-2. C-5)*.79.4 [s, C(CH₃)₃], 121.0 (d, C-4), 135.8 (s, C-3), 154.1 (s, NCOO), 169.0 (s, COOMe) ppm. h) 3-(2-Methoxycarbonyl-ethyl)-2,5-dihydropyrrole-1-carboxylic acid tert. butyl ester

To a solution of 4.52 g (144 mmol) 2-(1-tert.-butoxycarbonyl-2,5-dihydro-1H- pyrrol-3-yl-methyl)-malonic acid idimethylester n 140 ml DMF were added 1.94 g (108 mmol) water and 1.26 g (21.6 mmol) sodium chloride. The mixture was degassed and heated to 1 50 °C for 30 h under an atmosphere of argon After this period of time no starting material could be detected by TLC. The mixture was cooled to room temperature, diluted with 200 ml ether and washed three times with water, then with brine. The organic layer was dried over MgSO₄ and evaporated. Purification by bulb-to-bulb distillation gave 3.38 g (92 %) of 3-(2-methoxycarbonyl-ethyl)-2,5-dihydropyrrole- 1 -carboxylic acid tert. butylester as a colorless oil, b. p. 1 30 °C (0.2 mbar).

GC/MS (HP 5890 II/HP 5972, column HP 5, 30 m × 25 mm × 0.25 μm film thickness, carrier gas helium; temperature gradient 50 °C, 3 min, then with 20

°C/min to 250 °C).

t_R = 12.63 min

m/z [%] = 255 (M + , 0.2), 199 (48), 196 (2), 1 82 ( 10), 126 (26), 82 (54), 80 (32), 57

( 100).

¹ H-NMR (CDCI₃, 300 MHz)

δ = 1 3.2, 13.2 [2s, 9H, C(CH₃)₃]*, 2.30 - 2.35, 2.40 - 2.44 (2m, 2H each, -CH₂-CH₂- ), 3.58 (s, 3H, OCH ₃), 3.91 - 4.00 (m, 4H, 2-H. 5-H), 5.29 - 5.34 (m, 1 H, 4-H) ppm ¹³C-NM R (CDCI ₃, 75 MHz)

δ = 23.7, 23.8 (t, 3-CH₂)*, 28.2 [q, C(CH ₃)₃], 3 1.7 (t, CH₂COOMe), 5 1.4 (q, COOCH₃), 52.8, 53. 1 , 54.4, 54.7 (4t, C-2, C-5)*, 78.9 [s, C(CH₃)₃], 1 18.9 (d, C-4), 1 37.8 (s, C-3 ), 1 53 .9 (s, NCOO), 1 72.8 (s, COOCH₃) ppm i) 3-[2-(2,2,2-Trichlorethoxycarbonyl)-amino-ethyl]-2,5-dihydro-pyrrole- 1 -carboxylic acid tert. butyl ester

To a solution of 3.57 g ( 14 mmol) 3-(2-methoxycarbonyl-ethyl)-2,5-dihydropyrrole¬1 -carboxylic acid tert butyl ester in 45 ml THF/methanol/water 3: 1 : 1 was added 1 1 8 g (28 mmol) LiOH*H₂O and the mixture was stirred for 1 h at room temperature. The solution was diluted with water and washed three times with ethyl acetate. The aqueous layer was cooled in an ice bath and acidified with 1 N hydrochloric acid against methyi orange. The turbid mixture was extracted three times with ether, the combined organic layers were dried over MgSO₄ and evaporated to yield 3 4 1 g of a colorless soiid. which turned dark on standing. The crude acid was dissolved in 140 ml dry toluene and 4.06 g ( 14 mmol) diphenyl phosphoryl azide and 1 .47 g ( 14.5 mmol) triethylamine were added. The mixture was heated to 80 °C overnight. The sol vent was removed in vacuo, the residual brown oil was dissolved in 20 ml THF and

3.14 g (21 mmol) 2,2,2-trichloroethanol and a small amount of cuprous chloride were added. The mixture was heated to reflux for 2 h, then the solvent was evaporated and the residue was purified by flash chromatography (petrol ether/ethyl acetate 3: 1 to 2: 1 ) to yield 4.31 g (79 %) 3-[2-(2,2,2-trichlorethoxycarbonyl)-amino-ethyl]-2,5-dihydro-pyrrole-1-carboxylic acid ten butyl ester as a colorless solid, m p 97-98°C.

¹H-NMR (CDCl₃, 200 MHz)

δ = 1.41 [s, 9H, C(CH₃)₃], 2.31 (br m, 2H, 3-CH₂-), 3.29 - 3.39 (m, 2H, CH₂NH),

4.67 (br m, 4H, 2-H, 5-H).4.67 (s, 2H. CH₂CCI₃), 5.43 (br m, 1H, 4-H) ppm

¹³C-NMR (CDCl₃, 50 MHz)

δ = 28.6 [q, C(CH₃)₃], 29.2 (t, -CH₂-CH₂-NH), 39.2 (t, -CH₂-CH₂-NH), 53.2, 53.4, 54.6, 549, (4t, C-2, C-5), 74.5 (d, CH₂CCl₃), 79.5 [s, C(CH₃)₃], 95.8 (s, CH₂CCl₃), 1208. 121.0(2d. C-4), 136.3 (s, C-3), 154.2, 154.6 (2s. NCOO) ppm j) 3-[2-(2,2,2-Trichlorethoxycarbonyl)-amino-ethyl]-2,5-dihydropyrrole-1-(N,N -di-tert.-butoxycarbonyi)carboxamidine

To an ice-cooled solution of 1936 g (5 mmol) 3-[2-(2,2,2-trichlorethoxycarbonyl)-amino-ethyl]-2,5-dihydro-pyrrole-1-carboxylic acid tert butyl ester in 10 ml dry dioxane was added 10 ml 4N hydrogen chloride in dioxane. The mixture was allowed to stand at 4°C for 16 h. The solvent was then evaporated in vacuo without heating and then evacuated in high vacuum. The residue was suspended in 20 ml dry acetonitrile and 711 mg (55 mmol) ethyldiisopropylamine followed by 1.614 mg (52 mmol) N,N -bis-tert.-butyloxycarbonyl-1H-pyrazole-1-carboxamidine were added. The clear solution was stirred for 2 h at room temperature, then the solvent was distilled off and the residue was purified by flash chromatography (petrol ether/ethyl acetate 3: 1 to 2:1) to yield 2.234 g (84 %) of a colorless solid, m. p.121 - 123°C

¹H-NMR (CDCl₃, 200 MHz)

δ - 1.43 (s, 18H, C(CH₃)₃].227 - 2.33 (br m, 2H, 3-CH₂-), 328 - 338 (m, 2H.

CH₂NH), 4.31 (br m, 4H, 2-H, 5-H), 4.65 (s, 2H, CH₂CCl₃), 547 (br m, 1H, 4-H) pm. ¹³C-N MR (CDCl₃, 50 MHz)

δ = 28.0, 28.1 [2q, C(CH₃)₃] 29.0 (t, 3-CH₂), 39.0 (t, CH₂NH₂), 55.4, 56.0 (2 br t, C-2, C-5), 74.5 (d, CH₂CCl₃), 79.5, 82.0 [2s, C(CH₃)₃], 95.6 (s, CH₂CCl₃), 1 19.9 (d C-4), 1 35.3 (s, C-3), 1 50.4, 1 54.0, 1 54.5, 162.5 (4s, NCOO, N=C-N) ppm k) 3-(2-Amino-ethyI)-2,5-dihydropyrrole- 1-(N,N '-di-tert. -butoxycarbonyl) carboxamidine

To a solution of 2.234 g (4.22 mmol) 3-[2-(2,2,2-trichlorethoxycarbonyl)-amino-ethyl]-2,5-dihydropyrrole- 1 -(N,N'-di-tert.-butoxycarbonyl) carboxamidine in 20 ml glacial acetic acid was added 1.3 1 g (40 g-atom) activated zinc and the mixture was stirred at room temperature for 2 h. Methanol was added, the mixture was filtered through celite, washed thoroughly with methanol and the filtrate was concentrated in vacuo. The residue was dissolved in water and made strongly alkaline with solid sodium hydroxide. The aqueous layer was extracted three times with ether, the combined organic layers were dried over MgSO₄ and evaporated to yield 622 mg (41 %) 3-(2-amino-ethyl)-2,5-dihydropyrrole- 1 -(N,N'-di-tert.-butoxycarbonyl)carboxamidine as a slightly yellow, amorphous solid.

¹H-NMR (CDCl₃, 300 MHz)

δ = 1.45 [s, 18H, C(CH₃)₃], 2.2 1 - 2.26, (m, 2H, 3-CH₂-), 2.83 (t, J = 6.9 Hz, 2H, -CH₂-NH₂), 4.28 - 4.34 (br m, 4H, 2-H, 5-H), 5.46 (br s, 1 H, 4-H) ppm.

¹³C-NMR (CDCl3, 75 MHz)

δ = 27.85, 27.94 [2q, C(CH₃)₃], 32.2 (t, 3-CH₂), 39.5 (t, CH₂NH₂), 55.2, 56.7 (2t, C-2, C-5), ca 8 1 [br. s, C(CH₃)₃] , 1 19.0 (d, C-4), 136.1 (s, C-3), 1 53.7 (s, NCOO) ppm.

1) HOOC-CH₂-D-Cha-(N-cyclopentyl)-Gly-Adc

A mixture of 0.4 1 g (0.8 1 mmol) N-(tert.-butyloxycarbonyl)-N-(tert butyloxycarbonylmethyl)-(D)-cyclohexylalanyl-N-cyclopentylglycine, 0.1 5 ml (0.9 mmol)

diisopropylmethylamine, and 0.29 g (0.9 mmol) TBTU in 25 ml dry DMF was stirred at room temperature for 30 min. Then 0.3 g (0.85 mmol) (3-(2-amino-ethyl)-2,5-dihydropyrrole-( 1 -(N,N'-di-tert, butoxycarbonyl)-carboxamidine was added and starred for 70 h. The solvent was removed 1. vac ,. water was added and extracted with ethyl acetate. The ethyl acetate was separated, washed with I M hydrochloric acid and 5% aqueous sodium bicarbonate and dried over sodium sulfate. Filtration and removal of the solvent 1. vac. produced 0 35 g (5 1 %) N-(2- { [ 1 -(N,N'-di- tert butoxycarbonyl)-carboxamidino]-2,5-dihydro-pyrrol-3-yl}-ethyl)-[N- (tert butγloxγcarbonyl)-N-(tert. butyloxycarbonyl-methyl)-D-cyclohexylalanvl-(N-cyclopentylglycin)] amide as a colorless oil FAB-MS m/z 847 MH A solution of the above product (0.35 g, 041 mmol) in 10 ml 4 N hydrogen chloride in dioxane was stored for 24 h at 5°C. The solvent was removed i vac, and the oily residue was triturated with diethyl ether to yield the title compound as hydochloride

+

quantitatively FAB-MS m/z 491 MH ¹H-NMR (d₆-DMSO, 250 MHz).

δ = 0.8 - 4.8 ppm (in broad), 5.68(s,1)

The title compound was synthesized as hydrochloride from Boc-N-Me-D-Phe-ProOH (Bajusz et al. , J. Med Chem.1990, 33, 1729-1735) and 3-(2-amino-ethyl)-2,5-dihvdropyrrole-1-(N,N -di-tert.-butoxycarbonyl)carboxamidine (example 3k) by the same method as described in example 31) FAB-MS m/z 412 MH Example 5:

The title compound was synthesized as hydrochloride from N-(tert.-butyloxycdrbonylmethyl)-N-Boc-D-Cha-ProOH and 3-(2-amino-ethyl)-2 5-dihydropyrrole- 1 -(N, N -di-tert.-butoxycarbonyl) carboxamidine (example 3k) by the same method as described in example 31) FAB-MS: m/z 463 MH

Example 6: 1 -(3-[2-( 1 -amidino-2,5-dihydro- 1 H-pyrrol-3-yl)-ethyl]-2-oxo-oxazolidin-5-ylmethyl}-piperidine-4-carboxylic acid

(a) A mixture of 3.1 g piperidine-4-carboxylic acid ethyl ester 6.4 ml epichlorohydrm and 0.1 g tetrabutyl-aminonium bromide in 1 5 ml toluene and 1 5 ml concentrated sodium hydroxide solution was stirred for 4 h at room temperature and subsequently admixed with 50 ml water. The organic phase was separated, the aqueous phase was shaken three times with 20 ml methylene chloride each time, the combined organic phases were dried over sodium sulfate and the solvent was removed in a vacuum 2.1 g (rac)- 1 -oxiran-2-ylmethylpiperidine-4-carboxylic acid ethyl ester was obtained EI-MS m/z 2 13 M .

(b) A solution of 3 g of the amine prepared in example 3k) and 1 .73 g of the oxirane produced in 7a) in 20 ml ethanol was heated for 48 h under reflux. Subsequently the ethanol was removed in a vacuum and the residue was punfied by column

chromatography on silica gel (ethyl acetate/ saturated methanolic aminonia 85/ 1 5) 1.5 g 1 -{ 3-[2-( 1 -(N,N'-di-tert.-butoxycarbonyl)carboxamidino-2,5-dihydro- 1H-pyrrol-3-yl)-ethylamino]-2-hydroxy-propyl }-piperidine-4-carboxylic acid ethyl ester was obtained in this way. (c) A solution of 0.5 g of the aminoalcohol 7b) and 0.4 g carbonyldnmidazole in 5 ml dimethylformamide was stirred for 24 h at room temperature. Subsequently the reaction solution was concentrated to dryness by evaporation and the residue was purified by means of preparative HPLC (Merck, Select B, methanol/buffer (pH=7.5) 65/35). 0.35 g 1 -{ 3-[2-( 1 -(N,N' -di-tert.-butoxycarbonyl)carboxamidino-2,5-dihydro-1 H-pyrrol-3-yl)-ethylamino]-2-hydroxy-propyl }-piperidine-4-carboxvlic acid ethyl ester was obtamed in this manner. (d) A solution of 0.35 g of the ethyl ester 6c) and 2 ml 1 N sodium hydroxide solution in 5 ml methanol was stirred for 1 h at room temperature. Subsequently the methanol was removed in a vacuum and tthe residue was trearted with 4M Hcl in dioxane for 3 hours at room temperature. Then the solvent was removed until drying in vacuo 0.2 g of the title compound was obtained as hydrochlioride FAB-MS m/z366 [MH ]

Example 7 Troc-Ada-Gly-Asp-Ser a) 3-(2-Benzhydrilideneamino-2-ethoxycarbonyl-ethyl)-2,5-dihydropyrrole- 1 -carboxylic acid tert.-butylester

To a solution of lithium hexamethyldisilazide, freshly prepared at 0 °C from 1.77g ( 1 1 mmol ) hexamethyldisilazane in 10 ml THF and 4 80 g ( 1 1 mmol) n-Butyl-lithium, (2.29 mmol/g in hexanes) and cooled to - 78 °C was dropwise added a solution of 3.06 g ( 1 1 mmol) ethyl N-(diphenylmethylene)-glycinate in 10 ml THF. The deep orange enolate solution was stirred at this temperature for 30 min, then a solution of 2.4 1 g ( 10 mmol) 3-acetoxymethyl-2,5-dihydro-pyrrole- 1 -carboxylic acid tert -butylester from example 30 and 426 mg (0.4 mmol) Pd(PPh₃)₄ in 10 ml THF was added dropwise. The mixture was allowed to warm to room temperature overnight and was then diluted with ether and quenched by addition of sat sodium bicarbonate. The aqueous layer was extracted with ether, the combined organic layers were washed with brine, dried over MgSO₄ and evaporated. Flash chromatography of the residual oil (elution with petrol ether/ethyl acetate 3 1 + 1 % triethylamine) gave 3.91 g (8 1 %) 3-(2-benzhydrilidene-amino-2-ethoxycarbonyl-ethyl)-2,5-dihydropyrrole- 1 -carboxylic acid tert.-butylester as a slightly yellow oil. ¹H-N M R (CDCl3, 300 MHz)

δ = 1.27 (t, J = 7.1 Hz, 3H, OCH₂CH₃), 1.43 [s, 9H, C(CH₃)₃], 2.66 - 2.76 (m, 2H, 3-CH₂-), 3.73 - 3.99 (m, 1H, CH-N), 4.04 - 4.09 (br m, 4H, 2-H, 5-H), 4.17 (q, J = 7.1 Hz, 2H, OCH₂CH₃), 5.42 (br m, 1H, 4-H), 7.11 - 7.81 (m, 10 H, Ar-H) ppm

¹³C-NMR(CDCl3, 75 Mhz)

δ = 14.2 (q, OCH₂CH,), 28.5 [q, C(CH₃)₃], 33.1 (t, 3-CH₂), 52.9, 55.1 (2t, C-2, C-5), 61.1 (t, OCH₂CH₃), 63.9 (d, CH-NH₂), 79.1 [s, C(CH₃)₃], 121.9 (d, C-4), 127.7, 128.1, 128.3, 128.4, 128.5, 128.7 (6d, Ar-CH), 135.7, 135.8 (2s, Ar-C), 139.3 (s, C-3), 154.1 (s, NCOO), 170.8 (s, N=CPh₂), 171.2 (s, OCOCH₂CH₃) ppm b) 3-(2-Amino-2-ethoxycarbonyl-ethyI)-2,5-dihydropyrrole- 1 -carboxylic acid tert.-butylester

To 25 ml of a 0.5 M solution of methoxylamine hydrochloride in 80 % ethanol was added a solution of 448 mg ( 1 mmol) 3-(2-benzhydrilideneamino-2-ethoxycarbonylethyl)-2,5-dihydropyrrole- l -carboxylic acid tert. -butylester in 5 ml chloroform . After 5 min TLC analysis

indicated the complete consumption of the starting material. The mixture was stirred for additional 30 min and then evaporated to dryness. The residue was dissolved in water and washed twice with ether. The aqueous layer was made alkaline by addition of 1 N potassium hydroxide and extracted three times with ether. The combined organic extracts were dried over MgSO₄ and evaporated to yield 2 14 mg (75%) 3-( 2-amino-2-ethoxycarbonyl-ethyl)-2, 5-dihydropyrrole- 1 -carboxylic acid tert-butylester as a colorless oil which was pure according to GC.

GC/MS (HP 5890 II/HP 5972, column: HP 5, 30 m × 25 mm × 0.25 μm film thickness, carrier gas helium, temperature gradient 50 °C, 3 min, then with 20 °C/min to 250 °C)

t_R = 1 3.84 min

m/z [%] = 227 (M - C₄H₉, < 1 ), 21 1 (7), 182 ( 10), 1 55 ( 1 1 ), 137 (6), 126 (56), 108 ( 18), 94 (23), 82 ( 100), 74 (20), 57 (92). ¹H-NMR (CDCl3, 300 MHz)

δ = 1.23 (t, J = 7.1 Hz, 3H, OCH₂CH₃), 1.42 [s, 9H, C(CH₃)₃], 2.35 (dd, 2J = 14.2 Hz, ²J = 8 Hz, 1H, CH_aH_bCHNH₂), 2.50 - 2.55 (m, 1H, CH_aH_bCHNH₂), 3.54 (dd, ³J = 8, 5.5 Hz, 1H, CHNH₂), 4.02 - 4.11 (br m, 4H, 2-H, 5-H), 4.13 (q, J = 7.1 Hz, 2H, OCH₂CH₃), 5.51 (br m, 1H, 4-H) ppm ¹³C-NMR (CDCI3, 75 MHz)

δ = 14.1 (q, OCH₂CH₃), 28.5 [q, C(CH₃)₃], 34.5 (t, 3-CH₂), 52.9 (d, CH-NH₂), 530. 54.8 (2t, C-2, C-5), 61.0 (t, OCH₂CH₃), 79.3 [s, C(CH₃)₃], 122.2 (d, C-4), 135.5 (s, C-3). 154.1 (s, NCOO), 175.0 (s, OCOCH₂CH₃) ppm c) 3-[2-(2,2,2-Trichloroethoxycarbonyl-amino)-2-ethoxycarbonyl-ethyl]-2,5-di-hydro-pyrrole-1-carboxylic acid tert.-butylester

To an ice-cooled solution of 214 mg (0.75 mmol) 3-(2-amino-2-ethoxycarbonylethyl)-2,5-dihydropyrrole- 1 -carboxylic acid tert.-butylester and 1 19 mg ( 1 5 mmol ) pyridine in 2 ml methylene chloride was added a small amount of DMAP followed by 2 12 mg ( 1 mmol) 2.2,2-trichloroethoxycarbonyl chloride. The mixture was allowed to warm to room temperature overnight. The mixture was diluted with ether, washed with water, sat CuSO₄, water and brine, dried over MgSO₄ and evaporated.

Purification of the residue by flash-chromatography (elution with petrol ether/ethyl acetate 3. 1 ) gave 320 mg (93 %) 3-[2-(2,2,2-trichloroethoxycarbonyl-amino)-2-ethoxycarbonyl-ethyl]-2,5-dihydropyrrole- 1-carboxylic acid tert.-butylester as a colorless oil, which was immediately used for the next step d) 3-[2-(2,2,2-Trichloroethoxycarbonyl-amino)-2-ethoxycarbonyl-ethyl]-2,5-di-hydropyrrole- 1 -(N,N'-di-tert.- butoxycarbonyl) carboxamidine

To an ice-cooled solution of 320 mg (0.67 mmol) 3-[2-(2,2,2¬trichloroethoxycarbonyl-amino)-2-ethoxycarbonyl-ethyl]-2,5-dihydropyrrole- 1 -carboxylic acid tert.-butylester in 1 .5 ml dry dioxane was added 1.5 ml 4 N hydrogen chloride in dioxane. The mixture was allowed to stand at 4 °C for 16 h. The solvent was then evaporated in vacuo without heating. The residue was suspended in 4 ml dry acetonitrile and 2 1 7 mg (0.7 mmol) ethyldiisopropylamine followed by 97 mg (0.75 mmol ) N ,N '-bis-tert -butyloxycarbonyl- 1 H-pyrazole- 1 -carboxamidine were added The resulting clear solution was stirred for 2 h at room temperature, then the solvent was distilled off and the residue was purified by flash chromatography (petrol ether/ethyl acetate 3: 1 to 2 : 1 ) to yield 380 mg (94 %) of a colorless foam

¹H-NMR (CDCl3, 200 MHz)

δ = 1 2 1 (t. J = 7.0 Hz. 3H, OCH₂CH₃), 1.43 [s, 9H. C(CH₃)₃ ]. 2 53 - 2.64 ( m, 2 H, CH₂CHNH ), 4.16 (q, J = 7.0 Hz. 2H, OCH₂CH₃). 4.29 (br m, 4H, 2-H. 5-H ), 4.67 s, 2H, CH ₂CCI ₃), 5.52 - 5.6 1 (m, 3 H, -CHNH, 4-H) ppm

¹³C-N M R (CDCl3, 50 MHz)

δ = 14.1 (q, OCH₂CH₃), 28.0.28.2 [2q, C(CH₃)₃], 31.8 (t, 3-CH₂), 52.9 (d, CH-NH₂), 55.4, 57.1 (2br,t, C-2. C-5), 61.9 (t, OCH₂CH₃), 74.7 (t, CH₂CCl₃), 79.5, 83.5 [2s, C(CH₃)₃], 95.3 (s, CH₂CCl₃), 121.9 (d, C-4), 133.3 (s, C-3), 154.0 (s. NCOO), 1 7 1. 1 (s, COOEt) ppm ( BOC-NCOO- and amidine -N-C = N-signals not v isible due to line broadening). e) 3-[ 2-(2,2,2-Trichloroethoxycarbonyl-amino)-2-carboxy-ethyl]-2,5-dihydro pyrrole- 1 -(N,N'-di-tert.-butoxycarbonyl) carboxamidine

To a solution of 2 1 9 mg (0 36 mmol) 3-[2-(2,2,2-trichloroethoxycarbonyl-amino)-2-ethυxycarbonyl-ethyl]-2,5-dihydropyrrole- 1 -(N,N'-di-tert.-butoxycarbonyl) carboxamidine in 4 ml THF/methanol/water 3: 1: 1 was added 30 mg (0.72 mmol)

LiOH*H2O. After stirring for 1 h at room temperature no starting material could be detected by TLC. The mixture was diluted with water, acidified by addition of 1 N hydrogen chloride and extracted three times with ethyl acetate. The combined organic extracts were dried over MgSO₄ and evaporated. The residue was purified by flash-chromatography (elution with ether + 1 % acetic acid ) to vield 1 56 mg (76 %) 3-[2-(2,2,2-trichloroethoxycarbonyl-amino)-2-carboxy-ethyl]-2, 5-dihydropyrrole- 1 -( N N '- di-ter t -butoxycarbonyl ) carboxamidine (Troc-Ada(Boo)-OH ) as a colorless amorphous solid.

¹ H-NM R (CDCl3, 250 MHz)

δ = 1.42 [s 1 8H, C(CH₃)₃], 2.58 - 2.79 (br m. 2H, CH₂CHNH ), 4.30 - 4.38 ( m 4H 2-H, 5-H), 4.58 (d, J = 12.2 Hz, 1 H, CH_aH_bCCI₃), 4.75 (d, J = 12.2 Hz, 1 H.

CH_aH_bCCl₃), 5.53 (br s 1 H, CHNH ), 5.99 (br. m, 1 H 4-H ) ppm f) T roc-Ada-Gly-Asp-Ser

I he title compound was synthesized by solid-phase methodology on a SyRo I I multiple peptide synthesizer (MultiSynTech, Bochum) on a 0.03 mmol scale using

Fmoc-Ser(t-Bu)-trityl-polystyrene( 1 %)divinylbenzene resin (Fmoc-L-Ser(t-Bu)-TCP, loading 0.57 mmol/g, PepChem Tubingen) as starting material. The α-amino groups of the protemogenic amino acids Gly and Asp were protected by 9-fluorenylmethoxycarbonyl (Fmoc), the side chain carboxy group of Asp by tert.-buty l The non-proteinogenic amino acid Ada was used as Troc-Ada(Boc₂ )-OH (from example 8e). The Fmoc-protected amino acids were coupled in a 6-told excess tor 30 min in DMF TBTU ( 1 eq) and NNM ( 1 eq) were used as activating reagents Cleavage of the Fmoc group was carried out in piperidine/dimethylformamtde ( 1 : 1 v/v ) tor 2 × 10 min C oupling of Troc-Ada(Boc₂)-OH was performed manually in DMF within I h by using 0.048 mmol of the protected amino acid ( 1 65-fold excess) and equimolare amounts of TBTU and NMM for activation The e peptide was cleaved from the resin with 750 ul of acetic acid/trifluoroethanol/dichloromethane ( 30 10 70) within 2 h. After washing five times with 1 50 ul of the same solvent mixture the filtrates were combined, diluted with 10 ml heptane and concentrated. This procedure was repeated twice in order to remove the acetic acid completely. The oily residue was dissolved in 5 ml 4 N hydrogen chloride in dioxane. To this solution 270 ul ethanedithiol were added and the mixture was stirred for 3 h at room temperature. Then the solvent was removed and the residue dissolved in heptane and concentrated again several times until the ethanedithiol was almost completely removed. The crude peptide w as lyophili/ed from tert-butanol/water ( 1 1 ) and yielded 1 5 mg of Troc-Ada-Gly- Asp-Ser● HCl as white lyophilisat./

Amino acid analysis: Gly 1.09( 1 ), Asp 1.00( 1 ), Ser 0.95( 1 ), peptide content: 69.9 % ESI-MS: m/z 63 1.1 M⁺

Example 8: T roc-Ada-Gly-Asp-Trp

The title peptide was prepared in the same manner as example 70 starting from 50 mg (0.03 mmol) Fmoc-L-Trp-TCP resin 16 mg of Troc-Ada-Gly-Asp-Trp● HCl were obtained as white lyophilisate.

Amino acid analysis: Gly 1 .1 9 ( 1 ), Asp 0.88 ( 1 ), Trp 1.00 ( 1 ), peptide content 6. 2. %

ESI-MS: m/z 730.2 M⁺

Example 9: Troc-Ada-Gly-Asp-Phe

The title peptide was prepared in the same manner as example 70 starting from 50 mg (0.03 mmol) Fmoc-L-Phe- TCP resin. 14 mg of Troc-Ada-Gly-Asp-Phe● HCl were obtained as white lyophilisate.

Amino acid analysis: Gly 1.08 ( 1 ). Asp 1.00 ( 1 ), Phe 0.93 ( 1 ), peptide content 65.0 %

pos. LSIMS: m/z 692 1 MH⁺

The Troc protecting group of the compounds of example 7 to 9 can be removed by standard chemical reactions. Example 10: Ada-Gly-Asp-Tyr a) 3-Acetoxymethyl-2,5-dihydro-pyrrole-1-(N,N'-di-tert.-butoxycarbonyl) carboxamidine

To an ice-cooled solution of 1.21 g (5 mmol) 3-acetoxymethyl-2,5-dihydro-pyrrole-1-carboxylic acid tert.-butylestei from example 3f) in 10 ml dry dioxane was added 10 ml 4N hydrogen chloride in dioxane. The mixture was stirred at 0°C for 16 h. The mixture was evaporated to dryness without heating and then evacuated in high vacuum for several hours. The dark residue was suspended in 20 ml dry acetonitrile and 776 mg (6 mmol) ethyl diisopropylamine, followed by 1.71 g (55 mmol) N,N -bis-tert-butyloxycarbonyl-1H-pyrazole-1-carboxamidine were added The mixture was stirred for 2 h at room temperature and then evaporated and purified by flash chromatography (petrol ether/ethyl acetate 3: 1 to 2:1) to yield 1.87 g (97 %) of 3-acetoxvmethyl-2,5-dihydro-pyrrole-1-(N,N"-di-tert-butoxycarbonyl)carboxamidine as a colorless, sticky solid

¹H-NMR (CDCl₃ 300 MHz)

δ = 1.45 (s, 18H, 2 t-Bu), 2.03 (s, 3H, OAc), 4.38 (br m, 4H, 2-H, 5-H), 461 (s, 2H. CH₂OAc), 5.72 (br m, 1H, 4-H), 1022 (br s, 1H, NH) ppm.

¹³C-NMR(CDCI₃, 75 MHz)

δ - 204 (q, OOCCH₃).277, 279 [2q, C(CH,)₃|, 55.0 (br: 1. C-2, C-5) 602 (t. CH₂OAc).793, 818 [2 br s, C(CH₃)₃], 1224 (d, C-4), 1335 (s. C-3). 15.0 (br s. NCOO), 1539 (s, NC=N), 162 (br s, NCOO), 170.2 (s, OOCH₂CH₃) ppm.

b) 3-(2-Benzhydrilideneamino-2-ethoxycarbonyl-ethyl)-2,5-dihydropyrrole-1-(N,N'-di-tert.-butoxycarbonyl)carboxamidine

To a solution of lithium hexamethyldisilazide, freshly prepared at 0°C from 710 mg (44 mmol) hexamethyldisiiazane in 8 ml THF and 192 g (44 mmol) n-Butyl-lithium. (229 mmol/g in hexanes) and cooled to - 78°C was added a solution of 1069 g (4 mmol) ethyl N-(diphenylmethviene)-glycmate in 8 ml THF The orange enolate solution was stirred for 30 min at -78°C, then a solution of 1039 g (37 mmol) 3-acetoxymethyl-2,5-dihydro-pyrroie-1-(N,N-di-tert.-butoxycarbonyl) carboxamidine and 426 mg (04 mmol) Pd(PPh.)₄ in 12 ml THF was added dropwise. The reaction mixture was allowed to warm to room temperature over 2 h and was stirred for additional 12 h. The mixture was diluted with ether and quenched by addition of sat NaHCO. Ihe organic layer was washed with sat NaHCO₃ and brine, dried over MgSO₄ and evaporated Purification by flash chromatography (ethyl acetate/petrol ether I 5 T 1% triethylamine) gave 1.03 g (47 %) of 3-(2-benzhydrylideneamino-2-ethoxycarbonyl-ethyl)-2,5-dihydropyrrole-1-(N,N'-di-tert.-butoxycarbonyl) carboxamidine as a colorless, amorphous solid.

¹H-NMR (CDCl₃, 300 MHz)

6= 12.3 (t, J = 71 Hz, 3H, OCH₂CH₃), 146 [br s, 18H, C(CH₃)₃], 268 (br m, 2H, 3-CH₂-), 3.96 (br m, 1H, CH-N), 4.15 (q, j = 71 Hz, 2H, OCH₂CH₃), 416-4.29 (br m, 4H, 2-H, 5-H), 541 (br m, 1H, 4-H), 707 - 760 (m, 10 H, Ar-H) ppm

¹³C-NMR(CDCl₃, 75 MHz)

δ = 13.9 (q, OCH₂CH₃), 280 [q, C(CH₃)₃], 325 (t, 3-CH₂), 552, 569 (2t. C-2, C-5), 60.9 (t, OCH₂CH₃), 636 (d, CH-NH₂), 79, 81.6 [2 br. s, C(CH₃)₃], 120.7 (d, C-4), 127.5, 1278.1284, 128.5, 128.6, 130.2 (6d, Ar-CH), 1348 (s, C-3), 1358, 1391 (2s, Ar-C), 150 (br s. NCOO), 153.7 (s, NC=N), 162 (br s. NCOO). 1707 (s.

N=CPh₂), 1712 (s, OOCH₂CH₃) ppm.

c) 3-(2-Amino-2-ethoxycarbonyl-ethyl)-2,5-dihydropyrrole-1-(N,N'-di-tert.-butoxycarbonyl)carboxamidine

To a solution of 118 mg (0.2 mmol) 3-(2-benzhydrilideneamino-2-ethoxycarbonylethyl)-2,5-dihydropyrrole-1-(N,N -di-tert.-butoxycarbonyl)carboxamidine in 2 ml THF was added 1 ml I1 hydrochloric acid. The mixture was stirred at room temperature for 30 min. Water (5 ml) was added, the aqueous layer was separated and washed twice with ether. The aqueous layer was brought to pH = 8.5 by addition of 1N NaHCO₃ and was extracted five times with ether. The combined ether layers were washed with brine, dried over MgSO₄ and evaporated. The residue was purified by flash chromatography (chloroform/methanol 20:1) to yield 79 mg (93 %) 3-(2-amino-2-ethoxycarbonyl-ethyl)-2,5-dihydropyrrole-1-(N,N -di-tert.-butoxycarbonyl)carboxamidine as a colorless oil ¹H-NMR (CDCl₃, 300 MHz)

δ = 1.22 (t, J= 7.1 Hz, 3H, OCH₂CH₃), 1.45 [s, 18H, C(CH₃)₃].2.33 (dd, ²J - 16.0 Hz, ³J 8.1 Hz, 1H, CH_aH_bCHNH₂), 2.54 (dd, ²J = 166 Hz, ³J = 5.3 Hz, 111, CH_aH_bCHNH₂), 3.54 (dd, ³J = 81, 5.3 Hz, 1H, CH_aH_bCHNH₂), 413 (q, J= 71 Hz, 2H, OCH₂CH₃), 4.33 (br. m, 4H, 2-H, 5-H), 5.53 (br m, 1H.4-H) ppm

¹³C-NMR (CDCI₃, 75 MHz)

δ = 139 (q, OCH₂CH₃), 27.9 [q, C(CH₃)₃], 34.1 (t.3-CH₂).527 (d. CHNH₂), 55.3, 56.9 (2d , C-2. C-5), 61.1 (t, OCH₂CH₃), ca 80 [2 br s, C(CH₃)₃]. 120.7 (d. C-4). 134.6 (s, C-3), 153.8 (s, NC-N), 174.6 (s, OOCH₂CH₃) ppm

d) 3-(2-tert.-Butoxycarbonyl-amino-2-ethoxycarbonyl-ethyl)-2,5-dihydropyrrole-1-(N,N'-di-tert.-butoxycarbonyl)carboxamidine

To a solution of 79 mg (019 mmol) 3-(2-amino-2-ethoxycarbonvl-ethyl)-2.5-dihydropyrrole-1-(N,N -di-tert.-butoxycarbonyl)carboxamidine in 1 ml dry acetonitrile was added 40 mg (0.3 mmol) ethyl diisopropylamine and 65 mg (0.3 mmol) di-tert-butyl dicarbonate (Boc₂O) and the mixture was stirred for 16 h at room temperature. The solvent was evaporated and the residue was purified by flash chromatography (petrol ether/ethyl acetate 21) to yield 8.3 mg ( 76 %) 3-(2-tert-butoxycarbonyl-amino-2-ethoxycarbonyl-ethyl)-2,5-dihydropyrrole-1-(N,N'-di-tert.-butoxycarbonyl)carboxamidine as a colorless oil ¹H-NMR (CDCI₃, 200 MHz)

δ = 1.22 (t, J = 7.1 Hz, 3H, OCH₂CH₃), 1.42, 1.47, 1.48 [3 s, 9H each, C(CH₃)₃], 2.41 - 2.66 (br m, 2H, 3-CH₂-), 4.17 (q, J = 7.1 Hz, 2H, OCH₂CH₃), 4.32 (br m, 4H, 2-H, 5-H), 5.02 (br m.1H, CHNH), 5.52 (br s, 1H, 4-H) ppm ¹³C-NMR (CDCl₃, 50 MHz)

δ = 14.1 (q, OCH₂CH₃), 281.283, 28.5 [3q, C(CH₃)₃], 31.8 (t.3-CH₂), 483 (d. CHNH), 52.0, 55.3 (2t, C-2, C-5), 61.6 (t, OCH₂CH₃), 121.3 (d, C-4), 133.5 (s, C-3), 153.9 (s, N=C-N), 171.8 (s, COOEt) ppm

NCOO-. C(CH₃)₃-signals not visible due to line broadening e) 3-(2-tert.-Butoxycarbonyl-amino-2-carboxy-ethyl)-2,5-dihydropyrrole- 1 -(N,N -di-tert.-butoxycarbonyl) carboxamidine

To a solution of 267 mg (0 63 mmol) 3-(2-tert -butoxycarbonyl-amino-2-ethoxy-carbonyl-ethyl)-2,5-dihydropyrrole- 1 -(N,N -di-tert. -butoxycarbonyl) carboxamidine in 5 ml THF/methanol/water 3: I : I was added 50 mg ( 1.2 mmol) LiOH*H₂O. After 30 min stirring at room temperature no starting material could be detected by TLC. The mixture was made acidic by addition of 1 N HCl, diluted with water and extracted three times with ether. The combined organic extracts were washed with brine, dried over MgSO₄ and evaporated. The residue was purified by tlash-chromatography to give 98 mg (3 1 %) of 3-(2-tert.-Butoxycarbonyl-amino-2-carboxy-ethyl)-2,5-dihydropyrrole- 1 -( N,N -di-tert.-butoxycarbonyl ) carboxamidine ( Boc-Ada(Boc₂)-OH ) as a colorless amorphous solid ¹

H-N M R (CDCl3, 300 MHz)

δ = 1.39, 1 44 [2s, 9H, 18H, C(CH ₃)₃], 2.49 - 2.67 (br m. 2H, 3-CH₂-),4.33 (br m, 4H, 2-H, 5-H), 5.30 (br d, 1 H, CHNH), 5.56 (br s, 1 H, 4-H) ppm

¹³C-N M R (CDCl3, 75 MHz)

δ = 27.7, 28 9. 28 0 [3q, C(CH₃)₃], 3 1.3 (t, 3-CH₂), 52.0 (d, CHNH), 55.3, 56.9 (2t, C-2, C-5). 80.0, 80.9 [2s, (C(CH₃)₃], 121.1 (d, C-4), 133.6 (s, C-3), 1 53.2 (s, N=C-N ), 1 55.2 (br s, NCOO), 1 76.5 (s, COOH) ppm f) Ada-Gly-Asp-Tyr

The title peptide was prepared in same manner as example 80 starting from 50 mg (0.03 mmol) Fmoc-L-Tyr-TCP resin instead of Troc-Ada(Boc₂)-OH Boc- Ada(Boc₂)-OH from example 12e) was used for the N-terminal amino acid 1 2 mg of Ada-Gly-Asp-Tyr● HCl were obtained as white lyophilisate

Amino acid analysis: Gly 1 .05 ( 1 ) ; Asp 0.96 ( 1 ), Tyr 1 .00 ( 1 ); peptide content : 61 1%

pos. LSIMS: m/z 534.3 MH⁺ Example 1 1 Ada-Gly-Asp-Phe-N H₂

The ntle compound was sy nthesized by solid-phase methodology on a ACT90 automated peptide synthesizer (Advanced ChemTec, Louisville, Kentucky) using tritylchloride-polystyrene( 1 %)divinylbenzene (TCP, loading 0.96 mmol/g, PepChem, Tubingen) and Fmoc-Asp-Phe-NH₂ (NovaBiochem, Laufelfingen) as starting materials. The Fmoc-protected dipeptide amide (320.4 mg, 0.72 mmol) was dissolved in 4 ml dichloromethane After 1 eq N-methyl-morpholin ( NMM ) was added the solution was given to 444 mg (0.48 mmol) dry TCP resin After 5 mm an additional v olume of 1 30 ul NMM was added yielding a total amount of 1.80 mmol NMM in solut ion. The mixture was shaken for further 60 min. Then the residual tritylchloride groups were capped by the addition of 0.5 ml methanol. After further 20 mm the resin was filtered off and washed with dichloromethane, DMF and methanol. The resin was dried under reduced pressure. Loading of the resin was determined to be 0.057 mmol/g. The Fmoc group was removed by treatment with

piperidine/dimethylformamide ( 1.1 v/v) for 2 × 10 min Afterwards Fmoc-Gly-OH was coupled within 30 min in 30-fold excess in a double coupling procedure using 1 eq T B TU and 1 eq NMM as activing agents. After removal of the Fmoc group by the same procedure as described above Boc-Ada(Boc₂)-OH was coupled manually in DMF within 1 7 h by using a 2.5-fold excess of the protected amino acid and equimolar amounts of TBTU and NMM for activation. Cleavage from the resin and deprotection of the peptide was performed according to example 8f) Instead of heptane tntluoroethanol (2 ml ) was used to dissolve the deprotected peptide From this solution the crude peptide was precipitated bv the addition of 16 ml diethylether. After centrifugation the supernatant was discarded and the precipitate Ivophilized from tert -butanol/water ( 1 : 1 v/v) Ada-Gly-Asp-Phe-NH₂● HCl (28 mg) was obtained as white lyophilisate.

Amino acid analysis: Gly 1.05 ( 1 ), Asp 1. 03 ( I ), Phe 0.97 ( I ), peptide content 67.4%

pos. LSI MS: m/z 502.3 MH ⁺ Example 1 2 Description of the pharmacological experiments

Thrombin time

A common test in clinical coagulation diagnostics is the thrombin time. This parameter detects the action of thrombin on fibrinogen and the formation of blood clots Inhibitors of thrombin result in an increased thrombin time. in order to obtain plasma 9 parts fresh blood from healthy donors are mixed with one part sodium citrate solution (0. 1 1 mol/l) and centrifuged at ca 3000 rpm for 1 0 mm at room temperature. The plasma was removed by pipette and can be stored for ca. 8 h at room temperature.

200 μl citrate plasma was incubated for 2 min at 37°C in a sphere coagulometer (KC 10 from the Amelung Company). 10 μl dimethylsulfoxide (DMSO) or a solution of the active substance in DMSO was added to 190 μl preheated thrombin reagent (Boehringer Mannheim, GmbH, contains ca . 3 U/ml horse thrombin and 0.01 25 M Ca2+ ). A stopwatch was started when this 200 μl solution was added to the plasma and the time point at which coagulation starts was determined. In the control measurements the thrombin time was ca 24 seconds and was increased by the compound of example 3 depending on the concentration (test concentration/ inα ease of thrombin time 5 μ M / 300* sec; 0.5 μM / 96 sec; 0.05 μ M / 9 sec ) [ * t he experiment was stopped after 5 minutes.]

Thrombin inhibition

The kinetic measurements were carried out in 0.1 M phosphate buffer which contained 0.2 M sodium chloride and 0.5 % polyethylene glycol 6000 at a pH = 7.5 and 25°C using the substrate H-(D)-Phe-Pro-Arg-pN A ( S-2238 Kabu and human thrombin ( Sigma, specific activity = 2 1 50 NIH-units/mg) in polyslyrene semimicro -cuvettes in a total volume of 1 ml.

In a preexperiment is was determined whether the compound of formula ( I ) inhibits thrombin rapidly or slowly. For this the reaction was started first by adding 0.03 N IH units thrombin to a 100 μM solution of the substrate and the active substance. In a second experiment substrate was added to a solution of thrombin and the active substance w hich had been incubated for 5 min. The increase of the concent ration ot p- nitro-anilide with time was monitored spectrophotomeirically for 1 2 min at 405 nm ( UV-VIS spectrophotometer Lambda-2 from the Perkin-Elmer Company). Since the measurement curves obtained in both experiments were linear and parallel the active substance of formula (I) is a rapid thombin inhibitor. The inhibition constant Ki was determined as follows. The substrate was added at concentrations of 100 μM 50 μM 30 μM, 20 μM and at each substrate concentration a measurement was carried out without inhibitor and three measurements were carried out in the presence of various concentrations of the inhibitor of formula (I) . The reactions were started by addition of thrombin. The increase in absorbance at 405 nm caused by the for mation of p-nitroanilide was monitored for a time period of 12 min. Measurement points (time v ersus absorbance) w ere transferred to a PC at interv als of 20 sec T he rates Vo ( changes in absorbance per sec, measurements w ithout inhibitor) and V i

( measurements with inhibitor ) were determined f rom the data by linear regression Only that part of each measurement was used in which the substrate concentration had been reduced by less than 1 5 %. From one measurement series (constant inhibitor concentration, variable substrate concentrations) Km' and Vmax were determined by a non-linear fit to the equation

Finally Ki was determined from the total series of measurements by non-linear fit to the equation

The Michaelis constant Km was 3.8 + 2 μM in all measurements

The compound of example 4 inhibits thrombin.

Inhibition of trypsin 10 mg bovine pancreatic trypsin (Sigma) was dissolved in 100 ml mM hydrochloric acid and stored in a refrigerator 20 μl thereof was admixed with 980 μl 1 mM hydrochloric acid. 25 μl thereof was used for each measurement The measurement was carried out as described for thrombin Km - 45 μM. The compound of example 1 inhibits trypsin with an inhibition constant Ki of 100 nM. GpIIb/IIla inhibition

The GpIIb/IIIa fibrinogen Elisa is a modification of assays which are descnbed in the following literature Nachman, R.L. & Leung, L.L.K. ( 1982): J . Clin. Invest.69: 263-269 and Wright, P. S. et al . ( 1993) Biochem. J. 293 :263-267.

Microtitre plates were coated overnight with 2 μg/ml isolated activated Opl lb/I 1 la receptor. After unbound receptor had been removed by washing several times the surface of the plates is blocked with 1 % casein and it is washed again. The test substance is added at the required concentrations and the plates are incubated for 10 minutes while shaking. The natural ligand of the gpIIb/IIIa receptor, fibrinogen, is added. After incubating for 1 hour unbound fibrinogen is removed by washing several times and the bound fibrinogen is determined by means of a peroxidase-conjugated, anti-fibrinogen monoclonal antibody by measuring the optical density at 405 nm in an ELISA instrument. The inhibition of a fibrinogen-GpIIb/IIIa interaction results in a low optical density. The IC50 value was determined by a concentration/effect curve.

Claims

Claims

1. Compounds of formula 1

in which R 1 , R2 and Y can be the same or different and denote hydrogen or an organic residue and their optically active isomers as well as pharmacologically acceptable salts or prodrugs thereof

2. Compounds of formula I as claimed in claim I in which

R1 , R2 can be the same or different and denote hydrogen, an amino acid peptidyl, alkylsulfonyl or arylsulfonyl residue,

Y denotes hydrogen or a residue of formula COX,

X denotes hydrogen, an OR3 or NR 1'R2' residue

R3 denotes hydrogen or lower alkyl such as methyl, ethyl, piopyl or butyl and

R 1 ', R2' can be same or different and have the meanings oi the residues R1 and R2

and their optically active isomers as well as pharmacologically acceptable salts or prodrugs thereof.

3. Pharmacological composition containing at least one compound of the general formula I as claimed in one of the claims 1 or 2 in addition to the conventional carrier and auxiliary agents.

4. Use of compounds of formula 1 as claimed in one of the claims 1 or 2 for the production of a pharmaceutical composition for treatment of diseases which are due to thromboembolic events, osteoporosis, inflammations or tumour diseases

5. Use of the structure 1

as an arginine mimetic in a compound comprising a arginine structure or a known mimetic of said arginine structure wherein Y denotes for H or COR3 and R 1 , R2, R3 denote for different residues of an arginine or a known arginine mimetic structure of said compound