MXPA99001772A - Stable non-hygroscopic crystalline form of n-[n-n-(4-(piperidin-4-yl)butanoyl)-n-ethylglycyl]compounds - Google Patents

Abstract

The invention is directed to a non-hygroscopic stable crystalline form of the antithrombotic compound N-[N-[N-(4-piperidin-4-yl)butanoyl)-N-ethylglycyl]-(L)-aspartyl]-(L)-&bgr;-cyclohexyl-alanine amide, to processes for preparing said stable crystalline form, to a pharmaceutical composition thereof, and intermediates thereof, and the invention is directed also to processes for preparing a compound of formula (II) wherein:A, B, Z, E1, E2, G, R, m, n, and p are as defined herein.

Description

NON-HIGROSCOPIC AND STABLE CRYSTALLINE FORM OF N- [N-N- (4-PIPERIDIN-4-IL) BUTANOIL) -N-ETHYLGLYCAL COMPOUNDS BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION The invention is directed to a non-hygroscopic stable crystalline form of the N- [N- [N- (4-piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl- (L) - amide β-cyclohexyl-alanine of formula 1. The compound has antithrombotic activity, OH > including inhibition of platelet aggregation and clot formation in mammals, and is useful in the prevention and treatment of thrombosis associated with diseases such as myocardial infarction, seizure, peripheral arterial disease, and disseminated intravascular coagulation. In addition, the invention is directed to processes for preparing the crystalline form of the N- [N- [N- (4-piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl- (L) amide ) -β-cyclohexylalanine, a pharmaceutical composition thereof and the intermediates thereof. Haemostasis, the biochemistry of blood coagulation, is an extremely complex phenomenon in which whole normal blood and the tissues of the body spontaneously cease to bleed when there is a wound or damaged blood vessels. Effective hemostasis requires the combined activity of vascular, platelet and plasma factors, as well as a mechanism that controls these factors to prevent excessive clotting. Defects, deficiencies or excesses of any of these components can lead to hemorrhagic or thrombotic consequences. Platelet adhesion, its dispersion and aggregation on extracellular matrices are central events in the formation of thrombi or clots. These events are mediated by a family of adhesive glycoproteins, ie fibrinogen, fibronectin and von Willebrand factor. Fibrinogen is a cofactor in platelet aggregation, whereas fibronectin supports platelet junctions and dispersion reactions, and von Willebrand factor is important for platelet binding and for dispersion over sub-endothelial matrices. The binding sites for fibrinogen, fibronectin and von Willebrand factor have been located on the platelet membrane protein complex known as glycoprotein Ilb / IIIa.

Adhesive glycoproteins, such as fibrinogen, do not bind to normal circulating platelets. However, when a platelet is activated with an agonist such as thrombin or adenosine diphosphate, the platelet changes its shape, perhaps making the GPIIb / lIIa binding site more accessible to fibrinogen. The compound within the field of the present invention blocks the fibrinogen receptor, and therefore has the aforementioned antithrombotic activity 2. TECHNICAL BACKGROUND It has been observed that the presence of the tripeptide Arg-Gli-Asp (RGD) is necessary in fibrinogen, fibronectin and von Willebrand factor for its interaction with the cell surface receptor (Ruoslahti E., Pierschbacher, Cell 1986, 44,517 -18). Two other amino acid sequences also seem to take part in the function of fibrinogen in platelet binding, namely the Gli-Pro-Arg sequence, and the dodecapeptide sequence His-His-Leu-Gli-Ala-Lis-Gln-Ala-Gli -Asp-Val. It has been shown that small synthetic peptides containing the RGD or the dodecapeptide bind to the GPIIb / lIIa receptor on the platelet and competitively inhibit the binding of fibrinogen, fibronectin and von Willebrand factor as well as inhibit the aggregation of activated platelets ( Plow, et al., Proc. Nati, Acad. Sci USA 1985,82 8057-61; Ruggeri, et al., Proc. Nati, Acad. Sci. USA 1986, 5708-12; Ginsberg, et al., J. Biol. Chem. 1985, 260, 3931-36; and Gartner, et al., J. Biol. Chem. 1987. 260. 11, 891-94). It is reported to indolyl compounds that contain portions of guanidino-alkanoyl-aspartyl and guanidino-alkenoyl-aspartyl as inhibitors of platelet aggregation by Tjoeng, and others., patent E.U. No. 5,037,808 and 4,879,313. The Patent E.U.A. No. 4,992,463 (Tjoeng, et al.), Issued February 12, 1991, describes generically that a series of aryl- and aralkyl-guanidin-alkyl peptide mimetic compounds exhibit platelet aggregation inhibitory activity and specifically describe a series of mimetic compounds of mono- and dimethoxyphenyl peptide and a nimetic biphenyl-alkyl peptide compound. The Patent E.U.A. No. 4,857,508 (Adams, et al.), Issued August 15, 1989, describes generically that a series of guanidino-alkyl peptide derivatives containing terminal aralkyl substituents exhibit platelet aggregation inhibitory activity and specifically describes a series of derivatives of O-methyl tyrosine, biphenyl- and naphthyl- having a terminal amide functionality. Haverstick, D.M. et al., in Blood 66 (4), 946-952 (1985), discloses that a number of synthetic peptides, including arg-gli-asp-ser and gli-arg-gli-asp-ser, are capable of inhibiting Platelet aggregation induced by thrombin. Plow, E.F, and others., In Proc. Nati Acad. Sci. E.U.A. 79,3711-3715 (1982), disclose that the tetrapeptide glycyl-L-prolyl-L-arginyl-L-proline inhibits the binding of fibrinogen to human platelets. French Application No. 86/17507, completed on 15 December 1986, describes that the tetra-, penta- and hexapeptide derivatives containing the sequence -arg-gli-asp- are useful as antithrombotic. The Patent E.U.A. No. 4,683,291 (Zimmerman, et al.), Issued July 28, 1987, discloses that a series of peptides, comprising from 6 to 40 amino acids, which contain the sequence -ar-gli-asp- are inhibitors of the union platelet European application publication No. 0 319 506, published on June 7, 1989, discloses that a series of tetra-, penta-, and exapeptide derivatives containing the sequence -arg-gli-asp- are inhibitors of aggregation platelet It is reported that cyclic peptide analogues containing the gli-Asp moiety are fibrinogen receptor antagonists in the U.S. Patent. No. 5,023,233. Peptides and pseudopeptides containing amino-, guanidino-, imidizaloyl, and / or amidinoalkanoyl, and alkenoyl moieties are reported as antithrombotic agents in U.S. Patent applications. We of series 07 / 677,006, 07 / 534,385, and 07 / 460,777 pending, completed on March 28, 1991, June 7, 1990 and January 4, 1990, respectively, as well as in the Patent E.U.A. No. 4,952,562, and in International Application No. PCT / US90 / 05448, completed September 25, 1990, all assigned to the same assignee of the present invention. Peptides and pseudo-peptides containing amino- and guanidino-, alkyl- and alkenyl-, benzoyl, phenyl-alkanoyl, and phenylalkenoyl portions are reported as antithrombotic agents in pending application in the United States Serial No. 07 / 475,043, filled out on February 5, 1990, and in International Application No. PCT / US91 / 02471, completed on April 11, 1991, published as International Publication No. WO 92/13117 October 29, 1992, assigned to the same assignee of the present invention. The alkanoyl derivatives of aspartic acid and the substituted alkanoyl azacycloalkylformails of aspartic acid are reported as inhibitors of platelet aggregation in US Pat. No. 5,053,392, completed on December 1, 1989, and assigned to the same assignee who holds the invention title of the present invention. N-substituted cyclic aminoacylapartic acid azacycloalkylcarbonyl derivatives are reported as antithrombotic in US Pat. No. 5,064,814, filed on April 5, 1990 by the same inventor and assigned to the same assignee of the present invention. The azacycloalkyl formylglycyl derivatives of aspartic acid are reported as antithrombotic in US Pat. No. 5,051,405, filed October 10, 1989, and assigned to the same assignee of the present invention. European Patent Application No. 0 479 481, published on April 8, 1992, discloses amino acids of azacycloalkylalkanoylglycyl aspartyl as fibrinogen receptor antagonists. European Patent Application No. 0 478 362, published on April 1, 1992, describes the azacycloalkylalkanoyl peptidyl β-alanines as fibrinogen receptor antagonists. PCT Patent Application Publication No. W095 / 10295 discloses the azacycloalkylalkanoyl peptides and pseudo-peptides of the formula II, and in particular, the amide of N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cycloexilalanine as inhibitors of Platelet aggregation and clot formation in mammals and is useful in the prevention and treatment of thrombosis. The amide of N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cyclohexyl-alanine prepared according to PCT Patent Application Publication No. Wo95 / 10295, is amorphous, hygroscopic and physically unstable in that it absorbs moisture. The publication of Request for PCT Patent No. W095 / 10295 does not disclose a non-hygroscopic stable crystalline form of the N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl amide ] - (L) -β-cyclohexy-1-alanine. PCT Patent Application Publication No. W095 / 10295 also discloses that the azacycloalkylalkanoyl peptides and pseudopeptides are generally prepared by standard methods of peptide synthesis in solution phase or in solid phase using starting materials and / or intermediates already readily available to from suppliers such as Aldrich or Sigma (H. Paulsen, G. Merz, V. Weichart, "Solid-Phase Synthesis of O-Glycopeptide Sequences". Angew. Chem. Int. Ed. Engl. 27 (1988); H. Mergler, R. Tanner, J. Gosteli, and P. Grogg. "Peptide Synthesis by a Combination of Solid-Phase and Solution Methods I: A New Very Acid-Labile Anchor Group for the Solid-Phase Synthesis of Fully Protected Fragments, Tetrahedron Letters 29, 4005 (1988); Merrifield, RB," Solid Phase Peptide Synthesis after 25 Years: The Design and Synthesis of Antagonists of Glucagon, "Makromol, Chem Macromol, Symp. 19, 31 (1988).) Furthermore, PCT Patent Application Publication No. W095 / 10295 discloses that the amorphous form and hygroscopic amide of N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cyclohexyl-alanine is prepared by sequential synthesis from the C-terminal end as shown in scheme 1.

SCHEME 1 CH2-C-OP F r > B P 2) DESPR OTECTIO N II £ O The publication of PCT Patent Application No.

W095 / 10295 does not disclose the formation of tetra-azacycloalkylalkanoyl peptides and pseudopeptides or in particular of the N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) amide -aspartyl] - (L) -β-cyclohexylalanine from a central di (pseudopeptide or peptide) wherein the N-terminal and C-terminal ends of the di (pseudopeptide or peptide) are both coupled with pseudoamino acids and / or amino acids to form the tetra azacycloalkyl-alkanoyl peptides and pseudopeptides.

BRIEF DESCRIPTION OF THE INVENTION The present invention is directed to a stable, non-hygroscopic crystalline form of the N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - amide. L) -β-cyclohexyl-alanine of the formula 1. The compound has attrithrombotic activity, including inhibition of platelet aggregation and clot formation in mammals, and is useful in the prevention and treatment of thrombosis associated with disease states such as myocardial infarction, seizure, peripheral arterial disease and disseminated intravascular coagulation. The invention is also directed to a pharmaceutical composition of the stable non-hygroscopic crystalline form of the N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) - amide. aspartyl] - (L) -β-cyclohexylalanine and its intermediates thereof. The invention is also directed to processes for preparing a tetra-azacycloalkylalkanoyl peptide or pseudopeptide compound of the formula II where: A is H; B is alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, aralkyl, alkylaryl or alkylaryl; Z is E1 is H; E is an alpha carbon side chain of an naturally occurring alpha amino acid, H, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, substituted aryl, aralkyls, substituted aralkyls, heterocyclyls, substituted heterocyclyls, heterocyclylalkys, substituted heterocyclylalkyl, or and E2 taken together with the nitrogen and carbon atoms through which E and r r are joined to form an aza-cycloalkane ring of 4-, 5-, 6-, or 7 members; G is OR1 or NR1R2; R 1 and R are independently hydrogen, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, aralkyl, alkylaryl, or alkylaryl; R is H, alkyl, aryl, aralkyl; m is 1 to 5, - n is 0 to 6; and p is 1 to 14, and, in particular, the stable non-hygroscopic crystalline form of the N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) amide -particular] - (L) -β-cyclohexylalanine.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 depicts a powder X-ray diffraction graph of a sample of the non-hygroscopic crystalline form of the N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl amide ] - (L) -partil] - (L) -β-cyclohexyl-alanine prepared in example 13, method A. Figure 2 represents a powder X-ray diffraction graph of a sample of the non-hygroscopic crystalline form of the N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) -partyl] - (L) -β-cyclohexyl-alanine amide prepared in Example 13 , method B (a). Figure 3 depicts a powder X-ray diffraction graph of a sample of the non-hygroscopic crystalline form of the N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl amide ] - (L) -partsyl] - (L) -β-cyclohexyl-alanine prepared in example 13, method B (b). Figure 4 depicts a powder X-ray diffraction graph of a sample of the hygroscopic crystalline form of the N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl amide] - (L) -partyl] - (L) -β-cyclohexyl-alanine prepared as noted in example 14. Figure 5 represents a diffraction graph of X-ray powder of a sample of the non-hygroscopic crystalline form of the N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) -partyl] amide (L) -β-cyclohexyl-alanine prepared as noted in example 14. Figure 6 represents an isothermal microcalorimetric plot of the power output as a function of time for three different experiments which are performed as described in Experiment 15. The experiments monitor the thermal activity of different crystalline forms of the N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] amide - (L) -β-cyclohexylalanine when exposed to various solvent vapors. The trace (A) in Figure 6 demonstrates that a strongly exothermic event occurs when the hygroscopic amide N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) - aspartyl] - (L) -β-cyclohexylalanine prepared according to examples 5 or 11 is exposed to a RH of 80% (saturated solution of KCl) at 40 ° C within 30 hours, during which, with said exposure, the hygroscopic form of the compound is converted to the non-hygroscopic form of the compound. The trace (B) in Figure 6 demonstrates that there are no exothermic conversion events that take place when the hygroscopic amide of N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cyclohexylalanine prepared according to examples 5 or 11 is exposed to methanol vapors at 40 ° C, (a solvent other than water in which the soluble compound), and therefore, methanol does not support the mobility within the crystals in this way for the conversion to the non-hygroscopic form. The trace (C) of Figure 6 demonstrates that there are no exothermic conversion events that take place when the non-hygroscopic amide of N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl ] - (L) -partyl] - (L) -β-cyclohexylalanine prepared according to example 13 is exposed to RH of 80% / 40 ° C, and therefore the non-hygroscopic form of the compound does not undergo form conversion to those conditions, that is, that it is a stable form. Figure 7 represents an isothermal microcalorimetric plot of the power output as a function of time for three different experiments that are performed as described in experiment 15. The experiments monitor the thermal activity of the conversion of the hygroscopic crystalline form of the amide of N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cyclohexyl-alanine to its non-hygroscopic form when it is exposed to 80% RH at 40 ° C, 50 ° C and 60 ° C. The figure represents that the conversion requires approximately 24 hours at 40 ° C, 6.5 hours at 50 ° C and 3 hours at 60 ° C. Figure 8 represents an isothermal microcalorimetric plot of the power output as a function of time for 4 different experiments which are performed as described in experiment 15. The experiments monitor the thermal activity of the conversion of the hygroscopic crystalline form of the N- [N- [N- (4- (piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cyclohexyl-alanine amide to its non-hygroscopic form when is exposed to 60 ° C with 65% RH, 75% RH, 80% RH and 100% RH. A salient feature of Figure 8 is that the higher the relative humidity the faster the conversion occurs. Another salient characteristic is that the conversion of the non-hygroscopic form of the compound occurs at 100% RH at 60 ° C without the liquefaction occurring at the hygroscopic form at room temperature. Based on these results, it is expected that the conversion rate of the non-hygroscopic form will be much faster than the liquification rate of the hygroscopic form at 60 ° C. Figure 9 represents a comparison of graphs of% gain in weight versus% RH for the hygroscopic (Ü) and non-hygroscopic () forms of the amide of N- [N- [N- (4- (piperdin-4- il) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cyclohexylalanine at 25 ° C which are carried out as described in experiment 16. Figure 9 shows that the hygroscopic form takes more water that forms non-hygroscopic as the HR increases, and is more pronounced at HR greater than 60%. In addition, Figure 9 shows that the hygroscopic form of the compound does not desorb the water until its original percentage weight is obtained, while the non-hygroscopic form of the compound desorbs the water at its original percentage weight.

DETAILED DESCRIPTION OF THE INVENTION The following terms, as used above and as will be used throughout the description of this invention, should be understood with the following meaning, unless otherwise indicated: The following abbreviations used hereafter include; BOC (t-butyloxycarbonyl), CBZ (benzyloxycarbonyl), Gly (glycine), Asp (aspartic acid), Obzl (benzyloxy), TFA (trifluoroacetic acid), Cha (ß-cyclohexyl-alanine), EtOAc (ethyl acetate), DMF (dimethylformamide), DCC (dicyclohexylcarbodiimide), HOBT (hydroxybenzotriazole), TBTU (2-lH-Benzotriazol-1-yl) -1,1,3, 3-tetramethyluronotetrafluoroborate), DI (de-ionized water), PNP (p -nitrophenol), PFP (pentafluorophenol), DCU (dicyclohexyl urea), NMM (N-methylmorpholine), MTBE (methyl t-butyl ether), HR (Relative Humidity), THF (tetrahydrofuran), PipBu (4-piperidinbutyric acid) and PpBuen ((4-Piperidin) butylidenecarboxylic acid) is a compound of the formula "Patient" includes both humans and other mammals. "Pharmaceutically acceptable salt" means a salt form of the parent compound of formula I which is relatively harmless to a patient when used in therapeutic doses such that the beneficial pharmaceutical properties of the parent compound of formula I are not vitiated by effects side effects attributable to a counter ion of said saline form. The pharmaceutically acceptable salts also include an internal or zwitterion salt of the compound of formula I. "Alkyl" means a saturated aliphatic hydrocarbon which may be straight or branched and have from 1 to 20 carbon atoms in the chain. Branched means that a lower alkyl group such as methyl, ethyl, or propyl is attached to a linear alkyl chain. Preferred linear or branched alkyl groups are the groups "Lower alkyl" which are those alkyl groups having from 1 to 10 carbon atoms. More preferred lower alkyl groups have from 1 to 6 carbon atoms. "Cycloalkyl" means a saturated carbocyclic group having 1 or more rings and having from 3 to 10 carbon atoms. Preferred cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and decahydronaphthyl.

"Cycloalkylalkyl" means an alkyl group substituted with a cycloalkyl group. Preferred cycloalkylalkyl groups include cyclopentylmethyl, cyclohexylmethyl, cyclohexylethyl, decahydronaph-1-ylmethyl and decahydronaph-2-ylmethyl. "Alkylcycloalkyl" means a cycloalkyl group substituted with an alkyl group. Exemplary alkylcycloalkyl groups include 1-, 2-, 3-, or 4-methyl- or ethyl-cyclohexyl. "Alkylcycloalkylalkyl" means an alkyl group substituted by an alkylcycloalkyl group. Exemplary alkylcycloalkyl groups include 1-, 2-, 3-, or 4-methyl or ethylcyclohexylmethyl or 1-, 2-, 3-, or 4-methyl or ethyl cycloexylethyl. "Azacycloalkane" means a saturated aliphatic ring containing a nitrogen atom. Preferred azacycloalkanes include pyrrolidine and piperidine. "Alpha-amino acids occurring naturally" means glycine, alanine, valine, leucine, isoleucine, serine, threonine, phenylalanine, tyrosine, tryptophan, cysteine, methionine, proline, hydroxyproline, aspartic acid, asparagine, glutamine, glutamic acid, histidine, arginine , ornithine, and lysine. "Alpha-carbon side chain of an A-mino acid naturally occurring" means the portion which substitutes the alpha carbon of an alpha-amino acid that occurs naturally. Examples of naturally occurring alpha-mino acid alpha-carbon secondary chains include isopropyl, methyl, and carboxymethyl, for valine, alanine, and aspartic acid, respectively. The term "amino protecting group" means an easily removable group which is known in the art to protect an amino group against undesirable reactions during synthetic procedures and which is selectively removable. The use of amino protecting groups is well known in the art to protect groups against undesirable reactions during a synthetic process and many such protective groups are known, cf., for example, Greene and P.G.M. Wuts, Protective Groups in Organic Synthesis, 2nd edition, John Wiley & amp;; Sons, New York (1991), incorporated here for reference. Preferred amino protecting groups are acyl, including formyl, acetyl, chloroacetyl, trichloroacetyl, o-nitrophenylacetyl, o-nitrophenoxyacetyl, trifluoroacetyl, acetoacetyl, 4-chlorobutyryl, isobutyryl, o-nitrocinnamoyl, picolinoyl, acyl-isothiocyanate, aminocaproyl, benzoyl, and similar, and acyloxides including methoxycarbonyl, 9-fluorenylethoxycarbonyl, 2,2,2-trifluoroethoxycarbonyl, 2-trimethylsilylethoxycarbonyl, vinyloxycarbonyl, allyloxycarbonyl, tert-butyloxycarbonyl (BOC), 1,1-dimethylpropynyloxycarbonyl, benzyloxycarbonyl (CBZ), p-nitrobenzyloxycarbonyl, 2, 4 -dichlorobenzyloxycarbonyl, and the like. The term "amino protecting group susceptible to acids" means an amino protecting group as defined above which is easily removed by treatment with an acid while remaining relatively stable to other reagents. An amino-protecting group susceptible to acids is tert-butoxycarbonyl (BOC). The term "amino protecting group susceptible to hydrogenation" means an amino protecting group as described above which is easily removed by hydrogenation while remaining relatively stable to other reagents. A preferred amino-protecting group susceptible to hydrogenation is benzyloxycarbonyl (CBZ). The term "acid protecting group" means an easily removable group which is known in the art to protect a carboxylic acid (-CO2H) against undesirable reactions during synthetic procedures and which is selectively removable. The use of carboxylic acid protecting groups is well known in the art and many such protective groups are known, cf., for example, T.H. Greene and P.G.M Wuts, Protective Groups in Organic Syntheis, 2nd edition, John Wiley & Sons, New York (1991), incorporated here for reference. Examples of carboxylic acid protecting groups include esters such as methoxymethyl, methylthiomethyl, tetrahydropyranyl, benzyloxymethyl, substituted and unsubstituted phenacyl, 2,2,2-trichloroethyl, tert-butyl, cinnamyl, substituted and unsubstituted benzyl, trimethylsilyls and the like, and amides and hydrazides including N, N-dimethyl, 7-nitroindolyl, hydrazide, N-phenylhydrazide, and the like.

The term "acid protecting group susceptible to hydrogenation" means an acid protecting group as described above which is easily removed by hydrogenation while remaining relatively stable to other reagents. A protective group of acid susceptible to hydrogenation is benzyl. "Aryl" means a phenyl or naphthyl group. "Substituted aryl" means a naphthyl or phenyl group substituted by one or more substituents of the aryl group which may be the same or different, wherein "aryl group substituent" includes alkyl, alkenyl, alkynyl, aryl, aralkyl, hydroxy, alkoxy, aryloxy, aralkoxy, hydroxyalkyl, hydroxyalkyl, acyl, formyl, carboxy, alkenoyl, aroyl, halo, nitro, trihalomethyl, cyano, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, acylamino, aralkylamino, carbamoyl, alkylcarbamoyl, dialkylcarbamoyl, arylcarbamoyl, aralkylcarbamoyl, alkylsulfonyl, alkylsulfinyl, arylsulphonyl, arylsulfinyl, aralkylsulphonyl, aralkylsulfinyl, or -NRaR * Q wherein Ra and Rj- are independently hydrogen, alkyl, aryl or aralkyl. "Aralkyl" means an alkyl group substituted by an aryl radical Preferred aralkyl groups include benzyl, naph-1-ylmethyl, naph-2-ylmeitl and phenethyl "Substituted aralkyl means an aralkyl group substituted on the aryl portion by one or more substituents of the aryl group.

"Heterocyclyl" means monocyclic or multicyclic ring systems of 4 to 15 members in which one or more of the atoms in the ring is a non-carbon element, for example nitrogen, oxygen, or sulfur. Preferred heterocyclyl groups include pyridyl, pyrimidyl, and pyrrolidyl. "Substituted heterocyclyl" means a heterocyclyl group substituted by one or more substituents of the aryl group. "Heterocyclylalkyl" and "substituted heterocyclylalkyl" means an alkyl group which is substituted by a heterocyclyl and a substituted heterocyclyl group, respectively. "Hygroscopicity" means sorption involving an acquired quantity or state of water sufficient to affect the physical or chemical properties of the substance (Eds. J.

Swarbrick and J. C. Boylan, Encyclopedia of Pharmaceutical Technology, Vol. 10, 0 ,. 33).

PREFERRED MODALITIES A preferred compound prepared according to the present invention is described by formula II wherein E is H, alkyl, hydroxymethyl, 1-hydroxyethyl, mercapto methyl, 2-methylthioethyl, carboxymethyl, 2-carboxyethyl, 4-aminobutyl, 3-guanidinopropyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, substituted aryl, aralkyl, substituted aralkyl, heterocyclyl , substituted heterocyclic, heterocyclylalkyl, substituted heterocyclylalkyl, or E and E ^ are taken together with the carbon and nitrogen atoms with which E1 and E2 are the linked form of an azacycloalkane ring of 4-, 5-, 6, or 7 members, providing that the heterocyclylalkyl is other than indol-3-ylmethyl; A more preferred compound prepared according to the present invention is described by formula II wherein E is H, alkyl, hydroxymethyl, 1-hydroxyethyl, mercaptomethyl, 2-methylthioethyl, carboxymethyl, 2-carboxyethyl, 4-aminobutyl, 3-guanidinopropyl , cycloalkyl, cycloalkylalkyl, alkylcycloalkylalkyl, aryl, substituted aryl, aralkyls, substituted aralkyl, or E 1 and Ep are taken together with the nitrogen and carbon atoms whereby Ei and E .- * are the attached form of an azacycloalkane ring of 4-, 5-, 6-, or 7 members. A still more preferred compound prepared according to the present invention is described by formula II wherein p E is H, alkyl, hydroxymethyl, 1-hydroxyethyl, mercaptomethyl, 2-methylthioethyl, carboxymethyl, 2-carboxyethyl, 4-aminobutyl, -guanidinpropyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, or E and E taken together with the carbon and nitrogen atoms with which E and p E are the linked form of an azacycloalkane ring of 4-, 5-, 6-, or 7 members.

A more preferred compound still prepared according to the present invention is described by formula II wherein B is alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, or alkylcycloalkylalkyl. A special embodiment prepared according to the present invention is described by the formula wherein: B is alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, aralkyl, alkylaryl or alkylaryl. J is H, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl alkylcycloalkylalkyl, aryl, substituted aryl, aralkyl or substituted aralkyl. L is OR1 or NR1R2; -i p R and R are independently hydrogen, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, aralkyl, alkylaryl or alkylaryl. m is 1 to 5; n is 2 to 6; and p is 1 or 2.

A more preferred special embodiment prepared according to the present invention is described by the formula lia wherein B is alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl or alkylcycloalkylalkyl J is H, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl or alkylcycloalkylalkyl; m is 3; and n is 3 or 4. A special embodiment even more preferred prepared according to the present invention is described by the formula lia wherein B is alkyl; J is alkyl, cycloalkyl or cycloalkylalkyl R 1 and R are independently H, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, or alkylcycloalkylalkyl, m is 3; n is 3 or 4; and p is 1. A special embodiment still more preferred prepared according to the present invention is described by the formula Ia which is the amide of N- [N- [N- (4-piperdin-3-yl) butanoyl) -N -ethylglycyl] (L) -aspartyl] - (L) ß-cyclohexylalanine. Another embodiment according to the invention is the formation of a stable non-hygroscopic crystalline form of the N- [N- [N- (4-piperdin-3-yl) butanoyl) -N-ethylglycyl] (L) -aspartyl amide. ] - (L) -cyclohexylalanine. According to the invention, this form of the compound is capable of being developed as a stable formulation of the compound. The non-hygroscopic crystalline form of the N- [N- [N- (4-piperdin-3-yl) butanoyl) -N-ethylglycyl] (L) -aspartyl] - (L) β-cyclohexylalanine amide also has a point of high melting and shows that it has no tendency to absorb water. The stable form also exhibits unique and unexpected stability against moisture and temperatures well in excess of those normally encountered in parcel conditions, manufacture of the dosage form, or in long-term travel or long-term storage. These properties also facilitate the manufacture of the dosage form. Furthermore, conversion to the stable form does not result in loss of material or its purity, and does not adversely affect its particle properties. It should be understood that the present invention is directed to cover all combinations of preferred compounds, preferred embodiments and special modalities as described hereinafter. A compound of the present invention is useful in the form of the free base or acid, zwitterionic salt thereof or in the form of a pharmaceutically acceptable salt thereof. All forms are within the scope of the invention. Where a compound of the present invention is substituted with a basic portion, an acid addition salt is formed and is simply a more convenient form to be used; and in practice, the use of the salt form inherently increases its use or the use of the free base form. The acid which can be used to prepare an acid addition salt preferably includes those which produce, when combined with the free base, a pharmaceutically acceptable salt, that is, a salt whose anion is not toxic to the patient at pharmaceutical doses of salt, in such a way that the beneficial inhibitory effects of platelet aggregation and the formation of clots inherent in the free base are not vitiated by side effects attributable to the anion. Although the pharmaceutically acceptable salts of said basic compounds are preferred, all acid addition saare useful as sources of the free base form even if the particular salt, by itself, is desired only as an intermediate product as, for example, when the salt is formed only for purification purposes , and identification, or when used as an intermediate in the preparation of pharmaceutically acceptable saby ion exchange processes. The pharmaceutically acceptable sawithin the scope of the invention are those derived from the following acids: mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid and sulfamic acid; and organic acids such as acetic acid, citric acid, lactic acid, tartaric acid, malonic acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, cyclohexylsulfamic acid, quinic acid, and the like. The corresponding acid addition salts comprise the following: halohydrates ie hydrochloride and bromohydrate, sulfate, phosphate, nitrate, sulfamate, acetate, citrate, lactate, tartarate, malonate, oxalate, salicylate, propionate, succinate, fumarate, maleate, methylene-bis -β-hydroxynaphthoates, gentisatos, mesylates, isothionates and di-p-toluoyltartratomentansulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonate, cyclohexyl fumarate and quinate, respectively. According to a later characteristic of the invention, the acid addition salts of the compounds of this invention are prepared by reaction of the free base with the appropriate acid, by application or adaptation of the known methods. For example, the acid addition salts of the compounds of this invention are prepared either by dissolving the free base in aqueous solution or aqueous alcoholic solution or in other suitable solvents containing the appropriate acid and isolating the salt by evaporation of the solution, or by reacting the free base and the acid in an organic solvent in which case the salt is separated directly or can be obtained by concentrating the solution. The acid addition salts of the compounds of this invention can be regenerated from the salts by application or adaptation of known methods. For example, the parent compound of the invention can be regenerated by its acid addition salt by treatment with alkali, ie aqueous sodium bicarbonate in solution or aqueous ammonium solution. Where the compound of the invention is substituted with an acid portion, the basic addition salts can be formed and are simply a more convenient form for their use; and in practice as, the use of salt forms inherently raises the use of the free acid form. The bases which can be used to prepare the basic addition salt preferably include those which produce, when combined with the free acid, pharmaceutically acceptable salts, that is, salts whose cations are non-toxic to the animal organism in pharmaceutical doses of the salts , in such a way that the beneficial inhibitory effects of platelet aggregation and the formation of thrombi or clots inherent in the free acid are not vitiated by side effects attributable to the cations. Pharmaceutically acceptable salts, including for example alkali metal and alkaline earth salts, within the scope of the invention are those derived from the following bases: sodium hydride, sodium hydroxide, potassium hydroxide, calcium hydroxide, aluminum hydroxide, hydroxide lithium, magnesium hydroxide, zinc hydroxide, ammonium, ethylenediamine, n-methylglucamide, glycine, arginine, ornithine, culin, N, N'-dibenzylethylene diamine, chloroprocaine, diethanolamine, procaine, N-benzylphenethylamine, diethylamine, piperazine, tris (hydroxymethyl) -aminomethane, tetramethylammonium hydroxide, and the like. The metal salts of the compounds of the present invention can be obtained by contacting a hydride, hydroxide, carbonate or similar reactive compounds of the chosen metal in an aqueous or organic solvent with the free acid form of the compound. The aqueous solvent used can be water or it can be a mixture of water with an organic solvent, preferably an alcohol such as methanol or ethanol, an acetone such as acetone, or an aliphatic ether such as tetrahydrofuran, or an ester such as ethyl acetate. Such reactions are usually conducted at room temperature but could, if desired, be conducted or carried out with heat. The amino salts of the compounds of the present invention can be obtained by contacting an amine in an organic or aqueous solvent with the free acid form of the compound. Suitable aqueous solvents include water and mixtures of water with alcohols such as methanol or ethanol, ethers such as tetrahydrofuran, nitrile such as acetonitrile, or ketones such as ketone. Amino acid salts can be similarly prepared. The basic addition salts of the compounds of this invention can be regenerated from the salts by the application or adaptation of known methods. For example, the parent compounds of the invention can be regenerated from their basic addition salts by treatment with an acid, i.e., hydrochloric acid. As they are also useful by themselves as active compounds, the salts of the compounds of the invention are useful for the purification purposes of the compounds, for example by exploiting differences in solubility between the salts and the parent compounds, the products secondary and / or starting product by techniques well known to those skilled in the art. The compounds of the present invention may contain asymmetric centers. These asymmetric centers can independently be in either R or S configuration. It will also be apparent to those skilled in the art that certain compounds of formula I could exhibit geometric isomerism. Geometric isomers include the cis and trans forms of the compounds of the invention having alkenyl portions. The present invention includes the individual geometric isomers and stereoisomers and mixtures thereof. Such isomers can be separated from their mixtures, by the application or adaptation of known methods, for example chromatographic techniques and recrystallization techniques, or they can be prepared separately from the appropriate isomers of their intermediates, for example by the application or adaptation of the methods described hereinafter.

The Patent Applications of E.U.A. Nos. 08 / 138,820 and 08 / 138,820 and 08 / 476,750 which are incorporated herein by reference describe methods for the preparation of an amorphous compound of the formula II, and in particular, an amorphous compound of the formula I. A novel process according to the invention for preparing a compound of the formula II, and in particular, a crystalline compound of the formula I according to this invention is described by the synthesis shown in Scheme II wherein B, E- ^ E2, G, R, m, ny SCHEME II p are as defined above, and P is a hydrogenation-susceptible acid protecting group such as p-benzyl, P ^ is an acid-sensitive ammo protecting group such as t-butoxycarbonyl (BOC) and P is a group amino protector susceptible to hydrogenation, such as benzoyloxycarbonyl (CBZ). During the preparation of compounds of formula II or intermediates thereof, it may be desirable or necessary to prevent cross reactions between chemically active substituents and those present in naturally occurring amino acids or pseudoaminoacids. The substituents can be protected by standard blocking groups which can be subsequently removed or retained, as required, by known methods to obtain the desired products or intermediates (see, for example, Green, "Protective Groups in Organic Synthesis", Wiley , New York, 1981). Selective protection or deprotection may also be necessary or desirable to allow the conversion or elimination of existing substituents, or to allow subsequent reactions to obtain the desired end product. The procedures of Scheme II are exemplified for the preparation of the compound of formula II, however it should be understood that a compound of formula I is prepared using the appropriate starting materials. In the preparation of the compounds of the formula I according to scheme II, B is ethyl, E1 is H, E "is cyclohexylmethyl, G is NH2, R is H, m is 3, n is 3, p is 1, P1 is benzyl, P "is BOC, and P3 is a CBZ. An alternative process according to the invention for the preparation of a compound of the formula I is the same as that in scheme II except that the compound of the formula III, where P3 is as defined above, is used instead of the compound of formula IV wherein R is H, m is 3, n is 3, p is 1, and P is a CBZ to provide an intermediate of formula V, where B is ethyl, E is H, E "is cyclohexylmethyl, G is NH2, p is 1, P1 is benzyl, and P3 is CBZ. Scheme II demonstrates a 5-step method for preparing a compound according to the invention starting with the formation of a central dipeptide intermediate according to the invention of formula VI, wherein B, p, P "and p2_N_ (CH2) P J-1LL. MHNN.- .rCHu-- írCliO2H B CH2CO2P (VI) P are as described above. In the case of the preparation of the compound of the formula I, the central dipeptide intermediate according to the invention is BOC-N (Et) Gli- (L) -Asp (OBzl) -OH. The central dipeptide intermediate is prepared without protection of the free carboxylic acid portion. In step 2 of scheme II, the coupling to form the central dipeptide can be carried out either in dichloromethane or mixtures of ethyl acetate - with or without DMF as cosolvents - and organic bases such as NMM, and can be made from room temperature to about 40 ° C. Activation of the amino acid or pseudoamino acid of the following formula for coupling can be effected using O P2-N- (CH2) p-COH B active esters not isolated with p-nitrophenol, pentafluoro-phenol, and N-hydroxy-succinimide through the action of dicyclohexylcarbodiimide. The interval of the copulation times range from 1 to about 20 hours, depending on the amino acids or pseudoaminoacids that are going to copulate, the activating agent, the solvent, and the temperature. The central dipeptide product of step 1 does not have to be isolated. The reaction mixture of step 1 is typically washed with water or dilute aqueous acid (for example, aqueous hydrochloric acid), and then used directly without drying in step II. In the case that an active ester based on phenol is used, the central dipeptide product is extracted in alkaline water from the reaction mixture, then reextracted from the acidified aqueous solution and returned to the organic solvent; and the solution is reacted directly as in step 2. The dipeptide intermediate of formula VI is used to prepare a tridipeptide intermediate according to the invention of formula VII, wherein B, E, F, G, p and Px are as defined above, and P "is P" or TFA * H-. Where P "is TFA * H-," * "represents dissociation of TFA to form F3CCO2 and H +, wherein H + protonates the terminal amine in the compound of formula VII, v. Gr., Giving the TFA salt of the In the case of the preparation of the compound of CF-3CO2 ' (Vlla) formula I, the tripeptide intermediate according to the invention is P "'-N (et) Gli- (L) -Asp (OBzl) - (L (-Cha-NH2- In step 2, the coupling of an amino acid or pseudoamino acid to the central dipeptide can be carried out either in dichloromethane or in mixtures of ethyl acetate and DMF or THF, and at a temperature close to ambient The activation of the central dipeptide of the following formula for coupling can be P2-N-- (CH2) p HN-CH-C02H B CH2CO2P1 carried out using non-isolated active esters of pentafluorophenol or N-hydroxy-succinimide via the action of dicyclohexylcarbodiimide. Activation can also be effected using isopropyl chloroformate. The reaction times vary with the amino acids or pseudoamino acids that are coupled, the activating agent, the solvent, and the temperature, and the interval ranges from 1 to 20 hours. The tripeptide product does not have to be isolated. When the tripeptide intermediate is not isolated, the reaction mixture is washed with aqueous organic base such as aqueous N-methylmorpholine and aqueous acids such as aqueous hydrochloric acid and is reacted as is via the method of step II after the washes. watery and without drying. In step 3 of scheme II, removal of the protective group such as BOC from the tripeptide product of step 2 can be effected using a solution of trifluoroacetic acid in dichloromethane, or using a mixture of hydrobromic acid in acetic acid and ethyl acetate. The reaction can run at room temperature, and requires only about one hour (hydrobromic acid method) and about two hours (TFA method). The saline acid product of the tripeptide is isolated by filtration as a crystalline solid either directly from the reaction mixture by the (hydrobromic acid method), or after partial removal with solvents by distillation and addition of a non-polar solvent to the residue of the flask.

A further process according to the invention is described as a single concatenated procedure for rapidly and simply preparing TFA HN (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2 from BOC- (Et ) Gli-OH whose procedure is a single-vessel reaction that includes the first two steps of copulation in scheme II and treatment with TFA. TFA.HN (Et) Gli- (1) -Asp (OBzl) - (L) -Cha-NH2 is obtained uniquely as it crystallizes directly from the concatenated reaction solution. The concatenated procedure avoids the corresponding three reactions described in scheme two and solves the problem of establishing an efficient synthesis in time and cost which is useful in the manufacturing environment. Scheme II shows the construction of a polypeptide in reverse order, starting with a protected N-mino acid then added successively to the C-terminal end, as in the opposite way in conventional manner, in which a polypeptide is constructed by successive aminations at the end amino or a protected amino acid at the C-terminus. This inverse synthetic method according to the invention requires the protection of nitrogen only of the first amino acid, facilitating the use from that point forward, of successive amino acids that have no protection either at the end amino or acid (side chain functional groups are excepted). The inverse synthetic method also modernizes the production of a compound of the formula II, and in particular a compound of the formula I, by enabling the use of flow-type manufacturing technology in a manner opposite to the type normally required for the peptide chemistry in solution phase. The new proposal cuts production costs by eliminating the requirement to buy protected amino acids in the aminoterminal. No equipment is required, reagents or special analytical methodology. Another process according to the invention is the formation of the stable non-hygroscopic crystalline amide of N- [N- [N- (4-piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L)-β-cycloexilalanine reproducibly obtained by a novel conversion in solid state from the hygroscopic crystalline amide of N- [N- [N- (4-piperdin-4-yl) butanoyl) -N-ethylglycyl] - ( L) -particular] - (L) -β-cyclohexylalanine prepared by the method as described in Scheme II and the alternative reaction steps noted. The hygroscopic crystalline form of the N- [N- [N- (4-piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) -asparyl] - (L) -β-cyclohexylalanine amide is physically unstable and is converted upon exposure to moisture and temperature conditions to the highly stable non-hygroscopic crystalline form of the N- [N- [N- (4-piperdin-4-yl) butanoyl) -N-ethylglycyl] - amide ( L) -β-cycloexilalanine. The general conditions according to the invention for the conversion of the hygroscopic crystalline form of the N- [N- [N- (4-piperdin-4-yl) butanoyl) -N-ethylglycyl] - (1) -aspartyl amide ] - (L) -β-cyclohexylanine to the highly stable non-hygroscopic crystalline form of the N- [N- [N- (4-piperdin-4-yl) butanoyl) -N-ethylglycyl] - (L) - amide aspartyl] - (L) -β-cyclohexylalanine have been carried out under static and dynamic conditions. The static process according to the invention are described as a static conversion since it involves exposing the hygroscopic crystalline form of the N- [N- (N- (4-piperdin-4-yl) butanoyl) -N-ethylglycyl amide. ] - (L) -particular] (L) -β-cyclohexylalanine placed in a container that does not move such as in a vial or tray under certain conditions of temperature and humidity in a controlled environment chamber. This "static" conversion is developed at relative temperatures and humidities ranging from 20 ° C to 80 ° C, more preferably from about 40 ° C to 80 ° C and to HR from 40 to 100% preferably HR between 65 and 80%. The dynamic process according to the invention is described as a dynamic conversion since it involves exposing the hygroscopic crystalline form of the N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl amide. ] - (L) -partyl] - (L) -β-cyclohexylalanine under incubation at the temperature and humidity levels as in the static model, but also under a medium of agitation, including the enveloping of the hygroscopic crystalline form of the amide of N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cycloexilalanine in a rotary evaporating flask or in a a cylindrical container (in a humidity oven), with agitation of propellers.

The following examples are illustrative of the invention and are not intended to limit the field. Unless otherwise indicated, the mass spectral analysis data reported are with accelerated bombardment of low resolution atoms developed in a VG 70SE with "calculated values" being (M + H) +. The nuclear magnetic resonance (NMR) spectral data are obtained in a Brucker ACF 300, in D2O. The flash chromatography is done on silica gel. High performance liquid chromatography (HPLC) is made in Reverse Phase C-18 columns of particular size ranging from 8 to 15 microns. Unless otherwise indicated, the reported powder x-ray diffraction graphs are obtained using a Siemens D5000 diffractometer with a copper radiation source (1.8kW, 45kV and 40mA) to sweep dust samples. Samples are ground before measurements to eliminate the effect of particle size on peak intensities. Approximately 60 mg of the samples are loaded in sample cups of 1.5 x lcm and swept in the range of 3-40 ° 2 theta with step size of 0.04 ° and the total exposure being 1 second per step.

EXAMPLE 1 Preparation of BOC-N (Et) Gli- (L) -As (OBzl) -OH (Step 1 of Scheme II) In a round-bottomed flask with three necks of 1 L, 51 g (0.25 mmoles) of BOC-N (Et) Gli-OH, 35 g (0.35 mmoles) of PNP, 400 ml of ethyl acetate and 100 ml of DMF are charged. The mixture is stirred to form a solution and cooled to 4-6 ° C. A solution of 51.5 g (0.25 mmoles) of DCC in 125 ml of ethyl acetate is added dropwise in a period of 10 minutes, while maintaining the temperature from 5 ° C to 8 ° C. After all the DCC is added, the cooling bath is removed and the mixture is stirred for 1.5 hours as it warms to room temperature (20-22 ° C). A solid precipitate, DCU is formed during this period. The complete formation of PNP is determined by analytical CLAR (disappearance of BOC- (Et) Gli-OH). The reaction mixture is filtered, the residue DCU is washed with two 50 ml portions of ethyl acetate and the washes added to the filtrate. The DCU is discarded. To the filtered and stirred solution, 67 g (0.3 mmol) of H2N- (L) -Asp (OBzl) -OH are added as a suspension in 150 ml (138 g, 1.36 mmol) of NMM. The mixture is heated to 38-40 ° C and maintained at that temperature for 41 hours, at which point an analytical HPLC indicates the total consumption of BOC-N (Et) Gli-OPNP. The reaction mixture is cooled to 25 ° C and the H2N- (L) -Asp (OBzl) -OH that did not react is filtered. The solution is cooled and refiltered to obtain an additional 1.2 g (21.7 g recovered, -11.2 g represents 20% excess added and 10.5 g (0.047 mmoles represents the unreacted material) .The filtered solution is extracted in a Squib funnel. 2 L with a 500 ml portion of deionized water, followed by two 250 ml portions. The combined aqueous solutions are extracted with three 300 ml portions of MTBE / EtOAc 1: 1 to remove the residual PNP (analytical HPLC shows that only a few traces remain), then it is cooled to 5 ° C and acidified to a pH of 8.9 at pH .79 by dropwise addition of 150 ml of concentrated HCl. The acidified aqueous solution is extracted with two 200 ml portions of ethyl acetate. The HPLC analysis of the aqueous solution shows that there is no residual desired product. The ethyl acetate extracts are combined, dried over magnesium sulfate, filtered, and concentrated by rotary evaporation at 35 ° C. The resulting pale orange oil is pumped at 35 ° C to maximize the removal of residual solvent to obtain 85.68 g of BOC-N (Et) Gli- (L) -Asp (OBzl) -OH as an oil (21.3 mmol, 85.5% yield, not corrected for residual solvent). Characterization: NMR (250 MHz): 7.3 ppm (s), 5.1 ppm (s), 3.3 ppm (dq), 3.0 (dq), 1.4 ppm (s), 1.1 (t) MS: M = 408; M + l0] -, svc_. = 409 CLAR: 90.79A% (3.87A% p-nitrophenol, not corrected for e) Elemental Analysis: C2oH28N2 ° 7: H 'N' "cenc 57.54, Ccal.58.81 EXAMPLE 2 Preparation of BOC-N (Et) Gli- (L) -As (OBxl) - (L) -Cha-NH? (step 2 of scheme II) METHOD A; Isopropyl chloroformate method. Dissolve one equivalent of BOC-N (Et) Gli- (L) -Asp (OBzl) -OH in ethyl acetate, (6-8 volumes, 1: 6.5 p: vol) and maintained at a temperature between -15- 0 ° C. NMM (1 equivalent) is added while maintaining the temperature from -15 ° C to 0 ° C. Isopropyl chloroformate is added (1-1.1 equivalents) to the solution of the protected dipeptide at a temperature between -15-0 ° C. The reaction is maintained at a temperature between -15 ° C to 0 ° C for 2 to 15 minutes. A solution of H2N- (L) -Cha-NH, (1 equivalent), in THF, (10 volumes, 1:10 p: vol) is added to the cooled dipeptide solution maintaining the temperature between -15 ° C and 0 ° C. ° C. The reaction is monitored with procedural control samples (HPLC) obtained at 15 minutes, 1 hour, and 2 hours to evaluate the end of the reaction. (The reaction is complete when the amount of dipeptide observed is less than 10% per area with analysis (HPLC). The BOC-tripeptide product precipitates directly from the reaction solution and is filtered from the reaction mixture, washed with ethyl acetate (2 x 1 volume; weight: volume), and vacuum drying Typical yields are> 60%, with purities> 90A%; <1% of the epimeric diastate of aspartic acid have been typically observed. in ethyl acetate provides the final yield of about 60% BOC-N (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2 and increases the purity to> 95A% while reducing the diastereoisomer at <0.5% As a specific example of the isopropyl chloroformate method, when the general procedure of Example a is followed and 4.55 g (8.1 mmol) of BOC-N (Et) -Gli- (L) -Asp (OBzl) -OH is used, then the amount of BOC-N (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2 prepared is 3.26 g (97.9 A pure%, 0.3A% diastereomer), a theoretical yield of 70%.

Method B: Pentafuran-phenol-DCC complex method Penfluorophenol (PFP, 2.9 equivalents) and DCC (1 equivalent) are dissolved in ethyl acetate (5 volumes, 1: 5 weight: volume) at room temperature and cooled to a temperature between -15-0 ° C. An equivalent of BOC-N (Et) Gli- (L) -Asp (OBzl) -OH is dissolved in ethyl acetate, (6 volumes, 1: 6 p: vol) and mixed with one equivalent of H2N- (L) -Cha-NH2 which has been previously dissolved in DMF, (10 volumes, 1:10 p: vol), the solution of dipeptide / H2N- (L) -Cha-NH2 is added dropwise in the PFP solution and DCC, keeping the temperature between -15-0 ° C. The reaction is maintained at a temperature between 15-22 ° C for five to sixteen hours with control samples in procedure (HPLC) obtained at 1, 2, 3, 4, and 16 hours to evaluate the entire reaction. (The reaction is complete when the amount of dipeptide observed is less than 2% per area by HPLC analysis). The reaction mixture is filtered and the filter cake (DCU) is washed with ethyl acetate, (2 X 0.5 volumes, p: vol). The filtrate is treated with water (10 volumes, 1:10 p: vol) and the water layer is removed. The ethyl acetate layer is washed with water, (IX, 5 volumes, 1.-5 p: vol). The ethyl acetate layer is cooled to precipitate the product, which is filtered and washed with ethyl acetate, (2 X 0.4 volumes, 1: 0.4 p: vol). Isolated molar yields are > 60% with typical purities of > 90A%, with 1-4A% of the diastereomer of aspartic-epimeric acid. A resuspension in the ethyl acetate provides the final yield of -60% BOC-N (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2 and improves the purity to > 99A% while reducing the diastereomer to < 0.5% As a specific example of the pentafluoro-phenol-DCC complex method, when the general method of method B is followed and 10 g (24.5 mmol) of BOC-N (Et) Gli- (L) -Asp (OBzl) -OH are used, then the amount of BOC-N (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2 prepared is 8.15 g (99A% pure, 0.49A% of the diastereomer), or a yield Theoretical 59%.

Method C Hydroxybenzotriazole method (HOBT) / 2- (IH-benzotriazol-1-yl) -1, 1, 3,3-tetramethyluronium tetrafluoroborate (TBTU) One equivalent of BOC-N- (Et) Gli- (L) -Asp (OBzl) is dissolved -OH in DMF (9-10 volumes; 1:10 p / p) and maintained at room temperature. To this solution is added H2N- (L) -Cha-NH2 (1 equivalent) and hydroxybenzotriazole (HOBT, 1 equivalent). The resulting solution is cooled from about 0 ° C to about 10 ° C and NMM (1-1.1 equivalents) is added. The coupling reagent, TBTU, (1-1.1 equivalents) is dissolved in DMF (4-5 volumes, 1: 5 w / w) and added to the protected dipeptide solution at a temperature of 0 ° C to about 10 ° C. This solution is stirred at about 10 ° C-25 ° C for about 3 hours until the HPLC analysis indicates the conclusion of the reaction (less than 2% starting material per area). The reaction mixture is added to a stirred mixture of 5% aqueous sodium chloride (approximately 4 volumes vs. reaction volume) and EtOAc (approximately 2 volumes vs. reaction volume). The phases are separated and the aqueous phase is extracted with an additional portion of EtOAc (approximately 1.5 volumes vs. reaction volume). The organic phases are combined and washed sequentially with 0.5 N aqueous citric acid (approximately 0.6-0.7 volumes vs. organic phase volume), 10% aqueous sodium bicarbonate (twice, with approximately 0.6-0.7 volumes vs. volume of organic phase each) and 25% aqueous sodium chloride (approximately 0.3-0.4 volumes vs. organic phase volume). The resulting organic phase is concentrated to about 1/4 to 1/2 volume under reduced pressure at about 30-50 ° C, and an equal volume of heptane is added to this hot solution. The mixture is stirred and allowed to cool from about 0 ° C to about 20 ° C to precipitate the desired tripeptide. This solid is filtered, washed with a mixture of EtOAc and heptane and dried. A typical performance is > 60%, with typical purities of > 95.7 A% and diastereomer levels of aspartic acid / epim rich at < 2A%. As a specific example of the HOBT / TBTU method, when the general procedure is followed, 10 g (24.5 mmoles) of BOC-N (Et) Gli- (L) -Asp (OBzl) -OH is used, and then prepared 9.3 g of BOC-N (Et) Gli- (L) -Asp (OBzl) -Cha-NH2 (96.1A pure%, 1.77A% diasterete in Asp), in theoretical yield of 67.7%. Mass spectrum: Mca? C 560.7; M + loj-jg-y- ^ 561 mp 182.17 (DSC) -H NMR (delta vs. TMS, D6 DMSO): 0.89, M (1H); 0.94, M (ÍH) 1.0, dt (2H); 1.15, M (2H); 1.06-1.3, M (4H) 1.36, d (9H) 1.4-1.74, m (6H); 2.65, m (ÍH); 2.85, m (1H) 3.18, m (2H) 3.75, d (2H); 4.2, s (ÍH); 4.66, d (ÍH); 5.08, s (2H); 7. 02, s (ÍH); 7.18, d (ÍH); 7.36, s (5H); 7.88, dd (ÍH); 8.24, dd (ÍH).

EXAMPLE 3 Preparation of TFA-N (Et) Gli- (L) -Asp (OBzl) - (L) -Ch -NH2 (Step 3 of Scheme II) BOC- (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2 is dissolved in dichloromethane (~ 1: 2 w / w), and to that solution is added TFA at room temperature. It is then stirred until the HPLC indicates complete reaction (3-5 hours). The solution is concentrated to approximately 1/2 volume at 40-45 ° C. To this hot solution is added MTBE (-1:10 p / p vs. BOC- (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2 while maintaining a temperature> 40 ° C. The mixture is slowly cooled to about 5 ° C and stirred for 1 hour to ensure complete crystallization The resulting solids are filtered and washed with ice-cold MTBE The solids are dried under reduced pressure and analyzed for the content of TFA-N (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2 (HPLC test w / w) The yield is generally quasi-quantitative, purity> 95A%. : Mca? C> 460 (free base); M + l0] 3SV-¿461 Elemental analysis: C26H37N4? 7F3 H, N, F, C 54.35, fd., 53. 82 ^ -H NMR (delta vs TMS, D6 DMSO): 0.9, m (2H); 1.15, t (6H); 1.5, m (ÍH); 1.5-1.8, m (6H); 2.65, dd (ÍH); 2.9, m (3H); 3. 7, s (2H); 3.9, m (2H); 4.2, m (ÍH); 4.75, m (ÍH); 5.1, S (2H); 7.0, s (ÍH); 7.15, s (ÍH); 7.2, s (5H); 8.13, d (ÍH); 8.7-8.8, m (3H). 13C NMR (outgoing signals, delta vs. TMS, D6 DMSO): 10.76, 25349, 25.68, 31.66, 33.07, 33.36, 36.25, 38.59, 41.88, 47.02, 49.40, 50.47, 65.71, 127.81-128.34, 135.82, 165.10, 169.34, 173.79 The specific examples of deprotection are shown in Table A.

Table A EXAMPLE 4 Preparation of CBZ-PipBu-N (Et) Gli- (L) -As (OBzl) - (L) -Cha-NH2 (Step 4 of Scheme II) A suspension of approximately equimolar amounts of TFA.N (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2, CBZ-PipBu and TBTU in EtOAc, DMF and water (100: 8: 4 v / v, - 11.1 total w / w vs. TFA-N (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2). This suspension is cooled to 0-10 ° C and about 3-4 equivalents of NMM are added. This mixture is allowed to warm to room temperature and is stirred until the CLAR indicates the complete reaction (1-3 hours, the solution occurs during this time). Water (2-3 X original amount of added water) is added and the phases are allowed to separate. The aqueous phase is reserved and the organic phase is washed with two more portions of water. These combined aqueous washings are back-extracted with EtOAc and the combined organic phases are washed with 25% aqueous sodium chloride. The organic phase is concentrated under reduced pressure to almost 1/2 volume and MTBE is added (approximately 1/2 v: v vs. volume of solution). This mixture is allowed to crystallize (several hours) and the solids are collected by filtration, rinsing with a cold mixture of EtOAc and MTBE. The solids are dried under reduced pressure. The content of CBZ-PipBu-N (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2 is analyzed by HPLC test p / p. The performance is generally > 80%, purity > 95A%.

As a specific example of the above preparation, when the general procedure of step 4 is followed, 7.25 g of TFA.N (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2 provides 7.9 g of CBa-PipBu-N (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2 (> 99A% pure, 0.08A% diasterometer in Asp), a theoretical yield of 84%. Elemental analysis: C41H37N8: H, N, C, 65.84, fd. , 65.38 Mass spectrum: Mca? C 747; M + lQ ^ g - ^ - j 748 pf 101.6 (DSC) 1 H-NMR (delta vs. TMS, CDC13): 0.88 m (1H); 0.98, m (1H); 1.23, m (6H); 1.4, m (ÍH); 1.62-1.76, m (8H); 1.86, qd (ÍH); 2.35, t (ÍH); 2.74, dd (2H); 3.25, dd (ÍH); 3.47, q (2H); 3.7, d (ÍH); 3.84, d (1H); 4.15, ds (2H); 4.5, qd (1H); 4.68, dt (ÍH); 5.07, d (ÍH); 5.14, bd (2H); 5.16, d (ÍH); 7.28-7.39, m (10H); 7.57, dd (ÍH) NMR 13C NMR (delta vs TMS, CDCI3): [outgoing peaks] 66. 93 (both benzyl carbons), 127.78-128.64 (both phenyl rings), 155.249, 170.24, 171.69, 174.27, 175.21 (all carbonyl carbons).

EXAMPLE 5 Preparation of the hygroscopic crystalline amide form of N- [N- CN- (4-piperidin-4-yl) butanoyl) -N-ethyl-3-methyl- (L) -aspartyl] - (L) -i 5 -cyclohexylalanine (step 5 of scheme II) A mixture of CBZ-PipBu-N (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2, ammonium formate and 10% Pd / C in 20: 1 alcohol / water (10 : 1 v / p vs. CBZ-PipBu-N (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2). This mixture is heated to 40-50 ° C and stirred until the HPLC indicates the complete reaction (1-2 hours). The mixture is cooled to room temperature and filtered to remove the catalyst. The resulting solution is heated to 40-50 ° C and acetone (almost equal volume vs. filtered solution) is added, allowing the solution to cool to 35-40 ° C. Amide seeds of N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cyclohexylalanine are added to the mixture and the hygroscopic form of N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) -partyl] - (L) -β-cyclohexylalanine amide is crystallized therefrom while it is cooled to room temperature (several hours). The solids are collected by filtration under a nitrogen blanket by rinsing with acetone. The solids are dried under reduced pressure and analyzed to verify the content of the hygroscopic amide crystalline form of N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) - aspartyl] - (L) -β-cyclohexylalanine (HPLC p / p). The performance is generally > 85%, purity > 95A%.

As a specific example of the above preparation, when the general procedure of step 5 is followed, 5 g of CBZ-PipBu-N (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2 provide 3.1 g of a hygroscopic crystalline form of N- [N- [N- (4-piperidine- 4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cyclohexylalanine as a white solid (99.6% pure), a stoichiometric yield of 89.4%. Other compounds prepared according to the above examples 1-5, but using the appropriate starting materials, include the following: N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - aspartyl] valine, N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -D-valine, N- [N- [N- (4-piperidin-4 -yl) propanoyl) -N-ethylglycyl] -aspartyl] valine, N- [N- [N- (4-piperidin-4-yl) pentanoyl) -N-ethylglycyl] -aspartyl] valine, N- [N- [ N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -L-alpha-cyclohexylglycine, N- [N- [N- (4-piperidin-4-yl) butanoyl) -N- ethylglycyl] -aspartyl] norleucine, N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -L-alpha- (2, 2-dimethyl) prop-3 il glycine, N- [N- [N- (4-piperidin-4-yl) utanoyl) -N-ethylglycyl] -aspartyl] -L-β-decahydronaphth-l-yl alanine, N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -L-alpha- (2-cyclohexylethyl) glycine, N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] -aspart il] phenylalanine, N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -L-ß-naphth-l-yl-alanine, N- [N- [N - (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -L-ß-naphth-2-yl alanine, N- [N- (N- (4-piperidin-4-) ethyl ester il) butanoyl) -N-ethylglycyl] aspartyl] -L-β-cyclohexyl alanine, N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -L-β -cis-decahydronaphth-2-ylalanine, N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] aspartyl-alpha-aminocyclohexanecarboxylic acid, N- [N- [N- (4 -piperidin-4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -β-cyclohexyl-D-alanine, N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -β-decahydronaphth-1-ylalanine, N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -β-cyclohexylanine ethylamide N- [N-] [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -β-cyclooctylalanine, N- [N- [N- (4-piperidin-4-yl) utanoyl) amide] - N -ethylglycyl] -aspartyl] -β-cyclohexylmethyl anine, N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -β-adamant-1-ylalanine, N- [N- [N- (4-piperidine -4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -β- (1,2,3,4) -tetrahydronaphth-5-ylalanine, N- [N- [N- (4-piperidin-4-yl ) butanoyl) -N-ethylglycyl] -aspartyl] -β- (4-cyclohexyl) cyclohexylalanine, N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -β -cycloheptylalanine, N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -β-cyclooctylalanine amide, N- [N- [N- (4-piperidin- 4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -alpha-cyclohexylpropylglycine, N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -β-cyclooctylmethylalanine , N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -β-cyclopentylalanine, and ethyl ester of N- [N- [N- (4-piperidin- 4-yl) butanoyl) -N-ethylglycyl] -aspartyl] -β-cyclohexylmethylalanine.

EXAMPLE 6 Preparation of 4-N-CBZ-piperidone A mixture of 40 Kg of N-benzyloxycarbonyloxy) -succinimide and 26 Kg (175 mole) of 4-piperidone.HCl -H20 in 38.8 Kg of water and 88 Kg THF is stirred at 15 ° C ± 5 ° C until complete the dissolution (almost 15 minutes). NMM (22.8 Kg) is added to the stirred (exothermic) mixture while maintaining the temperature at or below 20 ° C. The batch is stirred at 20 ° C ± 5 ° C for 2.5 hours, at which point the HPLC indicated the complete reaction. The mixture is diluted with 115.2 Kg of MTBE and 3.8 Kg of water and stirred at 20 ° C ± 5 ° C for 5 minutes. Stirring is stopped, the layers are allowed to separate and the aqueous (lower) layer is removed and discarded. The organic layer is washed with 2 X 129.6 Kg of water (5 minutes are stirred, the phases are separated, the [lower] aqueous phase is removed / discarded). The organic layer is washed with 5.2 Kg of NaCl in 46.8 Kg of water (5 minutes are stirred, the phases are separated, the [lower] aqueous layer is removed / discarded). The organic layer is treated with 11.5 kg of MgSO 4, with stirring for 1 hour and then the mixture is filtered. The reactor is rinsed with 8 Kg of MTBE (filtrate, combined with the main filter material; total water content of the filtered material: 0.52%). The volume of the mixture is reduced by half by distillation under reduced pressure at 30 ° C. The vacuum is opened to nitrogen and the residue is cooled to 20 ° C (residual water content: 0.43%). The residue is diluted with 57.6 Kg of MTBE, then the volume of the mixture is reduced again by half by distillation under vacuum at 30 ° C. The vacuum is released to nitrogen and the mixture is cooled to 20 ° C (residual water content: 0.25%). This is repeated 5 times more. The final residue in the container is diluted with 28.8 kg of MTBE and mixed for 5 minutes, and then the water content and the content of 4-N-CBZ-piperidone is verified (water: 0.05%; test p / p 4 -N-CBZ-piperidone: 22.66% by weight, 35.36 kg, 155 mols, 88.65 pps stoichiq).

EXAMPLE 7 Preparation of PipBu Under a N2 purge and with stirring a solution of 53.5 Kg of 3-carboxypropyltriphenylphosphonium bromide in 230.1 Kg of 1,2-dimethoxy-ethane is prepared. Potassium tert-butoxide / THF (20% by weight, 141.8 Kg of solution) is added over 35 minutes maintaining the temperature at 24-28 ° C. The mixture is stirred at this temperature for 0.5 hours, at which point the HPLC indicates a complete reaction. The stirred mixture is cooled to 10 ° C ± 2 ° C, then 96.45 Kg (concentration: 1.15 molar equivalents vs.) Of 4-CBZ-pipiridone in MTBE is added to the mixture for 40 minutes so that the batch temperature remains at 12 ° C ± 2 ° C. The mixture is stirred at this temperature for 10 minutes and then heated to 20 ° C ± 2 ° C and stirred at that temperature for 2 hours. To the stirred mixture is added a solution of 22.5 Kg of concentrated aqueous HCl in 245.6 Kg of water to maintain the mixture at 20 ° C + 2 ° C; The final pH is 0.5. The mixture is extracted, with stirring, with 214.0 Kg of methyl-tert-butyl ether. The agitation is stopped, the faces are allowed to separate, and the aqueous layer (bottom) is removed and discarded. The organic phase is washed with 133.75 Kg of water (stir 5 minutes, separate, restitute / discard aqueous layer [lower]), then with 10.7 Kg of 50% NaOH in 126.8 Kg of water (stir 10 minutes, separate layers, remove / discard organic layer [superior]). The aqueous layer is extracted with 2 X 123.05 Kg of EtOAc (stir 5 minutes, separate layers, remove / discard [higher] organic layers). To the stirred aqueous layer is added 13.1 Kg of concentrated aqueous HCl at a pH of 2.5-3.5 (final: 2:82), then the mixture is extracted with 123.05 Kg of EtOAc (stir 5 minutes, separate layers, remove / discard aqueous layer [lower]). The EtOAc solution is washed with 133.75 Kg of water (stir 5 minutes, separate layers, remove / discard [lower] aqueous layer), then test (w / w) to verify the content of CBZ-PipBuen (total weight: 194.86 kg 17.05% CBZ-PipBuen [33.22 kg, 108 moles], 87.9% yield stoiq.). PipBuen's EtOAc solution, together with 6. 6 Kg of 5% Pd / C (50% water by weight) is charged with stirring to a stainless steel pressure tank, and then the mixture is heated to 55 ° C + 2 ° C. Potassium formate (38.2 Kg) dissolved in 66.4 Kg of water is added in such a way that the temperature of the reaction mixture remains at 55 ° C ± 2 ° C (x 30 minutes). The mixture is stirred at 55 ° C + 2 ° C for 2 hours, during which time the reaction is complete (HPLC). To the reactor is added 66.6 Kg of celite and 33.2 Kg of water, the mixture is stirred and then filtered. The reactor is rinsed with 33.2 Kg of water (filtered, added to the main filtrate). The filtered material is placed in a new container, cooled to 20-25 ° C, the layers are allowed to separate, and the organic layer is removed and discarded. The aqueous layer is acidified with 52.1 Kg of concentrated aqueous HCl at pH 2-3 (final: 2.82), then extracted with 4 X 129.5 Kg of methylene chloride (stir 5 minutes, separate layers, remove / discard organic layers [lower ]). The aqueous phase is adjusted to pH-6.1 by the addition, with stirring, of 17.85 Kg of aq NaOH. 50% The mixture is filtered to yield a 224 Kg solution containing 17.6 Kg (103 mole) of 4- (3'-carboxypropyl) piperidine.

EXAMPLE 8 Preparation of CBZ-PipBu The solution of 224 Kg of 4- (3'-carboxypropyl) piperidine in aqueous NaOH is combined with 55.3 Kg of THF and the mixture is cooled with stirring at 8 ° C ± 2 ° C. NMM (20.9 Kg) is added while maintaining the temperature at < 10 ° C. After the addition is complete, the temperature is adjusted to 8 ° C ± 2 ° C, then 25.7 kg of 1- (benzyloxycarbonyl) succinimide dissolved in 49.8 Kg of THF are added over 1 hour, keeping the temperature at < 15 ° C. The reaction is complete (analytical HPLC) after 3 hours at 10-15 ° C. Concentrated aqueous HCl (29.9 Kg) is added to adjust the pH to 2.5-3.5 (final: 3.3), then 61.4 Kg of MTBE are added and the mixture is stirred for 5 minutes. Agitation is stopped, the layers are allowed to separate and the aqueous layer (bottom) is separated (waste). The MTBE layer is washed with three portions of 83.1 Kg of water (stirring periods of 10 minutes, then 5 minutes and 5 minutes more); the aqueous phase is allowed to separate and removed (waste) in each case. A solution of 8.3 Kg of 50% aqueous NaOH in 95.7 Kg of water without stirring is added and after the complete addition the mixture is stirred for almost 5 minutes. Agitation is stopped, the phases are allowed to separate and the organic layer (upper) is separated and discarded. The aqueous layer is returned to the reactor and extracted with 2 X 38.4 Kg of methyl-tert-butyl ether (stirred for 5 minutes, the layers are separated, the [upper] organic layers are removed / discarded). This operation is repeated using 18.5 kg of methyl tert-butyl ether. The aqueous layer, returned to the reactor, is acidified to pH 2.5-3.5 (final: 3.37) with 9.9 Kg of ac HCl. concentrated. The mixture is extracted with 76.4 Kg of methyl-tert-butyl ether (stir 5 minutes, separate layers, remove / discard aqueous layer [lower]). The organic layer is washed (5 minutes of stirring) with a 1.1 Kg solution of NaHCO3 in 12.4 Kg of water (stir 5 minutes, separate layers, remove / discard [lower] aqueous layer), then with 41.5 Kg of water (shake) 5 minutes, separate layers, revomer / discard aqueous layer [lower]). The reactor is placed under reduced pressure and the volatile solvents are removed at 55 ° C until the distillation flow stops. Toluene (32.4 Kg) is added and the mixture is distilled under atmospheric pressure until the distillation flow stops, while the batch temperature rises to 90-95 ° C. The mixture is then cooled to 30-35 ° C, heptane (56.85 Kg) is charged to the reactor (two phases), the mixture is heated to 90-95 ° C, (single phase), then cooled to 38-42. ° C. CBZ-PipBu seed crystals are added and the product is crystallized from the mixture over a period of 1 hour.

The solid is collected by filtration and washed with 19.35 kg of toluene / heptane 1: 2, then with 33.4 kg of heptane. The filter cake is dried under vacuum at 40 ° C (at a loss of 0.13% in the drying analysis) to give 22.4 Kg (72.96 moles, 42% stoichiometric yield from 4-piperidone) of CBZ- PipBu.

EXAMPLE 9 Preparation of CBZ-PipBuen To a suspension of 82 g of 3-carboxypropyltriphenylphosphonium bromide in 407 ml of 1,2-diethoxyethane at 14 ° C, 220 g of 20% by weight potassium tert-butoxide in tetrahydrofuran is added over 25 minutes, maintaining the same Time the temperature of the reaction mixture at 24-28 ° C. The mixture is stirred for 1 hour, cooled to 10 ° C and then a solution of 52.5 g of 4-N-CBZ-piperidone in 246 mL of tert-butyl-methyl ether is added for 30 minutes, while maintaining the cooling. After the addition is complete, the mixture is stirred at 12 ° C for 10 minutes, then heated to 20 ° C and stirred for an additional 30 minutes. The reaction mixture is treated with 410 mL of ac HCl. at 1 N for 10 minutes, diluted with 328 mL of methyl t-butyl ether and then the phases are separated. The organic phase is washed with 205 mL of water, then 210 mL of aq NaOH. to 1 N. The NaOH layer, which contains the product, is cooled separately, washed with three portions of 189 g of ethyl acetate, acidified to pH 3.48 with concentrated HCl and then extracted with 189 mL of ethyl acetate. ethyl. The ethyl acetate layer is separated, washed with 211 mL of water and then dried over 30 minutes on 10 g of MgSO 4, filtered and concentrated in vacuo. The oily residue (50.7 g) is crystallized from toluene / heptane to give a total of 29.46 g (50.9% yield, -95A% pure) of CBZ-PipBuen. Mass spectrum: Mca c * 303, + lQ ^ g-y- ^ 304 1K NMR: (delta vs TMS, CDC13) 2.2, t (2H); 2.25, t (2H); 2.35, m (4H); 3.45, m (4H), 5.15, S (2H); 5.2, m (ÍH); 7.33.2 (5H). 13 C NMR (delta vs. TMS, CDCI3) 22.43, 28.2, 34.26, 35.66, 44.88, 45.74, 67.20, 122.02, 127.83, 127.95, 128.45, 128.69, 128.90, 136.17, 136.72, 155.34, 178.39 EXAMPLE 10 Preparation of CBZ-PipBuen-N (Et) Gly- (L) -Asp (OBzl) - (L) -Cha-NHp (alternative step 4 of scheme II) CBZ-PipBuen (70 g, 0.23 moles) and DMF (230 mL) are added to a 1 L covered flask and stirred with cooling at 0 ° C, then TBTU (74.9 g, 0.23 mole) is added in one fell swoop. . The mixture is maintained at 0 ° C and the addition of DIPEA (61.9 g, 0.61 mol) is initiated. After 45 minutes, TFA-N (Et) Gly- (L) -Asp (OBzl) - (L) -Cha-NH (138.7 g, 0.24 mol) is added as a solution in DMF (230 mL). The pH is adjusted to 7-8 by the addition of DIPEA (45 mL) and the mixture is allowed to reach room temperature. After 2 hours, the reaction is complete (HPLC analysis). The mixture is extinguished in water (2.5 L) and extracted with EtOAc (1 L). The aqueous phase is back-extracted with EtOAc (0.3 L). The organic layers are combined, washed with aqueous citric acid (5% w / w, 2 X 1 L), washed with NaHC 3 (5 w / w, 2 X 1 L) and washed with water (2 L ). The EtOAc layer is transferred to a 2L flask and heptane (500 mL) is added while stirring to effect crystallization. The solids are collected by suction in a Buchner funnel, washed with EtOAc / heptane (2: 1 v / v, 1 L) and dried to constant weight to produce CBZ-PipBuen-N (Et) Gly- (L) -Asp (OBzl) - (L) -Cha-NH (143.2 g, 0.19 moles, 83% yield). Elemental analysis: C41H55N5O C: clac. 66.02; fd. 65.53, H, N. Mass spectrum: Mca? C 745.91; + 1-Qbgvd 746 1 H NMR (delta vs TMS, CDCl 3): 0.86 qd (HH); 0.98, qd (ÍH); 1.16, t (2H), 1.24, dt (6H); 1.37, m (1H); 1.64-1.78, m (4H); 1.86, qd (ÍH); 2.2 bd (4H); 2.35, m (ÍH); 2.4, m (2H); 2.74, dd (ÍH); 3.07, m (4H); 3.52, d, (ÍH); 3.85, d (ÍH); 4.12, q (ÍH); 4.49, qd (1H); 4.68, dt (ÍH); 5.07, d (ÍH); 5.14, s (ÍH); 5.16, d (ÍH); 5.22, t (2H); 6.45, s (ÍH); 7.28, d (ÍH); 7. 26, s (5H); 7.35, s (5H); 7.56, d (HH) 13 C NMR (delta vs. TMS, CDCl 3): 14.15, 22.68, 24.95, 25.61, 26.03, 26.45, 28.20, 31.71, 32.89, 33.80, 33.89, 34.00, . 63, 38.37, 44.79, 45.13, 45.65, 50.23, 51.34, 60.40, 66.87, 67.06, 76.50, 77.13, 77.77, 122.46, 126.88, 127.80-128.60, 135.15, 155.19, 170.11, 170.20, 171.61, 173.76, 175.35.

EXAMPLE 11 Preparation of the hygroscopic crystalline form of N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethyl-butyl] - (L) -aspartyl] - (L) -iS-cyclohexylalanine amide (alternative step 5 of scheme II) CBZ-PipBuen-N (Et) Gly- (L) -Asp (OBzl) - (L) -ChaNH2 (140 G 0.19 mol), ammonium formate (61 g, 0.96 mol) and 10% Pd / C ( 50% moist Degussa type, 28 g) to a covered 5 L flask. EtOH (200, 1260 mL), iPrOH (70 mL) and water (DI, 70 g) are also added. This mixture is heated to 40-50 ° C, and stirred until the HPLC indicates that the reaction is complete (5 hours). The mixture is cooled to room temperature and filtered to remove the catalyst. The resulting solution is heated to 40-50 ° C and acetone is added (equal volume x vs. filtered solution), allowing the solution to cool to 35-40 ° C. N- [N- [N- (4-piperidin-4-4-yl) butanoyl) -N-ethyl-aglyl] - (L) -partyl] - (L) -β-cyclohexylalanine amide seeds are added to the mixture. and the hygroscopic amide form of N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cyclohexylalanine is crystallized from the same while cooling to room temperature (several hours). The solids are collected by suction in a Buchner funnel under a nitrogen blanket by rinsing with acetone and air drying at constant weight to produce N- [N- [N- (4-piperidin-4-yl) butanoyl) -N amide. -ethylglycyl] - (L) -aspartyl] - (L) -β-cyclohexyl-alanine (84.3 g, 0.16 moles, 84.8% yield,> 95A%).

EXAMPLE 12 Concatenated preparation of TFA-N (Et) Gly- (L) -Asp (OBzl) - (L) Cha-NH2 (toggle steps 1-3 of Scheme II) A 500 mL flask equipped with a temperature probe is charged with BOC-N (Et) -Gli (20.3 g, 0.1 mole), N-hydroxysuccinimide (11.5 g, 0.1 mole) and dichloromethane (200 mL). The mixture is stirred at a moderate speed and to the resulting solution is added DCC (20.6 g, 0.1 mol) in one portion as a solid. This solution is stirred for one hour, during which a small isotherm is observed (temperature rise from 20 ° C to 28 ° C) and DCU is precipitated. The resulting suspension is vacuum filtered using a Buchner funnel equipped with a Whatman # 1 paper filter. The cake is washed with dichloromethane (2 X 25 mL). The filtered materials are returned to the original 500 mL flask and then added successively (L) Asp (OBzl) (22.3 g, 0. 1 mol), NMM (33.8 mL, 0.3 mol) and DMF (80 g, 1.01 mol).

After stirring for 2 hours at room temperature, the formation of BOC-N (Et) Gli- (L) -Asp (OBzL) is completed. (monitoring by CLAR). The reaction mixture is poured into an extraction funnel containing water and ice (100 mL). The mixture is acidified with HCl (36%, 25 mL) to pH 1. The layers are separated and the dichloromethane layer is washed with water and ice (100 mL) and the phases are separated (aqueous phase pH 3-4). The dichloromethane layer is returned to the original 500 mL flask which is successively charged with NH2 ~ (1) -Cha-NH2 (17 g, 0.1 mol)), N-hydroxysuccinimide (11.5 g, 0.1 mol) and DCC (20.6 g, 0.1 moles) in one portion each as solids. After stirring for 2 hours at room temperature the formation of BOC-N (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2 (monitoring by CLAR) is complete and the DCU is vacuum filtered using a Buchner funnel equipped with a Whatman # 1 paper filter. The cake is washed with dichloromethane (2 X 25 mL). The filtrate is transferred to an extraction funnel and washed with deionized water (200 mL) containing N-methyl morpholine (15 mL, pH 8-9). The phases are separated and the dichloromethane layer is washed again with water (Di, 2 X 150 mL). The aqueous phase is washed with 150 mL of 1 N HCl (pH 1). The phases are separated and the dichloromethane layer is washed with deionized water (200 mL, pH 3). The dichloromethane solution of BOC-N (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2 is returned to a clean 500 mL flask and then loaded with TFA (100 mL). After stirring for two hours at room temperature, the formation of TFA is completed. HN (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2 (monitoring by CLAR). The reaction mixture is distilled under vacuum to remove dichloromethane and most of the TFA, then MTBE (500 mL) and seeds are added to carry out the crystallization of the product. The mixture is vacuum filtered using a Buchner funnel equipped with a Whatman # 1 paper filter. The cake is washed with MTBE (2 X 25 mL) and dried with air to produce TFA.HN (Et) Gli- (L) -Asp (OBzl) - (L) -Cha-NH2 (46.8 g, 81.5% of yield) as a white solid (> 97A% pure, < 0.2A% D-Asp diast.).

EXAMPLE 13 Preparation of the non-hygroscopic stable crystal form of N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethyl-butyl] - (L) -aspartyl] - (L) -S amide -cyclohexylalanine Method A. Static conversion The amide crystalline form of N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cyclohexyl -alanine (7.45 Kg) is milled in a hammer mill. The resulting solid, 7.35 kg, is placed in a stainless steel drying tray (90 X 28 cm) and the tray is covered with perforated aluminum foil. The tray is then sealed in a humidity oven (LUNAIRE Humidity Cabinet model No. CEO 941W-3); the furnace is kept sealed throughout the shape conversion process except for removing test samples. The oven is set at 40% RH and 60 ° C and is maintained at those levels for 1 hour. The humidity oven is then adjusted to 80% RH / 60 ° C and maintained at these levels for 12 hours. A sample is removed after 18 hours at 80% RH / 60 ° C and verified by X-ray powder diffraction analysis to determine the conversion to the non-hygroscopic amide form of N- [N- [N- ( 4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cyclohexylalanine. The humidity oven is resealed and adjusted to 40% RH / 60 ° C and kept there for 2 hours. The furnace is readjusted to ambient conditions and then the pan is removed from the furnace and the non-hygroscopic amide crystalline form of [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) -partsyl] - (L) -β-cyclohexylalanine (7.2 kg, 96.6% yield). The confirmation of the conversion is determined by an X-ray powder diffraction graph (figure 1) . X-ray powder diffraction is also tabulated as a function of the increasing order of the diffraction angle (2teta) that corresponds to the interplanar distance of the crystal (d) in angstrom units (Á), counts per second (Cps) and relative peak intensity (%) (Table 1).

TABLE 1 -N- 2teta --- d --- Cps% - 1 5.065 17.4314 86.00 5.82 2 6,323 13.9672 248.00 16.78 3 7.518 11.7489 221.00 14.95 4 8.163 10.8222 496.00 33.56 8.780 10.0633 155.00 10.49 6 10,383 8.5125 218.00 14.75 7 11,351 7,786 112.00 7.58 8 12,596 7.0218 999.00 67.59 9 13,858 6.3852 316.00 21.38 15,191 5.8274 1338.00 90.53 11 16,476 5.3759 481.00 32.54 12 16,745 5.2901 556.00 37.62 13 17,980 4.9294 6.79.00 45.95 14 18,572 4.7735 1079.00 73.00 18,799 4.7165 1230.00 83.22 16 19,147 4.6315 1229.00 83.15 17 19,619 4.5211 1380.00 93.37 18 20.200 4.3924 1246.00 84.30 19 20,466 4.3360 1478.00 100.00 20,870 4.2528 1088.00 73.61 21 21.625 4.1061 5841.00 39.51 22 22,088 4.0210 891.00 60.28 23 22,840 3.8903 613.00 41.47 24 23,947 3.7129 597.00 40.39 24,569 3.6203 680.00 46.01 26 25.608 3.4757 506.00 34.24 27 27,015 3.2978 1100.00 74.42 28 27,837 3.2022 420.00 28.42 29 27,967 3.1877 400.00 27.06 29,255 3.0502 536.00 36.27 31 29,689 3.0066 603.00 40.80 TABLE 1 (CONTINUED) 32 30,665 2.9130 518.00 35.05 33 31,318 2.8538 451.00 30.51 34 31.894 2.8036 533.00 36.06 33,370 2.6829 518.00 35.05 36 33,562 2.6679 552.00 37.35 37 33,919 2.6407 581.00 39.31 38 34,840 2.5730 561.00 37.96 39 35.789 2.5069 559.00 37.82 40 35,940 2.4967 560.00 37.89 41 36,780 2.4416 740.00 50.07 42 37,042 2.4249 736.00 49.80 43 37.959 2.3684 683.00 46.21 44 39,017 2.3066 643.00 43.50 Method B. Dynamic conditions shape conversion The hygroscopic amide crystalline form of N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cyclohexylalanine ( 50 g) is placed in a graduated cylinder of 400 mL (bed height 6 cm) on a ring support and equipped with a magnetic stirrer. The appliance is placed in a humidity controlled oven (LUNAIRE Humidity Cabinet model No. CEO 941W-3). The stirring is set at 275 rpm and the temperature and RH are adjusted for 30 minutes at 60 ° C and 40% respectively. The compound is kept under these conditions for 1 hour, and then the conditions are changed with 45 minutes at 80% RH / 60 ° C. The compound is then maintained at these conditions for 16 hours before the furnace is re-established at 40% RH / 60 ° C and held there for 3.25 hours. The compound is then allowed to return to ambient conditions (bed height 4 cm) and removed from the cylinder to produce the non-hygroscopic amide form of N- [N- [N- (4-piperidin-4-yl)] butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cyclohexylalanine (yield> 95%). The confirmation of the conversion is determined by X-ray powder diffraction analysis (Figure 2). X-ray powder diffraction is also tabulated as a function of the increasing order of the diffraction angle (2teta) corresponding to the interplanar distance of the crystal (d) in angstrom units (Á), counts per second (Cps) and peak intensity relative (%) (Table 2).

TABLE 2 -N- 2teta ___ d --- Cps ---% - 1 5.186 17.0268 196.00 8.43 2 6.371 13.8615 722.00 31.07 3 7.570 11.6689 516.00 22.20 4 8.232 10.7323 1094.00 47.07 8.817 10.0206 257.00 11.06 TABLE 2 (CONTINUED) 6 10,428 8.4761 365.00 15.71 7 11,377 7.7714 129.00 5.55 8 11,600 7.6223 117.00 5.55 9 12,667 6.9828 1805.00 77.67 13.913 6.3599 551.00 23.71 11 14,398 6.1468 178.00 7.66 12 15,226 5,844 2285.00 98.32 13 16,538 5.3557 861.00 37.05 14 16,773 5.2814 929.00 39.97 18,019 4.9190 1132.00 48.71 16 18,672 4.7483 1871.00 80.71 17 18,815 4.7125 2052.00 88.30 18 19,204 4.6178 2071.00 89.11 19 19,654 4.5132 2226.00 95.78 20,237 4.3845 1939.00 83.43 21 20,523 4.3240 2324.00 100.00 22 20,934 4.2400 1656.00 71.26 23 21,691 4.0938 923.00 39.72 24 22,143 4.0112 1411.00 60.71 22,910 3.8786 994.00 42.77 26 24,007 3.7037 964.00 41.48 27 24,642 3,6097 991.00 42.64 28 25,642 3.6097 991.00 42.64 29 27,070 3.2913 1687.00 72.59 TABLE 2 (CONTINUED) 27,855 3.2002 688.00 29.60 31 29,497 3.0258 843.00 36.27 32 29,497 3.0013 878.00 37.78 33 30.751 2.9051 809.00 34.81 34 31,916 2.8017 821.00 35.33 33.982 2.6360 882.00 37.95 36 35.200 2.5475 865.00 37.22 37 36.001 2.4926 841.00 36.19 38 36,927 2.4322 1106.00 47.59 39 38,389 2.3429 968.00 41.65 b. shape conversion The hygroscopic amide crystalline form of N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cyclohexylalanine ( 370 g) is loaded in a 2-L rotary evaporator flask. The flask is placed on the rotary evaporator (Heidolph UV 20202) and lowered in a preheated bath (58 ° C) (Heidolph MR 2002). The apparatus is placed under a vacuum of 60 mBar using a vacuum pump (Divatrion DVl), then the vacuum is bursted in a controlled manner to allow a humid atmosphere to be created in a flask containing hot and separate water. The admission of the humid atmosphere is controlled by a humidity control device (Vausalo Humiditique and Temperature Traumettor) to achieve a RH of 79% inside the apparatus (internal pressure of 130-180 mBar). The rotary evaporator vessel is then rotated at 145-160 revolutions per minute for a period of 5 hours while maintaining the heating bath at -60 ° C and the RH is maintained within the vessel at 71-79%. After the vacuum is opened to nitrogen, the vessel and its contents are allowed to cool to room temperature and the product is stirred to produce the non-hygroscopic crystalline form of amide of N- [N- [N- (4-piperidin-4- il) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cyclohexyl-alanine. A second batch of 317 g of the hygroscopic crystalline amide form of N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) - β-cyclohexyl-alanine is treated in a similar manner to provide the non-hygroscopic crystalline form of N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl amide ] - (L) -β-cyclohexyl-alanine. Confirmation of the conversion is determined by X-ray powder diffraction analysis (Figure 3). The two batches together produced 667 g of the non-hygroscopic amide form of N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) -partil] - (L ) -β-cyclohexylalanine (97% total yield). Confirmation of the conversion is determined by X-ray powder diffraction analysis (Figure 3). X-ray powder diffraction is also tabulated as a function of the increasing order of the diffraction angle (2teta) corresponding to the interplanar distance of the crystal (d) in angstrom units (Á), counts per second (Cps) and peak intensity relative (%) (Table 3).

TABLE 3 -N- 2teta d Cps% - 1 5.124 17.2309 180.00 10.17 2 6,328 13.9565 408.00 23.05 3 7.574 11.6623 305.00 17.23 4 8,191 10,781 556.00 31.41 8.797 10.0432 166.00 9.38 6 10,398 8.5004 353.00 19.94 7 12,628 7.0040 1198.00 67.68 8 13,871 6.3791 353.00 19.94 9 15,218 5.8172 1543.00 87.18 15,723 5.6317 187.00 10.56 11 16,538 5.3558 589.00 33.28 12 16,751 5,282 621.00 35.08 13 18,024 4.9175 869.00 49.10 14 18.640 4.7563 1156.00 65.31 18.809 4.7141 1241.00 70.11 16 19,191 4.6210 1521.00 85.93 17 19.659 4.5120 1413.00 79.83 18 20,865 4.4064 1303.00 73.62 19 20,495 4.3299 1770.00 100.00 20,865 4.2539 1120.00 63.28 21 21,616 4.1077 683.00 38.59 22 22,113 4.0166 919.00 51.92 TABLE 3 (CONTINUED) 23 22,950 3.8719 697.00 39.38 24 24,117 3.6871 659.00 37.23 24,618 3.6132 716.00 40.45 26 25,644 3.4709 662.00 37.40 27 26,297 3.3862 486.00 27.46 28 27,052 3.2934 1270.00 71.75 29 27,960 3,185 518.00 29.27 29.640 3.0115 705.00 39.38 31 30,744 2.9058 695.00 39.27 32 33,465 2.6755 697.00 39.38 33 33.840 2.6467 '764.00 43.16 34 35,812 2.5053 736.00 41.58 36,811 2.4396 858.00 48.47 36 37,076 2.4228 919.00 51.92 37 38,185 2.3549 870 49.15 38 39,622 2.2728 882.00 49.83 EXAMPLE 14 X-ray powder diffraction graphs of an amide sample of N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethyl-butyl] - (L) -aspartyl] - (L ) -β-cyclohexylalanine in its hygroscopic crystalline form and in its converted non-hygroscopic crystalline form A sample of the hygroscopic amide crystalline form of N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β- is prepared cyclohexylalanine as in example 5 or 11, and converted to the corresponding non-hygroscopic crystalline form according to a method of example 13. X-ray powder diffraction graphs of the hygroscopic crystalline form and the non-hygroscopic crystalline form are respectively show in Figures 4 and 5. X-ray powder diffraction graphs for the hygroscopic crystalline form and for the non-hygroscopic crystalline form are also tabulated as a function of the increasing order of the diffraction angle (2teta) corresponding to the interplanar distance of the crystal (d) in angstrom units (Á), counts per second (Cps) and relative peak intensity (%) in table 4 and table 5, respectively.

TABLE 4 -N- 2teta ___ d --- Cps ---% - 1 5.073 17.4037 1487.00 86.50 2 6,451 13,6905 447.00 26.00 3 7.837 11.2712 411.00 23.91 4 8,491 10,4049 602.00 35.02 9.699 9.1119 93.00 5.41 6 10,488 8.4278 421.00 24.49 7 11,570 7.6423 92.00 5.35 8 12,550 7.0474 411.00 23.91 9 13,576 6.5168 760.00 44.21 15,327 5.7763 606.00 35.25 11 15,790 5.6080 456.00 26.53 12 16,179 5.4739 346.00 20.13 13 16,770 5.2824 938.00 54.57 14 17,085 5,186 685.00 39.85 17,750 4.9927 924.00 53.75 16 18,151 4.8835 741.00 43.11 17 18.504 4.7909 593.00 34.50 18 19,323 4.5897 930.00 54.10 19 19,714 4.4996 792.00 46.07 20,545 4.3194 1719.00 100.00 21 21,388 4.1510 897.00 52.18 22 22,381 3.9691 373.00 21.70 23 22,870 3.8852 258.00 15.01 TABLE 4 (CONTINUED) 24 23,640 3.7604 563.00 32.75 23,841 3.7292 680.00 39.56 26 24,048 3.6976 623.00 36.24 27 24.746 3.5949 338.00 19.66 28 25,200 3.5311 366.00 21.29 29 25.792 3.4513 590.00 34.32 26,266 3.3901 731.00 42.52 31 26.959 3.3045 555.00 32.29 32 27,426 3.2494 769.00 44.74 33 27,967 3.1876 528.00 30.72 34 29,020 3.0744 771.00 44.85 29,992 2.9837 491.00 28.56 36 30,970 2.8851 384.00 22.34 37 31,552 2.8332 510.00 29.67 38 33,338 2,688 627.00 36.47 39 34.838 2.5731 520.00 30.25 40 36.107 2.5012 653.00 37.99 41 36.107 2.4855 639.00 37.17 42 37,162 2.4174 683.00 39.73 43 38,509 2.3359 775.00 45.08 44 39,701 2.2684 784.00 45.61 TABLE 5 -N- 2teta ___ d --- Cps - "5 - - 1 5,152 17.1371 123.00 7.34 2 6,386 13,8287 483.00 28.84 3 7.580 11.6540 389.00 23.22 4 8.225 10.7410 752.00 44.90 8.801 10.0390 180.00 10.75 6 10,408 8.4928 276.00 16.48 7 12,660 6.9863 1399.00 83.52 8 13.914 6.3594 391.00 23.34 9 15,251 5.8047 1675.00 100.00 16,541 5.3548 608.00 36.30 11 16.771 5.2818 652.00 38.93 12 18,047 4.9112 775.00 46.27 13 18,676 4.7472 1078.00 64.36 14 18.902 4.6910 1099.00 65.61 19,182 4.6231 1151.00 68.72 16 19.697 4.5035 1164.00 69.49 17 20,240 4.3838 1049.00 62.63 18 20,568 4.3147 1403.00 83.76 19 29,933 4.2403 1024.00 61.13 21,684 4.0951 569.00 33.97 21 22.122 4.0150 746.00 44.54 22 22,970 3.8685 564.00 33.67 23 24,080 3.6927 546.00 32.60 TABLE 5 (CONTINUED) 24 24.218 3.6720 556.00 33.91 24.694 3.6023 618.00 36.90 26 25,680 3.4662 510.00 30.45 27 26,400 3.3732 403.00 24.06 28 27.105 3.2871 1093.00 62.25 29 27,929 3.1920 450.00 26.87 29,360 3.0395 555.00 33.13 31 29,724 3.0031 595.00 35.52 32 30,340 2.9435 429.00 25.61 33 30,693 2.9105 552.00 32.96 34 31,353 2.8507 476.00 28.42 31,822 2.8098 531.00 31.70 36 32.006 2.7940 545.00 32.54 37 32.885 2.7213 485.00 28.96 38 33.508 2.6722 547.00 32.66 39 34,040 2.6316 606.00 36.18 40 34,839 2.5730 580.00 34.63 41 35,998 2.4928 596.00 35.58 42 36,680 2.4480 629.00 37.55 43 36,948 2.4309 727.00 43.40 44 37,191 2.4152 703.00 41.97 45 39,602 2.2739 697.00 41.61 EXAMPLE 15 Isothermal microcalorimetric experiments in the crystalline-hygroscopic and non-hygroscopic forms of N- [N- (N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) amide -particular] - (L) - &- cyclohexylalanine The isothermal microcalorimetry experiments in the hygroscopic and non-hygroscopic crystalline forms of N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) ) -ß-cyclohexylalanine are carried out in a Thermometric Thermal Activity Monitor (TAM). Conversions to the solid state of the different crystalline forms are studied by exposing the forms to different moisture or solvent vapors at different temperatures. The saturated salt solutions used to obtain the different humidities were: KCl (80% RH), NaCl (75% RH) and NaBr (65% RH). Quantities of approximately 100 mg of the forms are weighed in a TAM glass ampule and a microhygrostat containing a saturated salt solution (with excess solids) or an organic solvent is placed inside the ampule. The ampule is sealed, equilibrated at the temperature of the experiment and lowered in the measuring position of the TAM. An identical system containing washed sea sand, instead of the shape under test, is placed on the reference side. The output power (μW) is measured as a function of time (Figures 6-8).

EXAMPLE 16 Isotherms of moisture absorption of the hygroscopic and non-hygroscopic crystalline forms of N- [N- (N- (4-piperidin-4-yl) utanoyl) - N -ethylglycine] - (L) - amide aspartil] - (L) -ß- The isotherms of moisture absorption of the hygroscopic and non-hygroscopic crystalline forms of N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl- (L) amide ) -ß-cyclohexylalanine are obtained in a moisture balance VTI MB300G. The experiments are carried out either by subjecting about 15 mg of the crystalline form to increasing and decreasing steps of% RH and after weight gain (at each equilibrium step) as a function of% RH (Figure 9) or maintaining the crystalline form at a constant humidity and following the gain of weight as a function of time. The compound of formula II exhibits useful pharmacological activity and consequently is incorporated into pharmaceutical compositions and is used in the treatment of patients suffering from certain pathological conditions. The present invention is also directed to a method for the treatment of a patient suffering from, or subject to, conditions that can be diminished or prevented by the administration of a platelet aggregation inhibitor inhibiting the binding of fibrinogens to activated platelets. and other adhesive glycoproteins involved in the aggregation of platelets and blood coagulation. Furthermore, the present invention is directed to a method for preventing or treating thrombosis associated with certain disease states, such as myocardial infarction, seizures, peripheral arterial disease and disseminated intravascular coagulation in humans and other mammals. The reference aguí to the treatment should be understood as including prophylactic therapy as well as the treatment of established conditions. The present invention also includes within its scope a pharmaceutical composition comprising a pharmaceutically acceptable amount of at least one compound of formula I in association with a pharmaceutically acceptable carrier or excipient. In practice, the compounds or treatment compositions according to the present invention can be administered by any suitable means, for example, by the topical route, inhalation, parenterally, rectally or orally, but it is preferred to administer them orally. The compound of formula II can be presented in forms that allow its administration by the most suitable route, and the invention also relates to pharmaceutical compositions containing at least one compound according to the invention which are suitable for use in human medicine or veterinary These compositions can be prepared according to conventional methods, using one or more pharmaceutically acceptable auxiliaries or excipients. The auxiliaries comprise, among others, diluents, sterile aqueous media and the different non-toxic organic solvents. The compositions may be in the form of tablets, pills, capsules, granules, powders, aqueous solutions or suspensions, injectable solutions, elixirs, syrups and the like, and may contain one or more agents selected from the group comprising sweeteners, flavors, colorants, stabilizers. or preservatives to obtain pharmaceutically acceptable preparations. The choice of the vehicle and the content of active substance in the vehicle is generally determined in accordance with the solubility and chemical properties of the product, the particular route of administration and the conditions that will be observed in pharmaceutical practice. For example, excipients such as lactose, sodium citrate, calcium carbonate, dicalcium phosphate and disintegrating agents such as starch, alginic acids and certain complex silica gels combined with lubricants such as magnesium stearate, sodium lauryl sulfate and talc can be used for prepare tablets. To prepare a capsule, it is advantageous to use lactose and high molecular weight polyethylene glycols. When aqueous suspensions are used, these may contain emulsifying agents or agents that facilitate the suspension. Diluents such as sucrose, ethanol, polyethylene glycol, propylene glycol, glycerol and chloroform or combinations thereof, as well as other materials can be employed. For parenteral administration, the emulsions, suspensions or solutions of the compounds according to the invention are used in vegetable oil, for example, sesame oil, olive oil, or aqueous organic solutions such as water and propylene glycol, injectable organic esters such as ethyl oleate, as well as sterile aqueous solutions of the pharmaceutically acceptable salts. The solutions of the salts of the products according to the invention are also useful for administration by intramuscular or subcutaneous injection. Aqueous solutions, which also comprise solutions of the salts in pure distilled water, can be used for intravenous administration with the proviso that their pH is adjusted appropriately, that the pH is adequately regulated and made isotonic with a sufficient amount of glucose or sodium chloride and which are sterilized by heating, irradiation and / or microfiltration. For topical administration, gels (water or alcohol based), creams or ointments containing the compounds of the invention can be used. The compounds of the invention can also be incorporated in a gel or matrix base for application in a patch, which will allow a prolonged release of the compound through a transdermal barrier. Solid compositions for rectal administration include suppositories formulated according to known methods and containing at least one compound of formula II. The percentage of active ingredient in a composition according to the invention can vary such that it constitutes a proportion of a suitable dose. Obviously, several unit dosage forms may be administered at about the same time. A dose used can be determined by a doctor or qualified medical professional, and depends on the desired therapeutic effect, the route of administration and the duration of treatment, as well as the patient's condition. The dosage regimen for carrying out the method of this invention is that which ensures a maximum therapeutic response until an improvement is obtained and subsequently the minimum effective level that provides relief. In general, the oral dose may be between about 0.1 mg / kg and about 100 mg / kg, preferably between about 0.1 mg / kg to 20 mg / kg, most preferably between about 1 mg / kg and 20 mg / kg, and the intravenous dose of about 0.1 μg / kg, preferably between about 0.1 mg / kg to 50 mg / kg. In each particular case, the doses are determined according to the factors of each patient that will be treated, such as age, weight, general state of health and other characteristics that may influence the efficacy of the compound according to the invention. In addition, a compound of formula II can be administered as often as necessary to obtain the desired therapeutic effect. Some patients may respond quickly to a higher or lower dose and may find adequate maintenance doses much lower. For other patients, it may be necessary to have long-term treatments at the rate of 1 to 4 oral doses per day, preferably one to two per day, according to the physiological needs of each patient in particular. In general, the active product can be administered orally 1 to 4 times a day. Of course, for other patients it will be necessary to prescribe no more than one to two doses per day. A compound of formula II exhibits marked pharmacological activities according to tests described in the literature and whose results are believed to be correlated with the pharmacological activity in humans and other mammals. The following in vitro and in vivo pharmacological tests are typical for characterizing a compound to formula II. The following pharmacological tests evaluate the inhibitory activity of a compound of formula II on platelet aggregation mediated by fibrinogens, on the binding of fibrinogens to platelets stimulated by thrombin and on the inhibition of ex vivo platelet aggregation induced by ADP, and the results of these tests correlate with the inhibitory properties in vivo of a compound of formula II. The platelet aggregation test is based on that described in Blood 66 (4), 946-952 (1985). The fibrinogen binding test is essentially that of Ruggeri, Z.M., et al., Proc. Nati Acad. Sci. USA 83, 5708-5712 (1986) and Plow, E.F., et al., Proc. Nati Acad. Sci., USA 82, 8057-8061 (1985). The ADP induced platelet aggregation inhibition test is based on Zucker, "Platelet Aggregation Measured by the Photoelectric Method", Methods in Enzymology 169, 117-133 (1989).

Platelet aggregation test Preparation of fixed-activated platelets Platelets are isolated from human platelet concentrates using the gel filtration technique as described by Marguerie, G.A. et al., J. Biol. Chem. 254, 5357-5363 (1979) and Ruggeri, Z.M. et al., J. Clin. Invest. 72, 1-12 (1983). Platelets are suspended at a concentration of 2x10 cells / mL in a modified calcium-free Tyrode PH buffer containing 127 mM sodium chloride, 2 mM magnesium chloride, 0.42 mM Na2HP04, 11.9 mM NaHCO-3, 2.9 mM KCl, 5.5 mM glucose and 10 mM HEPES at a pH of 7.35 and 0.35% human serum albumin (HSA). These washed platelets are activated by the addition of human α-thrombin to a final concentration of 2 units / mL, followed by thrombin inhibitor 1-2581 at a final concentration of 40 μM. Activated platelets are added paraformaldehyde to a final concentration of 0.50% and this is incubated at room temperature for 30 minutes. The fixed activated platelets are then collected by centrifugation at 650 x g for 15 minutes. The platelet pellets are washed four times with the above 35% Tirode-HSA pH regulator and resuspended at 2 x 10 cells / mL in the same pH regulator.

Platelet aggregation test Fixed activated platelets are incubated with a selected dose of the compound that will be tested for the inhibition of platelet aggregation for one minute and aggregation is initiated by the addition of human fibrinogen to a final concentration of 250 μg / mL . A platelet aggregation checker model PAP-4 is used to record aggregation of platelets. The degree of inhibition of aggregation is expressed as the percentage of the aggregation rate observed in the absence of the inhibitor. The IC50, that is, the amount of inhibitor required to reduce the rate of aggregation by 50%, is then calculated for each compound (see, for example, Plow, EF et al., Proc. Nati. Acad. Sci., USA 82, 8057-8061 (1985)).

Fibrinogen Binding Test Platelets free from plasma constituents were washed by the Walsh albumin density gradient technique, P.N. et al., Br. J. Haematol. 281-296 (1977), modified by Trapani-Lombardo, V, et al., J.Clin Invest. 76, 1950-1958 (1985). In each experimental mixture platelets in modified Tyrode pH regulator (Ruggeri, ZM et al., J. Clin. Invest. 72, 1-12 (1983)) are stimulated with human a-thrombin at 22-25 ° C during 10 minutes (3.125 x 10 platelets per liter and thrombin at 0.1 NIH units / mL). Hirudin is then added to a 25-fold excess (unit / unit) for 5 minutes before the addition of 125-labeled fibrinogen. and the compound that will be tested. After these additions, the final platelet count in the mixture is 1 x 101: 1- / L. After incubation for an additional 30 minutes at 22-25 ° C, the bound free ligand is separated by centrifugation of 50 μL of the mixture through 300 μL of 20% sucrose at 12,000 x g for 4 minutes. The platelet pellet is then separated from the rest of the mixture to determine the radioactivity bound by platelets. Non-specific binding is measured in mixtures containing an excess of unlabeled ligand. When the binding curves are analyzed by Scatchard analysis, the non-specific binding is derived as a parameter adapted from the binding isothermy by means of a computer program (Munson, PJ, Methods Enzymol, 92, 542-576 (1983 )). To determine the concentration of each compound needed to inhibit 50% of the fibrinogen binding to platelets stimulated with thrombin (IC50), each compound is tested at 6 or more concentrations with labeled 125 I fibrinogen maintained at 0.176 μmol / L (60 μg / mL ). The IC50 is derived by plotting the binding of residual fibrinogen against the logarithm of the concentration of the sample compound.

Inhibition of ex vivo platelet aggregation induced by ADP Experimental Protocol Control blood samples are obtained 5-10 minutes before the administration of a test compound to Creole dogs weighing 10 to 20 kg. The compound is administered intragastrically by forced aqueous feeding, or orally by means of a gelatin capsule. Blood samples (5 mL) are then obtained at 30 minute intervals for three hours, and 6, 12 and 24 hours after dosing. Each blood sample is obtained by venipuncture of the cephalic vein and is collected directly in a plastic syringe containing one part of sodium citrate at 3.8% by nine parts of blood.

Aggregation of ex vivo canine platelets Blood samples are centrifuged at 1000 rpm for 10 minutes to obtain platelet-rich plasma (PRP). After removal of the PRP, the sample is centrifuged for an additional 10 minutes at 2000 rpm to obtain platelet deficient plasma (PPP). The platelet count in the PRP is determined using a Coulter counter (Coulter Electronics, Hialeah, FL). If the platelet concentration in the PRP is more than 300,000 platelets / μL, then the PRP is diluted with PPP to adjust the platelet count to 300,000 platelets / μL. Aliquots of PRP (250 μL) are then placed in siliconized glass tubes (7.25 x 55 mm, Bio / Data Corp., Horsham, PA). Epinephrine (final concentration of 1 μM) is then added to the PRP, which is incubated for one minute at 37 ° C. A platelet aggregation stimulator, ADP at a final concentration of 10 μM, is then added to the PRP. Platelet aggregation is monitored spectrophotometrically using a light transmission aggregometer (Bio / Data Platelet Aggregation Profiler, Model PAP-4, Bio / Data Corp., Horsham, PA). To test a compound, the rate of change (fall) of the light transmission and the maximum light transmission (maximum aggregation) are recorded in duplicate. Platelet aggregation data are reported as the percentage decrease (mean ± SEM) in maximum drop or aggregation compared to the data obtained from control PRP, which is prepared from blood samples obtained before the administration of the compound test. A compound of formula II exhibits marked activity in the above tests and is considered useful in the prevention and treatment of thrombosis associated with certain disease states. The antithrombotic activity in the ex vivo canine platelet aggregation test predicts such activity in humans (see, for example, Catalfamo, JL, and Dodds, W. Jean, "Isolation of Platelets from Laboratory Animáis", Methods Enzymol. Part A, 27 (1989)). The results of the test of a compound of formula II by means of the above methods are presented in the following table 6. Also presented in the table are the comparative test results for 4- (piperidyl) butanoyl glycyl aspartyl triptophan, ie , the compound described in European Patent Application Publication No. 0479,481.

TABLE 6 Inhibition of ex vivo platelet aggregation induced by ADP Inhibition of% inhibition of the platelet aggregation aggregation compound of the example platelets f- Ex vivo dose after the number jas (IC50 μM) (mg / kg) oral administration Ih 3h 6h 12h 24h 0.097 5 100 100 100 98 50 (Compound 0.047 5 53 <20 of EPA '481) One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objects of the invention, and to obtain the purposes and advantages mentioned, as well as those inherent to the same. The compounds, compositions and methods described herein are presented as representative of the preferred embodiments, or are intended to be exemplary and are not intended to be limitations of the scope of the present invention.

Claims (24)

1. NOVELTY OF THE INVENTION CLAIMS 1. - A compound that is β-benzyl ester of N- (N-t-butoxycarbonyl-N-ethylglycyl) - (L) -aspartic acid.
2. 2. A compound that is amide of N- [N- [N- [4- [N-benzyloxycarbonylpiperidin-4-yl] butanoyl] -N-ethylglycyl] - (L) -spartyl-benzyl ester] - ( L) -β-cyclohexylalanine.
3. 3. A compound that is 4- (4-piperidin) butylidenecarboxylic acid.
4. 4. A compound which is N- [N- [N- [3- [N-benzyloxycarbonyl-4-piperidine] propylidenecarbonyl] -N-ethylglycyl] - (L) -spartyl-benzyl ester - amide] - ( L) -β-cyclohexyl-alanine.
5. 5. A compound which is N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cyclohexylalanine amide is not hygroscopic or a pharmaceutically acceptable salt thereof.
6. 6. A pharmaceutical composition comprising the compound according to claim 1 and a pharmaceutically acceptable carrier.
7. 7. A method for preparing non-hygroscopic crystalline N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl- (L) -asparyl] - (L) -β-cyclohexylalanine amide, comprises exposing N- [N- [N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) -aspartyl] - (L) -β-cyclohexylalanine amide hygroscopic at relative humidity of about 40% to 100% and at approximately 20 ° C to approximately 80 ° C.
8. 8. The method according to claim 7, further characterized in that the exposure is at relative humidity of about 65% to about 80%.
9. 9. The method according to claim 7, further characterized in that the exposure is at about 40 ° C to about 80 ° C.
10. 10. The method according to claim 7, further characterized in that the exposure is carried out under static conditions.
11. 11. The method according to claim 7, further characterized in that the exposure is carried out under dynamic conditions. 12. - A method for preparing a salt compound of the formula: TFA « wherein B is alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, aralkyl, alkylaryl or alkylaryl; E1 is H; E2 is the side chain of the carbon-a of a naturally occurring a-amino acid, H, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, substituted aryl, aralkyl, substituted aralkyl, heterocyclyl, substituted heterocyclyl, heterocyclylalkyl, substituted heterocyclylalkyl, or Ex and E2 taken together with the nitrogen and carbon atoms through which E and E are attached form an azacycloalkane ring of 4-, 5-, 6- or 7-membered; G is OR1 or NR- ^ R2; R1 p and R are independently H, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, aralkyl, alkylaryl or alkylaryl; p is 1 to 4; and P is an acid protecting group, which comprises copying compounds of the formulas O O II II p2_N_ (CH2) p-COH H2 -CH-COH B CH2CO2P1 p wherein P is an acid-labile amine protecting group, to form a first intermediate compound of the formula: copulate a compound of the formula E1 E2 O I I II HN CH-C-G to the first intermediate compound to form a second intermediate compound of the formula: remove the protecting group P2 of the second intermediate compound with trifluoroacetic acid to produce the salt compound. 13. The method according to claim 12, further characterized in that P1 is a protective group of acid labile to hydrogenation. 14. - A compound of the formula: wherein P3 is an amine protecting group; B is alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, aralkyl, alkylaryl or alkylaryl; P is an acid protecting group; E1 is H; E2 is the side chain of the carbon-a of a naturally occurring α-amino acid, H, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkyl-alkyl, aryl, substituted aryl, aralkyl, substituted aralkyl, heterocyclyl, substituted heterocyclyl, heterocyclylalkyl, heterocyclic substituted alkyl, or E and E taken together with the nitrogen and carbon atoms through which E and E are attached form an azacycloalkane ring of 4-, 5-, 6- or 7-membered, G is OR 1 or NR1 R2; R1 and R2 are independently H, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkyl-alkyl, aryl, aralkyl, alkylaryl or alkylaryl; and P is 1-4. 15. A compound in accordance with the claim 14, further characterized in that P is a protecting group of acid labile to hydrogenation and P is a protecting group of amine labile to hydrogenation. 16. A compound in accordance with the claim 15, further characterized in that B is alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, aralkyl, alkylaryl or alkylaryl; E1 is H; E2 is H, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkyl-alkyl, aryl, substituted aryl, aralkyl or substituted aralkyl; L is OR1 or NR1 -'- R2; R1 and R2 are independently H, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, aralkyl, alkylaryl or alkylaryl; and P is 1 or 2. 17. A compound according to the claim 16, further characterized in that B is alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl or alkylcycloalkylalkyl; and E2 is H, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl or alkylcycloalkylalkyl. 18. A compound in accordance with the claim 17, further characterized in that B is alkyl; E2 is alkyl, cycloalkyl or cycloalkylalkyl; R1 and R2 are independently H, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkyl-alkyl; and p is 1. 19. A compound according to the claim 18, further characterized in that P3 is benzyloxycarbonyl; B is ethyl; P1 is benzyl; E2 is cyclohexylmethyl and G is NH2 • 20.- A method for preparing a compound of the formula: 3 wherein P is an amine protecting group; B is alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, aralkyl, alkylaryl or alkylaryl; P is an acid protecting group; E is H; E is the side chain of the carbon-a of a naturally occurring a-amino acid, H, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, substituted aryl, aralkyl, substituted aralkyl, heterocyclyl, substituted heterocyclyl, heterocyclylalkyl, substituted heterocyclylalkyl, or E 1 and E taken together with the nitrogen and carbon atoms through which E 1 and E 2 are joined, form an azacycloalkane ring of 4-, 5-, 6- or 7-membered; G is OR1 or NR1R2; R1 and R2 are independently H, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkyl-alkyl, aryl, aralkyl, alkylaryl or alkylaryl; and p is 1-4, which comprises copying a ((4-piperidin) utilidenylcarboxylic acid) compound of the formula with a tripeptide of the formula or an acid addition salt thereof. 21. The method according to claim 20, further characterized in that P is an acid protecting group ^ labile to hydrogenation and PJ is an amine protecting group labile to hydrogenation. 22. - A compound of the formula 3 wherein PJ is an amine protecting group. 23. - A compound according to claim 22, further characterized in that P is a protecting group of amine labile to hydrogenation. 24. - A compound according to claim 23, further characterized in that P3 is benzyloxycarbonyl.