CZ20001296A3 - Process for preparing azacycloalkyl alkanoyl pseudotetrapeptides - Google Patents

Abstract

A process for the preparation of a pseudotetrapeptide of the formula I wherein formula II is optionally protected on the nitrogen atom azahetrocyclic group, (a) single or double a bond, q is 1 to 5, B is an alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, aralkyl, alkylaryl or alkylaralkyl, Q 2 hydrogen or a carboxylic acid protecting group, J atom hydrogen, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, substituted aryl, aralkyl or substituted aralkyl, L group OR 1 or NR 11, wherein R 1 and R 2 are independently of one another a hydrogen atom, an alkyl group, a cycloalkyl group, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, arylalkyl, alkylaryl or alkylalalkyl and p number 1 or 2, thereof salts or prodrugs in which two dipeptides or two pseudopeptides.

Description

A process for the preparation of azacycloalkylalkanoylpseudotetrapeptides

Technical field

The invention relates to a process for the preparation of azacycloalkylalkanoylpseudotetrapeptides by coupling a dipeptide with a pseudodipeptide. The invention also relates to intermediates and to a process for preparing intermediates suitable for the preparation of a pseudotetrapeptide.

BACKGROUND OF THE INVENTION

Azacycloalkylalkanoylpseudotetrapeptides, exemplified by Ν- [N- [N- (N- (4-piperidin-4-yl) butanoyl) -N-ethylglycyl] - (L) -asparagyl] - (L) -β-cyclohexyl alaid, have antithrombic effects, including inhibition of platelet aggregation and thrombus formation in mammals, and are useful for the prevention and treatment of thrombosis associated with disease states such as myocardial infarction, stroke, peripheral arterial disease and covert intravascular coagulation (World Patent Publication No. WO95 / 10295) ).

To date, these pseudotetrapeptides have been prepared by C-terminal amino acid sequencing based on standard methods of solid or solution peptide synthesis. However, sequential amino acid coupling is less suitable for operational drug production because it hinders continuous belt production.

It is therefore an object of the present invention to provide an alternative approach to the preparation of pseudotetrapeptides. Such an approach should substantially increase the versatility and efficiency of production. The convergent approach is intended to provide the specified modifications of the pseudotetrapeptide by performing a specialized chemical treatment on one of the components rather than the pseudotetrapeptide as a whole, and is intended to simultaneously prepare a series of pseudotetrapeptide analogs.

94

4 4 4 4 4

4 4 4 4

4 9 9 4444444 44 4 4 4 4

9 4 * 9 4 45

SUMMARY OF THE INVENTION

A process for preparing a pseudotetrapeptide of formula (I)

Α- ^κ ν

Β n

° CH ₂ CO ₂ Q, where ^O is

optionally a nitrogen-protected azaheterocyclylΟνου group, single or double bond, number 1 to 5, an alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, aralkyl, alkylaryl or alkylaralkyl, n, hydrogen or alkyl protecting group; hydrogen, alkyl, cycloalkyl, cycloalkyl alkyl, alkylcycloalkyl, alkylcycloalkyl alkyl, aryl, substituted aryl, alkyl or substituted aralkyl OR ¹ or NR ¹ R ² , where R ¹ and R ² are independently of one another hydrogen, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, and al · ♦ ··

tt · »· •.>>

A compound of formula (1) or (2), or a salt or prodrug thereof, comprising (a) coupling an azahetrocyclyl pseudodipeptide of the formula

or a salt thereof, wherein K is a hydroxyl or acyl activating group, with a carboxylic acid substituted with a dipeptide of the formula

or a salt thereof, (b) optionally separating a nitrogen protecting group or a carboxylic acid protecting group to obtain a pseudotetrapeptide, and (c) optionally converting the pseudotetrapeptide into a salt or prodrug.

Individual terms used always have, unless specified, • 99 9 · • 999 9 9 · 9

9 9 · 9 9 «999

9,999 9999999 «9«

999 99 9 999 ·

99998 99 9 99 9 9

otherwise, the following meaning:

By azaheterocyclyl is meant a 4- to 8-membered, saturated or unsaturated or aromatic carbocyclic system in which one of the carbon atoms other than the carbon of the moiety is replaced by a nitrogen atom. When a nitrogen atom is incorporated into the ring system by two single bonds, it is generally substituted by a nitrogen protecting group Pi. Examples of azaheterocyclyl groups are piperidinyl, N-tert-butoxycarbonylpiperidinyl, N-benzyloxycarbonyperidinyl, pyrrolidinyl, N-tert-butoxycarbonylpyrrolidinyl, N-benzyloxycarbonypyrrolidinyl and pyrrolyl. Preferred azaheterocyclyl groups are pyridyl, N-tert-butoxycarbonylpiperidin-4-yl and N-benzyloxycarbonypiperidin-4-yl.

The term alkyl refers to a straight or branched chain saturated aliphatic hydrocarbon group having 1 to about 20 carbon atoms in the chain. Branched means that a linear alkyl chain is attached to a lower alkyl group such as a methyl, ethyl or propyl group. Preferred straight or branched chain alkyl groups include lower alkyl groups, which are groups having from 1 to about 10 carbon atoms. More preferred are lower alkyl groups having 1 to 6 carbon atoms.

By cycloalkyl is meant a saturated carbocyclic group with one or more rings having about 3 to 10 carbon atoms. Preferred cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and decahydronaphthyl.

• 9 9 9 9 9 9 9 9 9 9 9 9 9

9 9 9 9 9

999 98 9 · »« · * ·

The term "cycloalkylalkyl" refers to an alkyl group substituted with a cycloalkyl group. Preferred cycloalkylalkyl groups include cyclopentylmethyl, cyclohexylmethyl, cyclohexylethyl, decahydro-naphth-1-ylmethyl and decahydro-naphth-2-ylmethyl.

The term alkylcycloalkyl refers to a cycloalkyl group substituted with an alkyl group. Exemplary alkylcycloalkyl groups include 1-, 2-, 3- and 4-methylcyclohexyl or 1-, 2-, 3- and 4-ethylcyclohexyl.

By alkylcycloalkylalkyl is meant an alkyl group substituted with an alkylcycloalkyl group. Exemplary alkylcycloalkyl groups include 1-, 2-, 3- and 4-methylcyclohexylmethyl or 1-, 2-, 3- and 4-ethylcyclohexylmethyl or 1-, 2-, 3- and 4-methylcyclohexylethyl or 1-, 2-, 2-, 3- and 4-methylcyclohexylmethyl groups. 3- and 4-ethylcyclohexylethyl.

By aryl is meant phenyl or naphthyl.

By substituted aryl is meant a phenyl or naphthyl group substituted by one or more aryl groups which may be the same or different, the aryl substituents being alkyl, alkenyl, alkynyl, aryl, aralkyl, hydroxy, alkoxy, aryloxy, aralkoxy, aryl. hydroxyalkyl, acyl, formyl, carboxy, alkenoyl, aroyl, halogen, nitro, tri-halomethyl, cyano, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, acylaminoalkyl, acarbamoyl, alkylcarbamoyl, carbamoyl, carbamoyl, carbamoyl, carbamoyl sulphinyl, arylsulphonyl, arylsulphinyl, aralkylsulphonyl, aralkylsulphinyl, the group -NR a R b, where R a and R are as follows; ··· «··· to It «« · #

R b is independently hydrogen, alkyl, aryl or aralkyl. Preferred aryl substituents are alkyl, hydroxyl, alkoxy, halogen and trihalomethyl.

By aralkyl is meant an alkyl group substituted with an aryl group. Preferred aralkyl groups include benzyl, naphth-1-ylmethyl, naphth-2-ylmethyl and phenethyl.

By substituted aralkyl is meant an aralkyl group substituted on the aryl moiety with at least one aryl group.

The term alcohol refers to an alkyl group as defined herein with 1 to about 10 carbon atoms, substituted with one or more hydroxyl groups. By lower alcohol is meant an alkyl group having 1 to about 4 carbon atoms, substituted with one hydroxyl group. Exemplary lower alcohols include methanol, ethanol, 2-propanol and 1-butanol. By glycol is meant an alkyl group substituted with two or more hydroxyl groups. Exemplary glycols include ethylene glycol and propylene glycol.

By ether is meant a compound of the formula R-O-R ', where R and R' are lower alkyl. The groups R and R 'may be linked by one or more methylene groups or an additional oxygen atom. Exemplary ethers include diethyl ether, methyl tert-butyl ether, tetrahydrofuran and dioxane.

By polar aprotic is meant solvents which do not contain hydroxyl groups but have a relatively high dipole moment. Exemplary polar aprotic solvents include acetonitrile, N, N-dimethylformamide (DMF), dimethyl-dimethylformamide (DMF), dimethyl-dimethylformamide (DMF). Phosphate Phosphate sulfoxide (DMSO), 1,1-dimethoxyethane (DME), and hexamethylphosphoric triamide.

By M-OH is meant a base wherein M is an alkali metal selected from sodium, calcium, lithium and potassium.

By carbonate or carbonate is meant a base of the general formula M 2 CO 3, where M is magnesium, sodium, calcium, lithium and potassium.

The term "bicarbonate" refers to a base of the formula MHCO 3, where M is sodium, calcium, lithium and potassium.

By natural amino acid is meant a carboxylic acid having an amino group in the α position to the carboxylate group, that is, a compound of formula H2N-CHR-CO2Η wherein R is alkyl, cycloalkyl, aralkyl or -CH2CO2Q wherein Q is as defined above. Preferred natural amino acids include those of the above formula wherein R is cyclohexylmethyl. Preferred amino acids have L stereochemistry at the α carbon atom.

By "peptide and polypeptide" is meant a polymer whose monomers are natural or non-natural amino acid residues linked to each other by amide bonds. By peptide skeleton is meant a series of peptide bonds through which amino acid residues are linked.

By amino acid new amino acid residue is meant the individual units incorporated into the peptide of the invention.

The term pseudopeptide is one or more non-natural to the peptide backbone. By this means a peptide that incorporates the amino acid monomers of the exemplary non-amino acid new 0 0 00 9 9 9 0 90 00 90

9 0 9 9 · 90 ·· · · 9 · 9 • 09 99 9 9999

99990 99 9 9 * 09 monomers mention 1 - [(phenylmethoxy) carbonyl] -4-piperidinobutanoic acid and 4-pyridine butyric acid.

The term "non-natural amino acid" refers to a carboxylic acid containing an amino group in a position other than and to the carboxylate group. Preferred non-natural amino acids are compounds of formula

A1

wherein it is azaheterocyclyl. Exemplary non-natural amino acids include 4-piperidinobutanoic acid, 3- (4-piperidinylmethylene) propionic acid and 4-piperidobutyric acid.

By N-protecting group and nitrogen protecting group is meant an easily removable group known in the art to protect the amino group against an undesired reaction during the process for preparing the desired compound and selectively removable. The use of nitrogen protecting groups is well known in the art for protecting groups against an adverse reaction during the preparation of a desired compound, and many of these are described in the literature (e.g., TH Greene and PGM Wuts, Protective Groups in Organic Synthesis, 2nd Edition, John Wiley & Sons, New York, 1991). Preferred nitrogen protecting groups include, but are not limited to, acyl, including formyl, acetyl, chloroacetyl, trichloroacetyl, o-nitrophenylcetyl, o-nitrophenoxycetyl, trifluoroacetyl, acetocetyl, 4-chlorobutyryl, isobutyric acid, o-nitro, isobutyryl, o-nitro, isobutyrate, o-nitro, and acyloxy, including methoxycarbonyl, 9-fluorenylmethoxycarbonyl, 2,2,2-trifluoroethoxycarbonyl, 2-trimethylsilyl-ethoxycarbonyl, vinyloxycarbonyl, alkyloxycarbonyl, 4 '

4 ··········· 4 · · · ·

4, 4 " nyl, tert-butyloxycarbonyl (BOC), 1,1-chloropropylpropinyloxycarbonyl, benzyloxycarbonyl (CBZ), p-nitrobenzyloxycarbonyl, 2,4-dichlorobenzyloxycarbonyl and alkyloxycarbonyl (Alloc) groups.

By acid labile N-protecting group and nitrogen atom protecting acid labile is meant the nitrogen protecting group mentioned above, readily removable by acidic treatment while being relatively resistant to the action of other agents. A preferred acid labile nitrogen protecting group is tert-butyloxycarbonyl (BOC).

By the term hydrogenation labile N-protecting group and the nitrogen atom protecting a hydrogenation labile group is meant the nitrogen protecting group mentioned above, easily removable by hydrogenation, while being relatively resistant to the action of other agents. A preferred labile nitrogen protecting group is the benzyloxycarbonyl (CBZ) group.

The term metal-labile N-protecting group and a metal-labile nitrogen protecting group refers to the nitrogen-protecting group mentioned above, easily removable by metal action. A preferred nitrogen-labile metal protecting group is the allyl group which is removable by Pd (O) treatment.

By N-protecting agent is meant an agent used to introduce a nitrogen protecting group into a molecular unit. Such protecting groups are generally introduced by replacing the liberated group from the N-protecting agent with a nucleophilic nitrogen atom to be protected. Exemplary N-protecting agents include acyl halides and aryl halides including, for example, acetyl chloride and benzoyl chloride; acyl anhydrides and arylanhydrides including, for example, acetic anhydride, trifluoroacetic anhydride and benzoic anhydride; formats including benzylphenol 9 9 9 9

9 9 9 9 9 9 9 9 9

9 9 9 9 9 9 9 9 9

9 9 9 9 9999999 99 9

9 9 9 9 9

999 99 9 9 9 9 9 99 mint; and carbonates such as di-tert-butyl dicarbonate and benzyl N-succinate dicarbonate.

By the term "carboxylic acid protecting group" and "acid protecting group" is meant an easily removable group known in the art to protect the carboxylic acid group (-CO 2 H) against an undesired reaction during the process for preparing the desired compound and selectively removable. The use of carboxylic acid protecting groups is well known in the art and many of these are described in the literature (for example, T. H. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis, 2nd Edition, John Wiley & Sons, New York, 1991). Exemplary carboxylic acid protecting groups include ester groups such as methoxymethyl, methylthiomethyl, tetrahydropyranyl, benzyloxymethyl, substituted and unsubstituted phenacyl, 2,2,2-trichloroethyl, tert-butyl, cinnamyl, substituted and unsubstituted benzyl, trimethylsilyl allyl, amide, and hydrazide groups including N, N-dimethyl, 7-nitroindolyl, hydrazide, and N-phenylhydrazide groups. Particularly preferred carboxyl-containing groups are tert-butyl and benzyl.

The terms hydrogenation-labile carboxylic acid-protecting group and hydrogenation-labile acid-protecting group refers to an acid-protecting group as defined above, readily removable by hydrogenation, while being relatively resistant to the action of other agents. A preferred carboxylic acid-labile hydrogenation labile group is benzyl.

By acidic labile protecting group and acidic labile protecting group is meant an acid protecting group as defined above, readily removable by acid treatment, while being relatively resistant to the action of other agents. As a preferred acid labile group, the labile acid labile group is preferably a labile acid labile group. The tert-butyl group is indicated on the protective acid.

By metal-labile carboxylic acid-protecting group and metal-labile acid-labile group is meant an acid-protecting group as defined above, readily removable by metal action. A preferred acid-labile metal protecting group is phenacyl and allyl, which are removable by treatment with zinc or Pd (O).

By acyl activating group is meant a group which, when replacing a hydroxyl group in a carboxylic acid, makes the carbonyl group more sensitive to a nucleophilic reaction and thereby facilitates the replacement of the hydroxyl group by nucleophilic groups. Exemplary acyl activating groups include halogen atoms (being acyl halides); carboxylic acid esters with hydroxybenzotriazole, N-hydroxysuccinimide, pentafluorophenol and p-nitrophenol; asymmetric anhydrides; asymmetric anhydrides prepared, for example, by reaction of a carboxylic acid with isopropyl chloroformate, ethyl chloroformate and isobutyl chloroformate; products obtained by reaction of a carboxylic acid with carbodiimides such as dicyclohexyldiisopropylcarbodiimide and Ν, Ν-dimethylpropylethylcarbodiimide; and derivatives obtained by the reaction of a carboxylic acid with (benzotriazol-1-yloxy) tris (pyrrolidino) phosphonium umhexafluorophosphate, with 2- (1H-benzotriazol-1-yl) -1,1,3,3-trimethyl uronate with rt-fluoroborate, 2- (1H-benzotriazol-1-yl) -1,1,3,3-tetramethyluronium hexafluorophosphate and diphenylphosphorazate.

The term salt refers to a pseudotetrapeptide, a pseudodipeptide and a dipeptide to an acid or base addition salt.

If the basic group of the pseudotetrapeptide, pseudodipeptide and dipeptide are reacted with an acid, acid addition salts are formed which may be more preferred for use.

4 4 4 4 4 4 4 4 4 • 9 4 4 4 4 4

4 4 4444 44 44 4

4 4 4 4 4 4 4 4

444 44 44 4 44 44 The acids used to form the acid addition salt are those which, when reacted with the free base, form pharmaceutically acceptable salts, i.e. salts whose anions are non-toxic to the patient in pharmaceutical doses, so that their favorable action of the free base compound it is not disturbed by side effects attributable to the anion. While the pharmaceutically acceptable salts of the basic compounds of the invention are preferred, all acid addition salts are useful sources of the free base form, particularly certain salts, when they are intermediates, for example, when salts are formed solely for purification and identification purposes or when used. as intermediates in the preparation of pharmaceutically acceptable salts using ion exchange resins. Pharmaceutically acceptable salts of the invention are those derived from acids such as: mineral acids such as hydrochloric, sulfuric, phosphoric and sulfamic acids; and organic acids such as acetic, citric, lactic, tartaric, malonic, methanesulfonic, ethanesulfonic, benzenesulfonic, p-toluenesulfonic, cyclohexylsulfamic and quinic acids. Corresponding acid addition salts are hydrohalides such as hydrochloride and hydrobromide, sulfate, phosphate, nitrate, sulfamate, acetate, trifluoroacetate, citrate, lactate, tartrate, malonate, oxalate, salicylate, propionate, succinate, fumarate, maleate, methylene-bis-p-p hydroxynaphthoate, gentisate, mesylate, isethionate, di-p-toluoyltartrate, methanesulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonate, cyclohexylsulfamate and quinate.

According to the invention, the acid addition salts of pseudotetrapeptide, pseudodipeptide and dipeptide are prepared by reacting the free base with a suitable acid using or adapting methods known per se. For example, the acid addition salts of the peptides of the invention are prepared either by dissolving the free base in an aqueous or aqueous alcoholic solution or other suitable aqueous solvent mixture containing a suitable acid, and isolating the salt by evaporating the solution or reacting the free base and acid in an organic solvent. it separates directly this to this this to this totototo to this to This may be obtained by concentrating the solution. The pseudotetrapeptide, pseudodipeptide or dipeptide may be regenerated from its salts using or adapting methods known in the art. For example, the pseudotetrapeptide, pseudodipeptide or dipeptide can be regenerated from their acid addition salts by treatment with an alkali, for example an aqueous sodium bicarbonate solution or an aqueous ammonia solution.

If the pseudotetrapeptide, pseudodipeptide or dipeptide is substituted with an acid moiety, base addition salts may be prepared and may be a more convenient form for use. The bases used to form the base addition salt are bases which, when reacted with the free acid, form pharmaceutically acceptable salts, i.e. salts whose cations are non-toxic to the patient in pharmaceutical doses, so that the beneficial effect of the free acid compound is not disturbed by side effects attributable to cations. Pharmaceutically acceptable salts of the invention, including, for example, alkali metal, alkaline earth metal or amine salts, are those derived from the following bases: sodium hydride, sodium, potassium, calcium, aluminum, lithium, magnesium, and zinc, ammonia, trimethylammonium, triethylammonium, ethylenediamine, n-methylglucamine, lysine, arginine, ornithine, choline, Ν, N'-Dibenzylethylenediamine, chloroprocaine, diethanolamine, procaine, n-benzylphenethylamine, diethylamine, dicyclohexylamine, piperethylamine, tris (hydroxymethyl).

The metal salts of the pseudotetrapeptides, pseudodipeptide or dipeptides may be prepared by contacting a hydride, hydroxide, carbonate or similar reactive compound of the selected metal in an aqueous or organic solvent with a pseudotetrapeptide, a pseudodipeptide or a dipeptide in the free acid form. The aqueous solvent may be water, or it may be a mixture of water and an organic solvent, preferably an alcohol such as methanol or ethanol, a ketone such as acetone, an aliphatic et.

9,999,9999

9 9 · 9 9 9 9999

9 9 9 9 9 9999 9 9 9 9 9

999 99 · 9999 • 99 99 99 9 99 99 games like tetrahydrofuran or ester like ethyl acetate. Such reactions are generally carried out at room temperature, but can optionally be carried out with heating or cooling.

The amine salts can be obtained by contacting the amine in an aqueous or organic solvent with a pseudotetrapeptide, a pseudodipeptide or a dipeptide in the free acid form. Suitable aqueous solvents include water and mixtures of water with alcohols such as methanol or ethanol, ethers such as tetrahydrofuran, nitriles such as acetonitrile or ketones such as acetone. Amino acid salts can be prepared similarly

The pseudotetrapeptide, pseudodipeptide or dipeptide can be regenerated from their base addition salts by using or adapting methods known in the art, for example by treating the base addition salt with an acid such as hydrochloric acid.

Salts of a pseudotetrapeptide, pseudodipeptide or dipeptide are also useful for purification, for example, by utilizing differences in their solubility and parent peptides, byproducts and / or starting materials by methods known to those skilled in the art.

By "pharmaceutically acceptable ester" is meant esters that hydrolyze in vivo so that they readily cleave in the human body to release the parent azacyclic alkylalkanoylpseudotetrapeptide or salt thereof. Suitable ester groups are derived, for example, from pharmaceutically acceptable aliphatic carboxylic acids, in particular alkanoic, alkenic, cycloalkanoic and alkenoic acids, the alkyl or alkenyl moiety preferably having at most 6 carbon atoms. Examples of particularly suitable esters are the formats, acetates, propionates, butyrates, acrylates and ethyl succinates.

By a pharmaceutically acceptable prodrug is meant a peptide suitable for pharmaceutical purposes without, for example, undesirable toxicity, irritability and allergic responses and effective for the intended use.

0 0

0 0

0 0 0

00 0

00

0 0 0

0 0 0

0 0 I

0 0 0

Wherein a pharmaceutically acceptable ester or double ion form of the peptides of the invention is included. By prodrug is meant a peptide that is rapidly converted in vivo to the parent peptide, for example, by hydrolysis in blood. Pharmaceutically acceptable prodrugs of the invention are described in the literature (T. Higuchi and V. Stella, Pro-drugs as Novel Delivery Systems, Vol. 14, ACS Symposium Series, and Edward B. Roche, Ed. Bioreversible Carriers in Drug Design, American Pharmaceutical). Association and Pergamon Press, 1987).

Pseudotetrapeptides, pseudodipeptides and dipeptides may contain asymmetric centers in addition to chiral centers in the peptide backbone. These asymmetric centers may be independently in either the R or S configuration. It will be apparent to those skilled in the art that certain peptides of Formula I may exhibit optical isomerism. Geometric isomers include cis and trans forms of peptides of the invention having alkenyl moieties. The invention encompasses the preparation of individual geometric isomers and stereoisomers and mixtures thereof.

Such isomers may be separated from their mixtures by the use or adaptation of methods known per se, for example by chromatography and recrystallization, or may be prepared separately from suitable isomers of their intermediates, for example, by the use or adaptation of the methods described below.

The pseudotetrapeptides of the formula II are preferred for the process according to the invention

(CH ₂ ).

P

o (II) 9 9 9 99 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9

999 * · 9,999

999 ·· 99 9 99 99 where it means

P1 nitrogen protecting group,

B an alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl or alkylcycloalkylalkyl group,

Q2 is a hydrogen atom or a carboxylic acid protecting group

P2,

J is hydrogen, alkyl, cycloalkyl, cycloalkyl, alkyl, alkylcycloalkyl, or alkylcycloalkylalkyl,

L is OR ¹ or NR ¹ R ² , wherein R ¹ and R ² independently of one another are hydrogen, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, aralkyl, alkylaryl or alkylaralkyl, respectively; number 3 or 4.

More preferred for the process of the invention are the pseudotetrapeptides of formula II wherein B is alkyl, J is alkyl or cycloalkylalkyl, L is OR ¹ or NR ¹ R ² , wherein R ¹ and R ^{2 are} each independently hydrogen, alkyl, cycloalkyl , cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, m number 3, n number 3 or 4 and p number 1.

Also preferred for the process according to the invention are the pseudotetrapeptides of the general formula (III). ····· * «fefe ς · fefe ·« · · · · · · fefefefefe fefe 9 · · fefe

wherein P 1 is a nitrogen protecting group, B is an alkyl group, Q 2 is hydrogen or a carboxylic acid protecting group P2, J is alkyl, cycloalkyl or cycloalkylalkyl and L is OR ¹ or NR ¹ R ² , where R ¹ and R ² are independently of each other a hydrogen atom, an alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl or alkylcycloalkylalkyl group.

Most preferred for the process of the invention are the pseudotetrapeptides of formula III wherein B is alkyl, J is cycloalkylalkyl, and L is NR ¹ R ² , where R ¹ and R ^{2 are} each independently hydrogen or alkyl.

The method of the invention relates to pseudotetrapeptides wherein Q 2 is a carboxylic acid protecting group.

The method of the invention relates to pseudotetrapeptides wherein P 1 is benzyloxycarbonyl and Q 2 is benzyl.

The method of the invention relates to pseudotetrapeptides wherein P 1 is benzyloxycarbonyl and Q 2 is hydrogen.

The method of the invention relates to pseudotetrapeptides wherein P ¹ is benzyloxycarbonyl, Q 2 is benzyl and L is NR ¹ R ² .

The method of the invention relates to pseudotetrapeptides wherein P 1 represents a benzyloxycarbonyl group, a Q 2 hydrogen atom and L 1.

Ο ·

«· · · 9 9 999 • · · ·

e ·: i • «

9 of NR ¹ R ² .

The invention also relates to a process wherein the salt of an azaheterocyclic pseudodipeptide is coupled with a salt of a carboxylic acid substituted dipeptide.

The invention also relates to a process wherein the azaheterocyclyl pseudodipeptide addition salt is basically coupled with an acid addition salt of a carboxylic acid substituted dipeptide.

The invention also relates to a process wherein the dicyclohexylamine salt of azahet erocyclylpseudi peptide is coupled with the carboxylic acid trifluoroacetate salt.

The invention relates to a process for the preparation of:

a) coupling an azaheterocyclyl pseudodipeptide of the formula

or a base addition salt thereof, wherein P 1 is a nitrogen protecting group and B is an alkyl group, with a carboxylic acid substituted with a dipeptide of the formula

Or CO ₂ Q ₂ or an acid addition salt thereof, wherein Q 2 is a hydrogen atom or a carboxylic acid protecting group, J is alkyl, cycloalkyl or cycloalkylalkyl, and L is OR ¹ or NR ¹ R ² , wherein R ¹ and R ^{2 are} independently vo19 <·· »»

0 »·· · 8

0 ♦

An alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl or aralkyl group for the preparation of a pseudotetrapeptide of the formula

(b) optionally removing a nitrogen protecting group or carboxylic acid; and

c) optionally converting the pseudotetrapeptide into its salt or prodrug.

The invention also relates to the aforementioned process wherein P 1 is a benzyloxycarbonyl group and Q 2 is a benzyl group.

The invention also relates to the above process wherein P 1 is benzyloxycarbonyl and Q 2 is hydrogen.

The invention also relates to the aforementioned method, wherein P 1 is benzyloxycarbonyl, Q 2 is benzyl, B is ethyl, J is cyclohexylmethyl, and L is NH 2.

The invention also relates to the aforementioned process, wherein P 1 is benzyloxycarbonyl, Q 2 is hydrogen, B is ethyl, J is cyclohexylmethyl, and L is NH 2.

The invention also relates to a process for the preparation of a cyclohexylmethyl-substituted dipeptide of the general formula

• · «« w «q ··» · # «4 · i <·« 9 9 9

9 »9 · 9 ··· 9 ···

Where Q2 is hydrogen or a protecting group and Q3 is a hydrogen or protecting group

a) reduces the phenylmethyl-substituted peptide of the general formula by a carboxyl nitrogen atom,

b) optionally removing a nitrogen protecting group or carboxylic acid.

The invention also relates to the above process, wherein the reduction is carried out by catalytic hydrogenation.

The invention also relates to the above process, wherein the catalytic hydrogenation is carried out in the presence of a platinum catalyst.

The invention also relates to the above process, wherein platinum oxide or platinum on alumina is used as the platinum catalyst.

The invention also relates to a process for the preparation of an amidodipeptide of the general formula

Wherein Q2 is hydrogen or a base addition salt group or group a carboxyl-protecting group and Q 3 a hydrogen atom or a nitrogen protecting group in which:

a) amidates the ester of the peptides of the general formula

wherein R3 is lower alkyl.

The invention also relates to the above process, wherein the amidation is carried out using ammonia in an alcohol.

The invention also relates to the above process, wherein the alcohol is a lower alcohol.

The invention also relates to the above process, wherein the amidation is carried out using ammonia in a mixture of a lower alcohol and a glycol.

The invention also relates to the above process, wherein a mixture of a lower alcohol and a glycol is a mixture of methanol and ethylene glycol.

The invention also relates to a process for preparing an aspartame compound of the general formula

♦ ·

• «9 • •

• 9; í • 9

Wherein Q2 is a hydrogen atom or a carboxylic acid protecting group and Q3 is a nitrogen protecting group and R3 is a lower alkyl group introducing a nitrogen protecting group into an aspartame compound of formula

The invention also relates to the above process wherein Q 3 is a benzyloxycarbonyl or tert-butyloxycarbonyl group.

The invention also relates to the aforementioned process, wherein Q 2 is a hydrogen atom.

The invention also relates to a process for the preparation of an amidodipeptide of formula ₃

wherein Q3 is a nitrogen protecting group and Q2 is a hydrogen atom in which Q3 is hydrogen

(a) introducing a base and a nitrogen protecting agent into a solution of aspartame in a solvent to form a solution of a compound of formula ## STR3 ##

Q, NH

^ CO ₂ Q ₂ wherein Q 2 represents a hydrogen atom or a base addition salts and

b) ammonia is introduced into the solution obtained.

The invention also relates to the above process wherein Q 3 is a tert-butoxycarbonyl or benzyloxycarbonyl group.

The invention also relates to the above process wherein Q 3 is a tert-butyloxycarbonyl group.

The invention also relates to the above process, wherein the solvent is an alcohol.

The invention also relates to the above process, wherein the alcohol is a lower alcohol or a mixture of a lower alcohol and a glycol.

The invention also relates to the above process, wherein the alcohol is methanol or a mixture of methanol and ethyl englycol.

The invention also relates to a process for the preparation of a cyclohexylmethyl substituted dipeptide of the formula

»♦

9 9

9 9 ·

Or an acid addition salt thereof;

a) preparing in a solvent a mixture of a catalyst and a phenylmethyl substituted peptide of the general formula

where Q 3 is a tert-butyloxycarbonyl group,

(b) the mixture is treated with hydrogen;

(c) removing the catalyst from the mixture; and

d) Hydrogen chloride gas is introduced into the mixture.

The invention also relates to the above process, wherein acetic acid is used as the solvent.

The invention also relates to a process for preparing an azaheterocyclyl-substituted acidic compound of formula

wherein R 4 is a hydrogen atom or a lower alkyl group and P 1 is a nitrogen protecting group in which:

a) decarboxylates the 2-pyridylethyl di (lower alkyl) malonate of the general formula

_CO2 R @ ₅ 0009 • < «where R represents a lower alkyl acid; ny formula to obtain pyridyl

b) hydrogenating pyridylic acid with hydrogen in the presence of a catalyst to give the piperidine acid of formula

c) optionally removing the catalyst

d) protected piperidine acid at the nitrogen atom to protect the nitrogen atom to give the piperidine acid of formula

e) coupling the protected piperidine acid to the N atom with an N-ethylglycine of the general formula

STEED,

HN

to obtain an azaheterocyclyl substituted acidic compound and a

♦ 0 0 0 ♦ 0 0 0 0 0!! 0!!!!! 0 0 0!!!! 0! »

f) optionally, the ester is an azaheterocyclyl-substituted acidic compound wherein F4 is lower alkyl.

The invention also relates to the above process wherein P 1 is benzyloxycarbonyl and R 4 is hydrogen.

The invention also relates to the above process, wherein the decarboxylation is carried out by heating 2-pyridylethyl di (lower alkyl) malonate in an aqueous acid solution.

The invention also relates to the above process, wherein aqueous hydrochloric acid is used as the aqueous acid solution.

The invention also relates to the above process wherein the hydrogenation is carried out in an aqueous acid solution.

The invention also relates to the above process, wherein aqueous hydrochloric acid is used as the aqueous acid solution.

The invention also relates to the above process, wherein the introduction of the protecting group on the nitrogen atom is carried out in an aqueous solution of the base.

The invention also relates to the above process wherein P 1 is a benzyloxycarbonyl group.

The invention also relates to the above process, wherein a) a solution of 2-pyridylethyl-di (lower alkyl) malonate in an aqueous acid solution is heated to obtain a solution of pyridylic acid in an aqueous acid,

b) a catalyst is added to the pyridylic acid solution and the mixture is treated with hydrogen to obtain a mixture of catalyst and piperidine acid,

c) separating the catalyst from the mixture to obtain an aqueous piperidine acid solution,

d) adding the base and the nitrogen protecting agent to the aqueous solution to obtain the protected piperidine acid on the nitrogen atom.

The invention also relates to the above process, wherein aqueous hydrochloric acid is used as the aqueous acid solution.

The invention also relates to the aforementioned process, wherein F? 4 is hydrogen.

The invention also relates to the above process, wherein P 1 is a benzyloxycarbonyl group.

The invention also relates to a process for preparing a pseudotetrapeptide of the general formula

a cyclohexylmethyl group and L an OR ¹ or NR ¹ R ^{2 group} , wherein R ¹ and R ^{2 are} each independently hydrogen, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, salts thereof or prodrugs thereof;

a) reduces a compound of the general formula • *

·· · · · · · · · · · · · · · · · ·

a nitrogen atom, a Q2 hydrogen atom or a carboxylic acid protecting group and a J phenylmethyl group,

b) optionally removing a nitrogen protecting group or a carboxylic acid protecting group,

c) optionally converting the pseudotet rapept id into its salt or prodrug.

The invention also relates to the above process, wherein the reduction is carried out by catalytic hydrogenation.

The invention also relates to the above process wherein:

represents a group

wherein m is 3, P 1 or a nitrogen protecting group, n 3, p 1 and Q 2 are a carboxylic acid protecting group.

The invention also relates to the aforementioned process, wherein P 1 is a hydrogen-labile nitrogen protecting group and Q 2 is a carboxylic acid-labile hydrogenation group.

The invention also relates to the aforementioned method, wherein the catalytic reduction is carried out simultaneously with the reduction and with the removal of this. · · Toto · · · · »» ♦ ♦

group P1 and Q2.

The invention also relates to the aforementioned method, wherein it is a pyridyl group and a Q2 carboxylic acid protecting group.

The invention also relates to the aforementioned method, wherein Q 2 is a labile carboxylic acid protecting group.

The invention also relates to the above process, wherein the catalytic reduction is carried out simultaneously with the reduction and removal of the Q2 group.

The invention also relates to a pseudotetrapeptide of formula *

a pyridyl group; or

- (CH ₂ )

where m 3 and P 1 are hydrogen or a nitrogen protecting group, n 2 to 6, B alkyl, p 1 or 2, Q 2 are hydrogen or a carboxylic acid protecting group, J is phenylmethyl and L is OR ¹ or NR ¹ R ² wherein R ¹ and R ² are independently hydrogen, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl or alkylcyk1oalkylalkylovou, its salts or prodrugs.

·· · · · · · · · · · · · ·

4 · 99 • 9

99 · 0 · 0 · 0 · 0 · 0 · 0 · 0 · 0 · 0 ·

The invention also relates to the aforementioned pseudotetrapeptide, wherein

wherein m is 3, P 1 is a nitrogen protecting group, n 3, p 1, and Q 2 is a carboxylic acid protecting group.

The invention also relates to the aforementioned pseudotetrapeptide, wherein P 1 is a hydrogen-labile nitrogen protecting group and Q 2 is a carboxylic acid-labile hydrogenation group.

The invention also relates to a pseudotetrapeptide of the general formula

wherein P 1 is a hydrogen atom or a nitrogen protecting group, B is an alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, aralkyl, alkyl, aryl or alkylaralkyl and FU a hydrogen or lower alkyl group or salts thereof.

The invention also relates to the aforementioned pseudodipeptide, wherein P 1 represents a nitrogen protecting group, B an alkyl group and FN a hydrogen atom.

The invention also relates to the aforementioned pseudodipeptide, wherein P 1 represents a benzyloxycarbonyl group and B represents an ethyl group.

9

9 9 9 9 9 999 999 9 9 9 9 9 9 9999 99 99 9

9 9 99 9 9999 • * 999 9 9 9 99

The following schemes and examples illustrate the process of the invention in more detail, but are not intended to limit the invention in any way.

The individual scraps used have the following meanings: BOC (tert-butyloxycarbonyl), CBZ or Z (benzyloxycarbonyl), Gly (glycine), Asp (aspartic acid), Obzl (benzyloxy), TFA (trifluoroacetic acid), Cha (β-cyclohexylalanine), EtOAc (ethyl acetate), DMF (dimethylformamide), DCC (dicyclohexylcarbodiimide)), HOBT (hydroxybenzotriazole), TBTU (2- (1H-benzotriazol-1-yl) -1,1,3,3-tetramethyluronium tetrafluoroborate), D1 (deionized water) ), PNP (p-nitrophenol), PFP (pentafluorophenol), DCU (dicyclohexylurea), NMM (N-methylmorpholine) and MTBE (methyl tert-butyl ether).

As can be seen in Scheme 1, the process of the invention comprises coupling the azaheterocyclyl pseudodipeptide of formula IV with a carboxylic acid substituted dipeptide of formula V to give a pseudotetrapeptide of formula I. The individual symbols B, J, K, L, m, p, q and Q2 in Scheme 1 are as defined above.

In the preparation of the azaheterocyclyl pseudotetrapeptides of formula I or intermediates therefor, it may be desirable or necessary to avoid crosslinking reactions between chemically active substituents on natural amino acids or peptides or on pseudoamino acids or pseudopeptides. Substituents may be protected by well-known protecting groups which may subsequently be optionally removed or left using known methods for this purpose to obtain the desired products or intermediates (e.g. Green, Protective Groups in Organic Synthesis, Wiley, New York, 1981). . Selective protection or selective removal of protecting groups may also be necessary or desirable to allow conversion or removal of existing substituents, or to 9, 9, 9, 9, 9 or 9. 9 possible subsequent reactions to obtain the desired end product.

Scheme 1

IV with the dipeptia-substituted carboxylic acid of formula V as described above is carried out in the presence of an organic base such as N-methylmorpholine, diisopropylethylamine or triethylamine. Suitable solvents for this coupling reaction include dichloromethane, toluene, Ν, Ν-dimethylformamide, ethyl acetate, acetonitrile, dimethylacetamide, methylpyrrolidone and water, and mixtures thereof. The coupling is performed for about 30 minutes to about 24 hours, depending on the dipeptide and pseudodipeptide to be coupled, the activating agent, the solvent used and the temperature. The coupling is carried out at a temperature of about -10 to about 50 ° C, preferably at about room temperature. The carboxylic acid moiety in the compound of formula (IV) is preferably activated with a suitable activating agent. Representative activating agents include, for example, isopropyl chloroformate in the presence of N-methylpiperidine, 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride (EDC) in the presence of 1-hydroxybenzotriazole (HOBT), bis (2-oxo-3-oxazolidinyl) chloride phosphonic acid (B0P-C1) in the presence of triethylamine, 2- (1H-benzotriazol-1-yl) -1,1,3,3-tetrafluoroboronate and refluoroborate (TBTU)

In the presence of diisopropylethylamine, N-hydroxysuccinimide in the presence of N, N'-dicyclohexylcarbodiimide (DCC). The activation is preferably carried out at a temperature of about 0 to about 10 ° C for about five minutes to about five hours.

Where the acyl activated moiety is stable, it can be prepared and isolated beforehand for use in the coupling reaction. Suitable acyl activating groups suitable for the preparation of the isolated pseudodipeptides of the general formula IV wherein K is acyl activating groups include, for example, esters with hydroxybenzotriazole, N-hydroxysuccinimide, pentafluorophenol, p-nitophenol, symmetrical anhydrides and acyl halides.

In the coupling reaction described above, wherein K is a hydroxyl group, the azaheterocyclyl pseudodipeptide of formula IV can be used in the form of a free carboxylic acid or in the form of a base addition salt of a carboxylic acid. Preferred base addition salts include amine salts such as dicyclohexylamine and triethylamine and metal salts such as sodium and potassium. Particularly preferred as base addition salts are dicyclohexylamine salts. If a base addition salt is used, the free acid is released in situ prior to the coupling reaction using a suitable acid.

Similarly, the dipeptide of formula V may be used in the form of the free base, acid addition salt, or base addition salt. An acid addition salt is preferred. Suitable acid addition salts include, for example, hydrochloride, hydrobromide, trifluoroacetate, acetate and toxylate. A particularly preferred acid addition salt is hydrochloride and trifluoroacetate.

The use of acid and base addition salts is particularly advantageous as it allows the purification of the azaheterocyclyl pseudodi peptide and carboxylic acid-substituted building block 444 4 4444

4 4 4 4 4 4 4 4

4 4 4

4 4 4

The dipeptides of formula (IV) and (V) are extracted by an acid extraction technique as well as by recrystallization of salts, thereby eliminating the need for purification, for example by chromatography, and the use of intermediates in the form of aqueous solutions.

Coupling reactions are particularly preferred when Q 2 is hydrogen. The unexpected fact that the coupling proceeds purely without protecting the side chain of the carboxylic acid moiety contributes to the advantages of the process. The total number of steps decreases as the deprotection and deprotection reactions are eliminated and, in addition, the unprotected acid allows isolation and purification of the dipeptide of formula V and coupling of product I by an acid-base extraction technique or by recrystallization of the base addition salt as above.

The pseudotetrapeptide of formula I in which ring A is unsaturated can be converted to a saturated derivative by selective reduction of ring double bonds, for example, by catalytic hydrogenation using platinum oxide. Any nitrogen protecting group P1 and carboxylic acid protecting P2 group in the pseudotetrapeptide of formula I can also be removed as described below.

Compounds of formula (II) are preferably prepared by the method of Scheme 2. In Scheme 2, m, η, Β, K, J and L are as defined above. P1 is a nitrogen labile protecting group such as tert-butyloxycarbonyl or hydrogenated labile nitrogen protecting group such as benzyloxycarbonyl, and Q2 is a hydrogen atom, carboxylic acid labile protecting group such as tert-butyl or hydrogenation labile carboxylic acid protecting group, such as methyl or ethyl group, hydrogenation labile group 0 0

A carboxylic acid protecting group such as a benzylic group or a carboxylic acid protecting group that is readily cleaved by treatment with a metal such as zinc or Pd (O) such as a phenacyl group.

Scheme 2

According to Scheme 2, a pseudodipeptide of formula VI is coupled with a dipeptide of formula V by the method of Scheme 1. The coupling product of formula II is purified by recrystallization from an organic solvent or mixture of organic solvents, preferably ethyl acetate / heptane or precipitation of a base addition salt. A preferred base addition salt is the dicyclohexylamine salt. The salt formation is generally carried out at a temperature from room temperature to about 75 ° C. Suitable salt-forming solvents include alcohols, esters, ethers and polar aprotic solvents with or without water. A preferred salt-forming solvent system is a mixture of acetonitrile and water.

• · ♦ 00 9 00 90 _o 00 09009 0000 - 36 “000 9900 9990

099 9 0990 90 00 0

009 00 9 0910

0 · 0 00 90 9 90 00

After coupling of the compound of formula VI and V to give the compound of formula II, the optionally present nitrogen protecting group P1 and the optionally present carboxylic acid protecting group P2 are sequentially removed or removed simultaneously to give the tetrapeptide or pseudopeptide of formula VII. The acid labile protecting group is preferably removed with trifluoroacetic acid. The hydrogenation-labile protecting group is preferably removed by hydrogenation in the presence of palladium on carbon. The metal labile protecting group is preferably removed by treatment with zinc or Pd (O). Preferred solvents for the hydrogenation reaction are lower alcohols, for example methanol, ethanol or propanol, or mixtures of alcohol with water, such as a mixture of ethanol and water or propanol and water. The pseudotetrapeptide of formula (VII) is purified by recrystallization from lower alcohols or mixtures of lower alcohols and water, preferably mixtures of methanol and water or ethanol and water.

The process for preparing the pseudotetrapeptides of formula (III) according to the invention is shown in Scheme 3. In Scheme 3, P 1 for hydrogenation is a labile nitrogen protecting group, Q 2 is hydrogen or hydrogenated labile protecting group, B alkyl, J alkyl, cycloalkyl or L is OR ¹ or NR ¹ R ² , wherein R ¹ and R ^{2 are} each independently alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl or alkylcycloalkylalkyl.

• φφ φφ φ • ΦΦΦ ΦΦΦ

ΦΦΦ φ φ φ φ φ φ ΦΦΦ «φφφφ

ΦΦΦ ΦΦΦ

ΦΦΦ φφ «φ ·

Φ φ

φ • φ φ φ φ φ φ φ φ φ φ φ φ φ φ φ

Scheme 3

Ρ

According to Scheme 3, a pseudodipeptide of formula VIII is activated and coupled with a dipeptide of formula IX by the method of Scheme 1. Preferred activating agents include, for example, 2- (1H-benzotriazol-1-yl) -1,1,3,3-tet. ramyl hyluronic umtetrafluoroborate (TBTU) in the presence of diisopropylethylamine and N-hydroxysuccinimide in the presence of Ν, N'-dicyclohexylcarbodiimide (DCC). The activation is preferably carried out at a temperature of about 0 to about 10 ° C for about five minutes to about five hours.

In the coupling reaction described in Scheme 3, the pseudodipeptide of formula VIII is preferably used in the form of a base addition salt. Preferred base addition salts include salts with amines, such as dicyclohexylamine and triethylamine, and salts with metals such as sodium and potassium. Particularly preferred are addition salts with a base which is dicyclohexylamine.

00 * 00 00 ♦ 00 00 0 0 0 0 0 0 0 0 0

0 0 · · · · φ φ · ·

000 0000000 »0 0 000 · 0 0 0000

000 00 00 00 00 00

The dipeptide of formula (IX) is preferably used in the form of an acid addition salt. Suitable acid addition salts include hydrochloride, hydrobromide, trifluoroacetate, acetate and tosylate. Particularly preferred acid addition salts are hydrochloride and trifluoroacetate.

The coupling product of formula III is purified by recrystallization from an organic solvent or a mixture of organic solvents, preferably from a mixture of ethyl acetate and heptane, or by precipitation of a base addition salt. A preferred base addition salt is the dicyclohexylamine salt. The salt formation is generally carried out at a temperature of from about room temperature to about 75 ° C. Suitable salt-forming solvents are alcohols, ethers, esters and polar aprotic solvents with or without water. A preferred salt-forming solvent system is a mixture of acetonitrile and water.

It is particularly preferred for the coupling reaction of Scheme 3 that Q 2 is hydrogen.

After coupling of the pseudodipeptide of formula VIII and the dipeptide of formula IX to give the product of formula III, hydrogenation-labile protecting groups P1 and Q2 are removed by hydrogenation in the presence of palladium on carbon. Preferred solvents for the hydrogenation reaction include lower alcohols such as methanol or ethanol, or mixtures of alcohol with water such as a mixture of ethanol and water. The tetrapeptide or pseudopeptide of formula (X) is purified by recrystallization from lower alcohols or mixtures of lower alcohols and water, preferably methanol or ethanol or mixtures of methanol and water or ethanol and water.

The process for the preparation of representative pseudodipeptides of the general formula (VIII), wherein P 1 represents a benzyloxycarbonyl group and B represents an ethyl group, is illustrated in Scheme 4. Methodology, clarified

· Tot tot ♦ tot tot tot tot tot - tot - tot - - tot <<i i i i i i i i i - - - - - Scheme 4 can also be readily utilized to prepare pseudodipeptides of formula (VIII) wherein P 1 and B are other than benzyloxycarbonyl and ethyl.

Scheme 4

Z = benzyloxyAarbonyl

According to Scheme 4, 2- (4-pyridyl) ethylmalonic acid diethyl ester (compound of formula XI, prepared for example by condensation of diethyl malonate with 4-vinylpyridine) is decarboxylated by heating in aqueous acid to give 4- (4-pyridyl) butanoic acid of formula XII. The pyridine ring is then reduced by catalytic hydrogenation to give 4- (piperidin-4-yl) butanoic acid of formula XIII. Platinum catalysts are preferred, for example platinum on carbon, platinum oxide and platinum on alumina. Platinum on alumina is particularly preferred as it is easy to regenerate. Hydrogenation is carried out in alcohol, aqueous alcohol, or water under a hydrogen pressure of from about ambient pressure to about 0.5 MPa at a temperature from about room temperature to about 70 ° C. Lower temperatures i · · ♦ ·· 0 • · 0 · «>

0 · 4 · 0 · 4 · 0 · · · «« can be used if the hydrogen pressure increases. Subsequently, the nitrogen atom of the piperidyl moiety is protected, for example, by reacting a compound of formula XIII with an aqueous base and benzyl chloroformate or with benzyl N-succinimidyl carbonate to give a compound of formula XIV. Coupling of the compound of formula XIV with N-ethylglycine or with N-ethylglycinethyl ester followed by saponification of the ester with an aqueous solution of the alkoxide affords the compound of formula VIII. The coupling is preferably carried out by activating the carboxylic acid moiety of formula XIV by conversion to the acid chloride and adding N-ethylglycine or N-ethyl glycyl ester in the presence of a base. Acid addition salts of N-ethylglycine or N-ethylglycine ethyl ester, preferably trifluoroacetate, may also be used. Suitable bases include amines such as diisopropylethylamine or aqueous alkoxide.

According to a particularly preferred embodiment of the preparation of the compound of formula VIII, 2- (4-pyridyl) ethylmalonic acid diethyl ester is taken up in aqueous acid, preferably aqueous hydrochloric acid, and decarboxylated by maintaining it at reflux temperature. To the obtained solution of 2- (4-pyridyl) ethyl malonic acid of formula XIII, the above catalyst is added and the reaction mixture is catalytically hydrogenated to give an aqueous solution of 4- (4-piperidyl) butanoic acid of formula XIV. The catalyst is filtered off, the acidic solution of the compound of formula (XIV) is basified with an aqueous alkoxide solution and the benzyloxycarbonyl protecting group is introduced as described above. 1 - [(Phenylmethoxy) carbonyl] -4-piperidinobutanoic acid is extracted into an organic solvent and condensed with N-ethylglycine as described above to give a compound of formula VIII.

This process is particularly useful as it is not necessary to isolate intermediates and involves only a single purification step. The various intermediates are used in the form of aqueous or organic «». . »♦ · · · · · (···.

4 4 ·.......... 4 4 4 4 4 4 4 4 4 4 4 4 4 4, 4 4 4 roztok 4 company.

Process for the preparation of the dipeptide of the formula IX in which Q2 is hydrogen, J cyclohexylmethyl and L amino group _NH2 is outlined in Scheme 5. The key feature of the process according to Scheme 5, aspartame, previously we undescribed protected by a protecting group labile to acid Q3 or hydrogenation, and subsequent mild amidation ammonia, which is maintained while maintaining stereochemistry. There is an unexpected acceleration of the amidation reaction when the reaction is carried out in a solvent mixture of methanol and ethyl alcohol.

Scheme 5

Asparatam

In the process of Scheme 5, aspartame is protected with an acid labile nitrogen protecting group, preferably a tert-butyloxycarbonyl group, or hydrogenated with a labile group, preferably a benzyloxycarbonyl group. The tert-butyloxycarbonyl protecting group is introduced by reacting aspartame with di-tert-butyl dicarbonate in the presence of an amine, preferably triethylamine, alloxide, preferably lithium hydroxide or carbonate. The protecting group is preferably introduced at a temperature of from about room temperature to about 50 ° C in a lower alcohol, for example methanol as solvent or in a solvent mixture containing a lower alcohol and a glycol, for example methanol and ethylene glycol.

The protected aspartame is amidated by treating a solution of the protected aspartame with ammonia gas in an alcohol to give a compound of formula XVI. Suitable solvents for the amidation reaction include lower alcohols, glycols or mixtures thereof. Preferred alcohols are methanol, ethylene glycol and mixtures of methanol and ethylene glycol. The amidation is carried out at a temperature from room temperature to about 65 ° C for about six hours to about two days. The protected aspartame may be isolated and purified prior to amidation, or may preferably be amidated by introducing ammonia gas into the reaction mixture at the deprotection step.

The benzene nucleus of the compound of formula XVI is reduced by catalytic hydrogenation to give a compound of formula XVII. Platinum catalysts such as patina and platinum on alumina are preferred. Platinum on alumina is particularly preferred as a catalyst because it is easy to regenerate. The hydrogenation is carried out in a lower alcohol, preferably in butanol or in a saturated organic acid of 1 to 10 carbon atoms, preferably in acetic acid. The hydrogenation is carried out under a hydrogen pressure of about 0.2 to about 0.5 MPa at a temperature of about 40 to about 80 ° C. Lower temperatures can be used when the hydrogen pressure is increased.

«Tt tt tt tt tt 4 tt tt tt» »<

tt tt · f) ttttttt »» »

When Q3 is a labile protecting group in hydrogenation, the protecting group is removed to give the compound of formula (IX) simultaneously with the reduction of the benzene ring described above. When Q3 is an acid labile protecting group, such as a tert-butyloxycarbonyl group, the protecting group is removed by treating a solution of the compound of formula (XVII) with hydrogen chloride gas. It is particularly preferred to remove the protecting group for the labinic acid by introducing hydrogen chloride gas into the reaction mixture during hydrogenation.

It is clear to those skilled in the art that the method of the invention is well adaptable and advantageous. The possibilities described are merely for clarification and not for limiting the method.

The invention is illustrated by the following examples.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

Preparation of N- [N-ethyl-N- [1-oxo-4- (4-piperidinyl) butyl] glycyl (L) -α-aspartyl-3-cyclohexyl- (L) -alanine

Method A

Stage 1

N- [N-Ethyl-N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycyl- (L) -α-aspartyl-3- cyclohexyl- (L) -alaniamide-phenylmethyl ester

15.9 g (66.4 mmol) of N- [N-ethyl-N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] -4] are added to a magnetically stirred solution at 0-5 ° C. -piperidinyl] butyl] glycine in 70 ml of dimethylformamide is added 20.9 g (65 mmol) of 2- (1H-benzotriazol-1-yl) -1,1,3,3,4,4,4,4-d.

4 ·

- 44 etr tetramethyluronium tetrafluoroborate followed by the dropwise addition of 17.6 g (130 mmol) of diisopropylethylamine. The resulting homogeneous solution was poured into a stirred mixture of 31.8 g (65 mmol) of (L) -? - asparagyl-3-cyclohexyl- (L) -alanimidophenylmethyl ester trifluoroacetate in 30 ml of dimethylformamide at 0-5 ° C. Diisopropylethylamine is added to achieve a neutral or slightly alkaline pH. The resulting mixture was removed from the cold bath and stirred overnight at 23 ° C. The mixture was diluted with water and extracted with four portions of ethyl acetate. The combined ethyl acetate extracts were washed with 0.5N aqueous citric acid (3X), brine, saturated aqueous sodium bicarbonate (3X) and brine (2X), dried over magnesium sulfate, filtered, and concentrated in vacuo to give an oil. solidifies on standing to give a light tan colored solid (50.97 g) with a purity of 90.9%. a portion of 36 g of solid is recrystallized from ethyl acetate / heptane to give the title compound (24 g, 95% yield, analytically pure).

MS (FAB) m / z 748, (M + Na) &lt; + & gt ^; 771.

Stage 2

N- [N-Ethyl-N- [1-oxo-4- (4-piperidinyl) butyl] glycyl- (L) -α-asparagyl-3-cyclohexyl- (L) -alaninamide

N- [N-ethyl-N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycyl- (L) -α-asparagyl-3-cyclohexyl- ( The l-alanine diphenylmethyl ester prepared in step 1 was dissolved in methanol and 10% palladium on carbon was added. The mixture is shaken for 18 hours under a hydrogen pressure of 345 Pa. The mixture was filtered through a pad of celite and the filtrate was evaporated in vacuo to give N- [N-ethyl-N- [1-oxo-4- (4-piperidinyl) butyl] glycyl- (L) -a- asparyl 3-cyclohexyl- (L) -alaninamide. MS (FAB) m / z 524 (M + H) &lt; + & gt ^; .

NMR (300 MHz, D ₂ O) δ 8.4 (1H, d), 8.1 (1H, d), 4.2 (2H, q), 4.1 (1H, s), 3.9 ( 4H, q), 3.4 (2H, q), 3.3 (4H, d), 2.8-3.0 (6H, m), 2.4 (2H, t), 2.2 (1H , m), 1.8 (4H, d), 1.4-1.7 (7H, m), 0.7-1.3 <· *

(10H, m).

Method Β

Stage 1

N- [N-ethyl-N- [1-oxo-4- [1 - [(phenylethoxy) carbonyl] -4-piperidinyl] butyl] glycyl- (L) -α-asparagyl-3-cyclohexyl - (L) -alani us d

To a suspension of N-ethyl-N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycindicyclohexylamine (112.5 kg) in toluene (550 kg) and water (570 kg) aqueous sulfuric acid (210 kg) was added at about 30 ° C in a 2300 L glass lined reactor. After decantation, the toluene solution was washed with aqueous sulfuric acid (210 kg) and water (390 kg). The mixture was decanted and the organic phase was washed with water (390 kg) and dried by distillation until the water content was reduced to below 0.5%. Acetonitrile (220 kg) and N-hydroxysuccinimide (27 kg) were added to the toluene solution. The suspension is cooled to about 5 ° C under nitrogen and a solution of dicyclohexylcarbodiimide (45 kg) in toluene (35 kg) is added over one hour and the reaction is stirred for an additional five to six hours. (L) -aasparagyl-3-cyclohexyl- (L) -alaniamide hydrochloride (75 kg) and triethylamine (80 kg) were added and stirring was continued for about two hours. The reaction mixture was diluted with water (370 kg), the suspension was filtered, the filter cake was washed with water (30 kg) and the combined filtrates were transferred to a 2300 liter stainless steel reactor. Ethyl acetate (347 kg) was added to the solution. After decantation of the organic phase, the aqueous phase was acidified with hydrochloric acid (515 kg) and extracted with ethyl acetate (347 kg). The organic phase was washed twice with 20% aqueous ammonium chloride solution (109 kg) and concentrated in vacuo. Acetonotrile (1560 kg) and water (45 kg) were added, the solution was heated to about 75 ° C and dicyclohexylamine (35 kg) was added over one hour. The solution was seeded with N- [N-ethyl-N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycyl- (L) -a.

Aspartyl-3-cyclohexyl- (L) -alaninamide and held at 75 ° C for one hour. The suspension was then cooled to 20 ° C over six hours and filtered. The filter cake was washed three times with acetonitrile (100 kg) and dried under reduced pressure at about 40 ° C to give the desired compound (125 kg) as the dicyclohexylamine salt.

Stage 2

N- [N-ethyl-N- [1-oxo-4- (4-piperidinyl) butyl] glycyl- (L) -α-asparagyl-3-cyclohexyl- (L) -alanine

After thoroughly flushing the hydrogenator with nitrogen, the suspension of N- [N-ethyl-N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycyl- (L) -α-aspartyl- is hydrogenated. 3-cyclohexyl- (L) -aldehyde dicyclohexylamine (124 kg) in the presence of wet palladium on carbon (2 kg, 50% humidity, 5%) in a mixture of absolute ethanol (440 kg) and purified water (42 kg) at a temperature of approximately 25 ° C under a hydrogen pressure of 0.2 mPa for one hour. After flushing with nitrogen, the catalyst was filtered off and washed with a mixture of absolute ethanol (65 kg) and purified water (5 kg). The filtrate was heated to about 60 ° C, acetone (425 kg) was added and the mixture was seeded with N- [N-ethyl-N- [1-oxo-4- (4-piperidinyl) butyl] glycyl- (L). -? - asparagyl-3-cyclohexyl- (L) -a1 or by us (1.1 kg). The suspension is cooled to 20 ° C and filtered on a shaking filter dryer. The filter cake was washed with absolute ethanol (100 kg) and dried under vacuum at about 40 ° C to give the title compound (61 kg) as a white crystalline solid.

Method C

Stage 1

N- [N-Ethyl-N- [1-oxo-4- (4-pyridinyl) butyl] glycyl- (L) -α-asparagyl- (L) -phenylalaninamide-phenylmethyl ester • 00 00 • 0 0 0 0 • * 0 0 0 4 ••• 0 «· i» 0 0 0 0

A solution of 15.1 g (0.06 mol) of N-ethyl-N- [1-oxo-4- (4-pyridinyl) butyl] glycine in 200 ml of dichloromethane is prepared in a 1 liter flask under nitrogen and cooled. A solution of 6.95 ml (0.055 mol) of tert-butyl chloroformate in 25 ml of dichloromethane was prepared, cooled to 1 ° C and added dropwise to the reaction mixture maintained at 1 ° C over 45 minutes. The mixture was stirred for 3 hours at 1 ° C.

20 g (0.0498 mol) of La-asparagyl- (L) -phenylalanine diphenylmethyl methyl ester monohydrochloride (hydrochloride) are dissolved in a separate 800 ml flask in 200 ml of dichloromethane and treated dropwise with 15.8 ml (0.11 mol) of triethylamine. and the resulting solution is added over 1 hour to the above anhydride at 1 ° C. The mixture was stirred at -2 ° C for one hour, washed with 250 ml of water, 250 ml of saturated aqueous sodium hydrogen carbonate solution, 250 ml of 0.14M aqueous hydrochloric acid and 250 ml of water. In the organic phase, the presence of unreacted starting material is detected by chromatography and HPLC and the wash cycle is repeated until the corresponding HPLC peaks no longer show any changes. The organic layers were dried over magnesium sulfate, filtered, concentrated in vacuo and the solvents removed in vacuo to the maximum extent possible to give 23.5 g (yield 79.3%, analytical purity 96.8%) N - [N-methyl-N- [1-oxo-4- (4-pyridinyl) butyl] glycyl- (L) -α-asparagyl (L) -phenylalanine diphenylmethyl ester.

Stage 2

N-Ethyl-N- [1-oxo-4- (4-piperidinyl) butyl] glycyl- (L) -α-aspartyl 3-cyclohexyl- (L) -alanine d

To a solution of 76 mg of N-ethyl-N- [1-oxo-4- (4-pyridinyl) butyl] -glycyl- (L) - α-asparagyl- (L) -phenylalaninamide-phenylmethyl ester (0.126 mmol) in 1 mL of isopropanol / water (9: 1) add 6 mg of Pt2O-H2O platinum oxide system (79-84% Pt), 1.6 μΐ of 1N aqueous hydrochloric acid. The mixture was stirred and treated with 99.9-9% hydrogen at 0.4 mPa for 5 hours 40 minutes at 23 ° C, then for one hour at 60 ° C. The mixture was filtered and the filtrate was analyzed by HPLC to determine 100% consumption of the starting material to give Nethyl-N- [1-oxo-4- (4-piperidinyl) butyl] glycyl- (L) -α-asparagyl 3- cyclohexyl- (L) -alaniamide with traces of N-ethyl-N- [1-oxo-4- (4-piperidinyl) butyl] glycyl- (L) -α-asparagyl- (L) -alaniamide cyclo hexylmethyl ester.

Method D

Stage 1

N-Ethyl-N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycyl- (L) -α-aspartyl- (L) -phenylalanine diphenylmethyl ester

To a solution of 11.1 g (28.4 mmol) of N-ethyl-N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycine in 44 mL of ethyl acetate was added 6.13 g (28.7 mmol) of solid dicyclohexylcarbodiimide while maintaining a temperature of 25-33 ° C, forming a precipitate (dicyclohexylurea).

In a separate vessel, a suspension of 10.97 g (27 mmol) of L-α-asparagyl- (L) -phenylalanine phenyl phenyl methyl ester (hydro chloride) in 88 mL of ethyl acetate was treated with 4.2 mL (29.7 mmol) of triethylamine. The mixture was stirred for 15 minutes while simultaneously dissolving the dipeptide and precipitating the triethylamine hydrochloride. The suspension is added to a suspension of the activated N-ethyl N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycine prepared above while maintaining a temperature of 27-29 ° C. The mixture was stirred for one hour while the suspension thickened. An additional 100 mL of ethyl acetate was added and the mixture was stirred for an additional hour. 60 ml of water are added to form a mixture of two readily miscible liquid phases and a suspended solid dicyclohexylurea which is filtered off. The filtrate is washed with 60 ml of saturated this to this and this to this to this. sodium bicarbonate solution, 60 ml of 1N aqueous hydrochloric acid and 60 ml of saturated aqueous sodium chloride solution, and then the organic phase is dried over sodium sulphate. The mixture is filtered and concentrated in vacuo and the residue heated to 50 ° C at 0.13 kPa to give 17.6 g of N-ethyl-N- [1-oxo-4- [1 - [(phenylmethyl) (hydroxy) carbonyl] -4-piperidinyl] butyl] -glycyl- (L) -α-asparagyl- (L) -phenyl alanine diphenylmethyl ester.

A 400 mg sample is loaded onto prewashed Dowex 5OWX2 (10g) (2N aqueous hydrochloric acid, water, then 1: 1 water / ethanol) and collected by elution with 50 ml of a 70/30 ethanol / water system, then prewashed ( 2N sodium hydroxide solution, water then 1: 1 ethanol / water) Amberlyst A26 (10 g) eluting with 50 mL 70:30 ethanol / water. The eluent containing the product was concentrated in vacuo followed by further removal of the solvent under vacuum at 50 ° C (0.6665 kPa) to give 350 mg of N-ethyl-N- [1-oxo-4- [1]. - [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycyl- (L) -α-asparagyl- (L) -phenylalanine phenylmethyl ester.

Stage 2

N-Ethyl-N- [1-oxo-4- (4-piperidinyl) butyl] glycyl- (L) -α-aspartic acid 3-cyclohexyl- (L) -alanine

To a 2 ml dry sapphire NMR tube was added 25 mg (0.03 mmol) of N-ethyl-N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] 4- piperidinyl] butyl ] glycyl- (L) -? - asparagyl- (L) -phenylalanine diphenylmethyl ester, 12 mg PtO2-H2O (79-84% Pt) and 1 mL of 85/12 acetic acid / 2N aqueous hydrochloric acid by volume. The mixture was stirred under 0.4 mPa of hydrogen for five hours at room temperature. The mixture was filtered using a Millipore Milex filter. HPLC analysis of the filtrate shows 100% N-ethyl-N- [1-oxo-4- (4-piperidinyl) butyl] glycyl- (L) -aasparagyl-3-cyclohexyl- (L) -alaninamide.

«4 4» »• 9 9 9 9 9 9 9

9 · 4

4 4 4

4 0 «•« 3

0

4 «» · 9 10

Method E

A 100 ml beaker equipped with a magnetic stirrer was charged with 1.12 g (1.51 mmol) of N-ethyl-N- [1-oxo-4 - [[[(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycyl- (L) -α-asparagyl (L) -phenylalaninamide-phenylmethyl ester, 107 mg of 5% palladium on carbon and 10 mL of a 9: 1 2-propane / water system. The vessel was purged with argon at 40 ° C, then the mixture was heated to 50 ° C with vigorous stirring, and the vessel was purged several times with hydrogen. The mixture was stirred for 5 hours under 50 psi hydrogen at 50 ° C and allowed to cool to room temperature, filtered and the filtrate concentrated in vacuo to give 713 mg (90% yield) of N- ethyl N- [1-oxo-4- (4-piperidinyl) butyl] glycyl- (L) -α-asparagyl- (L) -phenylalanine. 50 mg of rhenium on alumina (Engelhard) and 1 ml of acetic acid are placed in a glass vial and the mixture is stirred for 17 hours at 80 DEG C. in a hydrogen atmosphere of 0.4 MPa. According to HPLC analysis, 100% methyl-N- [1-oxo-4- (4-piperidinyl) butyl] glycyl- (L) -? - asparagyl is 3-cyclohexyl- (L) -alaninamide.

Method F

N-Ethyl-N- [1-oxo-4- (4-piperidinyl) butyl] glycyl- (L) -α-asparagyl-3-cyclohexyl- (L) -alaniamide is prepared as described above. but using N-ethyl-N- [1-oxo-3- [1 [(phenylmethoxy) carbonyl] -4-piperidinylmethylene) propyl] glycine instead of N-ethyl-N- [1] - oxo-4- [1 - [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycine.

Example 2

Preparation of N-ethyl-N- [1-oxo-4-piperidinyl) butyl] glycyl- (L) -α-aspartyl-3-cyclohexyl- (L) -alanine

• · «* ·.

• · · 9 9 ♦ · · • * ··· 9

Stage 1

N- [N-Ethyl-N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycyl 1- (L) -α-aspartyl-3-cyclohexyl- (L) -alanine bisphenylmethyl ester

To a stirred suspension of N-ethyl-N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycine (0.858 g, 1.5 mmol) in 4 g dimethylformamide was added at 5 ° C. at once, the 2 (1H-benzotriazol-1-yl) -1,1,3,3-tetrafluoromethyl mercurofluoroborate (0.482 g, 1.5 mmol) was stirred for 3 minutes at 5 ° C. Diisopropylethylamine (0.482 g 1.5 mmol) was added and the resulting heterogeneous mixture was added with a Pasteur pipette to a solution of 0.755 g (1.5 mmol) of (L) -α-asparagyl-3-cyclohexyl- (L) -alaninbisphenylmethyl ester monono (hydrochloride) in 4 g of dimethylformamide. An additional 1 g of dimethylformamide was used for washing and an additional portion of 0.16 g (0.5 mmol) of diisopropylethylamine was added to make the mixture slightly basic. The cooling bath was removed and the suspension was stirred for 20 hours at room temperature. The resulting orange heterogeneous mixture was partitioned between methyl tert-butyl ether and water. The aqueous phase is extracted with methyl tert-butyl ether. The combined organic phases were washed sequentially with 1N aqueous hydrochloric acid, water, saturated sodium bicarbonate solution and brine, dried over magnesium sulfate and concentrated in vacuo to give N- [N-ethyl-N- [1-oxo-4- [1- [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycyl- (L) -α-asparagyl-3-cyclohexyl- (L) -alanine or phenylmethyl ester (1.21 g) as an amber resin ,

MS (ion spray) m / z 839 (M + H &lt; + & gt ^; ).

Stage 2

N- [N-Ethyl-N- [1-oxo-4-piperidinyl] butyl] glycyl- (L) -α-asparagyl-3-cyclohexyl- (L) -alanine

Solution 10.23 g (12.2 g (12.2 mmol)) of N- [N-ethyl-N- [1-oxo-452]

0 »9 9 9

99999 »

9 9

9 9

9 9

9 9 * 0 3

9

· · ·

0 »» 00 4 * 0

0 »V ·

- [1 - [(Phenylmethoxy) carbonyl-3,4-piperidinyl] butyl39lycyl- (L) -α-asparagyl-3-cyclohexyl- (L) -alanine-bisphenylmethyl ester in 200 ml by volume of 90% 2-propanol in water is poured onto 2 g of 5 % palladium on carbon (Degusa type E101 NO / W, 50% water by weight) in a 500 ml Parr shaker. The mixture is shaken overnight under 50 psi of hydrogen and filtered. The filtrate was concentrated to give N- [N-ethyl-N- [1-oxo-4-piperidinyl) butyl] glycyl- (L) -α-asparagyl-3-cyclohexyl- (L) -alanine (6.47). (g) in the form of a glassy solid.

MS (ion spray) m / z 525 (M + H &lt; + & gt ^; ).

Example 3

Preparation of N- [N-ethyl-N- [1-oxo-4- (4-piperidinyl) butyl] glycyl- (L) α-asparagyl-4-cyclohexyl-2- (L) -aminobutanoic acid

Stage 1

Bi phenylmethyl N- [N-ethyl-N- [1-oxo-4- [1- (phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycyl- (L) -α-asparagyl-4-cyclohexyl -2- (1) - aminobutanoic acid

To a magnetically stirred solution of 26.38 g (44.4 mmol) of N- [N-methyl-N- [1-oxo-4- [1- (phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycine in 70 ml of dimethylformamide is added at 70 ml. 15.7 g (48.8 mmol) of 2- (1H-benzotriazol-1-yl) -1,1,3,3-tetramethyluronium tetrafluoroborate are added at 0 to 5 ° C and 12.9 g (99.6 g) are added dropwise. mmol) of diisopropylethylamine. The resulting solution was poured into a suspension of 19 g (48.4 mmol) of L-.alpha.-aspartyl-4-cyclohexyl-2- (1H) -amino nobutanoic acid mono (trifluoroacetate) bisphenylmethyl ester in 20 ml of dimethylformamide at 0-5 ° C. The resulting mixture was removed from cooling and allowed to stir at 23 ° C overnight to give a homogeneous solution. The mixture was diluted with water to separate the orange oil. Methyl tert-butyl ether and water were added, the organic layer was removed, and the aqueous layer was removed.

4,949 9,9944 49 9 9 9

4 9 9 9 9 9 9 9

The extract was extracted twice with methyl tert-butyl ether. The combined organic layers were washed twice with 1N aqueous hydrochloric acid, twice with 1N aqueous sodium hydroxide solution and twice with brine, dried over magnesium sulfate, filtered and concentrated in vacuo to give an oil which was left under high vacuum for two days. . The oil (33.4 g) was purified on silica gel (80% ethyl acetate / heptane) to afford N- [N-ethyl-N- [1-oxo-4- [1- (phenylmethoxy) carbonyl] -4- (bisphenylmethyl) ester. piperidinyl] butyl] glycyl- (L) -? - asparagyl-4-cyclohexyl-2- (L) -aminobutanoic acid (27.8 g, 73% yield).

Stage 2

N- [N-Ethyl-N- [1-oxo-4- (piperidinyl) butyl] glycyl- (L) -α-asparagyl-4-cyclohexyl-2- (L) -aminomobutanoic acid

A solution of 1.2 g (1.4 mmol) of N- [N-ethyl-N- [1-oxo-4- [1- (phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycyl- (L) -a- bisphenylmethyl ester Asparagyl-4-cyclohexyl-2- (L) -aminobutanoic acid prepared in step 1 in 12 ml of dioxane is poured into 500 ml Parr shaker containing 83 mg of 10% palladium on carbon in 5 ml of water and 3 ml of dioxane. The reaction mixture is shaken overnight at room temperature (about 23 ° C) under a hydrogen pressure of 310.5 kPa. The mixture was filtered through a pad of celite in a medium sintered glass funnel and the filter cake was washed with a mixture of dioxane and water. The solution was lyophilized and the resulting white solid was dissolved in a minimum amount of water and lyophilized again to give the title compound as a white solid (710 mg, 93% yield). MS (FAB) m / z 539.56 (M + Na) &lt; + & gt ^; .

Example 4

Preparation of N-Ethylglycety net hyestest rifluoroacetate

Grade 1 fe · • fefefe

N - [(1,1-Dimethylethoxy) carbonyl] -N-ethylglycinethyl ester

To a solution of 3 ° C 86 g (423 mmol) of N - [(1,1-dimethylethoxy) carbonyl] -N-ethylglycine, 21.4 g (465 mmol) of ethanol and 5.17 g (42.3 mmol) 4-Dimethylaminopyridine in 600 ml of dichloromethane was added 47 g (46.2 mmol) of triethylamine, followed by portionwise addition of 89.1 g (46.5 mmol) of 3-N, N-dimethylaminopropylethylcarbodiimide hydrochloride. The stirred mixture was allowed to warm to ambient temperature and stirred overnight. The reaction mixture was washed with water, saturated sodium bicarbonate solution and brine, dried over magnesium sulfate, filtered, and concentrated in vacuo to give N - [(1,1-dimethylethoxy) carbonyl] -N-ethylglycine ethyl ester (88 g) in MS (FAB) 232 (M + H) &lt; + & gt ^; .

Stage 2

N-Etylglycyl net hysterest ri fluoractate

A stirred solution of 30.8 g (113 mmol) of N - [(1,1-dimethylethoxy) carbonyl] -N-ethylglycine ethyl ester in 50 mL of dichloromethane at 3 ° C was treated with 200 mL (1: 1 by volume) of trifluoroacetic acid in dichloromethane. The reaction mixture was stirred for two hours while warming to ambient temperature. The reaction mixture was concentrated in vacuo and the remaining highly mobile oil was subjected to high vacuum to give the title compound (55.2 g) which was used without further purification.

Example 5

Preparation of N-ethylglycine

In a nitrogen atmosphere, a solution of glyoxylic acid (25 kg) in isopropanol (25 kg) was added over 2 to 3 hours to a mixture of 5 ° C ethylamine (25 kg) and isopropanol (100 kg) in 250 liter glass reacted glass. hydrogenates • tt ttt tt tttt tttt tttttt tttttt · tt tttttttt tttttttt tttt · tt tttttttt tttt tttt · tttt tttt tttttt · t «tttt tttt tt tttt ·· (palladium content 50% on carbon) 5%, 2.5 kg) over 3 hours under 5 kPa of hydrogen. The reaction mixture was filtered and the filtrate was concentrated. Isopropanol (80 kg) is added to the suspension and the solid is filtered off, washed twice with isopropanol (7 kg) and dried under vacuum at about 40 ° C to give N-ethylglycine (21 kg) as a white crystalline solid. substances.

Example 6

Preparation of N-ethyl-N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycine

Method A

Stage 1

- [(Phenylmethoxy) carbonyl-3,4-piperidinedutanoic acid

To 100 g (622 mmol) of diethyl malonate at 25 ° C was added over 20 minutes 88 g (272 mmol) of a 21% ethanol solution of sodium ethoxide, maintaining the temperature at 23-25 ° C. The mixture was stirred for 10 minutes and 4-vinylpyridine (26.18 g, 248 mmol) was added. The mixture was warmed to 35 ° C, stirred for three hours and then at room temperature for another 15 hours. The reaction mixture was concentrated at 44 ° C to remove ethanol and the resulting yellow oil was subjected to high vacuum to remove residual solvent. The oil was partitioned between methyl tert-butyl ether and 2.2N aqueous hydrochloric acid. The aqueous phase was adjusted to pH 6 with 2N aqueous sodium hydroxide solution. The layers were separated and the organic phase was washed twice with brine. The organic phase was extracted with 2.2 N aqueous hydrochloric acid (3x). The combined aqueous extracts were refluxed overnight. The resulting solution (225 ml, assumed 248 mmol) is poured onto 2.5 g of platinum oxide hydrate in a 500 ml Parr shaker and shaken overnight under 50 psi of hydrogen pressure. The mixture is filtered, the filtrate is cooled to 10 ° C and treated with 417 ml of aqueous sodium hydroxide solution maintaining a temperature of not more than 10 ° C to reach a pH of 14 (over about 10 minutes). To the stirred solution was added 100 mL of tetrahydrofuran, followed by 68 g (273 mmol) of benzyl N-succinimidyl carbonate in 150 mL of tetrahydrofuran over 30 minutes, maintaining the temperature at 8 ° C. The mixture was allowed to warm to ambient temperature and stirred overnight. The mixture was extracted with methyl tert-butyl ether (3x), ethyl acetate, methyl tert-butyl ether, ethyl acetate and methyl tert-butyl ether. The aqueous phase is cooled to 5 ° C, acidified to pH 1.9 by the slow addition of 27 ml of concentrated hydrochloric acid and extracted with methyl tert-butyl ether (3x). The combined organic layers from the extraction were washed with brine, dried over magnesium sulfate, filtered and concentrated in vacuo to give 1 - [(phenylmethoxy) carbonyl] -4-piperidinebutanoic acid (42 g, 55% yield from vinylpyridine). MS (FAB) m / z 306.

Stage 2

N-Ethyl-N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycine ethyl ester

To a stirred solution of 40.7 g (133.3 mmol) of 1 - [(phenylmethoxy) carbonyl] -4-piperidinobutanoic acid in 667 mL of dichloromethane at 3 ° C was added 0.5 mL of dimethylformamide and dropwise 66.8 mL of 2M. oxalyl chloride in dichloromethane. The reaction mixture is maintained at 3-4 ° C during the addition and stirred at this temperature overnight. The reaction mixture was concentrated in vacuo. The resulting honey-like oil and 133.3 mmol of N-ethylglycine ethyl ester trifluoroacetate are dissolved in 250 mL of dichloromethane at 3 ° C. To the stirred mixture was added 52.84 g (408 mmol) of diisopropylethylamine. The mixture was allowed to warm to ambient temperature with stirring for two hours until HPLC showed complete reaction. The reaction mixture was concentrated in vacuo and concentrated

0 0 0

0 0 ·

0 0 0

0 0 0 ·

The resulting oil was dissolved in methyl tert-butyl ether. The methyl tert-butyl ether solution was washed with water (2x) and the combined aqueous layers were extracted with methyl tert-butyl ether. The combined organic solutions were washed with 1N aqueous sodium hydroxide solution (3x), brine (2x), dried over magnesium sulfate and concentrated in vacuo to give N-ethyl-N- [1-oxo-4- [1 - [( phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycinethyl ester (46.69 g), which was used without further purification.

MS (FAB) m / z 419 (M + H) &lt; + & gt ^; .

Stage 3

N-Ethyl-N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycine

To a solution of 46.7 g (112 mmol) of N-ethyl-N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycine ethyl ester in tetrahydrofuran at room temperature is added 200 mL of 1N aqueous sodium hydroxide solution and the heterogeneous mixture was stirred vigorously for one hour. The reaction mixture was concentrated in vacuo and the resulting aqueous mixture was diluted with water and extracted with methyl tert-butyl ether (3x). The aqueous layer was acidified to pH 3 with potassium bisulfate to form an oil. The mixture was extracted with methyl tert-butyl ether (3x). The combined organic solutions were washed with brine (2x), dried over magnesium sulfate, filtered, and concentrated in vacuo. The resulting oil was subjected to high vacuum to give N-ethyl-N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycine (35.5 g).

MS (FAB) m / z 391 (M + H) &lt; + & gt ^; .

Method B

To a solution of 0 ° C, 2.1 g (6.88 mmol) of 2 - [(phenylmethoxy) carbonyl] -4-piperidinebutanoic acid in 36 ml of dichloromethane is added 3.6 ml of 2M oxalyl chloride in dichloromethane and

- 57 »9 · 4

9 99

0.25 ml of dimethylformamide. The reaction mixture was stirred at 0 ° C for 2.5 hours. The reaction mixture was concentrated in vacuo and the residue was azeotroped twice with toluene.

An aqueous solution of 2.06 g (19.9 mmol) of N-ethyl glycine in 18.7 mL of water was cooled to 5 ° C and 3.78 g (35 mmol) of solid sodium carbonate was added portionwise followed by solution 6, 88 mmol (assumed crude) of 1 - [(phenylmethoxy) carbonyl-4-piperidinebutanoic acid in 18 mL of tetrahydrofuran. The mixture was warmed to ambient temperature and stirred overnight. The reaction mixture was diluted with water and extracted with ethyl acetate (3x). The aqueous phase is acidified to pH 2 with aqueous potassium hydrogen sulphate and extracted with methyl tert-butyl ether. The organic layer was concentrated in vacuo to give 2.21 g of an oil (MS corresponds to desired product). The oil was purified by HPLC chromatography (C-462.28 by preparative reverse mm x 250 cm, particle size 15 µm, pore size 30 nM) using aqueous acetonitrile doped with 0.1% trifluoroacetic acid by volume through a gradient of 36 to 45% acetonitrile. The fractions containing the product were collected, the solution was frozen and lyophilized. The resulting oil was taken up in ethyl acetate, the solution was concentrated in vacuo and the resulting oil was subjected to high vacuum to give N-ethyl-N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] -4- pperidinyl] butyl] glycine (1.01 g, 36% yield). MS (FAB) m / z 391 (M + H) &lt; + & gt ^; .

Method C

Stage 1

2- (4-Pyridyl) ethylmalonic acid diethyl ester hydrochloride

A mixture of 20% sodium ethoxide in ethanol (263.2 kg) and diethyl malonate (703 kg) under nitrogen was distilled in a 1600 L glass-lined reactor at ambient pressure and 108 ° C. 4-Vinylpyridine (80.5 kg) was added over three hours and the reaction stirred for four hours. The reaction mixture was 95 ° C

9

9

-99 9

9

9

9

9 was cooled to ambient temperature and water (358 kg) was added over one hour. The pH was adjusted to 4.5 with 33% aqueous hydrochloric acid and the aqueous layer was extracted with methyl tert-butyl ether (216 kg). Water (357.5 kg) was added and the biphasic mixture was acidified with aqueous 16.5% hydrochloric acid (29.6 kg) to pH 1. The layers were separated and an aqueous solution of 2- (4-pyridyl) ethylmalonic acid diethyl ester hydrochloride. is used as such.

Stage 2

4- (4-Pyridyl) butanoic acid hydrochloride

The aqueous solution of 2- (4-pyridyl) ethylmalonic acid diethyl ester hydrochloride prepared in Step 1 was distilled at ambient pressure at 105 ° C to remove methyl tert-butyl ether and ethanol and 33% aqueous hydrochloric acid (67 kg) was added over 50 minutes. . The reaction mixture was stirred for about six hours at 105 ° C and concentrated to give about 530 kg of distillate. The mixture was allowed to cool to 60 ° C and acetic acid (591 kg) was added. Distillation was continued under reduced pressure (1.33 kPa) to achieve a water content of 6.6% in the reaction mixture. Acetone (374 kg) was added to the suspension and the suspension was cooled to 15 ° C over three hours. The suspension was stirred for 1 hour at 15 ° C and the precipitate was filtered off, washed twice with acetone (94 kg) and dried under vacuum at 40 ° C for 24 hours to give 4- (4-pyridyl hydrochloride). ) butanoic acid (126 kg). The solid was dissolved in water (300 kg) to give a 30% by weight aqueous solution, which was used in step 3.

Stage 3

4- (4-Piperidyl) butanoic acid hydrochloride

- 60 ► ΦΦΦ φ

To a 30% aqueous solution of 4- (4-pyridyl) butanoic acid hydrochloride prepared in step 2 (208.9 kg) and water (145 kg) was added platinum on carbon (50% humidity, 5%, 2.52 kg). ). The mixture is hydrogenated at about 70 ° C under ambient pressure for 15 hours and allowed to cool to ambient temperature. The catalyst was filtered off and washed with water (20 kg). The resulting aqueous 16% 4-piperinebutanoic acid hydrochloride solution (388.5 kg) was used in step 4.

Stage 4

- [(Phenylmethoxy) carbonyl] -4-piperidinecutanoic acid

Either dissolve 4- (4-piperidyl) butyric acid hydrochloride (124 kg) in water (600 kg) or dilute the 16% aqueous solution of 4- (4-piperidyl) butyric acid hydrochloride prepared in step 3 (777 kg). aqueous sodium hydroxide (289 kg) in a 1600 liter glass-lined reactor cooled to 5 ° C. Benzyl chloroformate (112 kg) was added over two to three hours and the solution was warmed to about 25 ° C. The reaction mixture was extracted with methyl tert-butyl ether (476 kg).

was acidified with hydrochloric acid (187 kg) and toluene (450 kg). The organic layer was washed with water (240 kg) and dried by azeotropic distillation at ambient pressure under nitrogen. The obtained solution of 1 - [(phenylmethoxy) carbonyl] -4-piperidinobutanoic acid in toluene was used as in step 5. Product weight in solution: 179 kg. Quality: approximately 35% by volume in toluene.

The aqueous layer was extracted

Stage 5

N-ethyl-N- [1-oxo-4- [1 - [(phenylmethoxy) carbonyl] -4-piperidinyl] butyl] glycindicyclohexylamine

To a solution of 1 - [(phenylmethoxy) carbonyl] -4-piperidinobutanoic

- 60 99 9

9 9

9 9 9

9 9 999

4 9

9 in ethyl acetate at 10 ° C of the acid in toluene prepared in Step 4 (253 kg) was added thionyl chloride (42 kg) under nitrogen. The reaction mixture was diluted with methyl tert-butyl ether (85 kg) and stirred for approximately 24 hours at about 15 ° C in a 630 L glass-lined reactor. This solution was added to a biphasic mixture of water (177 kg), 30% aqueous sodium hydroxide (227 kg), N-ethylglycine (36 kg) and methyl tert-butyl ether (65 kg) in a 1600 liter glass-lined reactor over four to four hours. five hours and the mixture is stirred for 30 minutes. The biphasic mixture was diluted with water (100 kg) and acidified to pH 6.5 with hydrochloric acid. The aqueous phase was washed with methyl tert-butyl ether (65 kg) and ethyl acetate (157 kg) was added to the aqueous phase. The biphasic mixture was acidified to pH 4 with hydrochloric acid (84 kg). The layers were separated and ethyl acetate (385 kg) was added to the organic phase. The organic phase is heated to 60 ° C and a solution of dicyclohexylamine (63 kg) (230 kg) is added. The mixture was seeded and cooled to solid. The solid was filtered off, washed twice with ethyl acetate (150 kg) and dried under vacuum at about 40 ° C to give the desired compound (139 kg) as a white crystalline solid.

Example 7

Preparation of N-ethyl-N- [1-oxo-4- (4-pyridinyl) butylated] glycine

Stage 1

N-Etylglycylphenylmethylether mono (hydrochloride)

To 250 mL of a 2M solution of ethylamine in tetrahydrofuran was added 47.2 g (0.2 mol) of benzyl bromoacetate in 50 mL of tetrahydrofuran over half an hour while maintaining the reaction temperature at 22-26 ° C. The reaction mixture was cooled to 2 ° C, whereby ethylamine hydrobromide crystallized and was filtered off. The filtrate was concentrated in vacuo at 30 ° C to give 39.4 g of a yellow residue. The residue is taken up in 350 ml of 2-propanol with stirring and the precipitated white solid is filtered off. Under vigorous stirring, 59 ml of 3.6N hydrochloric acid in 2-propanol are added to the filtrate, the mixture is stirred and the resulting white solid is filtered off. The residue was dried to give 32.5 g of a solid. This product was triturated with 100 mL of tetrahydrofuran, then with 100 mL of 2-propanol and dried to give 30 g (0.13 mol, 65% yield, 87% analytical purity) of N-ethylglycinphenylmethyl ester monono (hydrochloride).

Stage 2

N-Ethyl-N- [1-oxo-4- (4-pyridinyl) butyl] glycenylphenylmethyl ester

A solution of 4-pyridinebutyric acid (32.5 g, 0.16 mol) and N-methylmorpholine (17.53 ml, 0.174 mol) in dichloromethane (300 ml) was cooled to 0 DEG C. under a nitrogen atmosphere and precooled (over half an hour). 0 ° C) solution of 18.75 mL (0.152 mol) of pivaloyl chloride in 100 mL of dichloromethane while maintaining the reaction mixture at 0 ° C. In a separate 500 ml beaker, 33.5 g (0.145 mol) of N-ethylglycinphenyl methyl esthermono (hydrobromide) are dissolved in 400 ml of dichloromethane and 35 ml (0.48 mol) of N-methylmorpholine are added. This mixture was added to the activated pyridine butyric acid solution at -0.5 ° C over two hours. After one hour, the mixture was diluted with water, stirred and the layers were separated. The organic phase was washed with a saturated aqueous solution of sodium bicarbonate, 0.1 M aqueous hydrochloric acid and water, dried over magnesium sulfate, filtered and concentrated in vacuo to give 46.2 g (0.135 mol, 93% yield) of N-ethyl. -N- [1-oxo-4- (4-pyridinylbutyl) glycinylphenylmethyl ester as a yellow oil.

Stage 3 • 99 49 4 44 49 • 4 9 9 4 9 9 9 4 9 4

9 9 9 9 4

4,949 9,9449 49 · 9 4 • 4 9 9 4 4 4 4 4 4

499 94 94 4 94 45

N-Ethyl-N- [1-oxo-4- (4-pyridinyl) butyl] glycine

A solution of 46 g (0.135 mol) of N-ethyl-N- [1-oxo-4- (4-pyridinyl) butyl] glycine phenylmethyl ester in 300 ml of methanol is added to 4 g of 10% palladium on carbon (50% water by weight) in an autoclave containing 1 liter. The vessel was evacuated and alternately evacuated three times with nitrogen, then evacuated and alternatively evacuated three times with hydrogen at ambient pressure. The vessel was sealed and heated to 25 ° C with stirring for two hours. The mixture was filtered under nitrogen to give a pale yellow filtrate, which was concentrated in vacuo at 40 ° C until a white solid began to appear. 150 ml of 2-propanol are added, causing rapid crystallization of the product. The mixture was stirred for half an hour and the product was filtered off. The solid was washed with 240 ml portions of 2-propanol, dried to give 19 g of product. The mother liquor was concentrated and the residue was taken up in 2-propanol to give a white precipitate. The mixture was stirred for half an hour, filtered and the solid was washed with 2-propanol, dried to give 5 g of product, a total of 24 g (0.095 mol; 70% yield; 99A% pure) N-ethyl-N- [1]. oxo-4- (4-pyridinyl) butyl] glycine.

Example 8

Preparation of (L) -α-asparagyl-3-cyclohexyl- (L) -alanine diphenylmethyl ester trifluoroacetate

Stage 1

N - [(1,1-Dimethylethoxy) carbonyl] - (L) -α-asparagyl-3-cyclohexyl (L) -alanine diphenylmethyl ester

To a mechanically stirred solution at 18 ° C, 37.5 g (116 mmol) of BOC-p-benzyl- (L) -aspartic acid in 270 ml of ethyl acetate was added a solution of 17.75 g (116 mmol) of hydroxybenzotriazole hydrate in 25 ml of dimethylformamide. . Added within 30 mi64 • 0 9 ·

A solution of 24.5 g (119 mmol) of dicyclohexylcarbodiimide in 50 mL of ethyl acetate using a water bath to maintain the temperature at a maximum of 25 ° C. The reaction mixture is stirred for one hour, after which 33 g (116 mmol) of 3-cyclohexyl- (L) -alaniamidestermono (trifluoroacetate) in 25 ml of dimethylformamide are added at 23 [deg.] C., whereupon pure N is added dropwise over two minutes. -methylmorpholine. The reaction mixture was allowed to warm to 30 ° C during the addition of N-methylmorpholine. The reaction mixture was stirred at ambient temperature overnight. The reaction mixture was filtered to remove dicyclohexylurea and the filtrate was diluted with ethyl acetate, washed twice with water, once with brine, twice with saturated aqueous sodium bicarbonate and once with 1: 1 0.5N citric acid / brine. The organic phase was dried over magnesium sulfate, filtered, and diluted with heptane. The mixture was allowed to stand overnight and the resulting crystals were filtered off, washed twice with heptane, dried in vacuo to give a first crop of 37.5 g and a second crop of 9.5 g. Both were of acceptable purity by HPLC chromatography and were physically combined to 47 g of N - [(1,1-dimethylethoxy) carbonyl] - (L) -? - asparagyl-3-cyclohexyl (L) -alanimidophenyl methyl ester (85% yield). MS (FAB) m / z 476 (M + H) &lt; + & gt ^; .

Step 2 (L) -α-Asparagyl-3-cyclohexyl- (L) -α-1-phenylphenylmethyl-trifluoroacetate

To a mechanically stirred solution of 45.4 g (95.5 mmol) of N - [(1,1-dimethylethoxy) carbonyl] - (L) -? - asparagyl-3-cyclohexyl (L) -alaninamide phenyl methyl ester in 350 ml of dichloromethane at temperature At 20 ° C, 67 g (590 mmol) of trifluoroacetic acid are added over 15 minutes. The reaction mixture was stirred for two hours. The reaction mixture was concentrated in vacuo to give an orange-yellow oil which was azeotroped with dichloromethane, subjected to high vacuum to further reduce to a minimum the solvent content. The concentrate, oil, was triturated with 1: 1 methyl tert-butyl ether / heptane to give a white solid. The mixture was stirred for two hours in methyl tert-butyl ether and allowed to stand for two days. The crystals were filtered off and dried under vacuum to give (L) -? - asparagyl-3-cyclohexyl- (L) -alanimidophenylmethyl ester mono (trifluoroacetate) (43 g, 92% yield). MS (FAB) m / z 376 (M + H) &lt; + & gt ^; .

Example 9

Preparation of (L) -α-asparagyl-4-cyclohexyl-2- (L) -aminobutanoic acid bisphenylmethyl ester trifluoroacetate

Stage 1

N - [(1,1-Dimethoxyethoxy) carbonyl] -4-cyclohexyl-2- (L) -aminobutanoic acid phenylmethyl ester

A solution of 30 g (107.5 mmol) of N - [(1,1-dimethylethoxy) carbonyl] (L) -homophenyl-alanine and 2 ml of acetic acid in 100 ml of methanol is poured onto 3 g of a 5% rhodium / alumina system in a Parr shaker. The reaction mixture was shaken overnight under 50 psi of hydrogen and filtered under a nitrogen atmosphere through Cellit 545 in a sintered glass funnel. The cellite layer was washed with methanol. The filtrate was concentrated in vacuo at 30 ° C. The resulting oil was taken up in methyl tert-butyl ether, washed twice with water and once with brine, and dried over magnesium sulfate, filtered and concentrated in vacuo. The residue (assumed 107.5 mmol) was dissolved in 250 mL of dichloromethane and the solution was treated with 12 g (118.5 mmol) of triethylamine followed by 18.4 g (107.5 mmol) of benzyl chloroformate to form a white solid. After addition of benzyl chloroformate, 1.3 g (10.75 mmol) of 4-dimethylaminopyridine are added in one portion. The mixture was allowed to stir at 0 ° C for two hours. The mixture is concentrated in vacuo, the residue is taken up in ethyl acetate and the solution is washed twice with water, twice with 1N hydrochloric acid, and the solution is washed with water.

• · * 44 4 4 4

444 44 4 4445

44444 44 · 44 44 twice with 1N sodium hydroxide solution and once with brine, dried over magnesium sulfate, filtered and concentrated to give N - [(1,1-dimethylethoxy) carbonyl] -4-cyclohexyl-2- (L) phenylmethyl ester aminobutyric acid (33.8 g) as an oil. MS (FAB) mlz 748 (M + Na).

Stage 2

4-Cyclohexyl-2- (L) -amino-butanoic acid, phenylmethyl ester, ermono (trifluoroacetate)

To a solution of 33 g (88 mmol) of N - [(1,1-dimethyl-ethoxy) -carbonyl] -4-cyclohexyl-2- (L) -aminobutanoic acid phenylmethyl ester in 136 mL of dichloromethane was added 136 mL of solution over 30 minutes. trifluoroacetic acid. The reaction temperature is kept below 23 ° C. The mixture was stirred for three hours at ambient temperature and concentrated in vacuo. The residue was redissolved in dichloromethane and concentrated again. The resulting mobile oil was taken up in 50 mL of methyl tert-butyl ether and 350 mL of heptane, seeded, cooled to -10 ° C and maintained at -10 ° C for 24 hours. The first portion was filtered, washed with heptane, and dried in vacuo (20.1 g). The mother liquor was concentrated in vacuo, redissolved in 12 mL of methyl tert-butyl ether and 84 mL of heptane. After inoculation and cooling to -10 ° C, a second batch of 5.2 g is obtained. Both batches are of comparable purity by HPLC chromatography and physically mixed to give 4-cyclohexyl-2- phenyl phenyl methyl ermono (trifluoroacetate). (L) -amino-nobutanoic acid (25.7 g, 75% yield).

MS (FAB) m / z 276 (M + H) &lt; + & gt ^; .

Stage 3

N - [(1,1-Dimethylethoxy) carbonyl] - (L) -aasparagyl-4-cyclohexyl-2- (L) -aminobutanoic acid, biphenylmethyl ester * 99 99 99 9 9 9 99 9

9 9 9 999 9 99 9 · · 9 9 99999 * 9 9 9 9 · 99 9 9 <<9

9 «9 100 99« 100 »»

To a mechanically stirred solution at 18 ° C of 20.4 g (63 mmol) of β-β-benzyl- (L) -aspartic acid in 154 ml of ethyl acetate was added a solution of 9.65 g (63 mmol) of hydroxybenzotriazole hydrate in 12 ml of dimethylformamide. A solution of 13.3 g (64.5 mmol) of dicyclohexylcarbodiimide in 25 ml of ethyl acetate was added over 15 minutes while maintaining the reaction temperature at a maximum of 25 ° C. The reaction mixture was stirred for one hour, syrup 24.5 g (63 mmol) of 4-cyclohexyl-2- (L) -aminobutanoic acid trifluoroacetate in 15 ml of dimethylformamide was added at 18 ° C and N-methylmorpholine was added dropwise over five hours. minutes. During the addition of N-methylmorpholine, the reaction mixture was allowed to warm to 25 ° C. The reaction mixture was stirred at ambient temperature overnight. The reaction mixture was filtered to remove dicyclohexylurea and the filtrate was washed twice with water, twice with saturated aqueous sodium bicarbonate solution, twice with 0.5N aqueous citric acid and once with brine, dried over magnesium sulfate, filtered and concentrated in vacuo. The resulting waxy solid was dissolved in methyl tert-butyl ether at 50 ° C and the solution was filtered hot to remove a small amount of fine white insoluble material, diluted with heptane at 50 ° C. The solution was cooled to ambient temperature and stored in a freezer at -10 ° C overnight. The resulting solid was filtered, washed with heptane and dried under vacuum to give N - [(1,1-dimethylethoxy) carbonyl] (L) -? - asparagyl-4-cyclohexyl-2- (L) -aminobutane bisphenylmethyl ester acid (29.8 g, 81% yield). MS (FAB) m / z 581;

Stage 4

Biophenyl methyl ermono (trifluoroacetate) (L) -α-aspartyl-4-cyclohexyl-2- (L) -aminobutanoic acid

To a mechanically stirred solution of 28.8 g (49.5 mmol) of N - [(1,1-dimethylethoxy) carbonyl] - (L) -α-asparagyl-4-cyclohexyl-2- (1_) -am bisphenylmethyl ester 222 g of nobutic acid in 300 ml of dichloromethane at 20 DEG C. are added over 30 minutes.

9 9 9 9 9 9 9 9 9 9 «· · Ρ · 9999999 99 9

9 9 9 9 9

9 99 9 9 ♦ ««. tt (1.94 mol) of trifluoroacetic acid and the reaction mixture was stirred for three hours. The reaction mixture was concentrated in vacuo to give an oil which was redissolved in dichloromethane and concentrated again. The residue was triturated with 1: 1 methyl tert-butyl ether / heptane to give a white solid. The solid was filtered off and dried under vacuum to give (L) -? - asparagyl-4-cyclohexyl-2- (L) -aminobutanoic acid biphenylmethyl ester tert-trifluoroacetate (27.4 g, 46 mmol, 92.9) 143-144 ° C.

Example 10

Preparation of (L) -α-asparagyl-3-cyclohexyl-2- (L) -alpha-1-methyl ester hydrochloride

Stage 1

N - [(1,1-Dimethylethoxy) carbonyl] -3-cyclohexyl- (L) -alaninophenylmethyl ester

Stirred milk solution 25.6 g (94.5 mmol) of N - [(1,1-dimethylethoxy) carbonyl] -3-cyclohexyl- (L) -alanine, 11.2 g (104 mmol) of alcohol and 1.15 g (9.45 mmol) of 4-dimethylaminopyridine in a mixture of 210 ml of dimethylformamide and 150 ml of dichloromethane are cooled to 5 DEG C. and 19.2 g of 3-N, N-dimethylaminopropyl is added over five minutes. ethylcarbodiimide hydrochloride. The mixture was warmed to ambient temperature and stirred overnight. The reaction mixture was filtered to remove a fine precipitate, and the filtrate was concentrated in vacuo. The residue was taken up in water and extracted (3x) with ethyl acetate. The combined organic solutions were washed with 0.5N aqueous citric acid and twice with water, dried over magnesium sulfate, filtered, and concentrated in vacuo. The resulting oil was subjected to high vacuum to minimize volatiles to give N - [(1,1-dimethylethoxy) carbonyl] -3-cyclohexyl (L) -alanine-phenylmethyl ester (35.3 g).

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MS (ion spray) m / z 362 (M + H) &lt; + & gt ^; .

Stage 2

3-Cyclohexyl- (L) -alanine-phenylmethyl-methyl ester (three-fluoroacetate)

To a stirred solution of N - [(1,1-dimethylethoxy) carbonyl] -3-cyclohexyl- (L) -alanine-phenyl-methyl ester in 100 mL of dichloromethane at 17 ° C was added 100 mL of trifluoroacetic acid over 15 minutes while raising the temperature to Deň: 18 ° C. The reaction mixture was stirred overnight and concentrated in vacuo. The residue was distilled azeotropically with dichloromethane, toluene and methyl tert-butyl ether. The resulting oil was subjected to high vacuum to give 3-cyclohexyl- (L) -alanine phenylmethyl ertrifluoroacetate (32.6 g) MS (ion spray) m / z 262 (M + H) ⁺ .

Stage 3

N - [(1,1-Dimethylethoxy) carbonyl] - (L) -α-aspartyl-3-cyclohexyl-1- (L) -biphenylmethyl ester

To a mechanically stirred solution of 27.6 g (85.5 mmol) of ΒΟΟ-β-benzyl- (L) -aspartic acid in 110 mL of ethyl acetate was added a solution of 13.1 g (85.5 mmol) of hydroxybenzotriazole hydrate in 21.4 mL of dimethylformamide. A solution of 18.15 g (88 mmol) of dicyclohexylcarbodiimide in 80 ml of ethyl acetate was added over 15 minutes while maintaining the reaction temperature at not more than 25 ° C. The reaction mixture was stirred for one hour and a solution of 32 g (85.5 mmol) of 3-cyclohexyl- (L) -alanine phenylmethyl ester trifluoroacetate in 120 ml of ethyl acetate was added at 20 ° C, dropwise over 14 minutes 14.6 g of N -methyl morpholine (final pH 4-5). The reaction mixture was allowed to warm to 25 ° C during the addition of N-methylmorpholine. The reaction mixture was stirred at ambient temperature overnight. The reaction mixture is filtered to remove dicyclohexylurea and the filtrate is washed twice with water, once with 0.5 N citric acid.

0 0 0000 0000 * · 0 0 0 0 «· 0 ·« «0 ₉ 0 0 •••» · 0 · 0 · 00 new and twice with saturated sodium bicarbonate solution, dried over magnesium sulfate, filtered and concentrated in vacuo . The resulting oil was dissolved in methyl tert-butyl ether and the solution was filtered to remove a small amount of fine white insoluble material. The filtrate was concentrated in vacuo and the resulting oil was subjected to high vacuum to give N [(1,1-dimethylethoxy) carbonyl] - (L) -? - asparagyl-3-cyclohexyl (L) -bisphenylmethyl ester (32.9 g) . MS (ion spray) m / z 566 (M + H) +, 584 (M + Na) ⁺ .

Step 4 (L) -α-Asparagyl-3-cyclohexyl- (L) -alanine-phenylphenylmethyl ester mono (hydrochloride)

Hydrochloric acid was bubbled through the magnetically stirred solution of 17 g (30 mmol) of N - [(1,1-dimethylethoxy) carbonyl] - (L) -? - asparagyl-3-cyclohexyl- (0 ° C) for about five minutes. L) -bis-L-alanine-bisphenylmethyl ester in 60 g ethyl acetate. During this time, the temperature of the solution rose from 5 ° C to 20 ° C and then began to fall. The ice bath was removed and the solution was stirred at ambient temperature for 90 minutes. Excess hydrogen chloride is expelled by bubbling nitrogen through the solution and the mixture solidifies. Ethyl acetate (100 g) was added to facilitate stirring (thixotropic) and nitrogen was bubbled through the mixture for an additional three minutes. The solid material was filtered on a Buchner funnel. The filter cake was washed with ethyl acetate and dried overnight under vacuum (2 kPa) with a mixture of nitrogen to give (L) -α-asparagyl-3-cyclohexyl- (L) -alanine-bisphenylmethyl ester monohydrochloride (10.7 g) as a white solid substances. MS (ion spray) m / z 467 (M + H) &lt; + & gt ^; .

Example 11

Preparation of N - [(1,1-dimethylethoxy) carbonyl] - (L) -α-aspartyl-3-phenyl- (L) -a-ananinamide

• · * · · · · · · · · · ·

Method A

To a mechanically stirred mixture of 38 ° C ethylene glycol (140 g) and methanol (35 g) was added di-tert-butyl dicarbonate (45 g) and aspartame (5 g). Triethylamine (17.5 g) was added via syringe at a rate of 0.2 ml / min. Aspartame is then added in nine doses at 12 minute intervals. The reaction temperature is maintained at 38 ° C for 30 minutes. The reaction mixture was degassed under vacuum for 45 minutes until evolution of gas was evident (approximately 20 minutes). Ammonia (19 g) was introduced via a pipette under the surface of the reaction mixture over a period of 45 minutes and the reaction mixture was heated to approximately 60 ° C overnight. The reaction mixture was diluted with water (280 g) and the reaction temperature was adjusted to about 45 ° C. Acetic acid (55 g) was added to adjust the pH to about 5.9. The mixture was cooled to 40 ° C, starting to form a solid. The mixture was cooled to 20 ° C over two hours and acetic acid (250 g) was added to adjust the pH to about 5 and the mixture was stirred for half an hour. The solid was filtered off, washed with water (3x) and dried under vacuum at 50 ° C to give N - [(1,1-dimethylethoxy) carbonyl] - (L) -? - asparagyl-3-phenyl- (L) -alaninamide (53 g) as a white crystalline solid.

Method B

A mixture of aspartame (25 kg) and di-tert-butylbicarbonate (22 kg) in methanol (250 kg) in a 400 liter glass-lined reactor is heated to about 30 ° C and 1 ithium hydroxide (3.6) is added over 30 minutes. kg) in a nitrogen environment. The suspension was stirred for about four hours and ammonia gas (39 kg) was introduced under nitrogen. The suspension was stirred for two days, concentrated in vacuo to remove ammonia and methanol. Water (170 kg) and acetic acid (8 kg) were added to the resulting suspension, the precipitate was filtered off and the filter cake was washed twice with water (25 kg) and dried in vacuo at about 40 ° C. · · · · ·

9 9 9 9 9 9 9 9 9

9 9 9 9 9 9 »

9 9 9 9 9 9999 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 to obtain N - [(1,1-dimethylethoxy) carbonyl] - (L 1α-asparagyl-3-phenyl- (L) -alaninamide (29 kg) as a white crystalline solid.

Example 12

Preparation of (L) -α-asparagyl-3-cyclohexyl- (L) -alanine dmono (hydrochloride)

A mixture of N - [(1,1-dimethylethoxy) carbonyl] - (L) -α-asparagyl-3-phenyl- (L) -alaniamide (129 kg) and filler oxide (5 kg), or Platinum on alumina (humidity 50%, 5%, 12 kg) in a 1600 liter reactor lined with glass in acetic acid (700 kg) is hydrogenated for three to five hours at about 60 ° C under a hydrogen pressure of 0.4 MPa. The catalyst was filtered off and washed with acetic acid (20 kg). Gaseous hydrochloric acid (7.8 kg) was added over a period of one to two hours to a 215 kg solution of acetic acid in a 400 liter reactor lined with glass in a nitrogen atmosphere. The suspension was stirred for one hour and filtered. The filter cake was washed twice with acetic acid (20 kg) and twice with acetone (20 kg) and dried under vacuum at about 40 ° C to give (L) -α-aspartyl-3-cyclohexyl - (L) -a 1ani us dmono (hydrochloride) (31 kg) as a white crystalline solid.

Example 13

Preparation of (L) -α-asparagyl- (L) -phenylalaninamide-phenylmethyl-methyl ester (hydrochloride)

Stage 1

N - [(1,1-Dimethylethoxy) carbonyl] - (L) -α-asparagyl- (L) -phenylalaninomethylestermono (sodium) salt

00 • 0 1

0 I

0 4 * 0 0 0

0- 00

A beaker was charged with 294.4 g (0.68 mol) of aspartame, 2000 ml of methanol, 2000 ml of water and 192.96 (0.88 mol) of di-tert-butyl dicarbonate and the mixture was cooled to 0 ° C. Aqueous sodium hydroxide solution (10N, 68.6 mL) was added over 15 minutes maintaining the temperature at 0-4 ° C. The cooling was removed and the mixture was allowed to warm to ambient temperature and stirred for 2 days. The clear solution was concentrated in vacuo to give an oil which was taken up in ethyl acetate (500 mL) and re-concentrated to an oil (297 g). The oil was dissolved in 1 L of ethyl acetate at 48 ° C to give a clear solution. The solution was allowed to cool to room temperature overnight. The crystalline product was filtered off, washed with 400 ml of ethyl acetate and dried in vacuo to give 165 g (0.42 mol, 62% yield) of N - [(1,1-dimethylethoxy) carbonyl] - (L) α-asparagyl - (L) -phenylalanine methyl ester mono (sodium) salt. Concentration of the mother liquor afforded an additional 95.4 g (0.24 mol) of solid product (total yield 97%).

Stage 2

N - [(1,1-Dimethylethoxy) carbonyl] - (L) -α-aspartyl- (L) -phenylaniamide, mono (sodium) salt

Ammonia (255 g, 15 mol) was condensed in a 4 L flask. A solution of 260 g (0.659 mol) of N - [(1,1-dimethylethoxy) carbonyl] - (L) -α-aspartyl- (L) -phenylalanine methyl ester mono (sodium) salt in 1300 ml of methanol is prepared in a separate vessel, which is added over half an hour to ammonia at -32 to -5 ° C. The mixture was warmed to ambient temperature over three hours and stirred for an additional two hours. The methanol was removed in vacuo at 40 ° C to give 501 g of a paste. The paste is taken up in 1 liter of ethyl acetate and the product crystallizes. The mixture was diluted with an additional 2 liters of ethyl acetate and filtered. The solid was dried under vacuum overnight at ambient temperature, then under vacuum at 50 ° C for 1.5 hours to give 243.5 g (0.645 mol) (98% yield) of N - [(1,1- dimethylethoxy) carbonyl] - (L) -α-as74

9 »9 ·

0 9 9

0 · 9 9

9 9 9 paragyl- (L) -phenylalanine methyl ester mono (sodium) salt i.

Stage 3

N - [(1,1-Dimethylethoxy) carbonyl] - (L) -α-asparagyl- (L) -phenylalanine phenylmethyl ester

A 1 liter round bottom flask was charged with 241 g (0.635 mol) of N - [(1,1-dimethylethoxy) carbonyl] - (L) -α-asparagyl- (L) -phenylalaninamidmonium (sodium) salt under nitrogen. and 2000 ml of dimethylformamide and stirred until dissolved. Pure benzyl bromide (75.4 g, 0.635 mol) was added over 5 minutes at 23-26 ° C. The mixture was stirred at ambient temperature for 21.5 hours, diluted slowly with 2500 ml of water, increasing the temperature to 32 ° C. The mixture was stirred for one hour with cooling to ambient temperature, whereupon the solid crystallized. The solid was filtered, washed with three portions of water (1 L each) and dried for two days at 50 ° C to give 232 g (0.495 mmol), 78% yield) N - [(1,1- dimethylethoxy) carbonyl] - (L) -? - asparagyl- (L) -phenylalanine diphenylmethyester.

Step 4 (L) -α-Asparagyl- (L) -phenylalanines diphenylmethyl ester mono (hydrochloride)

A solution of N - [(1,1-dimethylethoxy) carbonyl] - (L) -α-asparagyl (L) -phenylaniamphenylmethyl ester in 4N hydrochloric acid / ethyl acetate was stirred for one hour at ambient temperature. The mixture was concentrated and the residue was taken up in 1.1 L of ethyl acetate and stirred overnight. The resulting solid was filtered off and dissolved in 3 L of water. The solution was washed with three 500 ml portions of dichloromethane. The aqueous solution was partially evaporated on a rotary evaporator at 55 ° C. Leave the solution to 44

4 4 <

• 4 · 1 • 4 · 4

4 »44 cool down. The solid crystallized and was filtered in two portions (113.6 g and 34.1 g) with a total yield of 147.7 g (0.364 mol), (79% yield) as (L) -α-aspartyl- (L) -phenylalanine. dphenylmethyest ermono (hydrochloride).

Example 14

Preparation of N-ethyl-N- [1-oxo-3- [1- (phenylmethoxycarbonyl) -4-piperidinylmethylene] propyl] glycine

Stage 1

1-Phenylmethoxycarbonyl-4-piperidone

A mixture of 40 kg of N-benzyloxycarbonylsuccinimide and 26 kg (175 mol) of 4-piperidone hydrochloride hydrate in 38.8 kg of water and 88 kg of tetrahydrofuran is stirred at 15 ° C until complete dissolution (approximately 15 minutes). To the stirred (exothermic) mixture was added N-methylmorphine (22.8 kg) while maintaining the temperature below 20 ° C. The reaction mixture was stirred for approximately 2.5 hours at 20 ° C until reaction was complete by HPLC chromatography. The mixture is diluted with 115.2 kg of methyl tert-butyl ether and stirred with 38.8 kg of water for about five minutes at 20 ° C. Stirring is complete, the layers are allowed to separate and the aqueous (lower) layer is removed. The organic layer was washed twice with 129.6 kg of water (stirring for 5 minutes, phase separation, removal of the lower phase). The organic layer was washed with 5.3 kg of sodium chloride in 46.8 kg of water (stirring for five minutes, phase separation, removal of the aqueous [bottom] layer). The organic layer was treated with 11.5 kg of magnesium sulfate, stirred for one hour, and the mixture was filtered. The reactor is rinsed with 8 kg of methyl tert-butyl ether (filtered, combined with the main filtrate: total water content in the filtrate is 0.52%). The filtrate volume was reduced by half by distillation under reduced pressure at 30 ° C. The vacuum was broken with nitrogen and the residue was cooled to 20 ° C

TQ (residual water content: 0.43%). The residue is diluted with 57.6 kg of methyl tert -butyl ether and then reduced to half by distillation in vacuo at 30 ° C. The vacuum was released with nitrogen and the mixture was cooled to 20 ° C (residual water content: 0.25%). The procedure is repeated five times. The final residue was diluted with 28.8 kg of methyl tert-butyl ether and stirred for five minutes, and the water content and the 1-phenylmethoxycarbonyl-4-piperidone content (0.05 wt% water; 22-66 wt% 1-phenylmethoxyalkyl) were tested. 1-4-piperidone (35.36 kg, 155 mol, 88.6% yield).

Stage 2

3- (1-Phenylmethoxycarbonyl-4-piperidinylmethylene) propanoic acid

To a suspension of 82 g of 3-carboxypropyltriphenylphosphonium bromide in 407 ml of 1,2-diethoxyethane was added at 14 ° C over 25 minutes 220 g of 20% potassium tert-butoxide in tetrahydrofuran while maintaining the reaction mixture temperature at 24-28 ° C. The mixture was stirred for one hour, cooled to 10 ° C, and a solution of 52.5 g of 1-phenylmethoxycarbonyl-4-piperidone in 246 ml of methyl tert-butyl ether was added over 30 minutes with cooling. After completion of the additive, the mixture was stirred at 12 ° C for 10 minutes, warmed to 20 ° C and stirred for an additional 30 minutes. The reaction mixture was treated with 1 N aqueous hydrochloric acid (410 mL) over 10 min, diluted with methyl tert-butyl ether (328 mL) and the phases separated. The organic phase is washed with 205 ml of water, 210 ml of 1N aqueous sodium hydroxide solution. The sodium hydroxide layer containing the product was separated, washed with three portions of 189 g of ethyl acetate, acidified to pH 3.48 with concentrated hydrochloric acid, and extracted with 189 ml of ethyl acetate. The ethyl acetate layer was separated, washed with 211 mL of water, dried over 30 g of magnesium sulfate for 30 minutes, filtered and concentrated in vacuo. The residual oil (50.7 g) was crystallized from toluene / heptane to give a total of 29.46 g (51%). 4 4 444 4 4 9 4 4 4

4,994 9 ···· 49 · 9 ·

The yield was 3- (1-phenylmethoxycarbonyl-4-piperidinylmethylene) propanoic acid.

Mass spectrum: MH + 303, M + ¹ found 304 ¹ H NMR: (δ TMS, CDCl 3) 2.2 (t, 2H), 2.25 (t, 2H), 2.35 (m, 4H), 3.45 (m, 4H), 5.15 (S, 2H), 5.2 (m, 1H), 7.33.2 (5H), ¹³ CNMR (Γ vs. TMS CDCl 3) 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.

Stage 3

N-Ethyl-N- [1-oxo-3- [1- (phenylmethoxycarbonyl) -4-piperidinyl / methylene] propyl] glycine

N-Ethyl-N- [1-oxo-3- [1- (phenylmethoxycarbonyl) -4-piperidinylmethyl] propyl] glycine was prepared according to the method of Example 6, wherein 4- (1 -phenylmethoxycarbonyl-4-piperidinyl) butanoic acid replaces 3- (1-phenylmethoxycarbonyl-4-piperidinylmethylene) propanoic acid.

Industrial applicability

An alternative approach to the preparation of pseudotetrapeptides increasing the versatility and efficiency of production. Initially specified modifications of the pseudotetrapeptide by specialized chemical treatment of one of the components rather than the pseudotetrapeptide as a whole and allowing simultaneous preparation of a number of pseudotetrapeptide analogs.

Claims (9)

PATENT CLAIMS A process for the preparation of a pseudotetrapeptide of the general formula I wherein (Al optionally represents a nitrogen-protected azaheterocyclyl group on a nitrogen atom, .....> <A - a single or double bond, q number 1 to 5, B is alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, aralkyl, alkylaryl or alkylaralkyl, Q2 is a hydrogen atom or a carboxylic acid protecting group, J is H, alkyl, cycloalkyl, cycloalkyl alkyl, alkylcycloalkyl, alkylcycloalkyl alkyl, aryl, substituted aryl, aralkyl or substituted aralkyl, L is OR ¹ or NR ¹ R ² , wherein R ¹ and R ² are independently hydrogen, alkyl, cycloalkyl 79 999 99 9999 99 to this one, this, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, aralkyl, alkylaryl or alkylaralkyl and the number 1 or 2, salts or prodrugs thereof, characterized in that (a) the arahet / rocyclyl pseudodi peptide is coupled with the formula wherein K is a hydroxyl or acyl group activating group, or a salt thereof (b) optionally separating a nitrogen protecting group or a carboxylic acid protecting group to obtain a pseudotetrapeptide; and (c) optionally converting the pseudotetrapeptide into a salt or prodrug. • 99 9 · 99 99 99 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 • 9999999 9 9 9 ·· 99 9 9999 999 99 99 99 99 2. where m is 1 to 5, n is 2 to 6, and P1 is a nitrogen protecting group. 3. A method according to claim 2 wherein Q2 is a carboxylic acid protecting group. 4. A process according to claim 2 which is B is alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl or alkylcycloalkylalkyl, J is a hydrogen atom, an alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl or alkylcycloalkylalkyl group, n is 1 or 3 and n is 3 or 4. 5. A process according to claim 2 which is B is an alkyl group, J is an alkyl, cycloalkyl or cycloalkylalkyl group, R @ ¹ and R @ ² independently of one another are hydrogen, alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl or aryl, and the moiety is 1 to 3, n is 3 or 4; 4 4 4 9 4 4 4 4 4449 99 4 9 4 4 4 4 4 4 4 9 994 49 44 4 99 44 p o s 1 o 1. 6. A process according to claim 3, wherein P1 is benzyloxycarbonyl and Q2 is benzyl. 7. The process of claim 2 wherein P1 is benzyloxycarbonyl and Q2 is hydrogen. 8. A process according to claim 6, wherein L is -NR &^lt; ¹ &^gt; A process according to claim 7 wherein L is -NR ¹ R ² . 10. The process of claim 1 wherein the azaheterocyclyl pseudodipeptide salt is coupled with a carbocyclic acid substituted dipeptide salt. 11. The method of claim 10, wherein the azaheterocyclic pseudodipeptide addition salt is basically coupled to the acid-substituted dipeptide carbocyclic acid addition salt. 12. The process of claim 11 wherein the dicyclohexylamine salt of azaheterocyclyl pseudodipeptide is coupled with the trifluoroacetate salt by carbocyclic acid-substituted dipeptide. 13. The method of claim 1, wherein the method is: a) coupling azaheterocyk1ylpseudodipeptid formula ^{Ρ Γ} ~ Ν \ JI · OH 'I B ί 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0000 00 0000 000 A P1 nitrogen protecting group; and B is an alkyl group, or a base addition thereof, a carboxylic acid substituted with a dipeptide of the formula or an acid addition salt thereof, Q ₂ is a hydrogen atom or a carboxylic acid protecting group, J is alkyl, cycloalkyl or cycloalkylalkyl and L is OR ¹ or NR ¹ R ² , wherein R ¹ and R ² are independently hydrogen, alkyl, cycloalkyl, cycloalkyl alkyl, alkylcycloalkyl, alkylcycloalkylalkyl or aralkyl, for the preparation pseudotetrapeptide of the general formula carboxylic acid a c) optionally converting the pseudotetrapeptide into its salt or prodrug. 14. The method according to claim 13, characterized in that P represents benzy1oxykarbonylovou and Q ₂ benzyl. • 00 0 · 00 00 000 0 · 0 0 400 000 000 « 0 · 000 00000 0 0 00 0 0 0 * 00 · 0004 000 00 00 15. The process of claim 13 wherein P1 is benzyloxycarbonyl and Q2 is hydrogen. 16. The method of claim 14 wherein B is ethyl, J is cyclohexylmethyl, and L is NH2. 17. The method of claim 15 wherein B is ethyl, J is cyclohexylmethyl, and L is NH2. A process for the preparation of a cyclohexylmethyl-substituted peptide of the general formula wherein is Q2 is hydrogen or a carboxyl protecting group and Q3 is hydrogen or a nitrogen protecting group, characterized in that: a) reduces the phenylmethyl substituted peptide of the general formula b) optionally removing a nitrogen protecting group or carboxylic acid. 19. The process of claim 18 wherein the reduction is carried out by catalytic hydrogenation. 20. The process of claim 19 wherein the catalytic hydrogenation is carried out using a platinum catalyst. 21. The process of claim 20 wherein the platinum catalyst used is platinum oxide or platinum on alumina. 22nd A process for preparing an amidopeptide of formula q ₃ nh wherein (A) a hydrogen atom is a carboxyl protecting group addition group and a hydrogen atom or an atom protecting group characterized by amidating an ester of a peptide of formula (I) with a base or a nitrogen group wherein R3 is lower alkyl. • »a a a a>>>>> A * a a a a a a a a a a a a a a a a a a a a a 23. The process of claim 22 wherein the amidation is carried out using ammonia in an alcohol. 24. Way according to claim 23, v brand u i c s e t i m, that is as alcohol using lower alcohol. 25. Way according to claim 23, v brand u j i c i s e characterized in that the amidation is carried out using ammonia in a mixture of a lower alcohol and a glycol. 26. The process according to claim 25, wherein the mixture of the lower alcohol and the glycol is a mixture of methanol and ethylene glycol. 27 Mar: A process for the preparation of an aspartame compound of the general formula wherein Q 5 is a hydrogen atom or a carboxyl protecting group, Q3 a nitrogen protecting group and R3 a lower alkyl group, characterized in that a nitrogen protecting group is introduced into the aspartame compound of formula 28. The method of claim 27 wherein Qa is benzyloxycarbonyl or tert-butyloxy. 99 ··> · · 9 9 9 9 9 9 9 9 9 9 to 99 carbonyl group. 29. The method of claim 28 wherein Q2 is hydrogen. A process for the preparation of an amidodipeptide of the general formula wherein A nitrogen protecting group Q3; and Q2 is a hydrogen atom, characterized in that: a) introducing a base and a nitrogen protecting agent into a solution of aspartame in a solvent to form a solution of a compound of formula q ₃ nh co ₂ q ₂ where Q2 is a hydrogen atom or a base addition salt group and a b) ammonia is introduced into the solution obtained. 31. The process of claim 30 wherein Q3 is a tert-butyloxycarbonyl or benzyloxycarbonyl group. φφφφ φ ♦ φ · φ • • • • • * 32. The method of claim 31 wherein Q3 is a tert-butyloxycarbonyl group. 33. The process of claim 32 wherein the solvent is alcohol. 34. The method of claim 33, wherein the alcohol is a lower alcohol or a mixture of a lower alcohol and a glycol. 35. The process of claim 34 wherein the alcohol is methanol or a mixture of methanol and ethylene glycol. 36. A process for the preparation of an oxy-substituted methyl group, or an acid addition salt thereof, comprising: a) preparing in a solvent a mixture of a catalyst and a phenylmethyl-substituted peptide of the general formula where is Q3 tert-butoxycarbonyl group, fefefe fefefe fefefe fefefe fefefe fefe fefe fefe fefe fefe »Fefeefefe fefe · fefe fefe (b) the mixture is treated with hydrogen; (c) removing the catalyst from the mixture; and d) Hydrogen chloride gas is introduced into the mixture. 37. The process of claim 36, wherein the solvent is acetic acid. A process for the preparation of an azaheterocyclyl-substituted acid of the formula wherein is R4 is hydrogen or lower alkyl; and A P 1 nitrogen protecting group, characterized in that it is a) decarboxylates the 2-pyridylethyl-di (lower alkyl) malonate of the general formula ## STR3 ## wherein is R 5 is a lower alkyl group, to give the pyridylic acid of the formula ## STR2 ## in ₂ h. Pyridylic acid with hydrogen in the presence of obtaining the piperidine acid of formula ## STR3 ## b) hydrogenating the catalyst to form a catalyst c) optionally removing the catalyst d) piperidine acid is protected on the nitrogen to give a nitrogen-protected piperidine acid of formula ₂ as H e) coupling the protected piperidine acid with a N-ethylglycine of the general formula on a nitrogen atom HN OR, h ₃ c 'to give the azaheterocyclyl substituted acid a f) optionally de-esterifying an azaheterocyclyl substituted acid where R _{4 is} lower alkyl 39. The method according to claim 38, characterized in that P represents a benzyloxycarbonyl group and R ₄ represents hydrogen to. 0 0 0 00 0000 0000 0 000 0000000 0 0 40. The process of claim 39, wherein the decarboxylation is carried out by heating 2-pyridylethyl (lower alkyl) malonate in an aqueous acid solution. 41. The process of claim 40, wherein the aqueous acid solution is aqueous hydrochloric acid. 42. The process of claim 39, wherein the hydrogenation is carried out in an aqueous acid solution. 43. The process of claim 42, wherein the aqueous acid solution is aqueous hydrochloric acid. 44. The process of claim 39, wherein the introduction of the protecting group on the nitrogen atom is carried out in an aqueous base solution. 45. The method of claim 44, wherein P1 is benzyloxycarbonyl. 46. The method of claim 39, wherein the method is: a) heating a solution of 2-pyridylethyl di (lower alkyl) malonate in an aqueous acid solution to obtain a solution of pyridylic acid in aqueous acid, b) adding a catalyst to the pyridylic acid solution and treating the mixture with hydrogen to obtain a mixture of catalyst and piperidine acid, c) separating the catalyst from the mixture to obtain an aqueous piperidine acid solution, d) adding the base and the nitrogen protecting agent to the aqueous solution to obtain the protected piperidine acid on the nitrogen atom. 00 · · 0 00 0 0 0 00 0 00 00 0 0 0 0 • 0 0 0 0 0 0 0 0 0 0 0 00 00 47. The process of claim 46, wherein the aqueous acid solution is aqueous hydrochloric acid. 48. The process of claim 47 wherein R4 is hydrogen. 49. The method of claim 48, wherein P1 is benzyloxycarbonyl. A process for the preparation of a pseudotetrapeptide of the formula wherein m is 3, n is 2 to 6, B is an alkyl group, p is 1 or 2, J is cyclohexylmethyl and L is OR ¹ or NR ¹ R ² , wherein R ¹ and R ^{2 are} each independently hydrogen, alkyl, cycloalkyl, cycloalkyl alkyl, alkylcycloalkyl, alkylcycloalkylalkyl, salts or prodrugs thereof, characterized in that: a) reduces a compound of the formula wherein (CH 2) ~ m, pyr pyridyl or where ¹ m is 3, P 1 is a hydrogen atom or a nitrogen protecting group, Q2 a hydrogen atom or a carboxylic acid protecting group and J a phenylmethyl group, b) optionally removing a nitrogen protecting group or a carboxylic acid protecting group, c) optionally converting the pseudotetrapeptide into its salt or prodrug. 51. The process of claim 50 wherein the reduction is carried out by catalytic hydrogenation. 52. The method of claim 51 wherein m is 3; P 1 nitrogen protecting group, n number 3, p 1 s 1 a A Q2 carboxylic acid protecting group. 53. The method of claim 52 wherein P1 is a hydrogen labile protecting group and Q2 is hydrogen labile protecting a kai-φφ φ φφφφ φφφφ φ φφφφφ Y φ φ φ φ φ φ φ φ φ * * * φ φ φ φ φ φ φ φ φ φ φ φ φ box box box box y y y y y y y y y y 54. The process of claim 53 wherein the catalytic reduction is carried out simultaneously with the reduction and removal of the groups P1 and Q2. 55. The method of claim 51, wherein the group is pyridyl A Q2 carboxylic acid protecting group. 56. The process of claim 55 wherein Q2 is a labile carboxylic acid protecting group. 57. The process of claim 56 wherein the catalytic reduction is carried out simultaneously with the reduction and removal of the Q2 group. 58. A pseudotetrapeptide of the general formula ## STR2 ## or aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa · aa aa m number 3, P 1 is a hydrogen atom or a nitrogen protecting group, n is a number 2 to 6, B is an alkyl group, p is 1 or 2, Q2 is a hydrogen atom or a carboxylic acid protecting group, J is phenylmethyl and L is OR ¹ or NR ¹ R ² , wherein R ¹ and R ^{2 are} each independently hydrogen, alkyl, cycloalkyl, cycloalkyl alkyl, alkylcycloalkyl or alkylcycloalkyl alkyl, its salts or prodrugs. The pseudotetrapeptide of claim 58, wherein m is 3, P 1 nitrogen protecting group, n number 3, p 1 s 1 a A Q2 carboxylic acid protecting group. 60. A pseudotetrapeptide wherein P 1 is a hydrogen labile nitrogen protecting group and Q 2 is a carboxylic acid labile hydrogenating group. where it means P 1 is a hydrogen atom or a nitrogen protecting group, B is alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkylcycloalkylalkyl, aryl, aralkyl, alkylaryl or alkylaralkyl; and FU is a hydrogen atom or a lower alkyl group or salts thereof. 62. The pseudotetrapeptide of claim 61 wherein P1 is a nitrogen protecting group, B is alkyl, and FU is hydrogen. 63. The pseudotetrapeptide of claim 62 wherein P1 is benzyloxycarbonyl and B is ethyl.