FI80051C - FOERFARANDE FOER FRAMSTAELLNING AV FARMAKOLOGISKT VAERDEFULLA SUBSTITUERADE DIPEPTIDER. - Google Patents

Description

i 80051

The present invention relates to a process for the preparation of a pharmacologically valuable substituted dipeptide having the formula * 6 The present invention relates to a process for the preparation of a pharmacologically valuable substituted dipeptide.

R1 - HC - NH - X - CONH - CH - (CH2) y - R9 (I) R2 wherein

R 1 is phenyl- (C 1 -C 4) -alkyl, naphthyl- (C 1 -C 4) -alkyl, (C 1 -C 4) -alkylphenyl- (C 1 -C 4) -alkyl or phenyl- (C 1 -C 4) -alkylthio- (C 1 -C 4) -alkyl- -C 4) -alkyl, R 2 is carboxyl, -COO (C 1 -C 4) -alkyl or -COO (C 1 -C 4) -alkylphenyl, R 4 R 4 1 X is -CH- or -N-R 4 is thienyl- ( C 1 -C 4 alkyl, phenyl- (C 1 -C 4) alkyl, where phenyl may be substituted by halogen or phenyl, naphthyl- (C 1 -C 4) alkyl or (C 1 -C 4) alkyl, Y is 1 or 2,

R 9 is hydrogen, (C 1 -C 4) alkyl or phenyl- (C 1 -C 4) alkyl,

R 9 is carboxyl, -COO (C 1 -C 4) -alkyl, -COO (C 1 -C 4) -alkyl-phenyl, / R 20 -CON; wherein one of R 21 and R 20 is hydrogen and the other is phenyl (C 1 -C 4) alkyl, or together with the nitrogen atom to which they are attached, R 20 and R 21 form a 5-7 membered saturated ring containing oxygen as a ring heteroatom.

2 80051

A naturally occurring opiate receptor agonist known as "enkephalin" and believed to be two peptides, i. H-tyr-Gly-Gly-Phe-met-OH (methionine-enkephalin) and H-tyr-Gly-Gly-Phe-len-OH (leucine-enkephalin), both of which are hereinafter referred to generically as "enkephalin", are causing deep analgesia in rats when injected into rat ventricles (Beluzzic et al. nature 260, 625 (1976)).

Enkephalin, which is naturally formed in the body of warm-blooded animals, is known to be inactivated by encephalin, which is also naturally formed in these bodies by a group of enzymes known as. Therefore, it is interesting to look for compounds capable of inhibiting or alleviating the aforementioned inactivating effect of encephalin.

Typical such novel compounds are the following: N- (L-1-carboxy-3-phenylpropyl) -L-3- (3-thienyl) alanyl-L-alanine, m.p. 192.5-193 ° C; N- (D, L-1-carboxy-3-phenylpropyl) -L-3- (2-naphthyl) alanyl-L-alanine M.p. 149-155 ° C; N- (L-1-ethoxycarbonyl-3-phenylpropyl) -L-3- (2'-thienyl) -alanyl-L-alanine, or a maleate thereof, m.p. 124-124.5 ° C (100-110 ° C); N- (D-1-carboxy-3-phenylpropyl) -L- (4-fluorophenyl) -anyl-L-alanine, m.p. 147-152 ° C; N- (D-1-carboxy-3-phenylpropyl) -L-3- (3-thienyl) -alanyl-L-alanine, m.p. 163-164 ° C; N- (L-1-carboxy-3-phenylpropyl) -L-3- (1-naphthyl) -alanyl-L-alanine, m.p. 155-156 ° C; N- (1-carboxy-3-phenylpropyl) -L-3- (3-thienyl) -alanyl-L-alanine and its monoethanolate, m.p. 163-164 ° C;

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380051 N- (L- (1-carboxy-2-benzylthio) ethyl) -phenylalanyl- (L) -alanine and its sesquihydrate, m.p. 153-154 ° C; N- (L-1-carboxy-2-phenethyl) -L-phenylalanyl-Y-aminobutyric acid, m.p. 209-211 ° C (179-181 ° C); N- (L-1-carboxy-3-phenylpropyl) -L-phenylalanyl-A-alanine, m.p. 189-191 ° C or hemihydrate, m.p. 176-190 ° C; N- (L-1-carboxy-3-phenylpropyl) -D, L-3- (1-naphthyl) -alanyl-L-alanine M.p. 186-194 ° C.

[(D) -N- (1-ethoxycarbonyl-3-phenylpropyl) -phenylalanyl] -β-alanine (m.p. 101-103 ° C) or a maleate salt thereof,

Sp. 94-97 ° C

(D) -N- (1-carboxy-3-phenylpropyl) -phenylalanylϊ-β-alanine, m.p. 183-185 ° C (190-192 ° C).

N-L- (1-carboxy-3-phenylpropyl) -L-3- (2-naphthyl) -alanyl-L-alanine, m.p. 149-155 ° C.

N - [(L) -1-carboxy-2- (1-naphthyl) ethyl] - (L) - (4-phenyl-2-amino-butyroyl) -N-alanine, m.p. 206-207 ° C.

N- (L) - (1-carboxy-2-phenylethyl) - (L) -homophenylalanyl-N-alanine, m.p. 200-201 ° C.

N- (L) - (1-ethoxycarbonyl-3-phenylpropyl) - (D) -phenylalanyl-β-alanine, m.p. 103-105 ° C.

N- (L) - (1-carboxy-2-phenylethyl) - (L) -phenylalanyl-β-alanine-2-phenethylamide, m.p. 204-205 ° C.

N- (L) - (1-Benzyloxycarbonyl-2-phenylethyl) - (L) -phenylalanyl- [5-alanine] benzyl ester.

N- (L) - (1-benzyloxycarbonyl-2-phenylethyl) - (L) -phenyl-alanyli - ^ - alanine (2-methyl-3-trifluoromethyl) anilide;

Sp. 114-116 ° C.

N - [(D, L) -1-carboxy-2-phenylethyl] -L-leucyl- (L) -phenylalanine or its hemihydrate, m.p. 178-180 ° C.

N - [(L) -1-carboxy-2-phenylethyl] - (L) -leucyl-β-alanine trifluoroacetate, m.p. 70-72 ° C.

* 80051 N- (L) - (1-Carboxy-2-phenylethyl) - (U-phenylalanyl-A-alanine- (2-methyl-3-trifluoromethyl) anilide, mp 191-192 ° C N- ( L) - (1-Benzyloxycarbonyl-2-phenylethyl) - (L) -phenylalanyl- / 3-alanyl-morpholinamide, N-1 (L) -1-carboxy-2-phenylethyl] - (L ) -phenylalanyl- / 3-alanyl-morpholinamide, mp 127-129 ° C.

N- (L1-ethoxycarbonylethyl) -L-2-thienylalanylglycine, N- (L1-ethoxycarbonylethyl) -L-2-thienylalanyl-L-alanine, N- (L-1-ethoxycarbonylethyl) -L-3-thienylalanyl-L- alanine, N- (L1-ethoxycarbonylethyl) -L-3-thienylalanylglycine, N- (L1-carboxyethyl) -L-2-thienylalanyl-L-alanine, N- (L1-tert-butoxycarbonylethyl) -L-2-thienylalanyl -L-alanine, [(R) -1-benzyloxycarbonyl-2-phenylethyl] - (R) -phenylalanyl- [3-alanyl-2,2-dimethylpropionyloxy] methyl ester, N- (1-carboxy -2 (1-naphthylethyl)) - (R) -phenylalanyl- [3-alanine, m.p. 183-187 ° C, N- (S) - (1-carboxy-2-phenylethyl) - (S) -paraphenylalanyl- / 3-alanine, N- (L1-carboxy-2-paramethylphenylethyl) -L-phenylalanyl β-alanine, m.p. 222-224 ° C, N-t (S) -1-carboxyl-2-phenylethyl] - (S) -alanyl- (R, S) - <X-phenylmethyl- [3-alanine], m.p. 235-247 ° C, and N - [(S) -1-carboxy-2-phenylethyl] - (S) -leucyl- (S) -N-phenylmethyl- / 3-alanine hydrochloride, m.p. 185-190 ° C and pharmaceutically acceptable salts thereof.

We have found that the compounds of formula I are useful in inhibiting enkephalinase, as described with reference to the in vivo and in vitro assays set forth below. In addition to the compounds given above, typical such compounds include, for example, the following.

II 5 80051 N- (1-carboxy-1-phenylpropyl) -L-phenylalanyl-L-alanyl-1/2 isopropanol, m.p. 164-164.5 ° C, N- (D-1-carboxy-3-phenylpropyl) -L-phenylalanyl-L-alanine, m.p. 214-215 ° C, N- (L-1-ethoxycarbonyl-3-phenylpropyl) -L-phenylalanyl-L-alanine or a maleate thereof, m.p. 128-130 ° C (115-120 ° C), N- (1-carboxy-3-phenylpropyl) -L-phenylalanyl glycine hemihydrate, m.p. 140-145 ° C, N- (1-carboxy-1-methyl) -L-phenylalanylglycine and its hydrate, m.p. 125-132 ° C.

The compounds of this invention can be prepared by a number of methods described below.

a) reducing the compound of formula A in the C = N double bond r1-C = N-X-CONH - CH - (CH2) y "<9 R2 (A) in which the optional reactive groups are suitably protected, followed by the optional protecting groups if necessary, is removed to give a dipeptide of formula I.

If desired, the compound of formula I thus obtained can be converted into another compound of formula I, e.g. by suitably converting the groups R 2 and R 9.

This method can be carried out by reducing the Schiff base as it is formed in the reaction mixture from a ketone acid or ester and an amino acid or ester according to the following total reaction: 6 80051? «

H2N - X - CONHCH (CH2) y - Rg + R; 1 - C = O D

* 2

C

R1-C = N-X-CONHCH (CH2) y - Rg E

* 2

In the previous reductive condensation reaction, X is preferably r 4 -CH-.

The reaction between the primary amine C of the keto acid or ester can be carried out, for example, in solution using, for example, water or methanol as a solvent under substantially neutral conditions in the presence of a suitable reducing agent, e.g. sodium cyanoborohydride.

Alternatively, the Schiff base obtained from the reaction of a keto acid or ester C with an amino acid or ester D can be catalytically reduced in the presence of hydrogen at 1-4 atmospheric pressure; suitable catalysts are e.g. Raney nickel and palladium / carbon, e.g. 10% Pd / carbon.

The group Rg is usually a protected carboxyl group, e.g. benzyloxycarbonyl or a lower alkoxycarbonyl, e.g. t-butyloxycarbonyl. In such cases, the protecting group may be reduced to a compound of formula I wherein R 9 is carboxyl using conventional hydrolysis or hydrogenolysis methods, e.g. by hydrolysis under basic conditions, e.g. by reaction with sodium hydroxide in a suitable solvent.

7 80051

When R 9 is carboxyl, it can be converted to a -CON group or an alkoxy group by conventional methods. E.g.

The compound of formula I can be reacted with thionyl chloride or oxalyl chloride to convert the group Rg to an activated ester group, followed by reaction with the amine HNR20R21 ta * alcohol to give the desired compounds.

Compounds C can be prepared by the following series of reactions (examples of compounds wherein X is R * i -CH-).

r4 r6 P - NH - CH - CO2H + H2NCH (CH2) y - R9 -

F G

- ~ ψ r4 r4 r6 H2N - CHCONHCH2 (CH2) yRg P - NH - CH - CONHCH (CH2) yRg

C H

In the previous series of reactions, the amino group of amino acid F may be protected, e.g., with any conventional amino group protecting group P, e.g., benzyloxycarbonyl or t-butyloxycarbonyl.

Amino acid F can be condensed with an amino ester derivative G, e.g., using a condensing agent such as dicyclohexylcarbodiimide (DCC) or diphenylphosphoryl azide. An activating agent, e.g. 1-hydrodibenzene, can be used in the condensation reaction. The 8,80051 amino protecting group P attached to the resulting dipeptide H is then removed by conventional treatment, e.g. by treatment with acid or hydrogenation, e.g. using hydrogen in the presence of a metal catalyst.

b) Is compound A coupled with 'amino acid B'? *

H-HNCH (CH2) y - Rg + - CH - NH - X - COOH

«2 (A ') (B') in which all the reactive groups are suitably protected, after which these possible protecting groups are removed to give a dipeptide of the formula R4 Rc I 4 Γ

R 1 · - CH - NH - CH - CONHCH (CH 2) y R 9 R 2 and then, if desired, the compound of the formula I thus obtained is converted into another compound of the formula I.

r4

In preparing compounds wherein X is -CH- and R 2 is other than 0 = P - ORin, compound B 'can be prepared by condensing R 11 with a suitably substituted amino acid with a keto acid or ester to reduce it according to the following reaction scheme

Rd R4

1 I

R1-C = O + H2NCH - CO2H ----- R1 - CHNHCH - CO2H Bj_R2 r2

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9 80051

However, compound B 'is best prepared by condensing condensing an appropriately substituted keto acid with an amino acid ester according to the following reaction: r4

R4 - C = O + R1 - CHNH2 -> R1CHNHCHCO2H

COOH R2 R2 These condensations can be carried out under the conditions described above in process a) in the reaction between compounds D and C. The resulting compound B 'is then coupled with amino acid A', wherein R 9 is e.g. alkoxycarbonyl or dialkylaminocarbonyl or another non-reactive group in the above definition of Rg.

Route b) is suitable for compounds where R 2 is O = P - OR 10.

R11 The intermediate B 'of such compounds used as starting material is, for example, compound? 4

R1 - CH - NH - CH - CO2H

0 = P-ORiq D '* 11 wherein R 10 is alkyl or benzyl. Compound D 'can be prepared, e.g., by introducing an amine

R 1 - CH - NH 2 O = P-OR 10 P _! _ »U to react with a substituted pyruvic acid of formula 0 = C - CO 2 H to give a Schiff base which is reduced, preferably with sodium cyanoborohydride to give compound D '. The compound A 'which is reacted with the compound D' in this particular process is e.g. an appropriately substituted amino acid (i.e. Rg is COOMe), e.g. using a condensing agent, e.g. DCC.

By appropriately selecting protecting groups at R 9 and R 9, the resulting compound can be selectively deprotected at R 9 by conventional methods, wherein the terminal carboxyl group wherein R 8 is carboxyl, wherein R 8 is optionally retained; however, if desired, both Rg and -OR10 can be hydrolyzed under time conditions to a hydroxy group.

Compound B 'can be coupled to amino acid A' by standard methods, e.g., by first forming an activated ester group by reacting B 'with an activating agent such as 1-hydroxybenzotriazole, and then reacting with compound A' and treating with a condensing agent such as 1- (3-dimethylaminopropyl) - With 3-ethylcarbodiimide hydrochloride.

c) In another process for the preparation of compounds where X is -CH-, the compound of formula X is reduced in the C = N double bond H R4 R6 1 1 10 R1-CN = C-CONH - CH - (CH2) y - Rg * 2 ( X) followed, if desired, by the removal of any protecting groups and / or the formation of a salt thereof. This method is performed

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11 80051 by suitably condensing a ketone of the formula * 4? 6 0 = C - CONR5 - CH - (CH2) y-R9 EJ_ with an amino acid or ester of the formula

B

i

R1 - C - NH2 FJ_ r2 in the presence of a reducing agent, e.g. sodium cyanoborohydride.

The resulting compounds G 'having a carboxy group at the terminal position (Rg: -COOH), and most preferably the compounds wherein R2 is other than 0 = P - ORiq, can be further treated by the methods described above for R11 to give another compound of formula Compound I by suitable conversion of the functions R2 and Rg.

Intermediate E ', where Rg is -COOH, can be prepared following the following reaction scheme: R'4CH O

Si

NaOAC / \ R'4 - CHO + CH2CO2H -N0 Jl | Ac 2 O NHCOCH 3 HJ. CH3 h2nch-r9

HoO + »O Rg

H I

<- R'4CH = C-C-NHCH (CH2) yRg H2O NHCOCH3 12 80 051 wherein R'4 is a group which together with the methyl group with which it is attached to the peptide chain of the obtained compound E 'forms a group R4.

N-Acetylglycine H 'is suitably condensed with an R 4 -substituted aldehyde (preferably an aryl or heteroaryl or heteroalkylaldehyde) in the presence of acetic anhydride / sodium acetate to give a substituted azlactone J' which in turn is reacted with an amino acid. This gives a substituted N-acetyldehydrodipeptide which, in the presence of an aqueous acid, is converted into the corresponding R 4 -substituted pyruvic amino acid E '.

Alternatively, the starting compound E 'can be prepared by condensing an R 4 -substituted pyruvic acid with an amino acid ester by the action of dicyclohexylcarbodiimide (DCC), followed by hydrolysis of the alkali-obtained ester according to the following reaction scheme: R 4 Re DCC R. R 9 I 4 I 6 I 4 1b CO2H + H2NCH (CH2) yR9 -> 0 = C-CONHCH (CH2) yR9

LI Ml N_L

Rg in M 'may be, for example, carbomethoxy.

Hydrolysis of the ester N 'gives the free keto acid r4 r6

O-C - CONHCH (CH2) y CO2H (V

in the case of compounds in which R 2 is O = P - OR ^ q »the process R 11 c) can be carried out using compounds in which 11 13 80051 is other than hydrogen, e.g. benzyl or lower alkyl. The corresponding compounds with hydrogen can be easily obtained by reduction of R 10 * to benzyl, and when it is alkyl, by basic hydrolysis using conventional methods.

The intermediates which can be used in the preparation of the compounds of the invention by this process have the formula R 1 - - CH - NH 2 O = P-OR 10 - wherein R 10 is not hydrogen,

R11 and these are generally condensed with compound E 'in the presence of a reducing agent such as sodium cyanoborohydride. Said intermediates can be prepared, for example, by reacting an R 1 -substituted aldehyde, ammonia and an R 11 -substituted alkoxy or benzyloxyphosphonic or phosphinic acid.

The present invention comprises salts of compounds of formula I having one or more free acid or base groups with inorganic or organic acids or bases.

These salts include, for example, alkali metal salts, e.g. sodium and potassium salts, and salts of organic and inorganic acids, e.g. hydrochloric acid and maleic acid.

The salts may be prepared by a known method, e.g. by reacting the free acid or free base product with at least one equivalent of a suitable base or acid in a solvent or reaction medium, e.g. insoluble ethyl acetate or in a solvent which can be removed in vacuo or freeze-drying.

When water is formed in the reactions described above, either in the preparation of intermediates or final desired products of the invention, e.g. in condensation reactions, these reactions can be carried out by azeotropic distillation with a suitable high boiling solvent, e.g. toluene or xylene or in the presence of dehydration , e.g., a molecular sieve.

Many intermediates for the preparation of the compounds of the invention using the methods described above are commercially available, e.g. from Chemical Dynamics Corporation, or their preparation is described in the peptide literature or in the general chemical literature, e.g. J.H. Jones Comprehensive Organic Chemistry, Vol. 2, pp. 819-823 1979; references 2 and 29 to 31, and Tetrahedron Letters No. 4, 1978, pp. 375-378.

The compounds defined above may have chiral centers on asymmetric carbon atoms.

The compounds prepared by the methods described herein are generally diastereomeric mixtures of compounds which are 'D' and 1L ', respectively, in at least one of said chiral centers.

Such diastereomeric mixtures can be separated by methods well known in the art. The corresponding compounds can be separated, for example, by physical means such as crystallization or cormatography or by formation of diastereomeric salts followed by fractional crystallization.

The invention also relates to all stereomeric forms of the above dipeptide compounds.

Compounds with a similar configuration to naturally occurring L-amino acids are preferred. Natural amino acids usually have the S-configuration Cuhn-

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is 80051

According to the Ingold Prelog system. A notable exception is the natural amino acid cysteine, which has the R-configuration.

Pharmacological activity of the compounds

In the following, the inhibitory effect of some compounds on encephalinase, as measured after the list, is given. The numerical values represent the molar concentrations of the test compound that reduce the effect of encephalinase enzymes by 50% (IC50)

Compound IC 50 o / = \ (S).

Λ-CH2-NH-CH-CONH-CH2CH2COOH 1.0 x 10 "8 ^ -j I (S)

COOH

o / = v 'H2 °,.

Λ— CH2-CH-NH-CH-C-NH-CH2) 3COOH 5.5 x 10-8

'j COOH

(S) 0

/ \ (S) CH 2 O

L Λ-CH 2 CH 2 -CH-NHCH-C-NHCH 2 CH 2 COOH 2.6 x 10 "8 \ J I (S)

COOH

80051 BC

The dipeptide compounds defined above inhibit the activity of enkephalinases. Some of these compounds have been found to be useful in inhibiting rat striatal encephalinase A. These compounds, when used in a concentration range of 10 μm to 10 μM, have reduced the activity of the above enzyme by 50% or more in in vitro tests.

The enkephalinase used in the above assays was obtained by separating them from the brains of young male Sprague-dowley rats by the method described by C. Gorenstein et al., Life Sciences, Vol., 25, pages 2065-2070, Pergamon Press (1979).

In this method, the different enkephalin-degrading enzyme activities of the brain are distinguished by the following method described by Gorenstein and Synder (Life Sciences, Vo., 25, pages 2065-2070, 1979). The brain of a young Sprague-Dawley rat (minus cerebellum) was first homogenized in 30 volumes of 50 mM Tris buffer, pH 7.4. The resulting homogenate was centrifuged for 15 minutes at 50,000 xg and the pellet consisting of membrane-bound enzyme material was resuspended in Tris buffer, washed and centrifuged four times as described above.

The membrane pellet was dissolved by incubating for 45 minutes at 37 ° C in the presence of 15 volumes (based on brain initial weight) of 50 mM Tris - 1% TRITON X-100 buffer, pH 7.4. Insoluble material was removed by centrifugation at 100,000 xg for 60 minutes, after which the Triton-soluble supernatant was run on layers in a 1.5 x 30 cm DEAE Sephacel column pre-equilibrated with 50 mM Tris - 0.1 * Triton buffer, pH 7.4. The column was eluted using one liter of linear NaCl granite at a concentration between 0.0 and 0.5 M. The eluent was collected in 7 ml fractions, of which

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17 80051 of each was determined to have enkephalinase activity. Under these conditions, enkephalinase "A" activity (dipeptidyl carboxypeptidase) is observed to elute between 120 and 220 ml, followed by aminopeptidase activity (260-400 ml) and finally enkephalinase "B" activity (dipeptidyl aminopeptidase) between 420 and 450 ml.

Enkephalinase activity was monitored radiometrically in the experiment. The substrate was 3 H-meth-enkephalin (50.1 Ci / mmol, NEN) diluted in 0.05 M Tris buffer, pH 7.4 to a final concentration of 40 nM in the reaction mixture. The total volume of the reaction mixture, including enzyme and substrate, was 250 ml.

Incubation was performed for 90 minutes at 37 ° C. To stop the reaction, the tubes were transferred to a boiling water bath for 15 minutes. A 4 ml aliquot of the reaction mixture was taken on a Baker-Flex Silica Gel IB plate (20 x 20 cm) together with unlabeled standards (meth-enkephalin, tyrosine, tyrosyl-glycine, tyrosyl-lysyl-glycine) and the components were chromatographed in one solvent system (isopropanol-ethyl). acetate: 5% w / v acetic acid, (2: 2: 1), capable of separating meth-enkephalin from its degradation products, for a total run time of about 17 hours, TLC tanks were gassed with nitrogen before starting the run. These spots, together with the remaining plate areas, were separated from the plate and the corresponding radioactivity for each spot was determined by scintillation counting.

Thus, the amount of radioactivity was determined at the spots where Tyr, TryGly, TyrGlyGly and undegraded met-enkephalin are located, respectively.

For each plate, the radioactivity caused by each spot can be reported as a percentage of the total radioactivity on the plate.

80051 BC

To eliminate the effect of natural degradation of Met-enkephalin in the absence of enzymes, the percentages of radioactivity in the Tyr, TyrGly, TyrGlyGly spots of the non-enzyme zero are subtracted from the corresponding values obtained from each of the run samples using enzymes; the values obtained are added together to give the net percentages for each run.

The values by which the different dipeptides can be compared are obtained by placing in the formula (A-B) / P the net percentage (P) of each dipeptide type obtained in the presence of the corresponding type and the net percentage (A) obtained in the test run without the dipeptide type. The values obtained for the different dipeptide types measure the relative inhibitory activity of the different dipeptides.

Such compounds, when administered parenterally to mice in the dose range of 5 to 100 mg / kg, have also been found to potentiate the analgesic effects of intracerebrally administered D-ala-met-enkephalinamide in iv in vitro assays.

The pharmaceutical salts may be in any form known in the art, e.g., tablets, capsules or elixirs for oral administration or sterile solutions or suspensions for parenteral administration.

Dosage forms are preferably prepared using, in addition to the active dipeptide, a pharmaceutically acceptable and compatible carrier or excipient, binders, preservatives, stabilizers, and flavoring agents.

Dosage forms are usually prepared so that it is possible to administer the active compounds in a dosage range of 5 to 100 mg / kg, such doses being administered every 3 to 8 hours.

Il 19 80051

Typical acceptable pharmaceutical carriers that can be used in the formulations described above include, for example: sugars such as lactose, sucrose, mannitol and sorbitol; starches such as corn starch, tapioca starch, cellulose and derivatives such as sodium carboxymethylcellulose, ethylcellulose and methylcellulose; calcium phosphates such as di-calcium phosphate and tri-calcium phosphate; sodium sulfate, calcium sulfate, polyvinylpyrrolidone, polyvinyl alcohol, stearic acid; alkaline earth metal stearates such as magnesium stearate and calcium stearate, stearic acid; vegetable oils such as peanut oil, cottonseed oil, sesame oil and corn oil; cationic and anionic surfactants; a polymer of ethylene glycol ethers; beta-cyclodextrin; fatty alcohols and hydrolysed cereals.

The following examples illustrate the invention:

Example 1 Preparation of L-3- (31-thienyl) alanyl- [3-alanine] trifluoroacetate salt a) N-Tertiary butyloxycarbonyl-L-3- (3'-thienyl) -alanine 2.0 g (11.68 mM) L-3 (C3'-thienyl) alanine (Chemical Dynamics Inc.) was suspended in 1.6 ml of triethylamine. 2.6 g of di-tert-butyl dicarbonate were dissolved in a mixture of 22 ml of dimethylformamide (DMF) and 22 ml of methanol (already dried on a molecular sieve).

The DMF / methanol solution was added to the suspension with stirring and stirring was continued at ambient temperature for another 24 hours. The resulting homogeneous solution was diluted with 330 mL of 20 8 0 0 51 water and then acidified with citric acid. The resulting solution was extracted four times with 80 ml of ethyl acetate, the extract was washed with water and then brine, and dried over magnesium sulfate. The solvent was evaporated to give 3.2 g of the title compound.

b) N-Tertiary butyloxycarbonyl-L-3- (31-thienyl) alanyl-N-alanine ethyl ester 3.2 g (11.68 mM) of the title compound obtained in step a), 1.8 g of β-alanine ethyl ester hydrochloride and 3 .3 g of hydroxybenzyltriazole was suspended at ambient temperature with stirring in a mixture of 20 ml of dimethylformamide and 2.0 ml of triethylamine. Then, 2.5 g of N- (Ν, Ν-dimethylaminopropyl) -N'-ethylcarbodiimide and 2 ml of triethylamine were added to the suspension, and the resulting mixture was stirred overnight.

Then, 300 ml of water was added to the reaction mixture, and the mixture was extracted four times with 60 ml of ethyl acetate. The combined extracts were washed twice with 70 ml of 1N sodium bicarbonate, twice with 30 ml of 1N citric acid, twice with 70 ml of water and once with 70 ml of brine. The resulting extract was dried over magnesium sulfate, and the solvent was evaporated to give the title compound.

c) N-Tertiary butyloxycarbonyl-L-3- (3'-thienyl) -alanyl- / 3-alanine 4.4 g (11.8 mM) of the oyster compound obtained from step b) were dissolved in 30 ml of methanol. To the solution was added 30 ml of water, followed by 1.1 g (14.2 mM) of sodium hydroxide as a 50% (w / v) aqueous solution. The reaction mixture was stirred at ambient temperature and after 1 hour the presence of starting material was checked by thin layer chromatography (road).

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2i 80 051 using silica gel and a 5: 95: 0.5 by volume mixture of methanol, chloroform and acetic acid as the mobile phase. Stirring was continued and the reaction was monitored in this manner until the disappearance of starting material indicated that the reaction was complete. The reaction mixture was then concentrated under reduced pressure, and the residue was stirred with 30 ml of water; the resulting aqueous solution was washed twice with 30 ml of methylene chloride and then acidified to give a gummy precipitate. This precipitate was extracted with ethyl acetate, and the extract was dried over magnesium sulfate, followed by evaporation of the ethyl acetate to give the title compound.

d) L-3- (3-thienyl) -alanyl- [3-alanine-trifluoroacetate 5.8 g of the title compound obtained in step c) were dissolved with stirring in 15 ml of methylene chloride. To the solution was added 15 ml of trifluoroacetic acid, and the mixture was stirred for two hours at room temperature. The reaction was monitored by thin layer chromatography on silica gel using a 95: 5: 0.5 by volume mixture of methylene chloride, methanol and acetic acid as the mobile phase. When the starting material was no longer by road, the reaction mixture was concentrated to a gummy residue which was dissolved in benzene. The solution was distilled to a residue, redissolved in benzene and redistilled to give the title compound.

e) N- (1-Carboxy-3-phenylpropyl) -L-3- (3-thienyl) -alanyl-β-alanine L-3- (3-thienyl) -alanyl-L-alanine trifluoroacetate (4.75 g, 13.4 mM) and 2-oxo-4-phenylbutyric acid (11.0 g, 56.1 mM) were adjusted to pH 6.8 by the addition of 1N sodium hydroxide. Sodium cyanoborohydride (2.2 g, 34.8 mM) was added in one portion to the solution, and the resulting reaction mixture was stirred at room temperature for 22 hours. The pH of the solution was then adjusted to 2.9 by the addition of 1N hydrochloric acid. The gummy product separated from the solution was washed several times with water. This gummy product was dissolved in 20 ml of acetonitrile and the solution was diluted with 10 ml of ether. On cooling, a solid separated which was collected by filtration. The mother liquors were allowed to stand in a refrigerator for two days whereupon a white solid precipitated: this solid was filtered off, washed with acetonitrile and dried to give the N- (L-1) diastereoisomer of the title compound.

Examples 2-7

The following compounds and diastereomeric mixtures were prepared following the procedure of Example 1 and using the appropriate starting materials: 2) N- (L-1-carboxy-3-phenylpropyl) -L-phenylalanyl-L-alanine, m.p. 176-179 ° C.

3) N- (D, L-1-carboxy-3-phenylpropyl) -L-3- (2'-naphthyl) -alanyl-L-alanine, m.p. 149-155 ° C.

4) N- (L-1-ethoxycarbonyl-3-phenylpropyl) -L-3- (2'-thienyl) alanyl-L-alanine maleate, m.p. 124-125 ° C.

5) N- (D, L-1-carboxyl-ethyl) -L-phenylalanyl-L-alanine,

Sp. 125-135 ° C.

6) N- (D-1-carboxy-3-phenylpropyl) -L- (4-fluorophenyl) -alanyl-L-alanine, m.p. 147-152 ° C.

7) N- (D, L-1-carboxy-3-phenylpropyl) -L-phenylalanyl-glycine, m.p. 140-145 ° C.

Example 8 15 g (0.07 mol) of phenylalanine methyl ester hydrochloride were dissolved in 400 ml of methanol. Then 23 80051 2.4 g (0.105 moles) of sodium phenylpyruvate was added followed by 15 g of a powdered 3A molecular sieve (Aldrich Chemical). The slurry was stirred at ambient temperature while 6.6 g (0.105 mol) of sodium cyanoborohydride in 75 ml of methanol were added over a period of six hours. The slurry was then stirred for two days, filtered and the filtrate concentrated to a syrup. To the syrup was added 300 ml of 2.5% hydrochloric acid over three hours, and the resulting white crystals were filtered and dried under reduced pressure to constant weight. A representative sample of the dried product was chromatographed on silica gel plates using a chloroform-methanol: concentrated hydrochloric acid mixture (50: 15: 1 by volume) as the solvent system to evaluate the ratio of diastereoisomers. Based on the chromatogram, this was an approximately 50/50 mixture of diastereoisomers containing some 3-phenyl-2-hydroxypropionic acid.

Yield: 24 g, m.p. 119-130 ° C.

NMR corresponds to the desired product.

Crystallization from 400 ml of ethanol gave 14.7 g of the desired compound (again as a diastereoisomeric mixture which was enriched for the faster-moving isomer by thin-layer chromatography (road)), m.p. 135-150 ° C.

200 mg of the enriched diastereomeric mixture was recrystallized from 3 ml of methanol to give 100 mg of crystals which were almost pure, faster moving isomer (determined by tlc), m.p. 169-172 ° C.

14.5 g of the enriched diastereoisomeric mixture were recrystallized from 400 ml of methanol, but no crystals formed. The solution was concentrated to 200 ml, inoculated and allowed to stand. A gelatinous precipitate formed which, by tlc, was a mixture of isomers with the majority of the slower moving isomer: yield 7.0 g. This product was subjected to HPL chromatography on high performance liquid chromatography in Waters Prep.

500 Equipment chromatography using two silica gel columns in series. The solvent system was chloroform: methanol: ammonium hydroxide (volume ratio 500: 500: 10) and the flow rate was 0.2 liters per minute. Fractions 8 and 9 gave 450 mg of isomer I (see below). Fraction 10 gave 400 mg of product, from which recrystallization from methanol gave 150 mg of isomer I. Fractions 12-15 gave 1.2 g of pure isomer II (see below). Fraction 11 gave a mixture of isomer I and isomer II.

HPLC treatment was performed on the same product in another 3.5 g portion according to the previous paragraph using the same solvent ratios and absorbents. Fraction 4 gave 400 mg of pure isomer I, fraction 5 gave 1.0 g of product, which was recrystallized from methanol to give 550 mg of substantially pure isomer I. Fraction 6 gave 0.4 g of a mixture of isomer I and isomer II and fraction 7-10 gave 1 g. .6 g of pure isomer II.

Isomer I, mp 171-173 ° C.

Mass spectrum M + 1 328 282 (M-COOH) 268 (M-COOH3) 236 (M-91)

Formula yv

After cb2

HC - NH - CH.COOH

COOCH 3

II

25 80051

The filtrate obtained by filtering the gelatinous precipitate was concentrated to 50 ml, and 100 ml of acetonitrile was added thereto under cooling. There were thus obtained 1.0 g of white crystals, melting point 167-170 ° C. These crystals were recrystallized from methanol to give 0.7 g of white crystals,

Sp. 171-173 ° C.

L-N - [(1-Carboxy-2-phenyl) ethyl] -phenylalanyl-β-alanine methyl ester 1.0 g (3.05 mM) of isomer I was dissolved in 20 ml of dimethylformamide (DMF). 520 mg (3.4 mM) of 1-hydroxybenzotriazole hydrate (HOBT H2O) were then added, followed by 472 mg (3.4 mM) of β-alanine methyl ether hydrochloride, 1.3 ml (equivalent) of N-ethylmorpholine (NEM ) and 649 mg (3.4 mM) of N- (3-dimethylaminopropyl) -N-ethylcarbodiimide hydrochloride (EDCL). The resulting solution was stirred at room temperature for 48 hours and then poured into 150 ml of ice water with stirring. The aqueous solution was extracted twice with 150 ml of ethyl ether. The ethyl ether layer was washed three times with 150 ml, then with water to which a few drops of hydrochloric acid had been added, and finally with water. The ether layer was dried over magnesium carbonate, filtered, and the filtrate was concentrated to a gum; 1.1 g of the title compound were obtained.

L-N - [(l-carboxy-2-phenyl) ethyl] -phenylalanyl-ft-alanine

The gummy substance obtained from the previous step was dissolved in 20 ml of methanol, and 6.6 ml of 1-sodium hydroxide was added dropwise to the solution under stirring and external cooling over 10 minutes. The solution was allowed to stand overnight (15-20 hours) at room temperature. A 5% hydrochloric acid solution was added dropwise until the pH of the solution had dropped to 2.5 (during this addition, the solution was stirred and the precipitate was dried under reduced pressure at 40 ° C to constant weight.

Yield 900 mg, m.p. 218-219 ° C.

Mass spectrum M / e 385 (M + 1) 367 (M + 1-18) 340 (M + 1-COOH) 339 (M-45-COOH) 293 (M-91).

Examples 9-15

The following compounds and diastereomeric mixtures were prepared following the procedure of Example 8 using the appropriate starting materials.

9) N- (L-1-carboxy-3-phenylpropyl) -D, L-3- (1-naphthyl) -anyl-L-alanine, m.p. 186-194 ° C.

10) N- (L-1-carboxy-3-phenylpropyl) -L-3- (1-naphthyl) -anyl-β-alanine.

11) N- (L-1-carboxy-2-methylpropyl) -D, L-phenyl) -alanyl-L-alanine, m.p. 160-172 ° C.

12) N- (L-1-carboxy-2- (benzylthio) ethyl) -L-phenylalanyl- (3-alanine, mp 152-154 ° C).

13) N- (L-1-carboxy-3-phenylpropyl) -L-phenylalanyl-L-phenylalanyl-L-alanine.

14) N- (L-1-carboxy-2-phenylethyl) -L-phenylalanyl-Y-aminobutyric acid, m.p. 209-211 ° C.

15) N- (L-1-carboxy-3-phenylpropyl) -L-phenylalanine 1H-alanine hemihydrate, m.p. 176-190 ° C.

Example 16 N- (D, L-1-carboxyethyl) -L-phenylalanylglycine

To a solution containing 0.6 g (2.5 mM) of L-phenylalanyl glycol

II

A solution of 0.25 g (2.5 mM) of 2-chloropropionic acid in 5 ml of 1N sodium hydroxide was added dropwise and over one hour to 2780,051 sine, 5 ml of 1N sodium hydroxide and 20 ml of water. During the addition, the reaction solution was maintained between 80-90 ° C and pH 8-9. After the addition, the mixture was heated with heating at 80-90 ° C for 15 minutes and then evaporated to dryness under reduced pressure and neutralized with 5% (w / v) aqueous hydrochloric acid. Evaporation to dryness again gave a gray solid.

This gray material was mixed with ether and then decanted; the solid was mixed with cold ethanol. The insoluble matter was separated by filtration from the ethanol solution. The solution was evaporated to dryness to give a mixture of the title diastereomers, m.p. 90-120 ° C.

Example 17 a) Preparation of butyloxycarbonylhydrazine

To a stirred solution of 0.1 ml of hydrazine hydrate in 15 ml of isopropanol was added dropwise a solution of di-t-butyl carbonate in isopropanol (the solution contained 0.45 ml of dicarbonate in 7 ml of propanol). The rate of addition was one drop every 7 seconds. The reaction was stopped after about 6/7 parts of the t-butyl dicarbonate had elapsed.

The mother liquor was evaporated and the resulting solid was chromatographed on silica gel using a 97: 3 by volume mixture of chloroform and methanol as the mobile phase.

Recrystallization from ether / petroleum ether gave a solid with a melting point of 36.5-37 ° C.

28 80051 b) N-Benzylidine-N1-t-butyloxycarbonylhydrazine 3.47 g of the title compound of a) were dissolved in 30 ml of ethanol with stirring and 2.79 g of benzaldehyde were added. The reaction mixture was heated on a steam bath with stirring for 10 minutes and then cooled in an ice-water bath.

The resulting reaction mixture was filtered. 3.50 g of the title compound were obtained.

The mother liquor was evaporated to a solid which, after washing with hexane and filtration, gave 1.56 g of a solid.

Both fractions were thin layer chromatographed on silica gel plates using a 97: 3 by volume mixture of chloroform and methanol as the mobile phase.

Subsequent experiments showed that both fractions were essentially identical products. The total yield was 5.06 g,

Sp. 190-194.5 ° C.

c) N-Benzyl-N'-t-butyloxycarbonylhydrazine 1 g of the title compound of b) was dissolved in 30 ml of tetrahydrofuran. 0.23 g of 5% palladium / carbon catalyst was added and hydrogenated for about 15 minutes. The reaction mixture was filtered and the mother liquor evaporated to give 0.96 g of the title product.

d) L-methyl-2-isocyanato-4-methylvalerate 7 g of L-leucine methyl ester were suspended in 200 ml of toluene pre-dried with calcium hydride. The suspension was stirred and excess phosgene gas was bubbled through it. After dissolving the solid, the reaction mixture was raised to reflux for half an hour.

After the heating was stopped, excess phosgene and the hydrogen chloride reaction product dissolved in the solution were removed from the resulting solution by bubbling nitrogen gas through it. The solution was then evaporated and the resulting liquid product was distilled.

[.alpha.] D @ 20 = -25.55 DEG C. (C = 5.7% in toluene) Literature: -22.4 DEG C. Annalen 1952, 575, 217).

Sp. 71-72 ° C. (45 mm Hg) e) Nt-butyloxycarbonyl-oC-azaphenylalanyl-L-leucine methyl ester 1.90 g of product b) were added to 2.47 g of product a and then 1.12 g of product a was added to the reaction solution. g of triethylamine. The resulting reaction mixture was stirred for 16 hours, then diluted with 200 ml of ethyl acetate, washed once with 5% (w / v) aqueous citric acid solution, then once with brine and finally once with water.

The solution was dried over sodium sulfate, the sodium sulfate was separated by filtration, and the solution was concentrated to a residue. This residue was chromatographed on 75 g of silica gel using a 7/3 (v / v) mixture of hexane and chloroform as eluent.

After the usual work-up, 3.72 g of the title product are obtained. [α] 25 = -7 ° (c = 3.29% in chloroform).

D

f) ol-azaphenylalanyl-L-leucine methyl ester 8.0 ml of a mixture of anhydrous hydrochloric acid and acetic acid (1/80 by volume) were cooled with stirring to 4 ° C and the product of step e) was added thereto. Stirring was continued at 4 ° C for 20 minutes, after which the solvent was removed under reduced pressure. The residue was thin-layer chromatographed on silica gel using a mixture of chloroform and methanol (98/2 v / v) as eluent. Fractions with corresponding rf values were combined to give 0.163 g of the title product [o <] 26 = + 1.9 °

Mass spectrum M + 293 (-HCl) 262 (-m-OCH 3) 234 (-m-CO 2 CH 3) g) N- (D, L1-ethoxycarbonyl-3-phenylpropyl) - <x-azaphenyl-alanyl-L -leucine methyl ester 0.151 g (0.458 mM) of the title product obtained in step f) was dissolved in 3 ml of methanol, and 83.4 mg of ethyl 4-phenyl-2-oxobutanoate was added to the solution under stirring at 60 ° C. The reaction was monitored by tlc using silica gel plates and a mixture of chloroform and acetone (9/1, v / v) as eluent. After the reaction was substantially complete, 70 mg of sodium cyanoborohydride and 4 drops of a 10% (w / v) aqueous solution of acetic acid were added.

The reaction was monitored by tlc using silica gel plates and a mixture of chloroform and methanol (98/2, v / v) as eluent. Then 70 mg of sodium cyanoborohydride and 4 drops of the above-mentioned acetic acid solution were added again. The reaction solution was allowed to stand for 16 hours, after which the solvent was removed under reduced pressure. To the residue was added 40 ml of ethyl acetate, and the resulting solution was washed with 20 ml of aqueous sodium chloride and then twice with 20 ml of water. The organic solution was dried over magnesium sulfate, filtered and the solution removed under reduced pressure.

The residue (0.277 g) was chromatographed on silica gel using a mixture of hexane and chloroform (7/3, v / v) as the eluent. The corresponding fractions were combined on the basis of thin-layer migration to give the title compound.

II 3i 80051 h) N- (D, L1-Carboxy-3-phenyl-propyl) - <* - azaphenylalanyl-L-leucine 0.428 g (0.265 mM) of the title compound obtained from step g) was dissolved in 10 ml of aqueous acetone (acetone / water, 3/1, volume) and 1.06 ml of aqueous sodium hydroxide solution (containing 10.06 mM sodium hydroxide) was added to the reaction solution with stirring. The reaction was monitored by tlc using chloroform / methanol / ammonium hydroxide in a volume ratio of 1: 1: 1 as eluent. An additional 0.04 mL of concentrated sodium hydroxide (containing 0.4 mM sodium hydroxide) was added and the reaction was continued until the reaction was substantially complete.

To the reaction mixture was added 10 ml of water, followed by extraction twice with 30 ml of ethyl acetate. The extracts were combined, dried and concentrated to a residue.

The residue was chromatographed on silica gel using a lower phase of chloroform: methanol: arammonium hydroxide (2: 1: 1, v / v) as eluent.

The corresponding fractions were pooled based on their rf values. The combined fractions were recrystallized from diethyl ether. The mother liquor of the first recrystallization was further concentrated to give a second batch of crystals. The total yield of the title compound was 43 mg and M.p. 105-111 ° C.

Example 18 CH 2 C 6 H 5 CH 2 CH (CH 3) 2

I I

C6H5CH - NH - N - CONHCHCOOH

0 = P-0H

c2h5 32 80051

A solution of o <-azaphenylalanyl-L-leucine methyl ester (see Example 17) and one equivalent (relative to the ester) of benzaldehyde in anhydrous methanol was allowed to stand for 16 hours on a type 3A molecular sieve. To the resulting solution was added one equivalent (relative to the ester) of ethyl ethyl phosphonic acid and a little sodium ethoxide. The reaction solution was then allowed to stand for 6-8 hours. The molecular sieve was then removed by filtration, and the filtrate was concentrated under reduced pressure. To the concentrated solution was added 2.1 equivalents (relative to the ester) of sodium hydroxide as an 1N aqueous solution, and the mixture was stirred at room temperature for 6 hours. The organic material was extracted with ethyl acetate and the aqueous solution was acidified to pH 2.5 by the addition of 1N hydrochloric acid.

The resulting precipitate was filtered off and dried to give a mixture of diastereomers of the title compound.

Example 19 (L, D) CH 2 C 6 H 5 CH 3

I I

* I *

CH3 - CHNHCH - CO - NHCHCOOH

| (L)

0 = P-0H

OH

(IL) -1-Aminoethylphosphonic acid (see U.S. Patent 4,016,148) was dissolved in anhydrous methanol, and an equal molar amount of thionyl chloride was added dropwise to the solution while maintaining the temperature of the solution at 0 ° C. After the addition, the resulting solution was allowed to warm to room temperature and allowed to stand at this temperature for 6-8 hours. The volatiles were then removed under reduced pressure at room temperature to give crude (1H) -1-aminoethylphosphonidimethyl ester hydrochloride.

tl 33 80051

Dimethyl ester and an equal molar amount of sodium phenylpyruvate in methanol were dissolved and the pH of the solution was adjusted to 6.5-7 with sodium hydroxide solution and treated with 50% molar excess of sodium cyanoborohydride. The reaction mixture was stirred for two days at room temperature, after which it was poured into water. The pH of the resulting aqueous solution was adjusted to 2-3, and the resulting precipitate was extracted with ethyl acetate. The extracts were washed with water and dried. Evaporation of the solvent gave crude monoacid of the formula CH 2 C 6 H 5

CH3 - CH - NHCH - CO2H

0 = P / \

MeO OMe

Monoacid, equivalent (relative to monoacid) L-alanine methyl ester hydrochloride and equivalent (relative to monoacid) N-ethylmorpholine were co-dissolved in dimethylformamide. The resulting mixture was cooled to 0 ° C overnight, and one equivalent (relative to the monoacid) of N- (3-dimethylaminopropyl) -N * -ethylcarbodiimide hydrochloride and one equivalent of N-ethylmorpholine and dimethylformamide were added to the solution.

The reaction mixture was allowed to warm to room temperature, stirred overnight. It was then poured into water and the precipitated product was extracted with ethyl acetate. The extracts were washed with 0.5% (w / v) hydrochloric acid followed by saturated sodium bicarbonate solution, dried and evaporated to give the compound of formula CH 2 C 6 H 5 ch 3 CH 3 - CH - NH - CH - CO - NHCHCOOCH 3 o = p-och 3 6ch 3 34 8 0 0 51 This product was dissolved in methanol and 3.1 equivalents (relative to the product) of sodium hydroxide as an 1N solution were added dropwise to the resulting solution. The reaction mixture was stirred overnight at room temperature, then concentrated under reduced pressure, diluted with water and adjusted to pH 3-4 with 1N hydrochloric acid solution. The precipitated products were filtered, washed with water, dried to give a diastereomeric mixture of the title compound.

Example 20 N- (L1-Benzyloxycarbonyl-2-phenylethyl) -L-phenylalanyl- [3-alanine] benzyl ester N- [L1- (phenylmethoxy) carbonyl-2-phenylethyl] -L-phenylalanine ( 16 g, 39.7 mmol), β-alanine benzyl ester tosylate (13.9 g, 39.7 mmol), 1-hydroxybenzotriazole hydrate (6.07 g, 1 eq.), N-ethylmorpholine (14.8 ml, 3 eq.) and 250 ml of dry DMF were stirred at room temperature. To the mixture was added 1 eq. (7.58 g) 1- (3-dimethylamonopropyl) -3-ethylcarbodiimide hydrochloride. The clear solution was allowed to stand overnight. The resulting dark yellow solution was poured into about 600 ml of cold water and extracted three times with 300 ml of ether. The ether solution was washed repeatedly with water, dried and concentrated to an oil, (21 g) NMR consistent with product. TLC showed one spot, R 0.7 (CHCl 3 / CH 3 OH / AcOH.100: 5: 0.5).

Il

Claims (4)

A process for the preparation of pharmacologically valuable substituted dipeptides of the formula T1 - HC - NH - X - CONH - CH - (CH2> y - Rg (I) R2 wherein R1 is phenyl (C1-C4) alkyl, naphthyl - (C1-C4) -alkyl, (C1-C4) -alkyl-phenyl- (C1-C4) -alkyl or phenyl- (C1-C4) -alkylthio- (C1-C4) -alkyl, R 2 is carboxyl, - COO (C1-C4) alkyl or -COO (C1-C4) alkylphenyl, R4 Ra I * IX is -CH- or -N- R4 is thienyl- (C1-C4) -alkyl, phenyl- (C1-C4) ) -alkyl, where phenyl may be substituted by halogen or phenyl, naphthyl (C 1 -C 4) alkyl or (C 1 -C 4) alkyl, Y is 1 or 2, R 9 is hydrogen, (C 1 -C 4) alkyl or phenyl (C 1 -C 4) -alkyl, R 9 is carboxyl, -COO (C 1 -C 4) -alkyl, -COCKC 1 -C 4) -alkyphenyl, / R 2 O -CON; wherein one of the groups Xr21 r20 and r21 is hydrogen and the other phenyl (C1-C4) alkyl, or together with the nitrogen atom to which they are attached, R20 and R21 form a 5-7 membered saturated ring containing oxygen as the heteroatom of the ring, or its pharmaceutically acceptable site, characterized in that the compound is prepared by one of the following processes, wherein in the indicated formulas, R 1, R 2, R 4, R 9, R 9, R 10 / R 20 (a) a compound of the formula AT 1 R 1 - C = N - X - CONH - CH - (CH 2) y - R 9 * 2 (A) is reduced by the double bond C = N b) compound A 'is coupled with amino acid B' H-HNCH (CH2) y - R9 + R1 - CH - NH - X - COOH R2 (A ') (ΒΊ c) a compound of formula XH R4 R6 I r 1 ° R 1 - C - N = C - CONH - CH - (CH 2) y - R 9 * 2 (X) is reduced at the double bond C = N, whereupon if necessary, the protecting group is removed and / or its site formed. 2. A process according to claim 1a, b or c for the preparation of a compound of formula I or its pharmaceutically acceptable salt, in which compound T4 X on -CH- 80051 wherein R 4 Mr as defined above, characterized in that a surfactant is used. , where the group X Mr is defined in this requirement. A process according to claim 2 for the preparation of a compound of formula I or its pharmaceutically acceptable site, wherein compound R 1 is phenyl (C 1 -C 4) alkyl or naphthyl (C 1 -C 4) alkyl, R 4 Mr benzyl, 1- or 2-naphthylmethyl, (C1-C4) -alkyl, phenyl- (Cx-C4) -alkyl, naphthyl- (C1-C4) -alkyl or 2- or 3-thienylmethyl, Rg is hydrogen, Rg is carboxyl or R 20 -CON, where one of the groups R 21 R 10 and R 21 is hydrogen and the other phenyl (C 1 -C 4) alkyl, or together with the nitrogen atom to which they are attached, R 20 and R 21 form a 5-7 membered saturated ring, which contains oxygen as the ring's heteroatom, characterized in that the starting material groups R R, R4, Rg and R9 have been defined in this requirement and the other groups previously. 4. A process according to claim 1 for preparation (S) -N- (1-carboxy-3-phenylpropyl) - (S) -phenyl-alanyl- / i-alanine or (S) -N- (carboxy-2-phenylethyl) ) - (S) -phenylalanyl- (i-alanine, characterized in that a starting material is used where Y is the same as in claim 1, R1 is benzyl or phenylethyl, R2 and Rg are carboxy, X is -CH- and R * and X are hydrogen CH2 & II