CH639639A5 - Alpha-fluoromethyl-alpha-amino-alkanoic acids and their esters - Google Patents

Description

The invention therefore relates to new substituted a-fluoro-methyl-a-amino-alkanoic acids and their esters of the formula

CH-F

1 2

R—- C - COOR,

Hydrochloride, hydroiodide, hydromide; the sulfates and the phosphates. The hydrohalides and especially the hydrochlorides are particularly preferred.

The compounds of formula I have a chiral center and can be in optically active forms, i.e. occur as optical isomers. These isomers are commonly referred to by the symbols L and D, + and -, 1 and d, S and R, or by combinations thereof. If the name of the compound or the formula does not have an isomer name, the name or the formula comprises the individual isomers, the mixtures thereof and the race mate.

The compounds of the S isomer configuration are generally preferred.

R represents a substituted alkyl group; Examples include:

I.

NH.

20th

(I)

wherein R is a substituted Cj-C * alkyl group and Rt has the meaning of H or Q-C! 8-alkyl. 25th

The acid addition salts of the compounds of formula I are also included. In general, these salts are those of the base of the formula I with a suitable organic or inorganic acid. Preferred salts of inorganic acids are the hydrohalides, e.g. B. 30

wherein R2 is H or C2-C6-alkanoyl, e.g., CH3-CO, CH3 (CH2) 4-CO, (CH3) 3C-CO, and the like

H 1

N-

QH

»

9

[- or preferably

CH;

"07

I.

H

• CHJ

H00C-CH2 'NH

l 2

HOOC-CH2-CH2ï HOOC-CH-CH2-CH2CH2; H2N-CH2-CH2-CH ^; H2N-CH2CH2CH2CH2; 2 ;

NH

1 "

H2N-C-N-CH2-CH2-CH2; and H3CS-CH2-CH2-

639 639 6

Ri means H or Q-Cj 8-alkyl. Examples of suitable ethyl. The most preferred meaning for R is H.

nete alkyl groups are methyl, octadecyl, 2-ethylhexyl, preferred compounds of the formula I are those which

Butyl, hexyl, isopropyl, ethyl, undecyl and the like; in R has the meaning of C] -C6-alkyl is preferred, and particularly preferred is h2n- (ch2) 5 / hooc-ch-j-chj,

ho

2nd

nh ~

i 2

hooc-ch-ch2-ch2-chj nh h2n-ch2-ch2-

C-N-CH2 ~ CH2 ° = CH2 = "ìi and;

h3cs-ch2-ch2-

especially where R is hydrogen.

Particularly preferred compounds have the following formula:

h t

N "

ch0p i 2

_ch ~ -c -

2 I

NH.

coor,

, especially where Rj is hydrogen. The S isomer of Formula III is most preferred.

45 Particularly preferred compounds are those of the formulas

More preferred compounds of formula II are those in which R2 is hydrogen and R is hydrogen or ethyl. In particularly preferred compounds of formula II, Rj and R2 are hydrogen, with the configuration of the S isomer being most preferred.

Another particularly preferred compound has the formula

50

55

60

ho cooh

III

cooh ch0f

I 2

ch0 c— cooh

2 I

NH0

7

639 639

NH H

hooc ch.

-CH-— C COOH, and H-N-

l2

-n- (ch2) 3-

CH-F

I 2

C - COOH I

NH2

The compounds according to the invention are suitable for physiological or chemotherapeutic applications. In most cases, the biological activities of these compounds are largely due to their considerable decarboxylase inhibiting properties.

15 th. Decarboxylases are enzymes that act on a-amino acid substrates and cause decarboxylation to form the corresponding amine. This effect is illustrated by the following equation:

L-CH-CO-H

I 2

NH2

Decarboxylase

5>. l-ch- / ^ nh2

L = alkyl or

Aralkyl group a-amino acid substrate

By inhibiting this decarboxylation, the biosynthetic pathway can be modulated or inhibited into a number of biologically important amines, resulting in physiologically important consequences. For example, a-fluoromethyl dopa inhibits dopadecarboxylase and can be used in combination with dopa to potentiate the effect of the latter in the treatment of Parkinson's disease. a-Fluoromethyl-histidine inhibits the biosynthesis of histamine via the decarboxylation of histidine (EDS0 in mice ~ 0.4 mg / kg). Consequently, as well as combinations with histamine antagonists, it is effective in preventing gastric lesions or gastric injuries and in treating allergic conditions. a-Fluoro-methyl-ornithine interrupts polyamine biosynthesis due to its ornithine decarb-oxylase inhibition and is therefore suitable for the treatment of some neoplasms. a-Fluoromethyl-arginine is an effective antibacterial compound, a-fluoromethyl-glutamic acid is a stimulant for the CNS.

The present compounds are also essentially specific in their decarboxylase inhibitory activity, i.e. an a-fluoromethyl-a-amino acid generally inhibits the decarboxylation of the corresponding non-a-fluoromethylated acid. For example, cc-fluoromethyl dopa inhibits the decarboxylation of dopa; a-fluoromethyl-histidine inhibits the decarboxylation of histidine, etc.

Because of this specification and strong activity as decarboxylase inhibitors, the compounds according to the invention are also suitable as diagnostic aids for determining the presence and importance of the corresponding decarboxylase in diseases or in the function of biological systems. For example, the importance of y-aminobutyric acid in the central nervous

Amine system (CNS) are investigated by inhibiting their biosynthesis using an a-fluoromethyl-glut-30 amino acid etc. This diagnostic benefit is supported by the effective and in many cases irreversible decarboxylase inhibiting activity of the a-fluoromethyl amino acids according to the invention.

Representative compounds were shown to have decarboxylase inhibitory activity in usual 35 vitro studies.

a-Fluoromethyl-3,4-dihydroxyphenylalanine, a-fluoromethyl-tyrosine and a-fluoromethyl-metatyrosine also showed antihypertensive activity. This effectiveness is determined by observing the antihypertensive effect (reduction in blood pressure) when the compounds are administered (perorally or parenterally) to a spontaneously hypertensive (SH) rat. This observed activity indicates that the compounds are effective as antihypertensive agents when administered to a hypertensive human in the usual manner in appropriate amounts in a suitable pharmaceutical dosage form. The pharmaceutical dosage form is prepared in a conventional manner and generally contains customary pharmaceutically acceptable diluents.

The process according to the invention for the preparation of new compounds of the formula chf

I.

r - c - cooh nh.

(ia)

60 where R has the meaning of

639 639

h h2n-ch2-ch2-ch2-,

• ch2-

k00c-ch2-ch2-

UH

h2n-c-

H

-n-ch2-ch2-ch2-

CH2- or is characterized in that a compound of the A preferred embodiment of the described

Formula 30 process refers to the production of new connections

CH ^ OH fertilize the formula

1

r - c cooh

NH-

35

ch-p ■

ch —c cooh (iv)

Subject to fluorodehydroxation and, if appropriate, compounds obtained are converted into the corresponding salts, in which R 'has the meaning of.

«.0" 'CG3 "•

A

where a compound of the formula ch., oh

I.

R'-ch2-c cooh in.

or

§R with SF4 in liquid HF at temperatures of - 80 to + 20 ° C, and the reaction system BF3 or 55 AICI3 is added.

However, the compounds according to the invention (V) can also be prepared using any suitable methods.

The method according to the invention can be illustrated schematically as follows:

ch., oh

I 2

R - c cooh nh2

sf ^ / hf r-

ch-f i

c - cooh nh2

9

639639

This reaction is generally carried out at temperatures from - 80 to + 20 ÖC. This general reaction is also called fluorodehydroxylation and is described in Journal of Organic Chemistry 40, 3809-10 (1975). BF3 can be used to accelerate the reaction.

It has now been found that the fluorodehydroxylation of certain aryl-substituted a-hydroxymethyl-a-amino

Acids is significantly improved if BF3 or A1C13 is used as a coreagent with SF4. Specifically, this is an improved process for making a compound of Formula IV above.

In these compounds of formula IV, the substituent R 'is in particular an aryl radical.

Examples include ho w

ho '

preferably HO "vlJv ~ or \ - / t ho h

O-, Ocf f

H H N-1

Preferred groups R 'are ho

H

■ ö -.- <3 "

This process is preferably carried out at atmospheric pressure, although pressures above atmospheric can also be used. The reaction temperature is in particular in the range from - 80 to + 20 ° C, with - 80 to 0 ° C being preferred.

The process according to the invention can expediently be carried out by initially introducing the SF4 and BF3 or A1C13 into the reaction system of the formula V / HF. The process can also be carried out by first adding the SF4 to the reaction system, continuing the reaction for a period of time,

I 3

hooc- (j! -ch2ch2cooh. nho and then add the BF3 or A1C13 and let the reaction proceed completely.

The use of BF3 or A1C13 in the SF4 / HF-35 reaction system significantly improves the yield of the product of Formula IV.

Another preferred method for producing the substituted a-fluoromethyl-a-amino-alkanoic acids is by using photofluorination. This method 40 is described in Journal of the American Chemical Society, 92, 7494 (1970) and ibid., 98, 5591 (1976). For example, a-fluoromethyl-glutamic acid is produced:

Photo-

Fluorination ch0f

1 2

hooc-c-ch 0ch0cooh

I 22

nh-

Both optical isomers of a-methyl-glutamic acid are known; this method is suitable for the production of both optical isomers of a-fluoromethyl-glutamic acid.

ch.

hooc-c-ch2ch2ch2nh2

a-Fluoromethyl-ornithine can be prepared in the same way by photofluorination of a-methyl-or-nithine:

Photo-

k

Fluorination ch0f

I 2

-> hooc-c-ch „ch„ ch ~ nh,

H,

I.

nh.

Since both optical isomers of a-methyl-ornithine are accessible, this synthetic method can lead to either of the two optical isomers of a-fluoromethyl-ornithine.

ch2f hooc-c-ch 2 ch 2 ch 2nh 2

k h.

60 a-fluoromethyl-ornithine is a suitable starting material for the synthesis of a-fluoromethyl-arginine by reaction with S-methyl-isothiourea.

ch2f

- $ »hooc-c-chnch0ch0-nh-c-nh ~

J Z / £ II jC

nh2 nh

639 639

10th

An acid addition salt of a compound according to the invention can be prepared by conventional treatment of the free a-amino acid with a suitable acid, generally in a suitable solvent.

A single enantiomer of the compounds according to the invention can also be prepared by

1. Cleavage of the fluorinated amino acid racemate using conventional cleavage techniques or

2. Cleavage of the a-hydroxymethyl-a-amino acid precursor using customary cleavage techniques and subsequent fluorodehydroxylation of the precursor enantiomer.

A common cleavage technique involves the formation of a salt of the a-amino acid with an optically active base and the subsequent recovery of the special enantiomer from the salt.

Compounds of the formula

CH

where R2 is C2-C6alkanoyl can be prepared by acylating the corresponding compound, where R2 is hydrogen. As a rule, customary acylating agents and conditions are used.

Compounds of the formula

CH —F

I.

r c coor-j ^

nh2

where Rj is Q-Cjg-alkyl are usually prepared by esterifying the corresponding compound, wherein Rj is hydrogen. Conventional esterification reagents and conditions can also be used here.

The following examples serve to explain the preparation of representative compounds according to the invention. All temperatures are given in ° C. The fluorodehydroxylation reactions described in the examples were carried out in reactors made from KEL-FR. The melting points were determined in the open capillary and are not corrected.

example 1

Preparation of R, S-a- (fluoromethyl) -3-hydroxy-tyrosine ch-f

I.

ho -t ^ jj ch2 "c ~~ c00h ho äh2

1.5 g of R, S, -a- (hydroxymethyl) -3-hydroxityrosine hydrochloride (a-hydroxymethyl-DOPA • HCL) were dissolved in 50 ml of anhydrous hydrogen fluoride, cooling in a dry ice-acetone bath has been. The HF solvent was then evaporated with a stream of nitrogen gas after removal of the cooling bath. This process converts the HCI salt into the HF salt of the starting material. (Alternatively, 1.3 g of the free amino acid can be used as the starting material, making the above operation unnecessary.) The HF salt thus obtained was redissolved by introducing a HF gas stream into the reactor, after cooling it in a dry ice acetone -Bath until 30 ml of liquid HF was accumulated in the reactor. Subsequently, 1.2 ml of sulfur trafluoride gas (measured in the liquid state at -78 ° C.) were introduced, the dry ice-acetone cooling bath was then removed and replaced by a cooling bath kept at −12 ° C. After aging for 15 hours, the solvent was evaporated with a stream of N2, the residue was dissolved in 50 ml of 2.5 M aqueous HCl, evaporated to dryness in vacuo and subjected to amino acid analysis in a Spinco-Beckman amino acid analyzer. The analysis indicated the formation of a-fluoromethyl-3-hydroxy-ty-rosin. The product R, S-a-fluoromethyl-3-hydroxy-tyrosine is isolated by ion-exchange chromatography in the same way as described in Example 2 for S-a-fluoromethyl-3-hydroxy-tyro-sin.

Example 2

Preparation of S-a-fluoromethyl-3-hydroxy-tyrosine

A. Preparation of R-a-hydroximethyl-3-hydroxy-tyro-

sin

50 g of 3- [3 ', 4'-diacetoxiphenyl] -2-acetamino-2-acetoximethyl-propionic acid were added to 204 ml of 4m aqueous KOH with stirring. After stirring for one hour (under nitrogen), the solution contained the potassium salt of 3- (3 ', 4'-dihydroxiphenyl) -2-acetamino-2-hydroximethyl-propionic acid, which was formed in essentially quantitative yield. Without isolation, this compound was converted to 3- (3 ', 4'-dimethoxyphenyl) -2-acetamino-2-hydroximethyl-propionic acid by methylation with dimethyl sulfate. This operation was carried out at room temperature under N2 gas by dropwise addition of about 64 ml of dimethyl sulfate with vigorous stirring and about 148 ml of 4M aqueous KOH solution over a period of about 1 hour.

The reaction mixture was stirred for a further hour and then left to stand overnight. Acidification at 5-10 ° C with 55 ml of concentrated aqueous HCl, extraction with 12 × 300 ml of ethyl acetate, drying over Na2S04 and evaporation in vacuo gave R, S-3- (3 ', 4'-dimethoxiphenyl) -2- acetamino-2-hydroximethyl-propionic acid. It was purified by recrystallization from 1325 ml acetonitrile, F = 154-6 ° C. (dec.).

29.1 g of strychnine were suspended in 1.121 ethanol 2BA, heated to reflux, and then 26.1 g of R, S-3- (3 ', 4'-dimethoxiphenyl) -2-acetamino-2-hydroxymethyl-propionic acid added. The solution thus obtained was allowed to cool and was left to stand at room temperature overnight. Crystals of the strychnine salt of the antimer "A" deposited; F = 193-194 ° C ("HM").

The mother liquor from the above precipitation was evaporated to dryness in vacuo and recrystallized from 270 ml of ethanol 2BA; the hot solution was allowed to cool to room temperature and was left to stand at room temperature for about 3 hours and then kept in the refrigerator for about 4 hours. The crystals formed were collected on a filter and, after drying, recrystallized from acetonitrile, the strychnine salt of the antimer "B" of 3- (3 ', 4'-dimethoxyphenyl) -2-acetamino-2-hydroximethyl-propionic acid from F = 130-132 ° C (dec.) In a yield of 17.5 g.

17 g of this strychnine salt were decomposed by first dissolving in 160 ml of water; 31 ml in aqueous NaOH solution were added. The strychnine deposited was removed by filtration and the solution was evaporated in vacuo to a small volume and applied to a small column of ion exchange resin (150 ml AG-X2 cation exchange resin Dowex 50.0.074 / 0.037 mm = 200/400 mesh). It was eluted with water, after which the fractions were evaporated in vacuo, which showed an absorption, determined in an LKB-UV absorption monitor (UVICORD11-8300). This compound, the antimer "B" of 3- (3 ', 4'-dimethoxiphenyl) -2-acetammo-2-hy-

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

11

639 639

Droximethyl-propionic acid showed a value for [a] D of 78.3 + 0.5 ° (C, 1.425 in 0.1 M aqueous NaOH).

Conversion of the above compound into the corresponding stereo isomer of a-hydroximethyl-3-hydroxy-tyrosine: 4.43 g of the antimer "B" of 3- (3 ', 4'-dimeths oxiphenyl) -2-actamino- 2-hydroxymethylpropionic acid was dissolved in 100 ml of concentrated HCl and sealed in a Fisher-Porter tube and heated for 90 minutes by immersion in an oil bath at 130 ° C. The solvent was evaporated in vacuo and the above HCl treatment was repeated. The residue thus obtained is R-a-hydroximethyl-3-hydroxityrosine hydrochloride.

B. Fluorodehydroxilation

8 g of R-a-hydroximethyl-3-hydroxityrosine ■ HCl are introduced into a reactor. The reactor is immersed in a dry ice-acetone bath and 80 ml of liquid HF are condensed onto the substrate from above. To remove the HCl present, the cooling bath is removed and the HF solvent is removed by introducing an N2 gas stream. The reactor is immersed again in the cooling bath and a stream of HF gas is introduced until a liquid volume of approximately 250 ml has accumulated. 6.2 ml SF4 (17.6 mmol / ml: approx. 109 mmol) are then injected into the solution which has aged for about 1 hour, the cooling bath is replaced by an ethylene glycol bath which is kept at −16 ° C., and the solution is aged for about 22 hours. Boron trifluoride gas is introduced until saturation is reached and the solution is left to stand again at -16 ° C for 46 hours. The cooling bath is removed and the solvent evaporates by bubbling a vigorous stream of nitrogen gas through it. The residue is quenched in about 100 ml of ice-cold aqueous 2.5 M HCl, evaporated in vacuo, the residue is dissolved in water and added to a column of a cation exchange resin. 2.21 AG-50X-8 resin (0.074 / 0.037 mm = 200/400 mesh) was used. It was eluted with 0.25 M aqueous HCl containing 5% methanol; 7.21 of this solvent was pumped through the column over about 8.5 hours. This was followed by 7.21 0.4m aqueous HCl with 7.5% methanol for 8.5 hours and finally 0.6m aqueous HCl with 10% methanol. 22 ml fractions were collected, with 10 tubes per carrier. The tubes in Carrier Nos. 45-66 contained the desired compound. Evaporation in vacuo gave the HCl salt of the S isomer of a-fluoromethyl-3-hydroxityrosine.

To release the free amino acid, 4.826 g of this compound were dissolved in 90 ml of isopropanol and filtered through Celite. 6.2 ml of propylene oxide was added to the filtrate and the suspension was kept at room temperature for 3.5 hours and at about 5 C for a further 2.5 hours. The S-a-fluoromethyl-3-hydroxityrosine thus formed was collected by filtration, washed with isopropanol and dried overnight at 76 ° in vacuo. [a] D: + 9.3: + 0.5, c 1.82 in a 1: 1 mixture of trifluoroacetic acid and water.

Example 3

Preparation of Ra-fluoromethyl-3-hydroxityrosine To prepare the above compound, the strychnine salt of antimer A of 3- (3 ', 4'-dimethoxyphenyl) -2-acetamino-2-hydroximethyl-propionic acid (Example 2 "HM" ) subjected to analog stages as in Example 2. The end product of the successive stages was R-a-fluoromethyl-3-hydroxityrosine with [a] D: - 9 ° (c 2.5 in a 1: 1 mixture of H20-trifluoroacetic acid).

Example 4 R, S-a-fluoromethyl-tyrosine 1.05 g (0.005 mol) of R, S-a-hydroxymethyl-tyrosine was charged into a reactor. The reactor was immersed in a dry ice-acetone bath and about 50 ml of liquid HF was collected by introducing a HF gas stream. With further cooling, 4 ml of SF4 gas (measured in the liquid state at -78 ° C) were introduced and then BF3 gas until saturation at -78 ° C. (Stir with a magnetic stirrer.) The deep red solution so obtained was left overnight at -78 ° C; the cooling bath was then removed and the solvent evaporated by blowing through a dry nitrogen gas stream. The residue was dissolved in 20 ml of 2.5M aqueous HCl and evaporated to dryness in vacuo. The residue was dissolved in water and applied to a column with a strongly acidic cation exchange resin made with 100 ml AG50-X-8 resin (0.074 / 0.37 mm = 200/400 mesh). The column was first washed with 1.8 l of water and then with 0.5 M aqueous HCl. 20 ml fractions of the effluent were obtained and the course of the elution was monitored by a UV monitor, LKB, model UVICORD II. The fractions corresponding to the main peak in the UV curve were combined and evaporated to dryness in vacuo to form the hydrochloride salt of R, S-fluoromethyltyrosine. 400 mg of this salt was dissolved in 6 ml of water; after a few minutes the crystallization of R, S-fluoromethyl-tyrosine began. After standing overnight at 5 ° C, the product was filtered, washed with water, ethanol and diethyl ether and dried in vacuo at 76 ° C to give R, S-a-fluoromethyl-tyrosine.

25th

30th

35

40

45

Example 5

R, S-a-fluoromethyl histidine (FM HIST) h ck, oh

I I

^ ch, -c-co, h ch2-c-c0, h t / K si rcofIerun9 xjf k ch2c6h5 3) ^ * ch2c6h5

CL) i

(d, l) ii

639 639

12

CH? 03 -

1 2 ®2F

CH ~ -C-C0o "t

2 | -2 ch2-C-C0QH

Na / NH ^ Y, -f 1) 82 Hf / SF4BF3 ». / ™ 2

(D, L). PM-HIST

III IV

A. Racemic N (im) benzyl histidine

30 g of N (im) -benzyl-L-histidine were dissolved in 600 ml of water and the solution was heated in a high-pressure autoclave with shaking at 200 ° C. for 8 hours. The autoclave was cooled to room temperature and the clear supernatant solution was removed in vacuo evaporated to dryness to form R, Sa-fluoromethyl-histidine as colorless crystals.

B. R, S-a-hydroximethyl-N (im) -benzyl-histidine (II)

20 g of racemic N (im) -benzyl-histidine were in 11

dissolved hot water, and then 40 g of basic copper (II) carbonate was added in portions, and the mixture was heated under reflux for 1 hour. The mixture was filtered hot and the filtrate was evaporated in vacuo to give the Cu chelate of racemic N (im) benzyl histidine as a blue solid.

A mixture of 31 ml of formalin (38% H2CO), 3.1 ml of pyridine and 2.13 g of Na2C03 was heated to 70 ° C. with stirring and then 20 g of the above-mentioned Cu chelate were added, and the system was stirred and Heated to 75 ° for 90 minutes. Evaporation in vacuo gave a blue solid residue. This was dissolved in a mixture of 50 ml water with 50 ml concentrated NH4OH and applied to a column with a cation exchange resin (300 ml Dowex 50-X-8 resin in the NH ^ formula) and eluted with 2m aqueous NH4OH solution. The outflow was monitored with a UV absorption monitor (LKB UVICORD II) and the fraction of 1.11 of the outflow with UV absorption was combined and evaporated to a solid in vacuo. The residue was dissolved in a mixture of 60 ml of water with 5 ml of concentrated aqueous NH4OH and applied to a column with an anion exchange resin (300 ml of Dowex 1-X-2 resin in the OH form). The column was washed with 21 water and eluted with 2M aqueous HCl and monitored for UV absorption with UVICORD II. The effluent fractions with an ultraviolet absorption were combined and evaporated to dryness to form the essentially pure HCl salt of N (im) -benzyl-a-hydroximethyl-histidine (II) (new compound). This compound is converted into a-hydroximethyl-hi-stidine (III) in the following way: 12.5 g of II were dissolved in 200 ml of liquid NH3 (3-neck flask, equipped with a cold finger condenser, filled with dry ice acetone), whereupon 5.5 g of sodium (cut into small pieces) were added until the blue color persisted for 10 minutes. NH4C1 was added to consume excess Na (indicated by the discoloration) and the NH3 solvent was allowed to evaporate under a stream of nitrogen. The product III thus obtained was purified by chromatography on a column with cation exchanger 25 resin (2.21 Dowex-50-X-8.0.074 / 0.037 mm = 200/400 mesh). Crude HI was dissolved in 100 ml of water and applied to the column with the resin. The column was first washed with 41 water and then developed with aqueous HO (1.5 m, then 2 m). 20 ml of 30 fractions were obtained at a flow rate of 600 ml / hour.

Fraction No. Pauly reaction

35 1-400 1.5m HCl

401-670 2m HCl

671 and later +

Fractions 671-760 were combined and evaporated to dryness in vacuo 40 to form III; R, S-a-hydroxy-methyl-histidine • 2HC1 (new compound).

C. R, S-a-fluoromethyl-histidine (IV)

2.73 g of R, S-a-hydroximethyl-histidine • 2HC (III) 45 were dissolved in 70 ml of liquid HF, then the mixture was evaporated to dryness by passing in a stream of nitrogen. The residue obtained in this way represents the hydrofluoride salt of a-hydroximethyl-histidine. It was redissolved in 200 ml of liquid HF (dry ice-acetone cooling bath), and then 9 ml of SF4 were introduced (measured as a liquid at -78 ° C.) . The solution was stored overnight while being kept in a cooling bath at - 12 ° C. The solution was then saturated with BF3 gas, left to stand for 5 hours, saturated again at −12 ° C. and aged for 66 hours at 55 of the same temperature. The cooling bath was then removed and the solvent was evaporated by passing in a stream of nitrogen. The residue consists mainly of the HBF4 salt of a-fluoromethyl-histidine. This was dissolved in 100 ml of 2.5m aqueous 60 HCl, it was evaporated to dryness and then converted into the HCl salt as follows: it was redissolved in H20 and applied to a column with cation exchange resin (100 ml AG50-X -2.0.074 / 0.037 mm = 200/400 mesh), eluted with H20 to neutral and 65 from F ~ free effluent. The product was released from the column through 3M aqueous HCl, evaporated to dryness in vacuo to give a residue consisting mainly of the dihydrochloride of IV. To

13

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final purification was again chromatographed on another AG-50-X-2 column with 900 ml of resin.

Eluted with:

0.5m aq. HC1-1 1

1.0m aq. HCl-1.51

1.5m aq. HCl-3.31 (extraction begins here, 20 ml

Fractions)

2.0m aq. HCl-8.01

The desired product IV was localized by the Pauly test. Fractions 390-470 were combined, evaporated to dryness in vacuo and the pure di-hydrochloride of IV was obtained. The crystalline mono-hydrochloride salt of a-fluoromethyl was obtained by recrystallization from water-isopropanol (1: 9 vol / vol) -histidine, F = 226-7 ° (dec.).

Example 6

Synthesis of R, S-a-fluoromethyl-ornithine

A. R, S-a-hydroximethyl-ö-N-benzoyl-ornithine

7.995 g of the copper chelate of R, S-ö-N-benzoyl-ornithine was added in small portions with mechanical stirring to a mixture of 12.45 ml formalin (38% H2CO), 1.25 ml pyridine and 0.81 g sodium carbonate 70 ° C added. After stirring for a further 90 minutes at 75 C, the mixture was evaporated to dryness in vacuo, the dark blue residue was dissolved in a mixture of 30 ml of water and 30 ml of concentrated aqueous NH3 solution and applied to a column with cation exchange resin (130 ml of Dowex 50-X-8 in the NH + 4 form) applied to remove Cu2 +. The column was eluted with 250 ml of 2m aqueous NH3 and the effluent was evaporated to dryness in vacuo. The residue was redissolved in H20 and applied to a column with an anion exchange resin (130 ml Dowex 1-X-2 resin in the OH "form). The column was washed with 250 ml water and eluted with 3M aqueous HCl HCl effluent was concentrated in vacuo to give R, S, -a-hydroximethyl-8-N-benzoyl-ornithine.

B. R, S-a-hydroximethyl-ornithine dihydrochloride

3.5 g of the product obtained in A. were dissolved in 40 ml of 6M aqueous HCl and heated under reflux for 21 hours. The solution was extracted with 2 x 40 ml of toluene and the aqueous phase was evaporated to dryness in vacuo to give R, S-a-hydroximethyl-ornithine dihydrochloride (new compound).

C. R, S-a-fluoromethyl ornithine

1.1 g of the product obtained in B. was placed in a reactor, the reactor was placed in a dry ice-acetone bath and HF gas was introduced until an HF solution with a volume of 25 ml had formed in the reactor. The cooling bath was removed and the solvent evaporated by bubbling a stream of nitrogen. The residue thus obtained represented the HF salt of R, S-a-hydroximethyl-ornithine. This residue was redissolved in HF by cooling the reactor in the dry ice-acetone bath and introducing HF gas until the volume reached 50 ml. 4 ml of SF + gas (measured in the liquid state at −78 ° C.) were introduced, the dry ice-acetone cooling bath was removed and replaced by a bath which was kept at −15 ° C. After aging for 16 hours at -15 ° C, BF3 gas was introduced for saturation. After a further 5 hours of aging, the cooling bath was removed and the solvent was evaporated by passing in a stream of nitrogen. The residue was dissolved in 6M aqueous HCl, evaporated to dryness in vacuo and redissolved in 10 ml of water. This solution was based on a

Column applied with a Dowex 50-X-8 cation exchange resin (400 ml resin, 0.074 / 0.037 mm = 200/400 mesh, H + shape). The column was first washed with 800 ml of water and 15 ml of fractions were obtained with 2M aqueous HCl. The flow rate was 600 ml / hour. Every 5th fraction was applied to a thin layer plate and developed with ninhydrin spray. Fractions # 171-220 were combined and evaporated to dryness in vacuo to give a mixture of amino acids, the major component of which was R, S-a-fluoromethyl-ornithine • 2HC1. For further purification, this product was again chromatographed on another column made from Dowex 50-X-8 cation exchange resin (0.074 / 0.037 mm = 200/400 mesh). For development, the column was first washed with water and then with 1.5 M aqueous HCl at a flow rate of 0.6 l / hour. Fractions of 20 ml were collected. The residue obtained by evaporating fractions No. 521-540 represents pure R, S-a-fluoromethyl-orni-thin-dihydrochloride.

Example 7

Synthesis of S-a-fluoromethyl-tyrosine

A. Preparation of copper chelate from tyrosine methyl ether

25 g (128 mmol) of R, S-tyrosine methyl ether were dissolved in 646 ml of 0.2N NaOH at 80 ° C., and this solution was added to 16.1 g of copper sulfate pentahydrate, dissolved in 1600 ml of water at 80 ° C. A precipitate formed immediately and the solution was allowed to cool overnight, whereupon the mixture was filtered and 28.9 g of the copper chelate of the R, S-tyrosine methyl ether were obtained.

B. R, S-a-hydroxymethyl-tyrosine methyl ether

29 g (0.064 mol) of the copper (Cu ++) chelate of the tyrosine methyl ether were added at 70 ° C. with stirring to a solution of 3.9 g of sodium carbonate, 52 ml of 37% aqueous formaldehyde and 5.2 ml of pyridine ( under a nitrogen blanket). After the addition had ended, a further 18 ml of formaldehyde solution and 1.6 ml of pyridine were added. After heating at 70 ° C. for 3.5 hours and cooling the solution to room temperature for a further 1.5 hours, the solution was left overnight at room temperature. In the morning an abundance of blue crystals appeared which were filtered and the filtrate was concentrated to dryness in vacuo. After the residue was dissolved in water and concentrated again to dryness, it was dissolved in 90 ml of 4N HCl. After filtering, the solution was used to dissolve the above blue crystals. This required the addition of a further 300 ml of 4N HCl. The solution was then treated with hydrogen sulfide, filtered through a diatomaceous earth filter aid and concentrated to about 40 g of crude product. This was applied to a strongly acidic cation exchange resin (0.5% Dowex 50-X-8), eluted with 41 water and then with 2N aqueous ammonia. The effluent was monitored with a recording ultraviolet spectrophotometer (UVICORD II) and the UV absorption fraction was concentrated in vacuo to 22.16 g of pure R, S-a-hydroxymethyl-tyrosine methyl ether.

C. R, S-N-acetyl-a-hydroximethyl-tyrosine methyl ether

19.7 g (87.5 mmol) of R, S-a-hydroxymethyl-tyrosine-me-

ethyl ether were suspended in 200 ml of dry pyridine and then 68 ml of acetic acid anhydride were added. After aging overnight at room temperature, the solution was concentrated to dryness in vacuo and azeotroped with 2 × 50 ml of toluene. The residue was

5

10th

15

20th

25th

30th

35

40

45

50

55

SO

65

639639

14

dissolved in 118 ml of methanol and 130 ml of aqueous 2.5N NaOH solution and stirred at room temperature for 3.5 hours. Acidification with 30 ml of concentrated HCl, followed by extraction with 4 × 200 ml of ethyl acetate and subsequent drying and concentration gave 21 g of crude product. This was recrystallized from 75 ml of acetonitrile, giving 9.35 g of R, S-N-acetyl-a-hydroximethyl-tyrosine-methyl ether of F = 151-152 ° C. (dec.).

D. Optical separation of R, S-N-acetyl-a-hydroximethyl-tyrosine methyl ether

10 g of R, S-N-acetyl-a-hydroximethyl-tyrosine methyl ether and 6.18 g of d-ephedrine were dissolved in 50 ml of methanol. The solution was concentrated to dryness in vacuo and then redissolved in 50 ml of warm acetonitrile. Crystallization gave 7.34 g of the d-ephe-drinsalz of R-N-acetyl-a-hydroximethyl-tyrosine-methyl ether of F = 125-131 ° C (yield A). Yield A was recrystallized from 40 ml of acetonitrile, yielding 4.78 g of yield B with F = 130-134 ° C. The mother liquors of A and B were combined, concentrated, the residues were dissolved in 22.4 ml of 2.5N NaOH and 50 ml of water. The aqueous solutions were extracted with 2 x 75 ml of ethyl acetate. The aqueous solutions were cooled and acidified with 5 ml of concentrated HCl and the resulting solution was extracted with 3 x 70 ml of ethyl acetate. The dried organic solution was concentrated to 7.73 g (yield C). Yield C and 4.7 g of 1-ephedrine were dissolved in 50 ml of methanol and concentrated to 12.39 g (yield D). The yield D was recrystallized from 50 ml of acetonitrile to give 5.06 g of the 1-ephedrine salt of SN-acetyl-a-hydroximethyl-tyrosine-methyl ether (yield E), F = 131.5-133.5 ° C (dec .). The yield E was recrystallized from 27 ml of acetonitrile to give 4.72 g of the yield F of F = 130.5-134.5 ° C (dec.). The mother liquors of the yields F and E were combined and concentrated to 7.31 g of the yield G. Yield G was converted back to free acid using the procedure used to obtain Yield C, and 3.0 g of Yield H was obtained. Like the original R, S material, 1.9 g d -Ephedrine treated. By recrystallizing the salt from 17 ml of acetonitrile, 2.4 g of yield J of F = 127-130 C was obtained. Yield J was recrystallized to give 2.06 g of yield K of F = 130-134 C (dec. ).

The combined yields B and K (6.52 g) were recrystallized from 40 ml of acetonitrile to give 6.06 g of the d-ephedrine salt of RN-acetyl-a-hydroximethyl-ty-rosin-methyl ether (total 75.8%) .

The free acid was regenerated in the same way as in the conversion of the combined mother liquors of yields A and B to yield C, and 3.50 g of RN-acetyl-a-hydroximethyl-tyrosine methyl ether were obtained: [a] D = + 92 : (C, 1.35.0.27n NaOH).

E. R-a-hydroximethyl-tyrosine

3.3 g of R-N-acetyl-a-hydroximethyl-tyrosine-methyl ether were dissolved in 100 ml of concentrated HCl and heated to 130 ° C. in a pressure tube for 2 hours. The solution was concentrated to dryness, the residue was dissolved in 35 ml of H20, filtered and 1 ml of pyridine was added. 2.11 g (81%) of pure R-a-hydroxymethyl-tyrosine crystallized from: [a] D = 0.86 ° (C, 1.15, 50% strength aqueous trifluoroacetic acid). The spectrum of circular dichroism (CD) has the same direction as the CD of S-a-methyl-tyrosine.

F. S-a-fluoromethyl-tyrosine

Following the procedure of Example 4, S-a-fluoro-methyl-tyrosine was prepared from R-a-hydroximethyl-tyrosine.

Example 8 (±) -a-Fluoromethylglutamic acid i5 6.56 g of a-methylglutamic acid hemihydrate were photofluorinated in liquid HF solution using the methods described in Journal of the American Chemical Society, 92, 7494 (1970) and 98, 5591 (1976) general working method described. The substrate was dissolved in 120 ml of liquid HF and irradiated with 20 of an ultraviolet light source of 2500 W with stirring, while fluoroxitrifluoromethane gas (CF3OF) (3.0 ml measured in liquid form at -78 ° C.) over the course of 80 minutes were introduced with cooling in a dry ice-acetone bath. After a further period of 25 80 minutes under irradiation under the same conditions, a further dose of CF3OF was added over a period of 3 hours, stirring, cooling and irradiation being continued. The mixture was kept in the dry ice-acetone bath overnight and then further fluorinated (with 3 ml of 30 CF3OF, added over 5 hours under irradiation). Nitrogen gas was bubbled through the solution to remove the solvent and the residue was evaporated in vacuo with 2 x 2.5N aqueous HCl. The residue was dissolved in 40 ml of water. 10 ml of concentrated HCl was added to 10 ml of this solution 35 and the mixture was heated under reflux for about 68 hours. After treatment with DARCO G-60, the filtrate was evaporated in vacuo and the residue was refluxed with 30 ml of concentrated HCl for a further 68 hours. After treatment with DARCO, the solution was evaporated to dryness, dissolved in 10 ml of concentrated HCl and heated in a sealed glass tube for 24 hours in an oil bath kept at 130-135 ° C. Evaporation to dryness in vacuo gave a residue 45 which was dissolved in water and subjected to elution chromatography on a column with a cation exchange resin consisting of 360 ml AG50-X12 (0.074 / 0.037 mm = 200/400 mesh ) was prepared. Eluent: 2.61 HzO, followed by 1.510 in aqueous HCl and then 50 0.15N aqueous HCl The UV absorption of the effluent was monitored by UV recording at 206 nm. 15 ml fractions of the effluent were collected and 20 fractions corresponding to the first ultraviolet absorption peak were combined and evaporated to dryness in vacuo to give α-fluoromethyl-glutamic acid hydrochloride. To release the amino acid, it was dissolved in isopropanol, filtered, and then propylene oxide was added. a-Fluoromethyl-glutamic acid ■ 0.7 H20 crystallized from the solution. This compound is a time-60 dependent inhibitor for glutamic acid decarboxylase.

s

Claims (10)

639 639 2nd PATENT CLAIMS 2. Connection according to claim 1 with the configuration 1. Compound of the formula of the S isomer. ch0f 3. A compound according to claim 1, wherein the substituted | te alkyl group has the meaning of R C COO ^ (D r <50 wherein R is a substituted C, -C + alkyl group and Rj is the r. V x) K-Ç kh2 r2 ° —chj Has the meaning of H or C, -C18-alkyl and the acid 10 TT, _ _ dition salts of which R2 is H or C2-C6-alkanoyl, H ^ NjpCHj, HOH ^ -CH ^, Œ2 n- * h ° ——rrCH2 "W , hooc-ch ^, h2n-ö-nh-ch2-ch2-ch2, k h2n- (ch2) 2-ch2, hooc-ce ^ -ch ^, ho — ch ^, ch2 ~ / nh9 h I 2 HOOCr-ch-ch2-ch2ch2, h2n-ch2-ch2-ch2 ~ ch2, ho H ^ CS-CHj, or CE-2 r and R, has the meaning of H. 4. A compound according to claim 3, wherein the substituted alkyl group has the following meanings: H R2 ° y-, N -j- CHs; r2 ° r-c / ^ ch2 '. / h2n- (ch2) 2-ch2 ho ^ HO ^ CH5 nh ii h2n - c - nh-ch2-ch2ch2-, ■ ai2- hooc-ch2-ch2-, or À 639 639 5. A compound according to claim 1 or 2 of the formula ho or the formula ho '/ \ N ch, f i 2 ch - c coor, 2 years where Rj is hydrogen or ethyl, of the formula h f2p b-c-ch0 ~ c-co oh <J X ch-f 1 2 of the formula h2n-ch2-ch2-ch2-c cooh, nh2 the formula of the formula ho ch-f 1 ch-c cooh 2 l HH2 of the formula nh, n-ü-n- CH ^ F I 2 h, n-c-n-ch, -ch - ch, - c— cooh 2 | 2 2 z i h of the formula nh- ch2f hooc -ch-ch-, c cooh 2 2 I. nh. ch2f i .ch- l nh- -cooh io 6. The S isomer of a compound according to claim 1 of the formula 15 7. A compound according to claim 1 of the formula 20th 25th H C. n. ch-.f I. ch ~ - c— coor. 2, 1 nh- wherein Rj is H or C] -C18 alkyl. 8. The pharmaceutical composition is characterized in that it contains a compound of the formula ch0f as active ingredient 1 2 C. ! nh ~ coor, (I) wherein R is a substituted C1-C4-alkyl group and Rj has the meaning of H or Q-Q S-alkyl or contains a pharmaceutically usable or compatible acid addition salt thereof. 9. Pharmaceutical composition according to claim 8, characterized in that the compound of the formula 45 I is in the configuration of the S isomer. 10. Process for the preparation of new compounds of the formula R CH F I 2 C - COOH! NH " (IA) 55 where R has the meaning of ho 60 HO ~ ^ _ ^ * CH2- t HO ~ ^ J ^ ~~ CH2- 65 h2n-ch2-ch2-ch2- H • ch2- 639 639 4th nh ho hooc-ch2-ch2-ho. b- ch2- h k2n-c'— n-ch2-ch2-ch2-, CH2 ~ 'or characterized in that a compound of the formula ch-> oh i r - c cooh I. nh2 subject to fluorine dehydroxation and, if appropriate, compounds obtained are converted into the corresponding salts. 11. The method according to claim 10 for the preparation of new compounds of formula ch-f I 2 r * ch -— c cooh iL, (iv) where R 'has the meaning of -b-, .0-. isçr. ■  ho oaer IT characterized in that a compound of the form- The invention relates to new substituted a-fluoromethyl a-amino-alkanoic acids and their esters. An unsubstituted a-fluoromethyl-a-amino-alkanoic acid, namely 2-fluoromethylalanine with the formula mei ch, oh I. r1— ch2 — c cooh ah. (v) 55 60 ch-f i ch-, cooh 3 I nh2 (a) with SF4 in liquid HF at temperatures from - 80 to + 20 C, whereby the reaction system BF3 or is known [Kollonitsch et al. J. Org. Chem. 40, 3808-9 A1C13. 65 (1975)]. Nothing is known about a specific biological activity of the compound. This compound (A) is prepared by fluorodehydroxylation of the corresponding 2-hydroxymethylalanine. 5 639 639 It is known that a-methyl-amino acids, such as La-methyl-3,4-dihydroxyphenylalanine (a-methyldopa, an antihypertensive agent) have a decarboxylase inhibitory activity (Goodman, et al., "The Pharmacological Basis of Therapeutics », Mac Millan Company, New York, New York, 1970, p. 577; CA-PS 737 907). New substituted a-fluoromethyl-a-ami-no-alkanoic acids have now been found. These new acids or their alkyl esters have a decarboxylase-inhibiting activity which is considerably greater than that of the a-methyl-amino acids.