NO149036B - OUTPUT MATERIALS FOR THE PREPARATION OF THERAPEUTIC ACTIVE AMINO ACID DERIVATIVES - Google Patents

Description

The present invention relates to starting material for the production of therapeutically active amino acid derivatives with the general formula:

where

R is hydrogen or alkyl with 1-4 carbon atoms,

R 5 is hydrogen or carboxyl,

B<1> is -S02OH, -OS02OH or -OPO(OH)2,

n is an integer from 1 to 4,

m is an integer from 1 to 3, and

t is an integer from 1 to 3,

and their pharmacologically acceptable salts and optically active isomers,

The starting materials according to the invention are characterized by having the general formula:

where R, R 5 , n, m, t are as indicated above, and B 2 is -SC^OH,

-OSO 2 OH or -OPO(OH) 2 ,

R"*" is aralkylcarbony 1 with 7-9 carbon atoms, and ;A is aralkyl with 7-9 carbon atoms, ;and salts and optically active isomers thereof. ;Preparation of the therapeutically active amino acid derivatives of formula I, as well as their therapeutic activity is described in Norwegian patent document 146 430. ;The starting compounds of formula II can, for example, be prepared by a compound of general formula III: where R"*", A''" and n have the meanings indicated above, and where R denotes an easily cleavable group, is reacted with a compound of general formula IV:

where R, R 5 , B 2 , m and t have the meanings indicated above.

The reaction can be carried out in, for example, triethylamine at room temperature.

The following examples illustrate the invention:

Example 1

a) 40.85 g (0.11 mol) carbobenzyloxy-L-glutamic acid-α-benzyl ester (Liebigs annals 655, 200, 1962) are dissolved in 500 ml

acctonitrile. The solution is cooled to -15° C with the exclusion of air-moisture. While stirring, first 15.4 ml (0.11 mol) of triethylamine and then 15.4 ml (0.11 mol) of chlorine are added dropwise to the solution 1 es t is . The mixture is not stirred at -15° C. for 40 minutes, and then 28 ml (0.2 mol) of triethylamine are added, followed by 11.26 g (0.05 mol) of cystamine hydrochloride and finally 250 ml of acetonitrile. The BH respiration is stirred for another 2 hours at -15° C, and then at room temperature for a further 4 hours.

At the end of the reaction time, the mixture is evaporated at 30° C. in a vacuum. The residue is taken up with stirring and cooling in 200 ml of ice water and the mixture is evaporated again at 35° C. in vacuum. The residue is introduced together with 250 ml of water and 500 ml of ethyl acetate in a separatory funnel and the organic phase is separated. The organic phase is shaken successively with first 250 ml of water, then with 2 x 250 ml of 5% sodium carbonate solution, then with 2 x 250 ml of IN hydrochloric acid and finally with 250 ml of water.

(From the aqueous phase obtained by shaking with sodium carbonate solution, by acidifying with hydrochloric acid and shaking with ether, approx. 5 g of unreacted carbobenzyloxy-L-glutamic acid-cx-benzyl ester can be recovered). The ethyl acetate phase is dried over anhydrous sodium sulfate and then evaporated in vacuo at 30° C. to dryness. A thick, oily residue is obtained, which immediately solidifies into a crystalline mass. This is triturated with 250 ml of absolute ether, and the crystals are filtered off. The crude product (40 - 42 g) is recrystallized from a mixture of 100 ml ethyl acetate and 170 ml ether. 29.3 g of N,N 1 -bis-(N-carbobenzyloxy-γ-(ct-benzyl)-L-glutamyl]-cystamine is obtained which melts at 91 - 92° C.

Elemental analysis for 4H50N4°ioS2 ^M <=> 859.05)

Calculated: C 61.52%, H 5.89%, N 6.52%, S 7.46%

Found: C 60.85%, H 5.91%, N 6.61%, S 7.72% b) 25.77 g (0.03 mol) of the obtained N,N'-bis-[N- carbo-benzyloxy-γ-(α-benzyl)-L-glutamyl]-cystamine is dissolved in 75 ml of glacial acetic acid. A freshly prepared mixture of 75 ml of 30% hydrogen peroxide and 225 ml of glacial acetic acid is added dropwise over the course of 15 minutes to the ice-cooled solution. After addition, the cooling is removed, and the reaction mixture is stirred at room temperature for 4 hours. It is then evaporated in a vacuum at 30°C. The oily product is first dried in a desiccator over phosphorus pentoxide and then over solid potassium hydroxide. 28.5 g of carbobenzyloxy-γ-(o-benzyl)-L-glutamyltaurine is obtained. The raw product can be used without purification for the production of Y-L-glutamyl taurine.

To avoid loss of insulation, the connection was prepared in an unclean state. The compound is characterized by the R^ value and the characteristics of its triethylammonium salt.

Rf = 0.96 silica gel G (Merck), n-butanol-pyridine-glacial acetic acid-water, 15:10:3:12, developer: iodine vapor.

Triethylammonium salt

2 mM = 0.96 g of N-carbobenzyloxy-γ-(α-benzyl)-L-glutamyl taurine was dissolved in 30 ml of distilled water, and the pH was adjusted to 7-0.2 with analytical grade triethylamine. The resulting solution was evaporated in vacuo at a bath temperature not exceeding 30°C, and was then evaporated to constant weight and crystallized from a mixture of ethanol and ethyl acetate. 0.9 g of white crystalline material was obtained. Melting point: 237-239°C.

Analysis: C^H^IS^OgS (579)

Calculated: C 58.03, H 7.08, N 7.25, S 5.52%

Found: C 58.10, H 7.12, N 7.18, S 5.48%

c) 26.32 g (55 mmol) of the produced carbobenzyloxy-γ-(α-benzyl)-L-glutamyltaurine are dissolved in 50 ml of glacial acetic acid. 4 mol of hydrogen bromide dissolved in 50 ml of glacial acetic acid is added to the solution. A lively carbon dioxide development is observed. The reaction mixture is left at room temperature for 2 hours and then evaporated in vacuo at 30°C. The oily residue is dissolved in 170 ml of water and shaken out with 5 x 70 ml of ether. The water phase is evaporated in a vacuum at 35°C. 20.42 g of γ-(α-benzyl)-L-glutamyltaurine is obtained, which is recrystallized from

90% ethanol.

R^ (n-butanol-pyridine-glacial vinegar-water 15:10:3:12) = 0.53

Rf (n-butanol-glacial acetic acid-water 4:1:1) = "0.39

Example 2

a) 1.083 g (2.2 mmol) of carbobenzyloxy-L-glutamic acid-(α-benzyl)-γ-p-nitrophenyl ester are dissolved in 6 ml of a mixture of

pyridine and water in a ratio of 2:1. 78 mg (2 mmol) of homotaurine and then 0.59 ml (4.2 mmol) of triethylamine are first added to the solution. The yellow solution is left at room temperature for 72 hours and then evaporated in vacuo. The oily residue is dissolved in water, neutralized with hydrochloric acid and then extracted with ether for 8 hours in a continuous extractor to remove the p-nitrophenol. The water phase is evaporated in a vacuum. 1.68 g of carbobenzyloxy-γ-(α-benzyl)-L-glutamyl homotaurine is obtained.

b) Dissolve the entire quantity of the prepared material (1.68 g) in 10 ml of 50% aqueous ethanol, then add 0.3 g of 10%

palladium activated carbon and hydrogen are passed through the suspension for 4 hours. The solution is then filtered and evaporated in a vacuum. The residue is dissolved in 1 - 2 ml of water and passed over a Dowex 50 x 2 (H+<->form) column with a diameter of 1 cm and a height of 35 cm. Elute with water. 50 ml of eluate is collected and then evaporated in vacuum. 440 ml of γ-L-glutamyl homotaurine is obtained as a residue, which corresponds to a yield of 82%. The electrophoresis carried out at pH 6.5 shows a slight contamination of partially neutral, partially acidic substances (homotaurine or glutamic acid). The product can be cleaned e.g. by preparative electrophoresis.

Both in the electrophoresis at pH 6.5 and in the electrophoresis carried out at pH 1.8, the compound migrates in the direction of the cathode. Its relative mobility in relation to cysteic acid is at pH 6-5 0.68, and at pH 1.8 0.50.

R^ (n-butanol-pyridine-glacial acetic acid-water 15:10:3:12) = 0.19. Melting point: 206-209°C.

Calculated: C 35.81, H 6.01, N 10.41, S 11.93%

Found: C 35.88, H 6.15, N 10.37, S 11.45%

Example 3

1.083 g (2.2 mmol) of carbobenzyloxy-L-glutamic acid-(α-benzyl)-γ-p-nitrophenyl ester are dissolved in 6 ml of a mixture of pyridine and water in the ratio 2:1. 2.8 mg (2 mmol) of cholamine phosphate (US patent no. 2 730 542) and then 0.87 ml (6.2 mmol) of triethylamine are then added to the solution. The reaction mixture is left at room temperature for 72 hours and then evaporated in vacuo. The further processing takes place in the manner described in connection with carbobenzyloxy-γ-(α-benzyl)-L-glutamylhomotaurine (example 2a). 1.25 g of carbenzyloxy-γ-(α-benzyl)-L-glutamylcholamine phosphate are obtained.

For characterization, bis-dicyclohexylamine salt was used.

N- carbobenzyloxy- y-( a- benzyl)- L- glutamyl- cholamine phosphate, bis-dicyclohexylamine salt <C>.,<H__N>.<0>.<P> Ms. 856.

- z 46 73 4 9

0.95 g (2 mmol) of N-carbobenzyloxy-γ-(α-benzyl)-L-glutamyl-ethanolamine phosphate was dissolved in 5 ml of 96% ethanol and 0.8 ml of dicyclo-

hexylamine was added until a pH value of 7 was reached. The cloudy alcoholic solution was filtered, the filtrate evaporated in vacuo and dried to constant weight (1.50 g). The crystalline resin thus obtained was recrystallized from 5 ml of ethyl acetate. 0.9 g of white crystalline material was obtained. Melting point: 155-157°C.

Analysis:

Calculated: C 64.48, H 8.53, N 6.54%

Found: C 63.87, H 8.60, N 6.58%

Silica gel G (Merck), n-butanol-pyridine-glacial acetic acid-water, 15:10:3:12, developing agent: ninhydrin.

Claims (1)

Starting materials for the preparation of therapeutically active amino acid derivatives with the general formula: where R is hydrogen or alkyl with 1-4 carbon atoms, R r; is hydrogen or carboxyl, B<1> is -S020H, -0S090II or -0P0(0H)2, n is an integer from 1 to 4, m is an integer from 1 to 3, and t is an integer from 1 to 3, and their pharmacologically acceptable salts and optically active isomers, characterized in that they have the general formula: where R, R 5 , n, m, t are as indicated above, and B 2 is -SG^OH, -OSO9OH or -OPO(OH) , R 1 is aralkylcarbonyl with 7-9 carbon atoms, and A is aralkyl with 7-9 carbon atoms, and salts and optically active isomers thereof.