DD272092A1 - PROCESS FOR PREPARING N- (PHOSPHONOACETYL) -L-ASPARAGINIC ACID - Google Patents

Abstract

The invention relates to an improved process for the preparation of N- (phosphonoacetyl) -L-aspartic acid (PALA), a known antitumor agent. The new synthetic route is that phosphonoacetic acid P, P-dimethyl ester with L-aspartic acid di- (p-nitrobenzyl) ester to N- (phosphonoacetyl) -L-aspartic acid di- (p-nitrobenzyl) ester -P Reacted P-dimethyl ester and this product saponified and hydrogenated. Areas of application of the invention are the pharmaceutical industry and medicine.

Description

Ill OS I t

Process for the preparation of N- (phosphonoacetyl) -L-aspartic acid

Field of application of the invention

The invention relates to a process for the preparation of N- (phosphonoacetyl) -L-aspartic acid. The tetrasic acid or salts thereof are known compounds and known antitumour agents *

Fields of application of the invention are the pharmaceutical and chemical industry as well as medical facilities and facilities of the health service.

Characteristic of the known technical solutions

The tetraacid N- (phosphonoacetyl) -L-aspartic acid (PALA) was synthesized by Stark et al. (J. Biol. Chem. 246, 6599 (1971)). It has proven to be an anti-tumor agent (Cancer Res. 36, 2720 (1976)). So the over-

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lifetime of mice with intraperitoneal leukemia P38C after administration of PALA has been extended by up to 64% · PALA use was also successful in the treatment of Lewis lung saroom and melanoma B16. Mice treated with Ι-ΆΙιΑ lived in 77-86 % longer than untreated piglets (Hiremagalur N. Jayaram, Canoer Treatm., Reports 6 ^ 1291 (1979), B. Ardalau, Bioohem Pharmacol., 2045 (1981)). The synthase of the tetraacid PALA, its di- and tetra-alkali metal salts and other organic salts has been described several times (US Pat. Nos. 4,154,739 and 4,178,306, 4,215,070, 4,428,943, DE 2,849,396). All the processes described are based on the same production principle and differ essentially by the preparation of various salts. The key product of all syntheses is phosphonoacetyl chloride, which is prepared from phoephone acetic acid with thionyl chloride and used for the acylation of aspartic acid esters, such as di-benzyl ester or diethyl star. The processes lead to 87% pure products (US Pat. No. 4,428,943). The phosphonoacetyl chloride is used without further purification for the acylation. The hitherto customary work with the uncleaned product leads, however, to a series of undesirable by-products which disturb the course of further conversion to PALA. In the ³ P-UMR spectrum of the product of the reaction of phosphonoacetic acid with thionyl chloride (DE-PS 2849 396) we found 13 compounds containing phosphorus. Purely as a drug, however, the production of defined intermediates is desirable.

Object of the invention

The aim of the invention is the preparation of N- (ω-phosphonoacetyl) -L-aspartic acid or salts thereof by a process that circumvents the disadvantages described and leads to a high-quality product.

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Explanation of the essence of the invention

The object of the invention is to develop a process which avoids the difficulties of known processes and leads to N- (phosphonoacetyl) -L-aspartic acid or its salts in good yields. The object was achieved by obtaining trimethyl phosphonoacetate (Malavannaya, RA, Twetkov, E.I., Kabachnik, MI, Zh. Obahch. Khim., 41, 1426 (1971)), which according to the invention was obtained in a novel manner from methyl bromoacetate and trimethyl phosphite converted into phosphonoacetic acid P, P-dimethyl ester and L-aspartic acid di- (p-nitrobenzyl) ester to N- (phosphonoacetyl) -L-aspartic acid di (p-nitrobenzyl) ester -P, P- dimethyl ester is reacted. Surprisingly, it has been shown that when using the phosphonoacetic acid P, P-dimethyl ester a much purer target product is formed. This reaction path has not yet been taken. The tetraester is then succesively freed from the ester moieties and placed in a pharmaceutically acceptable form, e.g. the disodium salt, transferred. The process thus carried out bypasses the undesired stage of the phosphonoacetyl chloride and the synthesis problems that occur and leads to readily manageable intermediates. Another advantage is the good accessibility of the starting compounds and the ease of reaction. The use of L-aspartic acid di (p-nitrobenzyl) ester allows, in addition to simplified saponification, the gentle hydrogenation of the p-nitrobenzyl ester groups.

The resulting PALA is converted into the di-natriurase salt by methods known in the literature (e.g., as described in DE 2,849,396).

The di-sodium salt thus prepared shows better results on the animal model compared to the literature (Schabel, PM et al., Iivjs Cancer: Progress in Therapeutic Research, Raven Press, New York, 15-35). The cytostatic activity of the Na salt was detected on the F 388 leukemia and B 16 Melanoni model.

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Ausführungsbeispieile

Example 1: Phosphonoacetyl chloride

Produced according to DB 2 849 396.

³¹ P NMR

" ³¹ P: 26.6" 7.0 (intensity greater than 20%) 26.8, 8.7, 8.0, 7.7 (intensity greater than 5%) 16.0, 15.0, 7.5} -2,7} -2,9} -3,5; -3,9 (intensity

less than 5% 'j

Example 2x phosphonoacetic acid P ^ dimethyl ester

0.1 mol (18.2 g) of phosphonoacetic acid trimethylaster, prepared from methyl bromoacetate and trimethyl ^ hospij.it, are dissolved in 40 ml of absolute methanol. To this is slowly added dropwise a solution of 0.1 mol (5.6 g) of potassium hydroxide in 40 ml of absolute methanol and the solution is evaporated after standing for one hour at 50 ⁰ C in vacuo. The residue is taken up with 8 ml of absolute methanol was added to turbidity with absolute acetone (about 0.5 1) and after standing at 5 ⁰ C 24stündigera separated the Kaliv / iasalz under exclusion of atmospheric moisture. 14.8 * r (72 # yield); Pp 118-121 ⁰ C: ¹ H-NMR (D ₂ ^°): ^ p_ _CH 2.96 ppm, d (J «22 Hz);. ³¹ P NMR (H _? 0): £ '$ 0 ppm. ²

To the suspension of 0.072 mol (14i8 g) K salt in? 5 mL of absolute acetone HOl are added at 0 ⁰ C portionwise 205 ml ether, TFACH the separation of the KCl Piltrat is concentrated. After prolonged standing in the refrigerator, the syrup crystallizes. 11.6 g (96% yield - based on the K salt); ¹ H-NMR _(CDCl3): ^ _{p "CH} 2.97 ppm, d (J =" 22 Hz), cf _p _ _0ME 3.76 ppm, d (J = 11 Hz); ³¹ P-NMR ² (H ₉ 0i: ^ 26.3 ppm.

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Example 3 N, N-phosphono-1-ol-aspartic acid-di-ip-nitrobenzyl) -ei3ter-P, P-dimethyl ester

5mnol (2.2g) Aap (ONb) ΟΛ & Ή01 are dissolved in 20ml DLO ¹ and treated with 5mmol (0.7ml) triethylamine. After addition of 5 mmol (840 mg) phosphonoacetic acid PjP dimet'iylester and 7.5 mmol (1.3 g) HONB is au.f -20 ⁰ C cooled and treated with 5.5 mmol DCCI. It is stirred overnight at room temperature. After aspirating the resulting Dicyclo ^ xylharnstoffes is concentrated and the oil was taken up in 50 ml of ethyl acetate. Ee is shaken out with 20 ml of 5% KHSO.-solution, 5% NaHCO.sub.2 solution and water. The organic phase is separated, dried and the solvent removed in vacuo. Am yellow oil stays behind. 2.2 g (79% yield). ¹ H-NMR (CDClO), Γ ρ_ _0Η 2.88 ppm d (J »21 Hz), cf _{p _0Me} 3.70 ppm d (J-11 Ha); 13 ₀ _ ² _NHR (CDCl _3): P ^ ^{CH-34 '1 ppm'} · d (J = 132 Hz), <f _p-0ME 53.2 ppm, d (J 6 Hz.) <F 00- CH ₂ ³⁶ ' ^{1 ppa} / ^ CO-CH ⁴⁹ ' ^{1 ppm} »^ Ar-CH ₂ ⁶⁵ ' ^{4 and 66> O Ppm} '<iQQ 16§, 9 and 170, 2 ppm, <^ _Νσο 164,0 and 16 ^, 2 ppm.

Example 4: N-Phosphonoacetyl J-L-aspartic acid di-ip-nitrobenzene

3.25 mmol (1.8 g)! - (phosphonoacetyl-L-asparafic acid di-ip-nitrobenzyl) -eater-P, P-dimethyl ester are stirred at room temperature with 25 ml of 1.5N HBr / glacial acetic acid for one hour. The mixture is then added to 300 ml of absolute ether. The separating oily product solidifies after a short time. It is filtered off with suction, washed with ether and dried. Yield: 1.35 g (75% yield) Pp 197-203 ⁰ C..

Example 5: N-hosiphonoacetyl-L-aspartic acid di-sodium salt

a) 900 mg of N-iPhosphonuacötylJ-L-aspartic acid di-ip-nitrobenzyl) ester are generally hydrogenated 15 ml of methanol with the addition of catalytic amount of glacial acetic acid 3 h with 100 m ^ · palladium black, the lÖBung concentrated and the residue after DE OS 2 849 396 in. The disodium salt converted.

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b) 1.3 g of N- (phosphonoaoetyl) -L-aspartic acid di- (p-nitrobenzyl) ester are obtained with 0.6 g of NaOH in 9, 1? saponified HgO for 3 hours at 5-15 ⁰ C and transferred to the disodium scale. ¹ H-NM (D ₂ O), <T _p _ _CH 2.77 ppm, d (J = 20 Hz).

Example 6: Testing of the preparation PALA

Testing on Mouse LEWIS-lung carcinoma (LL).

The Tijnor was injected as a diluted slurry i.m. applied. The tumor rapidly metastasizes to the lungs, causing the animals to die from lung metastases.

Tumor: LL i.m

Animals: BDP ₁ male

Substance treatment: i.p., d 1-4 and 7-11 body weight: 4 · experimental day Results:

Dose MdST T / C '% ÄKG% Long term survival.

(mg / kg / Appl.) (days)

200 90 300 - 4 9 out of 10 animals

0 (Rontrolle) 27 +40 of 30 animals

Of the 10 animals treated, 1 animal with tumor died on the 45th day of the experiment. The surviving 9 animals were sacrificed 220 days after the start of the experiment. They were macroscopic without a tumor finding.

Claims (2)

IU 09L claims 1. A process for the preparation of N- (phosphonoacetyl) -L-asparagingsäure, characterized in that Phoaphonoessigsäure P, P-dimethyl ester with L-aspartic acid di (p-nitrobenayl) ester reacted and saponifying the resulting product and is hydrogenated. 2. Process according to Claim 1, characterized in that the phosphonoacetic acid trimethyl ester required for the preparation of the phosphonoacetic acid P 1 -dimethyl ester is prepared from bromoacetic acid methyl ester and trimethyl phosphite.