DD267495A1 - PROCESS FOR PREPARING A NEW METHOTREXATE DERIVATIVITY WITH REDUCED TOXICITY - Google Patents

Abstract

The invention describes a process for the preparation of a novel methotrexate derivative, a cancerostatic agent used in the medical field, preferably in human medicine, by hydroxymethylation of the amino groups of the pteridine ring with formaldehyde in aqueous alkaline solution.

Description

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By binding methotrexate to various natural and synthetic polymers, attempts have been made to reduce these toxic side effects. (Ringsdorf, H., Angewandte Chemie 93 (1981), pp. 311-332; Makromol. Chemie 179 [1978], pp. 1719-1733). This goal has not been achieved to date. Additional undesirable side effects caused by the polymeric carrier meant that these materials could not be used in the clinical trial. According to the current state of the elucidation of the mechanism of action of methotrexate, the free amino groups in the 2- and in particular the 4-position of methotrexate (see formula I) are an unconditional prerequisite for the desired antineoplastic action, ie the inhibition of dihydrofolic acid reductase (DHFR). Substitution of the hydrogen of the amino groups by acyl or alkyl groups, which is possible by reactions customary in organic chemistry, leads to the complete or partial loss of the ar.tineoplastic action (cf., Cancer Medicine, ed. JF Holland, E. Frei, Verlag Linda & Febinger, Philadelphia, USA. 1973, page 739ff.).

Object of the invention

The aim of the invention is the development of a process for the well reproducible production of a novel methotrexate derivative, which should have a reduced general toxicity and improved or at least the same effect effectiveness as the free MTX.

Object of the invention

The object of the invention is to develop a process for the preparation of a methotrexate derivative in which low molecular weight organic compounds are bonded to the NHj groups of the pteridine ring and whose product is to have an improved antineoplastic action.

According to the invention the object is achieved in that by reacting 1 mole with 4 to 10 moles of formaldehyde in alkaline aqueous solution over a period of 1.5 to 4 hours at a temperature of 303 K to 363 K and a pH of 7.5 to 11, a tetrahydroxymethyl-MTX, Formula II, is prepared.

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The product is isolated by removing water and excess formaldehyde under reduced pressure by adding dilute hydrochloric acid after adjusting to a pH of between 7.2 and 7.4, which is necessary for use in a living organism. It is present as a readily water-soluble di-sodium salt and can be used directly for the preparation of injection or infusion solutions.

The substance was tested in the in vivo screening test for its antineoplastic activity, obtaining the results summarized in Tables 1 and 2.

Test material was BDFp mice (10 animals per test group). Test tumors were the leukemia P388 and the molanoma B16. The test substance was injected intraperitoneally into the animals. The reference material was pure methotrexate disodium salt.

It is surprising to note that despite the complete substitution of all the hydrogen atoms of the amino groups, the product according to the invention has at least a comparable and sometimes even significantly better effect than MTX on the free MTX.

Ausführungsbelsplel

4.98 g (0.01 mol) of di-sodium methotrexate are dissolved in 100 ml of water and 5.0 ml of 30% aqueous formaldehyde solution (0.05 mol) are added. The pH of the reaction mixture is adjusted to 9.2 with dilute aqueous sodium hydroxide solution and the solution is heated to 323 K with stirring. The mixture is stirred for 2.5 hours at this temperature, then the mixture is cooled to room temperature and neutralized to adjust the pH to 9.2 amount of NaOH by addition of the equivalent amount of 1 η HCl neutralized.

By removing the water and the excess formaldehyde under reduced pressure (about 1 x 10 ³ Pa) at max. 303K, the tetrahydroxymethyl-MTX is obtained as the disodium salt.

It is heated in vacuo (<1 10 ² Pa) at max. 313K dried.

The product contains no ether bonds and no methylene bridges.

Table 1 Life of BDF, mice after i. p. Application άιΎ Loukemia P 388 and after administration of the test substance and MTX in comparison to untreated tumor-bearing control animals

Dose ι \ pplikationstag test substance Life in 1agen control [Mg / kg / lnj.] lachTumor- MTX nkubation 12 10 80 I, 14 12 10 60 11 10 10 30 , 10 13 10 20 _t 14 10 10 10 .-4. 14 6 10 5 .-4. 14 12 10 2.5 .-4. 14

Table 2 Life of BDF, mice after i. p. Application of melanoma B16 and after administration of the test substance and MTX in comparison to untreated tumor-bearing control animals

dose Applikationstag test substance Lifetime in days control [Mg / kg / lnj.) after tumor MTX incubation 34 30 80 1. 34 35 30 60 1. 33 31 30 40 1. 34 29 26 40 1st, 5th, 9th 33 24 26 20 1st, 5th, 9th 34 26 26 10 1st, 5th, 9th 26

Claims (1)

Claim: A process for the preparation of a novel methotrexate derivative of reduced toxicity, characterized in that tetrahydroxymethyl methotrexate from methotrexate in aqueous phase with 4-10 moles of formaldehyde mol methotrexate at 303 to 363K, a pH of 7.2 to 11.1, 5 to 4 hours is synthesized. Field of application of the invention The invention relates to a process for the preparation of a novel methotrexate derivative which can be used in the medical field, in particular in human medicine. Characteristic of the known state of the art It is known that the cytostatic methotrexate (MTX) (formula I) is not only toxic to neoplastic tissue but also severely damaged oral tissue and healthy organs.