DK157082B - PROCEDURE FOR THE PREPARATION OF ADRIAMYCINE AND ITS HALOGENEAL SALTS - Google Patents

Description

DK 157082 B

The present invention relates to a particular process for the preparation of adriamycin and its halide salts.

It is well known in the art that adriamycin is an anti-tumor anti-biotic used in the form of a halide for the treatment of tumor diseases. Adriamycin can be produced directly by fermentation (Belgian Patent No. 713,773) or by semisynthetic route from daunomycin (German Patent No. 1,917,874 and U.S. Patent No. 4,012,448).

De-semisynthetic processes based on daunomycin and comprising the preparation of daunomycinone and 7-deoxydaunomycinone as intermediates are very complicated, since not only the starting material must be converted during the process, but the adriamycin sugar component, daunozamine, must also be bound. molecule.

Adriamycin can be prepared by a simpler route from daunomycin via the latter's 14-halogen derivative without altering the structure of the sugar moiety of the molecule (German Patent No. 1,917,874).

According to this method, a bromination can be made directly by using a solution of bromine in chloroform while protecting the amino group of the daunozamine during an iodination by converting the daunozamine 20 to an acyl derivative or a Schiff base, then removing the protecting group and the adriam thus obtained. purified by column chromatography.

The simplest way to produce adriamycin from daunomycin by a semi-synthetic route seems to be by direct bromination of daunomycin.

In reproducing this process, however, the inventors have found that the daunozamine and side chain containing the 14-carbon atom can be readily cleaved, thereby forming 14-bromine daunomycinone and other side-chain degradation products. Thus, the bromination reaction results in a rather low yield, i.e. 58-59%. Given that the molecule is sensitive to acids and bases and sensitive to oxidation, further losses occur during the replacement of the bromine atom in 14-bromodonomycin by a hydroxy group and by purification of the product.

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2, whereby the yield calculated from the starting daunomycin is only approx. 6-13%.

The present invention aims to develop a semi-synthetic method based on daunomycin which enables the preparation of adriamycin in a simpler and more economical way.

The invention thus relates to a process for the preparation of adriamycin of the formula

O OH

CHgO O OH ή HO

10 and halide salts thereof from daunomycin or halide salts thereof, wherein daunomycin of the formula

O OH

CH, O O OH

d O

I hh2

HAY

15 or a halide salt thereof is reacted with bromine in an anhydrous organic solvent system providing a solvent suitable for ketal formation followed by conversion of the formed 14-bromo derivative to a 14-hydroxy derivative, the solution optionally being 20 g of acidic acid with a halogen followed by the extraction of the product, which is characterized by the fact that 3

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a) the bromination is carried out at a temperature in the range of 0-20 ° C; b) the 14-bromo derivative is converted to the 14-hydroxy derivative via the corresponding 14-formyloxy derivative; c) before hydrolysis of 14-forayloxydaunomycin, extraction at a pH of And d) the adriamycin phase formed is recovered by chloroform extraction.

From European Patent Specification No. 39,060, cf. Example 4, a process for preparing adriamycin from daunomycin is known, wherein 10 daunomycin in a solvent consisting of anhydrous methanol, methyl orthoformate and dioxane is brominated at a temperature of 25 ° C followed by extraction of the 14-bromo compound formed and its treatment. in a sodium phosphate buffer at pH 11, Applicants have found that the process of the invention provides a substantially better yield of adriamycin than that of European patent no.

39,060 known method.

During the reaction, the solvent suitable for ketal formation reacts; for example, triethyl orthoformate, with the enol form of the 13-keto group of daunomycin molecule formed due to the bromine present, 20 thereby forming a ketal which stabilizes the molecule and prevents side reactions and alkyl group cleavage.

The solvent suitable for ketone formation, for example triethyl orthoformate, may preferably be used in a molar amount of 1: 3-4 calculated from the daunomycin or hydrochloride salt thereof. In this way, the 25-bromodonomycin derivative can be obtained in higher yields. By using, for example, triethyl orthoacetate, methyl formate or ethyl acetate, similar good yields can also be obtained.

In the process of the invention, the 14-bromodonomycin derivative does not need to be recovered, since the acetonic solution of 14-bromodonomycin treated with hydrogen bromide can be used directly in a process in which the bromine atom is replaced by a hydroxy group.

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According to the experiments of the invention, this process can be carried out more favorably via the 14-formyloxy derivative than by the known direct conversion of the bromine atom to the hydroxy group by treatment with sodium hydroxide. The hydrolysis of the 14-formyloxy derivative at a pH of 7.6 to 8.0 ensures far more favorable conditions for the adriamycin, which is less resistant to alkaline reagents than to acids, than the basic treatment at pH 10.3.

After the alkaline hydrolysis of 4-formyloxydaunomycin, the reaction mixture is extracted with chloroform at pH 3.5-4.0 to remove 10 aglycone degradation products.

The pH of 7.6-8.0 required for the hydrolysis is preferably adjusted by a 5% by weight sodium hydrogen carbonate solution, the resulting adriamycin base being recovered from the reaction mixture by repeated extraction with chloroform. The extracts are concentrated and treated with a solution of hydrochloric acid in methanol to form adriamycin hydrochloride, which is then precipitated from the solution by ether.

Adriamycin is used in the form of a halide salt for the preparation of drugs, possibly after purification. Purification is performed in a manner known per se.

The invention is illustrated by the following Examples: Example 1 1.4 g (2.48 millimoles) of daunomycin hydrochloride is dissolved in a mixture of 20 ml of anhydrous methyl alcohol, 56 ml of anhydrous dioxane and 1.4 ml (8.47 millimoles) of anhydrous triethyl orthoformate. To the thus obtained solution, 0.5 g (3.16 millimoles) of bromine dissolved in 5.4 ml of anhydrous chloroform is added and the flask is closed and kept at 8 ° C for 5 hours. The reaction mixture is poured into a mixture of 280 ml of diethyl ether and 120 ml of petroleum ether, and the precipitated product is filtered off and washed with 30 3 x 30 ml of diethyl ether to remove impurities. The precipitate is then dissolved in a mixture of 40 ml of acetone and 40 ml of 0.25N aqueous hydrogel

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gene bromide and kept at 25 ° G for 17 hours. Then, a solution of 2.0 g (29.4 millimoles) of sodium formate in 20 ml of deionized water is added to the solution and stirred for 48 hours at 25 ° C. The pH of the reaction mixture is adjusted to 3.7 by the addition of 1N hydrochloric acid solution and extracted with 5 x 50 ml of chloroform. The pH of the aqueous phase is then adjusted to 7.6 by adding a 5% solution of sodium bicarbonate and the adriamycin base is extracted from the mixture. Extraction is continued until the chlorophore extract is stained. The chloroform extracts are washed with 5% deionized water calculated from the volume of the extracts and triturated over anhydrous sodium sulfate. After filtering the curing agent, the solution is concentrated to a volume of 50 ml. The free base is converted to its hydrochloride salt by treatment with a calculated amount of anhydrous hydrochloric acid solution in methanol and the salt is precipitated by 500 ml of diethyl ether. The precipitated product is filtered off, washed four times with 30 ml of diethyl ether, and terreserved in vacuum at room temperature. Yield: 0.61 g (42.4%) of adriamyein hydrochloride.

The analytical data of the product are listed below:

Analysis: Calculated for (1110, 36.580.0): C 55.9 H 5.21 N 2.42 Cl 6.11 Found: C 55.52 H 5.10 N 2.04 Cl 6.24

Melting point: 202-206 ° C (with transmitter division)

Thin-layer chromatography: Adsorbent: Kieselgel 60 (Merck 5724) impregnated with a 1% oxalic acid solution

Eluent: The evers phase of a 4: 1: 5 mixture of n-butanol / acetic acid / water Development: 10 cm 30 Rf Value: 0.33

Infrared spectrum (apparatus: Perkin-Elmer type 397, KBr tablet) .1 v cm * · 3420 O-H bond (hydrogen bond) 2980-2920 NH3 + and C-H bond (hydrogen bond)

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6 1725 0 = 0 ketone 1615 and 1580 OO (intrahydrogen bond, quinone) 1280 COC (ether) 1115 CO tert-alcohol.5 1070 C-0-sec alcohol 1010 C-0-primary alcohol NMR: (Uses WP 200 SY pulse FT;% NMR, DMSO-d6, room temperature, S ppm, 250 MHz) δ (ppm) 1.17 3H, d, CH3-5 '1.6 / 1.9 2H, m, CH 2 '2.15 2H, m, CH2-9 2.9 / 3.00 2H, AB, CH2-7 3.7 1H, m, H-4' 4.0 3H, s, OCH3 4.2 1H, m , H-5 '4.58 / 4.61 2H, AB, CH2-14 4.9 1H, m, H-10 5.3 1H, m, H1' 7.65 1H, m, H-3 7.9 5H, m, H-4, H-2, NH 3 + 13.25 1H, bs, OH-6 14.05 1H, s, OH-11 13 C NMR (50.3 MHz, D 2 O, 310 ° K) S (ppm ) carbon 217.1 13 188.1 (12), (5) x 163.0 1 30 158.2 11 156.6 6 139.2 3 13, 4 (10a), (4a), (6a) x 122.0 (4), (2) 35 ) x 7

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121.3 (12a) 113.1 (5a), (lla) x 101.5 1 '78.5 8 5 71.1 10 69.8 (4') x 68.9 (5 ') 67.1 14 10 59.1 OCH3 49.6 3' 37.9 9 34 EXAMPLE 2 1.4 g (2.48 millimoles) of daunomycin hydrochloride are dissolved in a mixture of 40 ml of anhydrous methyl alcohol and 0.55 ml (8.7 millimoles). anhydrous methyl formate. To the thus obtained solution is added 0.5 g (3.16 millimoles) of bromine in 5.4 ml of anhydrous chloroform and the flask is closed and kept at 10 ° C for 4.5 hours.

The reaction mixture is poured into a mixture of 280 ml of diethyl ether and 120 ml of petroleum ether, the precipitated product is filtered off and the impurities are removed by washing with 3 x 30 ml of diethyl ether. The product is dissolved in a mixture of 40 ml of acetone and 40 ml of 0.25N aqueous hydrogen bromide and kept at a temperature of 25 ° C for 17 hours. Then, a solution of 2.0 g (29.4 millimoles) of sodium formate in 20 ml of deionized water is added to the reaction mixture and the solution is stirred for 48 hours at 25 ° C.

The reaction mixture thus obtained is worked up like Example 1.

8

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Yield: 0.55 g (38.6%)

The end product identification data is the same as in Example 1.

EXAMPLE 3 0.70 g (1.24 millimoles) of daunomycin hydrochloride is dissolved in a mixture of 10 ml of anhydrous methyl alcohol, 30 ml of anhydrous dioxane and 0.42 ml (4.30 millimoles) of ethyl acetate. To the thus obtained solution is added 0.25 g (1.58 millimoles) of bromine in 2.7 ml of anhydrous chloroform and the flask is closed and kept at 6 ° C for 6 hours.

The reaction mixture is poured into a mixture of 140 ml diethyl ether and 60 ml petroleum ether, the precipitated product is filtered off and the impurities are removed by washing with 3 x 15 ml diethyl ether. The product is dissolved in a mixture of 20 ml of acetone and 20 ml of 0.25N aqueous hydrogen bromide and kept at a temperature of 25 ° C for 17 hours. Then, a solution of 1.0 g (14.7 millimoles) of sodium formate in 10 ml of deionized water is added to the reaction mixture and the mixture is stirred at 25 ° C for 48 hours.

The pH of the reaction mixture is adjusted to 3.7 by the addition of 1N hydrochloric acid solution and the mixture is extracted five times with chloroform. The pH of the aqueous phase is adjusted to 7.6 by the addition of a 5% solution of sodium bicarbonate and the adriamycin base is recovered by extraction. Extraction is continued until the chlorophore extract is colorless. The chloroform extracts are washed with 5% deionized water calculated from the volume of the extracts and thereafter triturated over anhydrous sodium sulfate. After filtration of the desiccant, the solution is concentrated in vacuo to a volume of 25 ml. The free base is converted to its hydrochloride salt by treatment with a calculated amount of 0.6N anhydrous methanolic hydrochloric acid solution, after which the salt is precipitated by 250 ml of diethyl ether. The 30 precipitated product is filtered off, washed with 4 x 15 ml of diethyl ether and dried in vacuo at room temperature.

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Yield: 0.29 g (40.3%).

The identification data are the same as in Example 1.

Example 4 0.70 g (1.24 millimoles) of daunomycin hydrochloride is dissolved in a mixture 5 of 10 ml of anhydrous methyl alcohol, 30 ml of dioxane and 0.8 ml (4.35 ml) of triethyl orthoacetate. To the thus obtained mixture is added 0.25 g (1.58 millimoles) of bromine in 2.7 ml of anhydrous chloroform and the flask is closed and kept at 6 ° C for 6 hours.

The reaction mixture is poured into a mixture of 140 ml diethyl ether and 60 ml petroleum ether, the precipitated product is filtered off and the impurities are removed by washing with 3 x 15 ml diethyl ether. The product is dissolved in a mixture of 20 ml of acetone and 20 ml of 0.25N aqueous hydrogen bromide and kept at 25 ° C for 17 hours. Then, a solution of 1.0 g (14.7 millimoles) of sodium formate in 10 ml of deionized water is added to the reaction mixture and the mixture is stirred at a temperature of 25 ° G for 48 hours.

The reaction mixture thus obtained is worked up like Example 3.

Yield: 0.30 g (41.7%).

The end product identification data is the same as that of Example 1.

Claims (7)

A process for the preparation of adriamycin of the formula O OH CH3 O O OH ^ 'fç = s'1 HO and their halide salts from daunomycin or halide salts thereof, wherein daunomycin of the formula o OH CH * 0 0 OH: 3 ό "W" NH2 10 H0 or a halide salt thereof is reacted with bromine in an anhydrous organic solvent system in the presence of a solvent suitable for ketal formation, followed by conversion of the formed 14-bromo derivative into a 14-hydroxydrivate, the solution optionally containing 15 g of acidic acid with a halogenated acid , followed by recovery of the product, characterized in that a) the bromination is carried out at a temperature in the range 0-20 ° C, b) the 14-bromo derivative is converted to the 14-hydroxy derivative via the corresponding 14-formyloxy derivative, c) before hydrolysis of 14 formyloxydaunomycin is extracted at a pH of 3.5-4.0, and DK 157082 B from the adriamyciribase formed is recovered by chloroform extraction. Process according to claim 1, characterized in that the bromination is carried out at 8 ° C and 5 is carried out for 3-30 hours, preferably for 5 hours. 3. A process according to claim 1 or 2, characterized in that as an solvent suitable for ketting, an alkyl orthoalkane carboxylate or alkyl alkanoylate containing 1-6 carbon atoms is used in the alkyl moieties. Process according to claim 3, characterized in that triethyl orthoformate is used as alkyl orthoalkane carboxylate. 5. A process according to claim 3, characterized in that ethyl acetate is used as alkyl alkanoylate. Process according to any one of claims 1-5, characterized in that a mixture of methanol and dioxane in a volume ratio of 1: 2-5 is used as an anhydrous organic solvent. Process according to any one of claims 1-6, characterized in that the conversion of the 14-bromo derivative to the 14-hydroxy derivative via the 14-formyloxy derivative is carried out by precipitating the 14-bromo derivative in an organic solvent, reacting with hydrogen bromide in the presence. of acetone and an alkaline formate, preferably sodium formate, extract the reaction mixture thus obtained in two steps with chloroform by adjusting the pH and recovering the product, optionally as a halide salt.