DE2414416A1 - 3',4'-Didesoxy-kanamycin B from protected gentamine Cla - by reaction with protected 3-amino-3-desoxy-D-glucopyranosyl halide - Google Patents

Abstract

31,41-Didesoxykanamycin B (I) is prepd. by reacting a 4-O-(1,6-diamino-2,3,4,6-tetradesoxy-alpha-D-glucopyranosyl) -2-desoxystreptamine (II) (i.e., gentamine C1a) in which the amino gps. are protected, with a 3-amino-3-desoxy-D-glucopyranosyl halide (III) in which the amino and hydroxyl gps. are protected, and subjecting the prodt. to hydrogenolysis and/or hydrolysis to remove the protecting gps. (I) is an antibacterial agent active against Gram-negative and -positive bacteria, including kanamycin-resistant strains.

Description

Process for the preparation of 3 ', 4'-dideoxykanamycin B 3', 4'-dideoxykanamycin B is a product known since 1971 that has antibacterial properties. It inhibits the growth of bacterial strains such as kanamycin B, however, is also very active Staphylococci resistant to kanamycin and kanamycin B, resistant Echericpia coli and resistant Pseudomonas strains. It shows a strong therapeutic effect with low toxicity (LD50 180 mg / kg mouse i.v.) against infections caused by Staphylococci, Klebsiella pneumonia, Salmonella typhosa and Pseudomonas aeruginosa in mice. The 3 ', 4'-dideoxykanamycin B is a valuable one Chemotherapy drug used to treat various infections caused by gram negative and gram-positive resistant bacteria are produced.

The procedure for preparing the 31,4'-dideoxykanamycin B was 1971 by H. Umezawa et. al. in Journal of Antibiotics 26,485 (1971) in a short communication released. The detailed description followed in 1972 in Bull. Chem. Soc. Japan 45, 3624 (1972), cf.

also DOS 2,135,191. Umezawa et al. take Kanamycin B as the starting product and convert it into the 3 ', 4t-dideoxykanamycin in an 11-step reaction sequence B around. The overall yield is 2.3% over all stages.

A simple process for the preparation of 3 ', 4'-dideoxykanamycin B of the formula I, which comprises only four steps and provides significantly higher yields, has now been found found that is characterized 'that the 4-0- (2,6-diamino-2,3,4,6-tetradeoxy-α D-glucopyranosyl) -2-deoxystreptamine (gentamine C1a) of the formula II 'whose amino groups are protected in a manner known per se, with a 3-amino-3-deoxy-D-gluocopyranosyl halide of the general formula III in which Hal stands for a halogen atom and whose amino and hydroxyl groups are likewise protected in a manner known per se, reacted and the 3,4'-dideoxykanamycin B of the formula I is obtained by hydrogenolysis and / or hydrolysis of the N and O protective groups.

Compounds of the formula II whose amino groups are protected are, in particular, compounds of the formula IV into consideration, wherein R1 is hydrogen, alkyl, aralkyl, aryl, alkyl-.

oxy, aralkyloxy or aryloxy and R2 stands for hydrogen, alkyl, aralkyl or aryl.

In addition to hydrogen, R1 can, for example, have the meaning of branched or unbranched alkyl having 1 to 12, preferably 1 to 4, carbon atoms, such as methyl, ethyl, propyl, iso-propyl, -n-butyl> sec.-butyl, iso-butyl, tert-butyl, from Aryi such as the group where R4 and R5 are identical or different and are each hydrogen, fluorine, chlorine, bromine, a hydroxyl or nitro group, low molecular weight alkyl such as methyl, ethyl, propyl or butyl low molecular weight alkoxy such as methoxy, ethoxy, propoxy or butoxy or aryl of the above definition, of aralkyl, in which aryl has the above meaning and alkyl zOB is methyl, ethyl, propyl or butyl, of alkyloxy, aryloxy and aralkyloxy, in which alkyl, aryl and aralkyl can also have the meanings given above.

R2 can, for example, stand for hydrogen, for alkyl with 1 to 12 carbon atoms, such as methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, tert. = Butyl, sec-butyl, eptyl, decyl, undecyl, dodecyl , for aryl, which, for example, can have the meaning given under R1 or the meaning of naphthyl or substituted naphthyl, but preferably of phenyl, or for aralkyl, where aryl and alkyl have the above meaning. 1 As protected compounds of the formula III @, in particular compounds of the formula V in respect of where Hal stands for a halogen atom, R3 stands for an alkyl, aralkyl or aryl radical and R1 has the above meaning.

Halogen can in particular stand for chlorine and bromine, preferably chlorine.

R3 can have the meaning of alkyl with 1 to 12, preferably 1 to 4 carbon atoms, such as methyl, ethyl, propyl, butyl, of aryl, for example with the meaning given under R1, of aralkyl, wherein aryl has the above Has meaning and alkyl can be e.g. methyl, methyl, propyl or butyl, preferably benzyl.

The amino-protected 4-0- (2,6-diamino-2,3,4,6-tetradeoxy-α-D-glucopyranosyl) -2-deoxystreptamine used as starting product is obtained by adding gentamine C1a of the formula II conventional acylation methods described, for example, in Houben-Weyl XI, 2, page 3 ff (1958), or by reaction with aldehydes in a known manner (cf., for example, Houben-Weyl Viel, 1, page 456 ff. (1954)) into the compounds of the formula is convicted.

For example, gentamine C1a with ethyl chloroformate can be used in acetone / water in the presence of sodium carbonate to tetra-N-ethoxycarbonylgentamine e cola or gentamine C 1a in ethanol with benzaldehyde to form tetra-N-benzylidenegentamine The other component, the N- and O-protected 3-amino-3-deoxy-D-glucopyranosyl halide is known from the literature and in Bull. Chem.

Soc. Yep 41, page 2765 (1968).

According to the invention, the two above-mentioned components are condensed in a reaction that can be carried out easily, whereby using the above-listed compounds of the formulas IV and V with elimination of hydrogen halide, products of the general formula VI arise, in which R1, R2 and R3 have the above meaning.

The condensation of the starting compounds, in particular of the formula IV and V are used in a polar or non-polar solvent or

Solvent mixture carried out, with the reaction components in the molar ratio or one of the components can be present in excess. Advantageous is to use the compound of formula V in about two to three times excess, in order to achieve the most complete implementation possible.

Suitable solvents are all those with the glucopyranosyl halide, especially of the formula V, cannot enter into a reaction, such as dimethyl sulfoxide, Dimethylformamide, ether, benzo, dioxane, nitroalkane, toluene, chloroform, methylene chloride, ÄthylenglYkoldialkyläther or ¢ emische the solvents. As particularly beneficial has proven to be a mixture of benzene / dioxane, which in the composition in one can be varied over a wide range of ratios. The ratio 3 is advantageous Parts of benzene: 1 part of dioxane (volume). Nitromethane and benzene are particularly suitable or ether.

The condensation reaction is carried out in the presence of metal salts, in particular salts of transition metals, which cause the detachment of the halogen from the Facilitate glucopyranosyl halide.

These include e.g. silver, cadmium and mercury salts, which in excess, in the molar ratio or less, but preferably about 5- to 20-fold excess can be applied.

The anion can be selected from the most varied organic or inorganic Acids originate, such as e.g. the sulfate ion, halide ion, perchlorate ion, nitrate ion, Carbonation, oxidation, 4-hydroxy-valeriation, salicylation, cyanide ion, acetate ion, Oxalation or succination. The condensation reaction according to the invention is preferred carried out in the presence of mercury cyanide, the total amount of the mercury salt not all at once, but also in portions after, for example, several hours of reaction intervals can be added.

It is advisable to carry out the condensation according to the invention under anhydrous Conditions to carry out. For this purpose, it is advantageous to add a dehydrating agent to the reaction mixture To add agents such as

anhydrous calcium sulfate, anhydrous sodium sulfate, calcium chloride, a molecular sieve or other neutral drying agent.

If calcium sulfate is used, it can be activated before addition by leaving it for a long time, e.g. 2 to 11 hours to 200 to 2800 heated.

The reaction temperature can be in a wide range between about -20 and the boiling point of the solvent or solvent mixture can be varied. In the case of a benzene / Dioxane mixture as a solvent worked between about 40 and about 1000. The reaction time is about 1 hour up to several days. It is largely dependent on the temperature used and the reactivity of the compounds used.

It is advantageous to monitor the progress of the condensation reaction by thin-layer chromatography Check control, for example on silica gel with a solvent mixture, that from the lower phase chloroform, methanol, conc. Ammonia 1: 1: 1, consists, chromatographed.

After the condensation reaction according to the invention, a product mixture is formed from which the 3 ',' 1-dideoxykanamycin B derivative in good yield, e.g. after precipitation inorganic by-products and evaporation of the reaction solution directly through crystallization is obtained in a suitable solvent, preferably benzene.

It is also possible, for example, the residue of the evaporated Working up the reaction solution by chromatography, with a chromatography on silica gel using chloroform / methanol 30: 1 as the eluent has proven particularly effective.

The smooth condensation reaction which preferably takes place to give the 3 ', 119-dideoxykanamycin B derivative is surprising, especially since there are two hydroxyl groups in the compound of the formula react with the compound of the formula #V and to this end, further α- and β-anomeric products can arise, so that, without considering further side reactions, the occurrence of at least four compounds in approximately the same proportions would have been expected.

It was therefore not to be expected that the N- and 0-protected 3 ', 4 '-Dideoxykanamycin B is preferably formed and, moreover, is also still can be separated immediately in a very simple form by crystallization.

One would have expected that the crystallization would take place at the same time by-products are also deposited.

The removal of the N and O protective groups can be carried out in a manner known per se Way.

So the crystalline condensation product of the formula VI is acylated with Amino groups converted into 3,4t-dideoxykanamycin B by methods known from the literature. The hydroxyl protecting groups in the 3-amino-3-deoxy-D-glucose part are hydrogenolytic in a polar or non-polar solvent or solvent mixture with addition a catalyst removed. To accelerate the reaction, catalytic Amounts of acid, for example acetic acid, are added. Used as a catalyst one expediently palladium black or palladium on charcoal, the palladium content can be varied over a wide range. 30% palladium is preferred Used coal. But it can, for example, also be platinum, Raney nickel or others customary hydrogenation catalysts are used. The hydrogenolysis takes place preferably in alcohols or in alcohol / water mixtures, for example ethanol / water 10: 3. The reaction temperature is between about 00 and the boiling point of the solvent or mixed solvent. Is preferred at room temperature under normal or Filtered overpressure. The compound with free hydroxyl groups can after evaporation of the solvent can be obtained in crystalline and pure form.

If the amino groups are protected over ship bases, the Schiff bases before hydrogenolysis e.g. with dilute acid according to known methods, such as, for example, Houben-Weyl VII, 1, page 458 (1954) on the compound with free amino groups split.

If the amino groups are protected via acyl compounds, the acyl protective groups are according to methods known from the literature (cf. Houben-Weyl XI, 1, page 926 ff (1957)), e.g. removed by alkaline hydrolysis or hydrazinolysis.

The hydrolysis is expediently carried out in such a way that For example, an acyl product with a low molecular weight alkoxycarbonyl radical, which was obtained after the hydroxyl protective group had been hydrated off, is heated with barite liquor. The temperature can be between about 200 and the boiling point of the aqueous solution.

It is advantageous to heat at about 1000 for about 2 to 6 hours. The end of the hydrolysis can be determined by thin layer chromatography (e.g. at Silica gel, mobile phase lower phase: chloroform / methanol / conc. Ammonia 1: 1: 1). To Cleavage of the acyl group with barite liquor removes excess barium ions e.g. by introducing carbon dioxide or by acidifying with dilute sulfuric acid. The barium salts are filtered off and removed from the aqueous mother liquor after evaporation the 3w, 4'-dideoxykanamycin B of the formula I was obtained.

If necessary, the 3 ', 4'-Dideoxykanamycln B can by ion exchange chromatography on a weakly acidic ion exchanger (e.g. Amberlite IRC 50 (NH4 + form) with 0.1 to 5 N ammonium hydroxide solution) can be obtained in pure form.

When splitting off the protective groups, it is expedient to proceed in such a way that first the O-protective groups and then the N-acyl groups are split off. One can but also first split off the N-acyl groups and only then the O-protective groups. If the amino group is protected by Schiff bases, these are expedient remove before hydrogenolysis.

For the reasons set out above, it was not to be expected that the inventive method for a preferred formation of the condensation product and thus would lead to a sharp increase in the yield. It wasn't to be expected either that it would be possible despite the presence of several reaction products by one extremely simple work-up to get to 3 ', 4'-dideoxykanamycin B.

The following examples illustrate some preferred forms of the invention Process for the preparation of 3 ', 4'-Dideoxykanamycin B described, but without it to restrict it.

Example 1 Tetra-N-Athoxycarbonylgentamine C1a To a mixture of 1.62 g gentamine C1a and 1.62 g anhydrous sodium carbonate in 40 ml aqueous acetone (1: 1) 2.4 ml of ethyl chloroformate are added at 0 ° with stirring. It was stirred for 2 hours at room temperature. The resulting precipitate was Sucked off, washed with water and dried.

Yield: 2.3 g of tetra-N-ethoxycarbonylgentamine C1a (71.8% of theory) Mp .: 126 to 1280 C24Ii42N4012 and 1 H2O Analysis: found: C 48.3 H 7.6 N 9.1% Calculated: to C 48.3 H 7.4 N 9.4% Example 2 2 ", 4", 6 "-Tri-0-benzyl-tetra-N-ethoxycarbonyl-3" -N-acetyl-3 ', 4 '-dideoxykanamycin B 1> 14 g of 3-acetamido-2 11, 6-tri-o-b enzyl-3-desoxy-dglucopyranosyl chloride and 560 mg of Drierite (R) are in a mixture of 13.9 ml of absolute benzene and 4.7 ml of absolute dioxane dissolved and stirred at 60 ° for 30 minutes. Then 820 mg of the N-tetraethoxycarbonylgentamine Ca shown in Example 1 around 1.14 g of mercury cyanide were added and the mixture was refluxed at 100 for 16 hours.

Then a further 1.14 g of mercury cyanide are added and more Refluxed for 32 hours. After another 1.14 g of mercury cyanide has been added refluxed for another 15 hours. After the solution has cooled, it is diluted with dioxane and sucked off the residue. The filtrate is concentrated, chloroform is added, suctioned off the resulting precipitate and the filtrate was concentrated. The one after narrowing The residue obtained is chromatographed over 250 g of silica gel.

It is eluted with a chloroform / methanol mixture (30: 1).

The first 150 ml of eluent are discarded and then 10 ml fractions collected.

Fraction 1 to 8 contains 0.8 g fraction 9 and 10 contains 0.6 g fraction 11 to 17 contains 0.5 g. Fractions 26 to 40 contain 0.1 g of tetra-N-ethoxy carbonylgentamine Approx. Fraction 9 to 17 are triturated with benzene, with 2 ", 4", 6't-tri-0-benzyl-tetra-N-ethoxycarbonyl-3 "-N-acetyl-3 ', 4'-dideoxykanamycin B crystallized in thin, colorless leaflets.

The above residue (2.1 g) obtained after concentrating the filtrate can be triturated immediately with 30 ml of benzene even without chromatography, whereby 2 ", 4", 6 "-Tri-0-benzyl-tetra-N-ethoxycarbonyl-3" -N-acetyl-3 ', 4'-dideoxykanamycin B crystallized out.

Yield: 500 mg of 2 ", 4", 6 "-Tri-O-benzyl-tetra-N-ethoxy carbonyl-3" -N-acetyl-3 ', 4'-dideoxykanamycin B (38 Z of theory) Mp .: 211 to 2140 NMR spectrum (in CD3OD): g 5.28 (1H) and 5.20 (1H) One doublet each with a coupling constant of 3 Hz each (anomeric protons) 4 7.4 up to 7.1 multiplet 15 aromatic protons Example 3 Tetra-N-ethoxyearbonyl-3 "-N-acetyl-3 ', 4'-dideoxykanamycin B 500 mg of the 3'j4'-dideoxykanamycin B derivative prepared according to Example 2 dissolved in 76 ml of aqueous ethanol (3:10). A spatula tip of palladium black is added to it and 10 drops of tisacetic acid and hydrogenated for 4 hours under normal pressure at room temperature. After the catalyst has been filtered off, the filtrate is concentrated to dryness.

The residue was taken up twice more with absolute alcohol and evaporated to leave a crystalline residue.

Yield: 300 mg of tetra-N-ethoxy-carbonyl-3 "-N-acetyl-3 '-, 4'-dideoxykanamycin B (75% of theory) m.p .: 267 to 2700 NMR spectrum (in DMSO-d6 at 70 ° C.): the aromatic Protons in the range # = 7.4 to 7.1 have disappeared9 5.04 (1H) and 4.96 (1H) one doublet each with a coupling constant of 3 Hz each (anomer protons).

Example 4 31, 111-Dideoxykanamycin B 450 mg of that according to Example 3 3 ', 4'-dideoxykanamycin B derivatives prepared were added to a mixture of 3.2 g of barium hydroxide octahydrates in 20 ml of water. It was 6 hours on one heated boiling water bath. After cooling, carbon dioxide was introduced, which Sucked off precipitate and boiled twice with water. The combined aqueous The filtrates were concentrated, and the residue was dissolved in a little water, from the precipitate suctioned off, concentrated, redissolved with water, suctioned off from the precipitate and concentrated. The residue was then dissolved in methanol several times and evaporated. The optical one Rotation was / α / D23 = 122 ° - 122 (C = 0.18, water). After subsequent Ion exchange chromatography on Amberlite IRC-50 (NH + form) with 0.1 to 0.5 N ammonium hydroxide gives 3 ', 11'-dideoxykanamycin B with / α / D20 = 130 ° (C = 0.6, water) in a yield of 200 mg (77% of theory).

Claims (3)

Claims 1. Process for the preparation of 3 ', 4'-dideoxykanamycin B of the formula I which is characterized in that the 4-0- (2,6-diamino-2,3,4,6-tetradeoxy-α-D-glucopyranosyl-2-deoxystreptamine (Gentamine Cla) of the formula II whose amino groups are protected in a manner known per se, with a 3-amino-3-deoxy-D-glucopyranosyl halide of the general formula III where Hal stands for a halogen atom and whose amino and hydroxyl groups are also protected in a manner known per se, reacted and the 3 ', 4'-dideoxykanamycin B of the formula I is obtained by hydrogenolysis and / or hydrolysis of the N and O protecting groups . 2. The method according to claim 1, characterized in that compounds of the formula IV are used as compounds of the formula II whose amino groups are protected is used in which R¹ is hydrogen, alkyl, aralkyl, aryl, alkyloxy, aralkyloxy or aryloxy and R2 is hydrogen, alkyl, aralkyl or aryl. 3. Process according to response 1 and 2, characterized in that compounds of the formula V are used as compounds of the formula III whose amino and hydroxyl groups are protected is used in which Hal is a halogen atom, R3 is alkyl, aralkyl or aryl and R1 has the above meaning.