DE2550168A1 - PROCESS FOR THE DEMETHYLATION OF AMINOGLYCOSIDE ANTIBIOTICS - Google Patents

Description

DIPL-CHEM. DR. VOLKER VOSSIUS PATENTAMWALT

C MUNICH 06, PO BOX 86 07 67

SIEBERTSTRASSE

PHONE: (0 89) 47 40

CABLE ADDRESS: BENZENE PATENT MÖNCHEN TELEX 5-29453 VOPAT D.

u.z .: L 495 (Vo / MüAd)

Case 173-4 KTOWA HAKKO KOGYO CO., LTD.

Tokyo j Japan

7th November 1975

Process for the demethylation of aminoglycoside antibiotics "

Priority: November 9, 1974, Japan No. 129 316 / 7.4 November 9, 1974, Japan No. 129 317/74

The invention relates to a process for the demethylation of aminoglycoside antibiotics which contain one or two Methylaaiinogrupp s exhibit. In particular, the invention relates to a process for the demethylation of aminoglycosides of the general formula

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-NH,

in either R., and R _? each represent CH ^ groups or one of the two radicals is a CEL-G group and the other is a hydrogen atom. The process according to the invention is characterized in that a compound of the above formula is reacted with an oxidizing agent, as a result of which, if both R .. and Rp each represent CEL groups, one or both CH_ groups are eliminated, or if one of the radicals R * and Rp represent a CEL group and the other represents a hydrogen atom, the CH “group is eliminated.

The process according to the invention can be represented by the following reaction scheme:

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Compound I.
(XK-62-2)

Reaction II

- Compound III (e'-N-demethyl XK-62-2, gentamicin

Compound II
(3 "-N-Queinethyl
XK-62-2)

Reaction III

-Reaction IV

Compound IV (6 * -N, 3 "-N-didemethyl XK-62-2)

HO

CP9R21 / 0896 ^NH 2 ^0H

The invention is explained in more detail below with the aid of the above reaction scheme.

In the demethylation reaction according to the invention, the partial reactions I, II, III and IY take place. The connection I is as Antibiotic XK-62-2 known from GB-PS 1,399,578. The compound I has a methylamino group in each of the 6 'and 3 "positions on. The compound I is reacted with an oxidizing agent to produce the compounds II and III.

The compounds II and IV are new, valuable antibiotics. ■ The invention therefore also relates to these compounds, as well as Medicinal preparations containing these antibiotics as active ingredients.

The compound II, 3'-N-demethyl-XK-62-2 has an antibiotic effect comparable to that of XK-62-2, but a lower toxicity than this. The 3 "amino group of the compound II can be methylated with a radioactive methyl group CH, whereby radioactive XK-62-2 is obtained, which is used for studies on the distribution of XK-62-2 in the organism and for metabolic studies of XK-62- 2 can be used.

The compound III is provided as gentamicin C ₁ from the US-PS 3 091

I el

known.

If the compounds II or III are reacted with an oxidizing agent, the 6'-K or 3 "-N-methyl groups are the

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respective compound eliminated to form compound IV,

The compound IV, 6'-N, 3 "-N-Dide.methyl-XK-62-2 is in his antibiotic effect also comparable to XK-62-2 and also has a lower toxicity than this known Antibiotic on.

The compound IV can also be converted into XK-62-2, whereby two radioactive methyl groups (CH,) are incorporated can. This labeled compound is valuable for studying physiological properties of XK-62-2.

In the demethylation of compound I into compounds II and III, reaction I predominates, since the 3 "-IT-methyl group is more easily ^{eliminated than the 6!} -ΪΤ-methyl group. Therefore, mild reaction conditions are preferably used for the preparation of compound II, while comparatively strict reaction conditions are used for the preparation of the compound III.

It should also be noted that in a demethylation of the compound I according to the invention, a further demethylation of compounds II and III is inevitable. So you get a reaction mixture which generally contains the compounds II, III and IV, although the quantitative ratio of the individual compounds to each other depending on the reaction conditions varies. As already mentioned, the yield of compound II is relatively high under mild reaction conditions,

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while the yield of compound III increases under comparatively strict reaction conditions. Eventually being under very strict reaction conditions, the yield of compound IV is high and that of compound III is very low.

To prepare compound IV from compound II via reaction III, relatively severe reaction conditions are preferred applied because the elimination of the 6'-N-methyl group doesn’t come off that easily.

On the other hand, for the preparation of the compound IV from compound III over reaction IV mild reaction conditions are sufficient.

Quite generally speaking, the detethylation according to the invention is carried out by reacting the starting compound with an oxidizing agent in an inactive medium.

Conventional oxidizing agents can be used to carry out the reaction according to the invention. In particular, heavy metal salts, Peroxides, halogens, oxygen compounds and oxygen acids of the halogens, nitrogen oxides and molecular * Oxygen can be used. Examples of suitable oxidizing agents are: permanganates, manganates, manganese dioxide, chromic anhydride, Bichromates, chromates, alkyl chromates, chromyl chloride, Selenium dioxide, cobalt (ill) salts, cerium (iv) salts, Potassium hexacyanoferrate (III), copper (II) oxide, lead oxide, Mercury oxide, mixtures of hydrogen peroxide with at least

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one of the compounds from the group of iron (II) salts, Iron (III) salts, selenium dioxide, osmium tetroxide, vanadates, tungstic acid and chromic acid, lead tetraacetate, chlorine, bromine, Iodine, hypochlorates, chlorates, hypobromates, bromates, periodates,

·; Nitric oxide, nitrogen dioxide and air. When using molecular oxygen are preferred Noble metal catalysts are used, such as platinum, nickel, palladium, rhodium, ruthenium and rhenium.

Preferred oxidizing agents are chlorine, bromine, iodine and potassium hexacyanoferrate (III), permanganates and air. Iodine is particularly preferred. In general, from 0.5 to 15 »0 moles of oxidizing agent used per 1 mole of starting compound. When using molecular oxygen or air, this becomes Oxidizing agent in the form of small bubbles bubbled through the reaction medium.

Solvents that can be used for carrying out the reaction according to the invention are those in which the respondents "resolve and those with the respondents do not react or react only to a very limited extent. For example, water or mixtures of water can be used with Methanol, ethanol, tetrahydrofuran, dimethy! Acetamide, dimethylformamide, Dioxane and ethylene glycol dimethyl ether are used,

The starting compounds are dissolved in the solvent in a concentration of 4.5 to 50 millimolar.

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The reaction of the present invention is used depending on the type of used Oxidizing agents carried out at a pH of 4 to 12. The pH can be adjusted by adding an appropriate acid or base. There are such acids or To use bases that neither decompose the starting compounds or the demethylated products cause a reduction of the oxidizing agent. Rather, it is an increase the effect of the oxidizing agent is desirable. Examples of corresponding inorganic acids are hydrochloric acid and sulfuric acid. Examples of appropriate organic Acids are acetic acid and formic acid. Examples of corresponding bases are alkali metal hydroxides, alkaline earth metal .. hydroxides, alkali metal carbonates, alkaline earth metal carbonates, alkali metal alkoxides and alkali and alkaline earth metal salts of Carboxylic acids.

The adjustment of the pH can be carried out either before the start of the reaction or during the reaction.

The present reaction is preferably carried out at temperatures from -20 to 100 ⁰ C, 0 to 7O ⁰ C for 0.5 to 50 hours.

The reaction conditions to be used in practice are -je chosen according to the nature of the desired product and the oxidizing agent used, so that the highest possible yields achieved and undesired reactions of other functional groups, such as the hydroxyl and amino groups of the starting compounds be avoided. Choosing the cheapest in each case

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The reaction conditions are left to the person skilled in the art.

For example, when using iodine, the preferred oxidizing agent, the following reaction conditions are preferred for reaction I: 0.7 to 10.0 mol, preferably 2.0 to 6.0 mol of iodine per 1 mol of XK-62-2; Reaction temperatures of from -10 to 9O ⁰ C, preferably 40 to 60 ⁰ C; and reaction times of 1 to 24 hours, preferably 2 to 15 hours. Further, for adjusting the pH-value 0.5 to 6.0 moles, preferably 0 _s mol, preferably 7) 0 was added 2.0 to _4} 0 moles of a strong base or 5 »0 to 25, to 15 moles of a weak base .

For carrying out reactions II, III and IV and for the preparation of the compound IV from the compound I, the following reaction conditions are preferred: 1 to 13 mol, preferably 5 to 9 moles; 2 to 15 moles, preferably 6 to 11 moles; 0.7 to 10 moles, preferably 2 to 6 moles; or 3 to 15 moles, preferably 7 to 11 moles of iodine per 1 mole of the starting compounds. The other reaction conditions are the same as in reaction I.

After the reaction has ended, the products are obtained in the usual way. For example, the reaction mixture is neutralized and concentrated under reduced pressure. The concentrate is placed on a column filled with a cation exchange resin, on which the unreacted starting compounds and the reaction products are adsorbed. The column is filled with water washed and then eluted with 2, On aqueous ammonia solution. The eluate is concentrated and the products are on

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isolated and purified in a conventional manner, for example by column chromatography and thin layer chromatography under Use of ion exchange resins, silica gel, aluminum oxide and cellulose.

In Table I are the acute toxicity values

of compounds I, II, III and IV are given for mice.

Table I.

I. ^{I: D} 50 mg / kg ' II (Iv) link III 93 link IV 200 link 88 link 138

In Table II is the antibacterial spectrum of the compounds I, II, III and IV indicated against various gram-positive and gram-negative bacteria. The minimum inhibitory concentrations aind determined by dilution to double the volume at pH 8.0.

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- 11 Table II

Tribal Minimal Inhibitory concentration
(Ml'Ö'pg / ml) Verb.
III Terb.
IV Vert).
I. Verb.
II 0.52 0.26 Pseudomonas aeruginosa 1.04 >
2.08 <0.004 <0j004 BMH 1
Staphylococcus aureus 0.008 0.016 <0.004 <0.004 ATCC 6538 P
Bacillus subtilis <0.004 0.008 0.033 0.033 No. 10707
Proteus vulgaris 0.065 0.13 0.065 0.065 ATCC 6897
Shigella sonnei 0.13 0.13 0, 016 0.033 ATCC 9290
Salmonella tvphosa 0.033 0.065 0.008 <0.004 ATCC 9992.
Klebsiella pneumoniae 0.016 0.033 0.033 0.016 ATCC 10031
Escherichia coli 0.065 0, 13 4.17 4jl7 ATCC 26
Escherichia coli 8.34 2.08 1.04 1.04 KY 8327
Escherichia coli 1.04 2.08 KY 8348

The microorganisms listed in Table II are Escherichia coli KY 8327 and KY 8348 produce intracellular adenyltransferase resp. Acetyltransferase. The former bacterial strain inactivates kanamycins and gentamycins by adenylation, during the the latter gentamycins inactivated by acetylation.

The compounds prepared by the process of the invention can optionally be converted into pharmacologically acceptable, non-toxic salts with acids. examples for corresponding acids are inorganic acids, such as hydrochloric acid,

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Hydrobromic acid, hydroiodic acid, sulfuric acid, Phosphoric acid and carbonic acid, as well as organic acids such as acetic acid, fumaric acid, malic acid, citric acid, mandelic acid. Tartaric acid and ascorbic acid. These salts with acids can be prepared by conventional methods. Explain the examples The invention.

example 1

2.9 g (6.3 mmol) of XK-62-2 and 9.4 g (69.1 mmol) of sodium acetate trihydrate are dissolved in 145 ml of aqueous 50 percent dimethylformamide. 7.3 g (28.8 mmol) of iodine are added to the solution and the mixture is reacted at 55 ° C. for 15 hours while stirring. The reaction mixture is then passed through a column charged with 150 ml Amberlite IRC-50 (H ⁺ -FOrDi). The column is washed with 600 ml of water. Then 2, On aqueous ammonia solution is applied. Approximately 250 ml of fractions positive for ninhydrin are collected and evaporated under reduced pressure. 2.60 g are obtained. of a slightly yellowish residue. This residue is treated by column chromatography using 130 g of silica gel with a mixture of isopropanol, chloroform and concentrated aqueous ammonia solution in a ratio of 4: 1: 1 as the eluent. The eluate is collected in fractions of 13 ml each. The fractions Kr. 55 to 68 are combined and evaporated to dryness under reduced pressure. 450 mg of unreacted XK-62-2 are obtained. Fractions No. 75 to 83 are also combined and reduced. Pressure evaporated to dryness. 70 mg of 6'-N-demethyl-

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XK-62-2 (Compound III, Gentamicin C _1q ).

113-117 ° C; specific rotation £ cj ^ + 171.1 ° (c = 0.98, water).

IR spectrum (KBr, cm " ¹ ): 3700 to 3000, 2940, 1630, 1575, 1480, 1380, 1340, 1286, 1146, 1108, 1052, 1021, 957, 820.

ι
NMR spectrum (in D ₃ O) δ (in ppm against DSS): 1.20 (3H ₁ s),

2.53 (3H, s), 5.13 (1H, d, J = 4.0 Hz), 5.23 (1H, d, J = 4.0 Hz)

C ₁₉ H ₃₉ N ₅ O ₇ -H ₂ O: CH Έ

calc .: 48.81, 8.84 14.98

Found: 49.36 8.65 14.77

The parliamentary groups Mr. 93 to 135 are under reduced pressure constricted. 1.38 g of 3 "-N-demethyl-XK-62-2 (compound

M.p. 105 to 115 ° C; specific rotation: / q / 5 ⁸ + 148.5 ° (c = 0.097, water).

IR spectrum (KBr, cm " ¹ ): 3800- to 3000, 2940, 1640, 1570, 1465, 1379, 1330, 1284, 1142, 1110, 1050, 1020, 955, 865, 810; see Fig. 1 .

NMR spectrum (in methanol -d.) Δ (in ppm against TMS): 1.16 (3H, s), 2.43 (3H, s), 5.06 (1H, d, J = 3.9 Hz), 5.20 (1H, d, J = 3.8 Hz); see Fig. 2.

O ₁₉ H ₃₉ N ₅ O ₇ ^ ₂ O: CH IT

calc .: 48.81 8.84 14.98 found: 49.36 8.65 14.77

The fractions 1fr. 151 to 179 are reduced under Pressure evaporated to dryness. 310 mg of 6'-N, 3 "- are obtained

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N-Didemethyl-XK-62-2 (Compound IV).

F. 130 to 14O ⁰ C; specific rotation: / ä7 ^? . _{an Λ} ο / _ _{n 1n}

Water).

IR spectrum (KBr, cm " ¹ ): 3700 to> 3000, 2950, 1630, 1570, 1480, 1380, 1333, 1290, 1149, 1113, 1052, 1025, 958; see Fig. 3. KMR spectrum ( in D ₃ O) 5 (ppm vs. DSS): 1.18 (3H, s), 5.12 (1H, d, J = 4.0 Hz), 5.29 (1H, d, J = 3.9 Hz); see Fig. 4.

.H ₂ O: ber .: C. 67 8th H 1 Έ , 44 found: 47, 54 8th , 67 1 5 , 23 47, , 39 5

Example 2

463 mg (1.0 mmol) of XK-62-2 and 160 mg (4.0 mmol) of sodium hydroxide are dissolved in 25 ml of aqueous 50 percent dimethylacetamide. 659 mg (2.0 mmol) of potassium hexacyanoferrate (III) are added to the solution. The mixture is reacted at 65 ° C. for 15 minutes with stirring. The mixture is then passed through a column charged with 30 ml of Amberlite IRG-50 (H ⁺ form). The column is then washed with 150 ml of water. Then 2, On aqueous ammonia solution is applied. About 70 ml of fractions positive for ninhydrin are collected and evaporated under reduced pressure. 430 mg of a slightly yellowish residue are obtained. This residue is worked up according to Example 1 by column chromatography using silica gel. 98 mg of unreacted XK-62-2 are obtained. In addition, 20 mg gentamycin C ₁ (compound III), 210 mg 3 "-N'-demethyl-XK-62-2 (compound II) and 55 mg 6" -N, 3 "-N-didemethyl-XK-6 are obtained ? - _? 2 (compound IV).

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Example 3

232 mg (0.5 mmol) of XK-62-2 are dissolved in 15 ml of water. the

fresh
293 mg / platinum black, which has previously been activated with hydrogen, is added to the solution. Subsequently, the reaction is carried out for 48 hours while the temperature is maintained at 40 to 5O ⁰ G and a heavy stream is bubbled of fine air bubbles through the reaction mixture. Each time the reaction has ended, the platinum black is filtered off and the filtrate is concentrated under reduced pressure. 211 mg of residue are obtained. This residue is worked up according to Example 1 by column chromatography using silica gel. 85 mg of unreacted XK-62-2 are obtained. In addition, 17 mg of G-entamycin O ₁ (compound III), 82 mg of 3'-N-demethyl-XK-62-2 (compound II) are obtained

and 24 mg 6'-II, 3 "-N-Didemethyl-XK-62-2 (Compound IV).

Example4 '

463 mg (1.0 mmol) of XK-62-2 are dissolved in 25 ml of water. The solution is mixed with 929 mg (5 ₅ 9 mmol) of potassium permanganate. The mixture is reacted for 17 hours at room temperature. The reaction mixture is then passed through a column charged with 30 ml of Amberlite IRC-50 (H form). After washing the column with 120 ml v / water, 2.0N aqueous ammonia solution is applied. About 80 ml of fractions which react positively with binhydrin are collected and evaporated under reduced pressure. 426 mg of a slightly yellowish residue are obtained. This residue is worked up according to Example 1 by column chromatography using silica gel. You get

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110 mg of unreacted XK-62-2. In addition, 15 mg gentamycin C ₁ (compound III), 135 mg 3 "-N-demethyl-XK-62-2 (compound II) and 70 mg 6'-N, 3" -N-didemethyl-XK-62- are obtained 2 (IT connection). ,

Example 5

449 mg (1.0 mmol) of 3 "-N-demethyl-XK-62-2 (compound II) and 2.04 g (15.0 mmol) of sodium acetate trihydrate are dissolved in 30 ml of aqueous 50 percent dioxane. the solution is treated with 2.04 g (8.0 mmol) of iodine, the mixture is reacted for 14 hours under stirring at 60 ⁰ C. then the reaction mixture is ■ a with 30 ml of Amberlite IRC-50 (H ^+.. - I ¹ OTm) of the column loaded. Compartment for washing the column with 150 ml of water, 2, On aqueous ammonia solution is added. About 50 ml of fractions which react positively with finhydrin are collected and evaporated under reduced pressure. 420 mg of one are obtained This residue is treated by column chromatography using 20 g of silica gel and a mixture of isopropanol, chloroform and concentrated aqueous ammonia solution in a ratio of 4: 1: 1. The eluate is removed in fractions of 13 ml volume Fractions EFr. 37 to 49 are united and under evaporated to dryness under reduced pressure. 150 mg of unreacted 3 "-N-demethyl-XK-62-2 (compound II) are obtained. Fractions 61 to 76 are combined and evaporated to dryness under reduced pressure. 170 mg of 6" - IT are obtained. 3 "-K'-Didemethyl-XK-62-2 (Compound IV).

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Examples

449 mg (1.0 mmol) of 3 "-ir-demethyl-XK-62-2 '(compound II) and 200 mg (5.0 mmol) of sodium hydroxide are dissolved in 30 ml of aqueous, 50% strength dimethyl acetamide. The solution is 824 mg (2.5 mmol) potassium hexacyanoferrate (III) are added. The mixture is reacted for 15 hours with stirring at 65 ° C. The reaction mixture is then poured over a 40 ml Amberlite IRC-50 (H ⁺ form) After washing the column with 140 ml of water, 2, On aqueous ammonia solution is added. About 65 ml of fractions which react positively with uinhydrin are collected and evaporated under reduced pressure. 410 mg of a slightly yellowish residue are obtained This residue is worked up by column chromatography using silica gel as in Example 5. 220 mg of unreacted 3 "-3T-demethyl-XK-62-2 (compound II) are obtained. In addition, 110 mg of € '-N, 3 "-H-didemethyl-XK-62-2 (compound IV) are obtained.

Example- 7

225 mg (0.5 mmol) of 3 "-N-demethyl-XK-62-2 (compound II) are dissolved in 20 ml of water. 400 mg of fresh platinum black, which has previously been activated with hydrogen, are added to the solution. subsequently, the reaction is performed 45 hour long, the temperature being maintained at 50 to 60 ⁰ C and a vigorous stream of fine air bubbles is bubbled through the reaction .gemisch. After completion of reaction, the platinum black is filtered off and the filtrate under reduced pressure 195 mg of residue are obtained

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worked up by column chromatography using silica gel according to Example 5. 115 mg of unreacted 3 »ur_demethyl-XK-62-2 (compound II) are obtained. In addition, 65 mg of 6'-F, 3 "-N-didemethyl-XK-62-2 (compound IV) are obtained.

i examples

225 mg (0.5 mmol) of 3 "-N-demethyl-XK-62-2 (compound II) are dissolved in 110 ml of water. The solution is mixed with 465 mg (3» 0 mmol) of potassium permanganate. The mixture is Reacted for 16 hours at room temperature. Then the reaction mixture is poured over a column filled with 15 ml Amberlite IRC-50 (H ⁺ form). After washing the column with 60 ml of water, 2, On aqueous About 40 ml of fractions which react positively with tinhydrin are obtained and evaporated under reduced pressure. 195 mg of a slightly yellowish residue are obtained. This residue is worked up by column chromatography using silica gel according to Example 5. 87 mg are not obtained reacted 3 "-H-demethyl-XK-62-2 - (compound II). In addition, 63 mg of 6'-F, 3 "-M-Didemethyl-XK- ^ 62-2 (compound IV) are obtained.

Example?. 449 mg (1.0 mmol) 6'-N-demethyl-XK-62-2 (Gentamicin C,, Ver

I el

binding.III) and 2.04 g (15.0 mmol) of sodium acetate trihydrate are dissolved in 40 ml of aqueous 50 percent dimethylformamide. 761 mg (3.0 mmol) of iodine are added to the solution. ^{The mixture is reacted at 50 °} C. for 15 hours with stirring.

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The reaction mixture is then passed through a column charged with 30 ml of Amberlite IRC-50 (H ⁺ form). After washing the column with 130 ml of water, 2On aqueous ammonia solution is applied. About 60 ml of fractions which react positively with ninhydrin are collected and evaporated under reduced pressure. 430 mg of a slightly yellowish residue are obtained. This residue is treated by column chromatography using 20 g of silica gel and a mixture of isopropanol, chloroform and concentrated aqueous ammonia solution in a ratio of 4: 1: 1. The eluate is removed in fractions with a volume of 13 ml. The fractions Fr. 33 • to 42 are combined and evaporated to dryness under reduced pressure, 89 mg of unreacted 6'-E-Demetl ^ l-XK-62-2 (compound III) are obtained. Fractions Kr. 63 to 85 are combined and evaporated to dryness under reduced pressure. 295 mg of 6'-N, 3 "-N-didemethyl-XK-62-2 (compound IV) are obtained.

Example 10

449 mg (Ί, Ο mmol) 6'-F-demethyl-XK-62-2 (Gentamicin C., Ver

ι a.

bond III) and 160 mg (4.0 mmol) of sodium hydroxide are dissolved in 25 ml of aqueous 50 percent dimethylacetamide. 659 mg (2.0 mmol) of potassium hexacyanoferrate (III) are added to the solution. ^{The mixture is reacted at 60 °} C. for 15 hours with stirring. The reaction mixture is then passed through a column charged with 30 ml of Amberlite IRC-50 (H ⁺ form). After washing the column with 150 ml of water, 2.0-on aqueous ammonia solution is passed through the column. About 80 ml of fractions,

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- PO -

those that react positively with ninhydrin are combined and under evaporated under reduced pressure. 415 mg of an easily obtained yellowish residue. This residue is worked up according to Example 9 by column chromatography using silica gel. 115 mg of unreacted 6'-F-demethyl-XK-62-2 are obtained (Compound III). 275 mg of 6'-N, 3 "-N-didemethyl-XK-62-2 are also obtained (Compound IV).

Example 11

225 mg (0.5 mmol) of 6 ^l -N-demethyl-XK-62-2 (gentamicin C, _a , compound III) are dissolved in 20 ml of v / water. 400 mg of fresh platinum black, which has previously been activated with hydrogen, are added to the solution. Subsequently, the reaction is carried out 50 hours ,, wherein the temperature to 40 to 5O ⁰ O is held and is bubbled a heavy stream of fine air bubbles in the reaction mixture. After the reaction has ended, the platinum pipe is filtered off and the filtrate is evaporated under reduced pressure. 210 mg of residue are obtained. This rear stand 'is purified by column chromatography using silica gel worked up according to Example. 9 105 mg of unreacted 6 are obtained ^! -: N-Detaethyl-XK-62-2 (Compound III). 87 mg of 6'-Ή, 3 "-N-didemethyl-XK-62-2 (compound IV) are also obtained.

..Example 12
315 mg (0.75 mmol) 6'-F-demethyl-XK-62-2 (Gentamicin C., Ver

'I et

binding III) are dissolved in 15 ml of water. The solution is mixed with 465 mg (30 mmol) of potassium permanganate. The mixture

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is reacted for 15 hours at room temperature. The reaction mixture is then passed through a column charged with 20 ml of Amberlite IRC-50 (H ⁺ form). After washing the column with 80 ml V / water, 2, One aqueous ammonia solution is added. About 45 ml of fractions which react positively with ninhydrin are combined and evaporated under reduced pressure. 290 mg of a slightly yellowish residue are obtained. This residue is worked up according to Example 9 by column chromatography using silica gel. 85 mg of 6'-IT-demethyl-XK-62-2 (compound III) are obtained. 119 mg of 6'-N, 3 "-N-didemethyl-XK-62-2 (compound IV) are also obtained.

Example 113

454 mg (1.0 mmol) 6'-N, 3 "-N-Didemethyl-XK-62-2 (Compound IV) are dissolved in 4 ml of water. The solution is cooled with a solution of 98 mg (1.0 mmol) of sulfuric acid in 1 ml of water offset. After 30 minutes, cold ethanol is added to the solution until it has precipitated completely. The white precipitate is filtered off. The monosulfate of 6'-N, 3 "-N-didemethyl-XK-62-2 is obtained.

Example 14

4.67 g (10.0 mmol) of 3 "-N-demethyl-XK-62-2 (Compound II) dissolved in 20 ml of water. The solution is made with 1.2 g (20.0 mmol) Glacial acetic acid added. After 30 minutes the solution will be complete Precipitation-mixed with cold ethanol. The white precipitate is filtered off. The diacetate is obtained from 3 "-N-De-

methyl XK-62-2. ' _Ä

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Claims (10)

Claims 1. Process for the demethylation of compounds of the general formula NHR in either R., and R _? each represent CEL-G groups or one of the two radicals is a CEL group and the other is a hydrogen atom, characterized in that one of the compounds mentioned is reacted with an oxidizing agent, as a result of which, when both R ₁ and R ₂ each represent · CH “groups, one of the two CH_ groups is eliminated or, if one of the radicals R- and Rp means one CH_ group and the other a hydrogen atom, the CH_ group is eliminated. 609821/0896 2. Process for the preparation of 3 "-N-demethyl-XK-62-2 of the formula -NHCH HO- characterized in that XK-6'2-2 the formula -NHCH., reacts with an oxidizing agent, 809821/0896 3. Process for the preparation of gentamicin C _{1 of} the formula ι a -NH, HO characterized by the fact that XK-62-2 the formula -NHCH HO- reacts with an oxidizing agent. 609821/08 96 4. Method of making 6 ^! -N, 3 "-N-Didemethyl-XK-62-2 of the formula • NH, HO- characterized in that 3 "-ST-demethyl-XK-62-2 -NHCH HO ' reacts with an oxidizing agent. 609821/0896 5. Method for making 6'-K, 3 "-N-Didemethyl-XK-62-2 the formula -NH. HC 'NH, characterized in that gentamicin C, _{n of} the formula NH HO reacts with an oxidizing agent. 609821/0896 6.. The method according to claim 1 "to 5, characterized in that that the reaction is 0.5 to 50 hours Temperatures from -20 to 100 C carries out. 7. The method according to claim 1 to 5, characterized in that that the oxidizing agent iodine, potassium hexacyanoferrate (ill), air or potassium permanganate are used. ν 8. Connection of the general formula ■ NHR Γ ^ - NH, HO- in which R means the CEL-G group or a Vifass erstoff atom, and their salts with acids. 809821/0896 9. Compound of Formula NH, NH, NH, HO CH. NH. OH and their salts with acids. 10. Compound of Formula " ^a 2 CH. NH, OH and their salts with acids. 609821/0896 Blank page