CS219307B2 - Process for the production of new pleuromutilins - Google Patents

Abstract

The subject of the invention is a method for producing new pleuromutilin amyloderivatives, which can be obtained by reacting pleuromutilins with a tertiary amine and the resulting substances are optionally converted into their acid addition salts or into quaternary salts. The new pleuromutilins obtained by the method according to the invention are antibacterial substances that can be used in particular against the Mycoplasma family, both in the form of drugs and in the form of disinfectants, and optionally as an additive to drinking water.

Description

The subject of the invention is a method for producing novel pleuromutilins of general formula I,

where

R1 is an ethyl or vinyl group, n is an integer 2 or 3,

Z denotes an oxygen or sulfur atom,

R2 and R5 each represent an alkyl group of up to 4 carbon atoms or

R2 and R5 together with the nitrogen atom form a piperidine ring, as well as their acid addition salts and quaternary salts, characterized in that the compound of general formula II,

where

R1 and Z have the meanings given above, in reaction with a compound of general formula III,

Rye

FROM

A—(CH ₂ ) _n —N

Rs (III), where n, R2 and Rs have the meanings given above and

A is an acidic residue of a reactive ester, and the obtained pleuromutilins of general formula I are optionally converted into their acid addition salts or quaternary salts.

The process according to the invention can be carried out, for example, by dissolving the compound of the general formula II in an inert solvent, for example an aliphatic ketone, such as ethyl methyl ketone, or in a lower alcohol, such as methanol or ethanol, then adding the compound of the general formula III and allowing the reaction mixture to react, optionally in the presence of a base, for example an alkali metal carbonate, such as potassium carbonate. The reaction is preferably carried out at room temperature up to the boiling point of the reaction mixture and lasts for, for example, 2 to 20 hours. The compounds of the general formula I can be converted into their acid addition salts or vice versa.

The corresponding quaternary salts can be obtained from the compounds of the general formula I by methods known per se.

The compounds of the general formula I and their pharmacologically harmless acid addition salts and quaternary salts have interesting biological and especially antimicrobial properties with low toxicity and can be used as medicines. They exert an inhibitory effect on the growth of bacteria, as can be demonstrated by in vitro studies, agar plate tests, or in vivo, experiments on mice using various strains of bacteria. This inhibitory effect was found starting from a concentration of approximately 0.002 to 5 /ml, in particular an inhibitory effect was found against mycoplasmas, which appeared from a concentration of 0.08 to 2.5 (µg/ml, therefore the compounds produced according to the invention can be used as antibacterially effective antibiotics.

The compounds of the general formula I and optionally their water-soluble, physiologically acceptable salts can be administered as pharmaceuticals in suitable pharmaceutical forms together with inorganic or organic pharmacologically acceptable excipients. For example, these substances are used as components in capsules, injection or infusion preparations containing an amount of active substance sufficient to achieve an optimal blood level, i.e. about 10 to 500 mg per capsule.

The inhibitory effect against mycoplasmas was tested in vitro on the following organisms:

1. M. hominis II,

2. M. bovigenitalium,

3. M. gallisepticum,

4. M. sp. ISRí,

5. M. laidlawii,

Substance

6. M. hominis I,

7. M. hyorhinis.

The results obtained using compounds corresponding to general formula I are shown in the following Table I.

TABLE I

Minimum inhibitory concentration in µg/ml of organisms

3 4 5 6 7

14-mutilyl-3-morpholinopropyl lamin-

-N,N-diacetate 15.6 3,125 0.078 12.5 250 7.81 15.6 14-deoxy-14-[(3-morpholinopropylamino)acetoxy]mutilin 62.5 5 1.25 31.25 500 12.5 25 14-deoxy-14-[(2-diethylaminoethylthio)acetoxy]mutilin 0.312 0.625 0.039 3,125 15.6 0.195 0.78 14-deoxy-14-[(2-dimethylaminoethylthio] acetoxy ] mutilin 1.56 0.31 0.019 3,125 15,625 <0.97 14-deoxy-14-[(2-diethylaminoethylamino)acetoxy] mutilin. 15,625 5 2.5 31.25 500 3,125 12.5 14-deoxy-14-[(2-piperidino-ethylthio)acetoxy]mutilin 1.25 0.39 0.156 6.25 15.6 1.9 14-deoxy-14-[(2-morpholino-ethylthio)acetoxy]mutilin 0.97 7.81 0.97 7.81

The following Table II summarizes the results of tests performed in vivo with the infections listed in these tables with DE95, expressed in mg/kg body weight.

TABLE II

Substance

Streptococcus infection.

DE95 in mg/kg per os subcutaneously

Streptococcus aronson infection

DE95 in mg/kg per os subcutaneously

Staph. aureus infection

DE951 in mg/kg per os subcutaneously

14-deoxy-14-[ (2-diethylami- noe thylthio) acetoxy ] mutilin 52.2 37.0 113 134 92.9 23.8 14-deoxy-14-[(2-trimethylammonioethylthio] acetoxy ] mutilin iodide - 8.1 14-deoxy-14-[(2-diethylaminoethylthio)acetoxy]dihydromutilin 78.5 87.1 101 229 112 42.4 Acute toxicity I was detected in mice. Results Acute toxicity of the compound general pattern- are listed in Table III and are the LD50 for some compounds. listed

2193.07

TABLE III

Substance

14-deoxy-14-[ (2-diethylaminoethyl-thio) acetoxy ] mutilin iodide 14-deoxy-14- [ (2-trimethylammonio-ethylthio) acetoxy ] mutilin 14-deoxy-14- [ (2-diethylaminoethylthio) acetoxy ] dihydro mutilin

The pleuromutilin derivatives according to the invention are furthermore excellent additives in animal feed mixtures. They can thus be added to feed for prophylactic purposes at concentrations between 0.05 and 5 ppm.

The starting materials of general formula II can be obtained by reacting the compound of general formula IV,

where Ri has the above meaning and Rs is an alkyl or aryl group, will give in reaction with a compound of general formula V,

(V) where Z has the above meaning and Me represents an alkali metal atom.

The process is carried out, for example, by reacting the compound of the general formula IV with the compound of the general formula V in an inert solvent miscible with water, for example in a lower aliphatic ketone, such as acetone or methyl ethyl ketone, or in a lower alcohol, such as methanol or ethanol, optionally also in the presence of water or a solvent which is inert in nature and immiscible with water, for example dimethylformamide, the reaction temperature being between 20 and 60 °C, but preferably between 20 and 50 °C.

Starting materials of general formula IVa, per os

DLso in mg/kg subcutaneously

477.9 197.5

727.6 10.62

620.6 256.0

where Rs has the above meaning, are known. Starting materials of general formula IVb,

where Rs has the above meaning, can be obtained by either

a) a compound of formula VI

is reacted with a compound of general formula VII,

218307

A—SOz—Rs (VII), where A and Rs have the meanings given above, or

$) the compound of general formula IVa is reduced.

The reaction according to the process a) can be carried out in an inert solvent, for example in an aromatic hydrocarbon, such as toluene, benzene and so on, but preferably in a solvent acting simultaneously as an acid-binding agent, for example in pyridine. For example, p-toluenesulfonyl chloride is used as a compound of the general formula VII. The reaction can, for example, take place at temperatures of -15 to -10 ° C and lasts between two and four hours.

The hydrogenation of the compound of the general formula IVa by the process according to (2) is conveniently carried out by the action of hydrogen in the presence of a hydrogenation catalyst, for example a palladium or platinum catalyst on carbon, in an inert solvent, for example ethyl acetate, and at room temperature.

If the production of starting materials is not described, these materials are known or can be produced in a known manner, or analogously to the methods described herein or known methods.

The following examples, which illustrate the invention, are not intended to limit the invention in any way and the temperature data are in degrees Celsius.

Example 1

14-Desoxy-14-[4-(2-dimethylaminoethoxy)phenylmercapto]acetoxymutilin

100 mg of 14-deoxy-14-(4-hydroxyphenylmercapto)-ethoxymutilin is dissolved in 10 ml of ethyl methyl ketone and after adding 30 mg of dimethylaminoethyl chloride hydrochloride, 150 milligrams of finely powdered dry potassium carbonate and 30 mg of potassium iodide, it is boiled under reflux for 11 hours. Then the solvent is distilled off, the residue is taken up with ethyl acetate, washed three times with water, dried with sodium sulfate and evaporated. Isolation is carried out by preparative thin-layer chromatography on silica gel with a 1:2 chloroform-methanol mixture.

Example 2

14-Desoxy-14-[4-(3-dimethylaminopropoxy)phenylmercapto]acetoxymutilin

100 mg of 14-deoxy-14-(4-hydroxyphenylmercaptoacetoxymethylene) is dissolved in 3 ml of ethyl methyl ketone, first 55 mg of sodium methoxide in 2 ml of methanol are added and then 35 mg of 3-dimethylaminopropyl chloride hydrochloride. The mixture is stirred at room temperature under nitrogen for 3 hours and then refluxed for another 14 hours.

After evaporation of the solvent, it is taken up in ethyl acetate, the residue is washed with water, dried over sodium sulfate and evaporated. Purification is carried out by thin layer chromatography on silica gel with a chloroform-methanol mixture 1:2.

Example 3

14-Desoxy-14-[4-(2-diethylaminoethoxy)phenylmercapto]acetoxymutilin

960 mg of 14-deoxy-14-(4-hydroxyphenylmercaptoacetoxymethylene) are dissolved in 20 ml of anhydrous methanol, then 120 mg of sodium methoxide are added and evaporated to dryness in vacuo. The residue is taken up in a mixture of 4 ml of water and 20 ml of xylene, 360 mg of diethylaminoethyl chloride hydrochloride and 420 mg of potassium carbonate are added and heated under reflux for 8 hours at a bath temperature of 150°. The xylene layer is then washed 5 times with water; the combined aqueous phases are extracted once with ethyl acetate and the combined organic phases are evaporated in vacuo. The residue is evaporated in 10 ml of methylene chloride and converted into the hydrochloride with 0.6 ml of 5.8 N ethereal hydrochloric acid. After removing the solvent in vacuo, this is dissolved in 6 ml of methanol, diluted with 30 ml of distilled water and then extracted six times in total. 80 ml of ether. The aqueous solution of the hydrochloride thus purified is evaporated in vacuo at a bath temperature of about 30°. In the thin-layer chromatogram on silica gel G, the substance is uniform in the chloroform-methanol system 1:2. The foamy product is dried in vacuo with potassium hydroxide. T. softening point of the hydrochloride 88 — 93°.

Example 4

14-Desoxy-14-(4-(2-diethylaminoethoxy)phenylmercapto]acetoxydihydromutilin

a) 14-Desoxy-14-tosyloxyacetoxydihydromutilin

Method or]

To a mixture of 8.86 g of dihydropleuromutilin in 30 ml of dry pyridine, 6.10 g of p-toluenesulfochloride are added all at once with vigorous stirring at -15°. The mixture is stirred for 2 hours at -15° and then for an hour at 0°. It is then poured onto ice water and the product is taken up in methylene chloride. The organic phase is washed with cooling successively with ice water and then with saturated sodium bicarbonate solution. Drying with sodium sulfate and evaporation gives a uniform product according to thin layer chromatography with a softening point of 78-80°.

Method /3)

0.53 g of 14-de ⁱ soxy-14-tosyloxyacetoxymutilin is hydrogenated in 10 ml of ethyl acetate using 0.10 g of 10% palladium on carbon as a catalyst at atmospheric pressure and room temperature. The calculated amount of hydrogen is bound after about one hour. The solution is filtered to remove the catalyst and evaporated in vacuo. Softening point 78 — 80°.

b) 14-Desoxy-14-(4-hydroxyphenylmercapto)acetoxydihydromutilin

6.00 g of 14-diesoxy-14-tosyloxyacetoxydihydromutilin are dissolved in 15 ml of ethyl methyl ketone. 1.60 g of thiohydroquinone are added to this solution under nitrogen. Then, with ice cooling and stirring, a solution of 0.35 g of sodium in 25 ml of anhydrous ethanol is added and the mixture is stirred for 5 hours at room temperature. It is worked up by acidifying the reaction mixture with 10% acetic acid (pH 4.5) and then evaporated in vacuo. The residue is taken up in ethyl acetate, then water is added and extracted four times with ethyl acetate. The combined organic phases are washed once with water, dried over sodium sulfate and evaporated in vacuo. The substance crystallizes from chloroform and hexane and has a melting point of 191-194°.

c) 14-Desoxy-14-[4-(2-diethylaminoethoxy)phenylmercapto]acetoxydihydromutilin

14-Desoxy-14-(4-hydroxyphenylmercapto)acetoxydihydromutilin is reacted with diethylaminoethyl chloride hydrochloride in analogy to the previous examples to form the title compound.

Example 5

14-Desoxy-14-[3-(dimethylaminoethylmercapto)phenylmercapto]acetoxymutilin

0.57 g of dithioresorcinol is dissolved under nitrogen in a solution of 46 mg of sodium in 5 ml of anhydrous ethanol. Then, with good stirring, a solution of 1.59 g of 14-deoxy-14-tosyloxyacetoxymutilin in 10 ml of ethyl methyl ketone is added dropwise. After stirring for two hours at room temperature, the reaction mixture is evaporated to dryness in vacuo. The residue is taken up in ethyl acetate, washed with water, dried over magnesium sulfate and evaporated. The crude product is taken up in a solution of 74 mg of sodium in 15 ml of anhydrous ethanol and, after adding 0.94 g of dimethylaminoethyl chloride hydrochloride, heated under reflux for 5 hours. Then, the solvent is removed in vacuo and the residue is chromatographed on a silica gel column (grain size 0.05 — 0.2 mm) with a mixture of chloroform and methanol (1:2).

Example 6

By analogy with Example 3, the following compounds are obtained using appropriate starting materials in appropriate amounts:

a) 14-deoxy-14-{4-[3-(N-piperidinO')propoxy]phenylmercaptoacetoxymutilin;

b) 5.33 g of 14-deoxy-14-tosyloxyacetoxymutilin are reacted with 1.57 g of 2-mercaptophenol and 0.25 g of sodium in 10 ml of anhydrous ethanol according to the method of Example 4b and processed as described there. 14-Deoxy-14-(2-hydroxyphenylmercapto)acetoxymutilin crystallizes from chloroform with a melting point of 150-152° and by reaction with diethylaminoethyl chloride hydrochloride according to the analogy of Example 3, 14-deoxy-14-[2-(2-diethylaminoethoxy)phenylmercapto]acetoxymutilin is formed.

c) 14-deoxy-14-[3-(diethylaminoethylmercapto-phenylmercapto)acetoxymulin.

Claims (4)

SUBJECT OF THE INVENTION A process for the preparation of the novel pleuromutlins of the general formula I, z R 2 and R 3 together with the nitrogen atom form a piperidine ring and acid addition salts and quaternary salts thereof, characterized in that the compound of formula (II) wherein: R 1 is ethyl or vinyl, n is an integer of 2 or 3, Z is an oxygen or sulfur atom, R 2 and R 5 each represent an alkyl group having 1 to 4 carbon atoms, or 218307 where Ri and Z have the meanings given above, in reaction with a compound of the formula ΠΙ, Rz OF A - (CH 2) n - where n, R 2 - and R 3 are as defined above and A is an acidic residue of a reactive ester, and the resulting pleuromutilins of formula (I) are optionally converted into their acid addition salts or quaternary salts. A process for the production of the novel pleuromutilins of the general formula Γ, wherein R 1 is ethyl or vinyl, n is an integer of 2 or 3, Z ¹ denotes an oxygen atom, R 2 and R 3 each denote an alkyl group having 1 to 4 carbon atoms, or R2 and R3 together with the nitrogen atom denote the piperidine ring as well as the acid addition salts and the quaternary salts thereof, characterized in that the compound of the formula II ¹ , wherein R, and ^T have the abovementioned meanings, is reacted with a compound of formula III, Rz z A - (CH 2 _{n -} N x Rs where (III), i 218307 n, R 2 and R 3 have the meanings given above and A is an acidic residue of a reactive ester, and the resulting pleuromutilins of the general formula popřípadě are optionally converted into their acid addition salts or quaternary salts. 3. A process for the preparation of the novel pleuromutilins of the general formula Γ according to item 2, wherein R1, Z 'have the meanings given in item 2 and R2 and R3 together with the nitrogen atom form a piperidine ring and their acid addition salts and quaternary salts. by reacting the compound of formula (II ') in (2) wherein R 1 and Z' are as defined in (2) in reaction with a compound of formula (III) wherein A is as defined in (2) and R 2 and R 3 are and the resulting pleuromutilins of the general formula popřípadě are optionally converted into their acid addition salts or quaternary salts. 4. A process for the preparation of the novel pleuromutilins of the general formula I according to item 1, wherein R1 and n have the meanings given in item 1, Z represents a sulfur atom, R2 and R3 each denote a C1 -C4 alkyl group or R2 and R3 together with the nitrogen piperidine ring, and acid addition and quaternary salts thereof, characterized in that the compound of formula (II) wherein R 1 is as defined in (1) and Z is as defined above, is reacted with a compound of formula (III) wherein A and n have the meanings given in 1 and R2 and R5 have the meanings given above and the pleuromutilins of the formula I obtained are optionally converted into their acid addition salts or quaternary salts.