DE2708827A1 - SUBSTITUTED PURINE COMPOUNDS, PROCESS FOR THEIR PRODUCTION AND PHARMACEUTICAL PREPARATIONS - Google Patents

Description

DR. BEFG DIPL-INO. STAPF DIPL-ING. SCHNVABE Dk DR. SANDMAIR

PATENT LAWYERS

8 MUNICH 86. POST BOX 8602

'S *

Attorney File 27 855 March 1, 1977

THE WELLCOME FOUNDATION LIMITED LONDON, NWL / UK

Substituted purine compounds,

Process for their manufacture and pharmaceutical

Preparations

Addendum to patent

(Patent application P 2 ^ 39 963.7)

The invention relates to substituted purine compounds and their pharmaceutically acceptable salts, as well as Process for their manufacture. In particular, the compound relates to the esters of the 9- (2-hydroxyethoxymethyl) derivatives of guanine and 2,6-diaminopurine and the pharmaceutically acceptable salts of these compounds.

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It has been found that substituted purines of the formula I

R ^J

K-

N>

(I)

CH-.0.CFi-.CH ₀ OC.R '
2 2 2 j,

1 2

in which R is a hydroxyl or amino group and R is hydrogen, an alkyl group with a straight or branched one Chain with 2 to 16 carbon atoms, an unsubstituted aryl group with 10 carbon atoms or a substituted one Aryl group with 6 to 18 carbon atoms, preferably less than 10 carbon atoms, means virostatic against different families of DNA and RNA viruses act in vitro and against DNA viruses in vivo. The connections are special effective against herpes, vaccinia and rhinoviruses; Herpes viruses include herpes simplex, H. zoster and varicella in mammals, the diseases such as herpetic keratitis in rabbits and herpetic encephalitis in mice cause.

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The invention relates to a compound of formula I in which

1 2 R and R have the meaning given above, or one their salts, especially in the form of a pharmaceutically acceptable salt.

The compounds of the formula I, or one of their salts, in which R is a hydroxyl group, are preferred; likewise compounds in which R is hydrogen or an alkyl group with a straight or branched chain having 2 to 8, preferably 2 to 4, carbon atoms. If R ^{2 is} a substituted aryl group with 6 to 18, preferably fewer than 10 carbon atoms, a halogen, an amino, nitrile or sulfamide group or acyl or alkyl group with 1 to 4 carbon atoms are preferred as substituents on the aryl group.

The compounds are particularly preferred, especially because of their extraordinarily high effectiveness against herpes viruses 9- (2-formyloxyethoxymethyl) guanine, 9- (2-propionyloxyethoxymethyl) guanine, 9- [2- (2,2-dimethylpropionyloxy) ethoxymethyl] guanine and 2-amino-9- (2-formyloxyethoxymethyl) adenine .

Salts particularly suitable for therapeutic purposes are the pharmaceutically acceptable salts of organic acids such as Lactic, acetic, malic or p-toluenesulfonic acid, as well as the Salts of pharmaceutically acceptable mineral acids, such as hydrochloric acid or sulfuric acid. If R is a hydroxy

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group, then you can also use the pharmaceutically acceptable Alkali metal salts, preferably the sodium salt, can be used. Other salts can also be produced and then used in the salts directly suitable for the treatment purposes being transformed.

The invention also relates to a process for the preparation of a substituted purine of the formula I, as described above, which is characterized in that a) a compound of the formula II

λ_

(II)

H "N ' ^{Μ /} |

with a compound of the formula III

A.CH ₀ .0.CH ₀ .CH ₀ .OC.R ² (III)

2 I / 11

wherein A represents atoms or groups which split off, and Q represents a hydrogen atom or an alkali metal, implements; or b) a compound of the formula IV

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(IV)

, * Q.CH ₀ .CH ₀ OC.R ² 2 2 2 j,

in which R has the meaning given above, and M and 6 represent precursors of R or the 2-amino group, converts into a compound of the formula I; or c) an alcohol of the formula V.

(V)

CH ₂ .0.CH _or .CH ₂ OH

esterified by reaction with an acylating agent; or d) blocking groups from a compound of formula I. removed in which the 2-amino group and the R substituent are blocked;

and optionally converting the compound of formula I prepared by one of processes a) to d) into another compound of formula I by transesterification. Is the product one of the reactions described above a base, it can optionally be converted into one of its acid addition salts or alkali salts

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convert; if the product is a salt of a compound of the formula I ₁ , it can optionally be converted into its base or another salt.

In process a) the atom or group A which is split off is preferably a reactive radical of a organic or inorganic acid such as a halogen atom or a sulfonate group, and Q is hydrogen or a Alkali metal, preferably sodium. In the preferred method, a purine with the desired 2- and 6-substitution is used with an acyl blocked 2-halomethoxyethanol or a acyl blocked acyloxymethoxyethanol, e.g. 2-propionoyloxyethoxymethyl chloride or butyryloxyethoxymethyl acetate, in a strong polar solvent such as dimethylformamide (DMF) and condensed in the presence of a base, e.g. sodium hydride. The reaction is preferably carried out at room temperature for an extended period of time, i.e. it can several hours or even days may be required to obtain a reasonable yield.

The conversion of a compound of the formula IV using process b) can be carried out in various ways; mean e.g. M and / or G azide groups, then they can be reduced by reduction using a suitable catalyst such as palladium Amino groups are converted.

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These and other known methods are described in "Heterocyclic Compounds - Fused Pyrimidines Part II Purines", Hrgb. DJ Brown, published by Wiley-Interscience, 1971.

The compounds which contain the precursor substituents Q and M and which are converted into compounds of formula I. can be viewed as intermediates in the synthesis of these compounds and can be analogous to processes a) are produced.

In process c), an alcohol of the formula V is treated with a suitable acylating agent such as a carboxylic acid, an aliphatic or aromatic anhydride, an aliphatic or aromatic acyl halide, a mixed carbonic acid-carboxylic acid anhydride or a carboxylic acid ester. Compounds of the formula V can be prepared using the processes described in German Offenlegungsschrift No. 2,539,963 getting produced.

In process d), one or both of the amino groups in the 2-position and the substitution in the 6-position can be reversible blocked by a blocking group such as a trialkylsilyl group, an activated acyl group, or a benzyloxycarbonyl group; these last two types of However, groups only block R if it means an amino group. If both amino groups are in the 2-position and the substitution in the 6-position by a trialkylsilyl group is then this compound is the condensation product

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of a trialkylsilylated purine and an ester or diester as in process a). These blocking groups are very labile and can be removed by solvolysis with alcoholic or aqueous ammonia solution or by alcoholysis will.

Either or both of the 2 and 6 positions in the purine ring can blocked by an activated acyl group, such as a trihaloacyl group, e.g. trichloroacetyl, which then together with the amino group it is blocking a trichloroacetamide group forms. The 6-position in the purine ring is only blocked if it is substituted by an amino group. These groups can be split off by reduction; a blocking benzyloxycarbonyl group can also be carried out by reductive Cleavage will be removed.

Processes a) to d) are all based on intermediates which can be prepared from monosubstituted purines. These purines are easy to prepare by known methods as described in the literature and in text books such as e.g. "Heterocyclic Compounds - Fused Pyrimidines Part II Purines", Ed. D.J. Brown, published by Wiley-Interscience (1971).

A compound of the formula I prepared with one of the processes a) to d) can optionally be converted into a other compound of formula I can be converted. A sol-

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before conversion can be carried out by reacting a compound of the formula I take place with a suitable carboxylic acid; for the production of 9- (2-propionoyloxyethoxymethyl) -guanine is e.g. Reaction with propionic acid required. In certain cases the acid can also act as a catalyst acid, in others however, an additional catalyst acid, e.g. paratoluenesulfonic acid, is necessary.

The invention also relates to a pharmaceutical preparation composed of a compound of the formula I as described above, or one of their pharmaceutically acceptable salts, and a pharmaceutically acceptable carrier. In particular contains a pharmaceutical preparation according to the invention a compound of the formula I in the form of an effective unit dose.

As used herein, "effective unit dose" means a predetermined amount of antiviral agent sufficient to to be effective against viruses in vivo. Pharmaceutically acceptable carriers are for the administration of the medicament usable substances; they can be solid, liquid or gaseous, but they must be inert, medically compatible and be compatible with the active ingredients.

These pharmaceutical preparations can be administered parenterally, orally, as suppositories or pessaries; you can Can be used locally as an ointment, cream, aerosol, powder or as eye or nose drops, etc., depending on whether with the

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'ff'

Preparation treats internal or external viral infections should be.

In the case of internal infections, the preparation is administered orally or parenterally in doses of (based on the free base) about 0.1 to 250 mg / kg, preferably 1 to 50 mg / kg of body weight administered; in humans it appears several times a day in the form of Unit doses of 1 to 2 50 mg are used.

For oral administration, fine powders or granules can be used as diluents, dispersants and / or surfactants Contain funds; they can be offered as a mixture, in water or in a syrup. They can also be used dry as capsules or sachets or in a non-aqueous solution or suspension, which may contain suspending agents, in tablets, which can contain binding agents and lubricants, or are offered as a suspension in water or a syrup. As far as necessary or flavoring agents, preservatives, suspending agents, thickening agents or emulsifying agents can also be desired attached. Tablets and granules are preferred; these can be provided with a coating.

For parenteral or drop-shaped administration, for example in the case of eye infections, the compounds can be used in aqueous solution in a concentration of about 0.1 to 10%, preferably 0.1 to 1%, most preferably 0.2% (weight / volume) Tobe offered. The solution can contain antioxidants, buffers, etc.

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In the case of infections of the eye or other external tissues, e.g. in the mouth or skin, the preparations are preferred also applied locally as an ointment or cream to the infected part of the patient's body. The connections can as an ointment, for example with a water-soluble ointment base, or in a cream, for example with an oil in water Cream base, offered in a concentration of about 0.1 to 10%, preferably 0.3 to 3%, preferably 1% (weight / volume) will.

The invention also relates to a method for treating viral infections in mammals by administering a effective unit dose of a compound of formula I or one of its pharmaceutically acceptable salts as described above. The administration is preferably carried out locally, orally or parenterally.

The following examples are intended to explain the invention in more detail.

example 1

A solution of H, 73 g of 9- (2-hydroxyethoxymethyl) -guanine, prepared according to German Offenlegungsschrift No. 2,539,963, in 2M ml of 97% formic acid was stirred overnight at room temperature. The amber solution was diluted with about 200 ml of dry ether and cooled. The white precipitate was filtered off, FormyloxyäthoxymethyD-guanine-2 (3.6 g dried and recrystallized from dry dimethylformamide to 9- (mp. 225-275 recrystallized ⁰ C).

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Example 2

A solution of 0.5 g of 2-amino-9- (2-hydroxyäthoxymethyD-adenine, prepared according to German Offenlegungsschrift No. 2,539,963, in 2.5 ml of 97% formic acid, was in an ice bath for 3 hours, then overnight 80 ml of dry ether was added and the mixture was cooled. The dye was filtered off and dissolved in 125 ml of hot acetonitrile; residual solids were filtered off. The filtrate was placed in a column containing 14 g of silica gel in acetonitrile column was eluted with of dry acetone. the eluate was evaporated and the solid residue from acetonitrile to give 2-amino-9- (2-formyloxyäthoxymethyl) adenine (93 mg, mp. 238-240 ⁰ C) recrystallized.

Example 3

Production of 9- (2-hexanoyloxyethoxymethyl) guanine. 1.0 g of 9- (2-hydroxyethoxymethyl) guanine, manufactured according to German Offenlegungsschrift No. 2 5 39 96 3, the solution was dissolved in 70 ml of dry dimethylformamide by heating in a steam bath was cooled to room temperature and 10 ml of dry pyridine and 9.4 g of caproic anhydride were added. To After stirring for 4 days at room temperature, thin layer chromatography (silica gel in 10% methanol chloroform) indicated that the Reaction ended.

The yellow reaction solution was made up to 800 ml with ethyl acetate diluted and refrigerated for several days. The precipitated fine white powder was filtered off, dried and dried out

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Acetonitrile recrystallized what "+00 mg (28%) of white granules, mp. 221-223 ⁰ C, resulted.

example

Production of 9- (2-propionoyloxyethoxymethyl) guanine.

A) 31 g of ethylene glycol, 18.5 g of propionic acid and 7.5 g of a strong hydrogen ion exchange resin, Bio Rod AG 50 WX-4 in 100 ml of toluene, were refluxed with stirring under a Dean-Stark trap for 18 hours.

The toluene was removed by flash evaporation and the remainder of the liquid was distilled. After the initial run of Ethylene glycol was used to distill the desired ethylene glycol monopropionate. The purity was measured by means of NMR test determined. Yield 70%.

B) Dry hydrogen chloride gas was bubbled into the cooled (0 ⁰ C) suspension of 7.1 g of Äthylenglycolmonopropionats prepared above and 1.8 g of paraformaldehyde in 50 ml of dichloromethane, passed dissolved to the solid and the mixture was saturated with hydrogen chloride. After drying over molecular sieves and calcium chloride, the mixture was filtered off and the solvent was removed by flash evaporation at 30.degree.

The oil residue from 2-propionoyloxyethoxymethyl chloride was used directly . Yield 60%.

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C) 2.53 g of sodium hydride in a 57% mineral oil dispersion was washed with dry hexane and a solution of 4.53 g of guanine in 100 ml of dry dimethyl sulfoxide was added. The mixture was ^{stirred at 30 °} C. for 23 hours.

5.5 g of 2-Propionoyloxyäthoxymethylchlorid were added and the reaction mixture stirred for 18 hours at 20 ⁰ C. The solution was filtered and the solvent removed by flash evaporation in vacuo. The residue was cooled in an ice bath, dissolved in water and neutralized with acetic acid.

After standing for 1 hour, the product was filtered off, washed with water and dried. Three-fold recrystallization from boiling acetonitrile gave 9- (2-Propionoyloxyäthoxymethyl) guanine. (Yield 35%, mp. 223-226 ⁰ C).

Example 5

Production of 9- (2-Tridecanoyloxyäthoxymethyl) -guanine, 300 mg of 9- (2-hydroxyethoxymethyl) -guanine, prepared according to German Offenlegungsschrift No. 2 5 39 96 3, were in 20 ml dry dimethylformamide and 30 ml dry pyridine in a steam bath until dissolved. The solution was at room temperature cooled, and 0.93 g of tridecanoyl chloride added. The solution was stirred at room temperature until thin layer chromatography indicated the completion of the reaction by the disappearance of the starting material (18 hours).

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The solution was evaporated quickly and a yellow oil residue appeared Acetonitrile crystallized giving an off-white solid. NMR analysis of the crude product indicated its presence multiple connections. The clarified mixture was purified by column chromatography.

Example 6

Production of 9- (2-dodecanoyloxyethoxymethyl) -2,6-diaminopurine.

1. Dry hydrogen chloride gas was passed into a cooled (0 ⁰ C) suspension of 14.66 g Äthylenglycolmonododecanat and 1.8 g of paraformaldehyde in 50 ml of dichloromethane, dissolved until the solids and the mixture was saturated with hydrogen chloride.

After drying the solution over molecular sieves and calcium chloride the mixture was filtered and the solvents were removed by flash evaporation at 30 ° C. The oil residue from 2-Dodecanoyloxyäthoxymethylchlorid was direct used. Yield 75%.

2. It became an anhydrous solution of 2,6-diaminopurine Prepared in dimethylformamide by adding 3.54 g of the monohydrate in 2 50 ml of solvent in a steam bath until it dissolves heated, cooled and allowed to stand over new molecular sieves for 18 hours.

To this mixture was added 0.95 g of a 57% mineral oil dispersion of sodium hydride. The slurry was

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Stirred overnight, then 6.35 g of 2-dodecanoyloxyethoxymethyl chloride were added dropwise and the reaction mixture was stirred overnight at room temperature. The solids were filtered, washed with chloroform and the combined washing and mother solutions flashed at 60 ⁰ C.
The oil residue was recrystallized from ethanol. Yield 20%.

Example 7

9- (2-propionoyloxyethoxymethyl) guanine.

A mixture of 1.0 g of 9- (2-hydroxyethoxymethyl) -guanine and 50 ml of dry dimethylformamide was heated in the steam bath until almost all of the solids had dissolved. It was then cooled to room temperature. 10 ml of dry pyridine and 2.9 ml of propionic anhydride were added and the mixture was stirred overnight at room temperature. An additional 1.0 ml of propionic anhydride was added and the mixture was stirred for an additional 18 hours. The reaction mixture was diluted with ethyl acetate, cooled and the solid obtained was filtered off. This was (0.9 g, mp. 223-226 ⁰ C) from dimethylformamide to 9- (2-Propionoyloxyäthoxymethy1) guanine recrystallized.

Example 8

9- [2- (2,2-dimethylpropionyloxy) ethoxymethyl] guanine. A mixture of 2, ^ 6 g 9- (2-Hydroxyäthoxymethyl) -guanine, UOO ml of dry pyridine and 6.5 ml of pivalic anhydride were heated in the steam bath for a total of 33 days. On the 11th day

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-vt- .14.

150 ml of pyridine were added, on the 27th day 50 ml of dimethylformamide. Volatiles were removed under reduced pressure, the residue was triturated with ethyl acetate * The insoluble solid was filtered off and dissolved in methanol acetone. 3 g silica gel was added and the solvent evaporated. The residue was placed in a column containing 180 g of silica gel in acetone. Elution with acetone gave an initial fraction of Ν, Ο-diacylated material, which was followed by a fraction with the desired monoacylated product. From this second fraction, the acetone was evaporated and the residue from dimethylformamide-Acetonitrilätheracetat to 9- [2- (2,2 dimethylpropionyloxy) ethoxymethyl] guanine recrystallized (0.5 g, mp. 245-2 * 6 ⁰ C).

Example 9

Production of 9- (2-palmitoyloxyethoxymethyl) guanine. 0.3 g of 9- (2-hydroxyethoxymethyl) guanine, prepared according to German Offenlegungsschrift No. 2,539,963, were partially dissolved in 15 ml of dry dymethylformamide and 30 ml of dry pyridine by heating in a steam bath for 1/2 hour. The mixture was cooled in an ice bath and 1.1 g (4.00) of palmitoyl chloride was added with stirring. The mixture was Returned to room temperature and stirred for 20 hours during which time all solids dissolved. Thin layer chromatography showed quantitative conversion of the starting material.

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• Λ.

The solution was diluted to 300 ml with ethyl acetate and cooled overnight. Filtration gave 0.49 g of white solid.

The crude material was once (190 mg, 31%, mp. 190-210 ⁰ C) from ethyl acetate and once from acetone to give analytically pure 9- (2-Palmitoyloxyäthoxymethyl) guanine recrystallized. NMR, UV and mass spectral data were consistent with the desired product.

Example 10

Production of 9- (2-butyryloxyethoxymethyl) guanine.

It was a solution of sodium methoxide in 10 ml of dry methanol of a methanolic solution of 9- (2-HydroxyäthoxymethyD-guanine added at room temperature. Removal of the solvent in vacuo gave the sodium salt of the purine as a white powder.

This sodium salt was suspended in a mixture of ethyl butyrate and 20 ml of dry DMF and stirred for Brought to reflux. After 3 1/2 days, almost all of the solid had dissolved. The reaction mixture dried to dryness in vacuo concentrated and the residue dissolved in 15 ml of 2N acetic acid.

Removal of the solvent in vacuo gave a semi-solid mass which, after treatment with 15 ml of water and 15 ml of SD3A solidified with removal of the solvent in vacuo.

This product was slurried with 25 ml SD3A, filtered, air dried to give 19 5.2 mg of a brownish solid.

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" P.3-

Example 11

A tablet preparation was made from a mixture of 100 mg of 9- (2-formyloxyethoxymethyl) guanine, 200 mg of lactose, 50 mg starch, 5 mg polyvinylpyrrolidone and U mg magnesium stearate produced by wet granulation.

Example 12

A tablet preparation was made from a mixture of 100 mg of 2-amino-9- (2-formyloxyethoxymethyl) adenine, 200 mg Lactose, 50 mg starch, 5 mg polyvinylpyrrolidone and 4 mg magnesium stearate produced by wet granulation.

Example 13

A tablet preparation was made from a mixture of 100 mg of 9- (2-propionoyloxyethoxymethyl) -guanine, 200 mg of lactose, 50 mg starch, 5 mg polyvinylpyrrolidone and 5 mg magnesium stearate produced by wet granulation.

Example It

A tablet preparation was made from a mixture of 100 mg of 9-2- (2,2-dimethylpropionoyloxy) ethoxymethylguanine, 200 mg lactose, 50 mg starch, 5 mg polyvinylpyrrolidone and U mg magnesium stearate produced by wet granulation.

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Claims (17)

Patent claims: 1. Substituted purine of the formula I. At/ cV.O.CH ".CH" OC R ² 1 2 wherein R represents a hydroxy or amino group and R Hydrogen, a straight or branched chain alkyl group with 2 to 16 carbon atoms, an unsubstituted one Represents aryl group having 10 carbon atoms or a substituted aryl group having 6 to 18 carbon atoms, or one of its salts, in particular in the form of a pharmaceutically acceptable salt. 2. Substituted purine of the formula I according to claim 1, characterized in that R is a hydroxyl group, or one of its salts, in particular in the form of a pharmaceutically acceptable salt. 3. Substituted purine of the formula I according to claim 1 or 2, characterized in that R is hydrogen or a straight or branched chain alkyl group - 21 - 709036/0855 -Arndt means 2 to 8 carbon atoms. 4. Substituted purine according to claim 1 or 2, characterized in that the aryl group is substituted with halogen, an amino, nitrile or sulfamide group or acyl or alkyl groups with 1 to U carbon atoms. 5. Substituted purine according to claim 1, 2 or U 2 characterized in that R, when it is a substituted aryl group, is less than 10 carbon has atoms. 6. Substituted purine of the formula I according to claim 1, characterized in that it 9- (2-formyloxyethoxymethyl) guanine. 7. Substituted purine of the formula I according to claim 1, characterized in that it 9- (2-propyonoyloxyethoxymethyl) guanine. 8. Substituted purine of the formula I according to claim 1, characterized in that it 9- [2- (2,2-dimethylpropionoyloxy) ethoxymethyl} guanine. 9. Substituted purine of the formula I according to claim 1, characterized in that it Is 2-amino-9- (2-formyloxyethoxymethyl) adenine. - 22 - 7 () «936/0855 10. Pharmaceutical preparation, characterized in that that they are a substituted purine of the formula I according to claim 1 together with a pharmaceutically acceptable one Includes carrier. 11. Preparation according to claim 10, characterized in that it is a substituted purine according to any one of claims 6 to 9 together with a pharmaceutically acceptable carrier. 12. Preparation according to claim 10 or 11, characterized in that it is in the form of an ointment or cream is present. 13. Preparation according to claim 10 or 11, characterized in that it is in tablet form. IU. Pharmaceutical preparation for oral or parenteral use Administration according to claim 10, 11 or 13, characterized in that it is the compound of Formula I in an amount of 1 to 250 mg per unit dose contains. 15. A pharmaceutical preparation according to claim 14 for parenteral use Administration as eye or nose drops, characterized in that it contains the compound of formula I in a concentration of 0.1 to 10% in - 23 - 709836/0855 a suitable medium. 16. A pharmaceutical preparation for local use according to any one of claims 10 to 12, characterized in that that it contains the compound of formula I in a concentration of 0.1 to 10%. 17. A pharmaceutical preparation according to claim 16, characterized in that it contains the compound in one Contains concentration of 1%. 709836/0855