CS228931B2 - Method of preparing 2-/2,4-difluorophenyl/-1,3-bis/1h-1,2,4-triazol-1-yl/propan-2-ol - Google Patents

Description

The invention relates to a process for the production of a novel bis-triazole derivative having atutifungal activity and useful for the treatment of fungal infections in animals, including humans.

A novel compound produced by the process of the invention is 2- (2,4-difluorophenyl) -1,3-bis (1H-1,2,4H-triazol-1-yl) ipropan-2-ol of formula I

OH r-N- CH _r C-CHe. i í

the invention also includes pharmaceutically acceptable salts of the compound.

British Patent Application No. 2 078 719A (ICIj, published January 13, 82), and European Patent Application No. 0 044 605 (ICIj, published January 27, 82) disclose compounds corresponding to the general formula in which:

R ¹ represents an optionally substituted alkyl, cycloalkyl (e.g. cyclopentyl or cyclohexyl), aryl (e.g. phenyl) or aralkyl (e.g. benzyl) group, and each of Y ¹ and Y ² is = CH- or = N-, and salts thereof or metal complexes, ethers or esters.

These compounds are said to be useful as fungicides and plant growth regulators. They are also reported to be effective against human fungal diseases.

These published applications, specifically in Example 2 and in the definition, describe 1,3-bis (1H-1,2,4-triazol-1-yl) -2- (2,4-dichlorophenyl) propan-2-ol. This compound corresponds to the formula

OH

The 2,4-difluorophenyl derivative produced by the process of the present invention is not specifically mentioned in the above-mentioned ICI applications, nor is there specifically a 2,4-difluorophenyl radical specifically exemplified by the substituent R ¹ .

The above 2,4-dichlorophenynyl derivative is teratogenic, while the 2,4-difluorophenylanalog of the invention is unexpectedly teratogenic.

In addition, the corresponding 2-, 3- and 4-chlorophenylanalogues as well as 4-bromophenylanalogues are also teratogenic.

Teratogenic properties are determined by the following teratological tests.

Female rats [Cr]: COBS-CD (SD) BR, Charles River Breeding Colony, France] were randomly divided into groups of 5 animals after fertilization. Ten consecutive days from the 6th to the 15th day after fertilization are daily after; give test compounds as a suspension in 0.1% aqueous melthylcellulose by gastric tube.

On the 20th day after fertilization, the animals are sacrificed and the number of dead fetuses as well as the number, sex and weight of live fetuses are determined. External, buccal and visceral abnormalities are detected in all fetuses.

Compounds corresponding to the general formula are tested

OH

L = -A and R in which

R is 2,4-dichlorophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 4-bromophenyl or 2,4-difluorophenyl.

All fruits from animals treated with a compound containing a 2,4-dichlorophenyl group in the meaning of the symbol R at 20 mg / kg body weight show external malformations, in particular cleft palate. Visceral and skeletal examinations show that the compound is teratogenic at as low a dose as 1 mg / kg, as evidenced by the occurrence of microiftalmia, increased incidence of ureteral and renal pelvis, delayed ossification of some bones, and increased incidence of 14th pair of ribs.

Also, a compound in which R is a 4-chlorophenyl group is extremely embryotoxic at a dose of 20 mg / kg, while a compound in which R is a 2-chlorophenyl group causes external abnormalities (cleft palate) at this dose. These compounds are specifically referred to as Compound Nos. 9 in Table 1 of the above-mentioned ICI applications. In addition, compounds in which R is 3-chlorophenyl or 4-bromophenyl, which are not claimed but specifically mentioned in the above ICI applications, also cause the same external abnormalities at a dose of 20 mg / kg. The latter compound is also embryotoxic at this dose.

The compound of the invention, i.e. the compound of the above formula wherein R is a 2,4-difluorophenyl moiety, most surprisingly, causes no external malformations when administered to pregnant rats under identical conditions. Internal examination of the fetuses from these animals does not indicate any significant visceral or skeletal abnormalities. !

Fetal toxicity (etheratogenicity and / or embryotoxicity) of those compounds in which R is a substituent other than the 2,4-difluorophenyl moiety is a major disadvantage of these compounds when they should be used to treat mycoses in human medicine.

The invention also provides a pharmaceutical composition comprising a compound of Formula I or a pharmaceutically acceptable salt thereof, together with a pharmaceutically acceptable diluent or carrier. The composition is preferably used in human medicine in the form of a tablet, capsule, injectable, or massage.

In addition, the invention provides a method of treating fungal infections in animals, including humans, comprising administering to a patient an effective amount of a compound of Formula I or a pharmaceutically acceptable salt thereof.

According to the invention, the above-mentioned compound of formula I is obtained by reacting an oxirane of formula II

with 1,2,4-trinzole in the presence of a base different from the triazole used.

Although the reaction proceeds without addition of another base, since triazole itself is basic, it is in β

in such a case, the reaction is so slow for practical purposes that it is desirable to add the aforementioned additional base to the reaction mixture.

A preferred further base is potassium carbonate or sodium hydride.

According to a typical embodiment of the process, 1,2,4-triazole, oxirane of formula II and anhydrous potassium carbonate are reacted in a suitable solvent, for example dry dimethylformamide, preferably by heating to 50 to 120 ° C to accelerate the reaction. . The reaction is generally complete in 8 hours or less. The product can be isolated and cleaned as usual *,

The starting triazole can also be used in the form of an acid addition salt (for example, in the form of a methanesulfonic acid salt), in which case an excess of base must be used.

The oxirane of the above formula II can be prepared in a conventional manner, usually from the corresponding ketone of formula III

by reacting this ketone with dimethyloxosulfonium methylide prepared from trimethylsulfoxoinium iodide and a mixture of centrimin and sodium hydroxide.

This reaction is usually carried out as follows: the kelt of formula III, trimethylsulfoxonium iodide and cetrimide are vigorously stirred for several hours in a mixture of toluene and aqueous sodium hydroxide at about 100 ° C. The resulting oxirane can then be isolated by conventional means.

The ketone of formula III can be prepared in a conventional manner, for example, as illustrated in the following reaction scheme!

F

In general, the process of the invention produces an isomer contaminated product of formula I wherein one of the triazole rings is attached to the adjacent CH ₂ group via the 4-position, but this undesired isomer can be removed by chromatography, for example silica gel, or recrystallization.

Preferred pharmaceutically acceptable salts of the compound of formula I are acid addition salts. Pharmaceutically useful addition salts of the compound of formula (I) are those derived from strong acids forming non-toxic addition salts containing pharmaceutically acceptable anonites such as hydrochlorides, hydrobromides and sulfates.

Salts can be obtained by conventional methods, for example by mixing solutions containing equimolar amounts of both the free base and the desired acid. The desired salt is isolated by filtration if insoluble or by evaporation of the solvent.

The compound of formula I and its pharmaceutically acceptable salts are very potent anti-fungal agents useful for combating fungal infections in animals, including humans. For example, the compounds may be used to treat local fungal infections in humans, caused, inter alia, by Candida, Trichophyton, Microsporum, or Epidermophyton, or by mucosal infections caused by Candida albicaps (such as neonatal oral candidiasis and vaginal ciandidiase).

The disclosed compounds can also be used to treat systemic fungal infections caused by, for example, Candida albicans, Cryptococcus neoformans, Asperglllus fumigatus, Coccidioides, Paracoccidioides, Histopliasma or Blasfomyces.

In vitro evaluation of the antifungal activity of a compound of Formula I may be accomplished by determining the minimum inhibitory concentration (MIC), which is the lowest concentration of test compound in a suitable environment that prevents growth of the microorganism in question. In practice, a series of agar plates, each containing the test compound at a particular concentration, are inoculated with a standard culture of, for example, Candida albicans, and each plate is then incubated at 37 ° C for 48 hours to determine if The fungus growth occurred or not and the MIC value was recorded.

Other microorganisms which may be used include Crypto-coccus neoformis, Aspergillus fumigatus, Trichophyton spp, Microsporum spp., Epidermophyton floccosum, Coccidioides immitis and Torulopsis glabrata.

An in vivo evaluation of the efficacy of the compounds of the invention can be carried out by administering a series of different doses of the test substance by intraperiodionic or intravenous injection or orally to mice inoculated with Candida albicans. Untreated mice die within 48 hours. The dose at which the test substance protects 50% of the animals against swelling due to infection is determined. The compound of formula I provides this 50% protection at a dose below 0.5 mg / kg, administered orally or intravenously.

When used in human medicine, the anti-fungally active compound of formula I or a salt thereof can be administered alone, but is usually administered in admixture with a pharmaceutical carrier selected taking into account the intended route of administration and standard pharmaceutical practice. For example, it may be administered orally in the form of a tablet containing excipients such as starch or lactose, or in the form of a capsule or globule containing either alone or in admixture with excipients, or in the form of an elixir or suspension containing flavorings. additives or dyes. The compound of the invention may also be administered by parenteral injection, for example by intravenous, initramuscular or subcutaneous injection. For parenteral administration, the compound of the invention is preferably used in the form of a sterile aqueous solution, which may contain other substances, for example, salts or glucose, in an amount that ensures the isotonic character of the solution.

Daily dosages of the antifungal active compound of Formula I for oral and parenteral administration in human medicine are expected to range from 0.1 to 5 mg / kg (in divided doses), both for oral and parenteral administration. Thus, tablets or capsules are likely to contain from 5 mg to 0.5 g of the active ingredient of the invention for single or double or multiple administrations over a period of time, as appropriate for each case. The appropriate dosage, which will be most suitable for an individual patient and will vary depending on the age, weight and response of the patient to the formulation, is ultimately determined by the attending physician. The above dosage is only an example of the average case. Of course, individual cases requiring higher or lower dosages may occur, and such cases are within the scope of the invention.

Alternatively, the antifungal compound of formula I may be administered in the form of a suppository or pessary, or administered topically in the form of a lotion, solution, ointment or powder. For example, the vaccine may be incorporated into an ointment base consisting of an aqueous emulsion of polyethylene glycols or liquid paraffin, or may be incorporated at a concentration of between 1 and 10% into an ointment base consisting of white wax or white soft paraffin, optionally together with stabilizers and preservatives.

The invention is illustrated by the following non-limiting example.

Example (AJ) Preparation of 2-chloro-2 ‘, 4‘-difluoroacetophenone

CTCH _s COO

To a mixture of 114 g (1.0 mol) and 146.6 g (1.1 mol) of anhydrous aluminum chloride at room temperature (20 ° C) was added dropwise 113 g (1.0 mol) of chloroacetyl chloride under stirring. After stirring at 50-55 ° C for 5 hours, 48.5 ml of methylene chloride was slowly added and the mixture was allowed to cool to room temperature. The methylene chloride layer was separated, washed twice with 320 ml of water and the solvent was distilled off under reduced pressure. to give 180 mg of a light yellow solid residue.

A portion of this crude product (145 g) was crystallized from 435 ml of n-hexane. This afforded < 113 g (73%) of the title compound, m.p.

D. Ehlers, H. Bercher, and A. Grisk, J. Prakt. Chem., 315, 1169 (1973) reported 46.5 ° C. IR (KBr) and NMR (CDCl3) spectra were consistent with the assigned structure.

(Bj Preparation of 2 ‘, 4‘-difluoro-2- (1H-1,2,4-triazol-1-yl) acetophenone hydrochloride

O

II

C-CH3 ethyl acetate →

triethylamine

F hn ^ n »

O

C-CH _? N

= = HCl

To a mixture of 1,2,4-triazole (30.4 g, 0.44 mol) a

15.1 g (0.15 mol) of triethylamine in 186 ml of refluxing ethyl acetate was added a solution of 38.1 g (0.2 mol) of 2-chloro-2‘, 4‘-difluoroacetdfenone in 80 ml of ethyl acetate. The mixture was refluxed for 6 hours, then cooled to room temperature and the insoluble material was filtered off. The filtrate is washed twice with 200 ml of water each time and the solvent is distilled off under reduced pressure. The crude product was dissolved in 150 mL of ethyl acetate and a 25% (w / v) solution of hydrogen chloride gas in isopropanol was added. A solid product was allowed to precipitate from the mixture for 1 hour at 0 ° C, which was then filtered off and dried. 21.6 g (40%) of the title compound melting at 167-170 ° C is obtained. IR (KBr) and NMR (dimethylsulfoxide) spectra correspond to the structure.

The intermediate is characterized as an aqueous base which is prepared as follows.

To a suspension of 16.8 g (0.2 mol) sodium bicarbonate and 27.6 g (0.4 mol) 1,2,4-triazole in 180 ml of refluxing toluene is added a solution of 38.1 g 2 mol) of 2-chloro-2,4 ' -difluoroacetophenone in 45 ml of toluene. The mixture was stirred at reflux for 3 hours while the water formed in the reaction was removed using a Dean-Stark trap. The reaction mixture was cooled to room temperature and 180 ml of water were added. The toluene layer was separated and the solvent was distilled off under reduced pressure. Crystallization from 70 ml of a mixture of equal parts of ethyl acetate and n-hexane gave 3.9 g of the title compound, m.p. IR (KBr) and NMR (CDCl3) were consistent with the assigned structure.

Calcd for C10H7F2N3O:

% C, 53.8%;% H, 3.16;% N, 18.82; found:

% C, 53.62;% H, 3.15;% N 18.68.

(Cj Preparation of 1- [2- (2,4-Diifluorophenyl) -2,3-epoxypropyl] - (1H-1,2,4-triazole) methanesulfonate

59.6 g (0.23 mol) of 2 ', 4'-difluoro-2- (1H-1,2,4-triazol-1-yl) acetophenone hydrochloride, 50.6 grams (0.23 mol) trimethylsulfoxonium iodide and 2.1 g of cetrimide were stirred at 60 DEG C. for 3 hours in a mixture of 370 ml of toluene and 20% w / w aqueous sodium hydroxide, and the toluene layer was separated, concentrated to a volume of 110 ml and diluted with 150 ml of ethyl acetate. A solution of 16.6 g (0.172 mol) of methanesulfonic acid in 20 ml of ethyl acetate was added, a further 100 ml of ethyl acetate was added thereto, and the reaction mixture was stirred at 0 ° C for 1 hour, then the precipitate formed was filtered off. 43 g (56%) of the title compound.

g of this crude product is dissolved in 140 ml of hot ethanol denatured with methanol and 2 g of activated carbon are added. The mixture was filtered, the filtrate was concentrated to 100 ml and the residue was stirred at 0 ° C for 1 hour. Filtration gave 7.8 g (39%) of the title compound, melting at 128-129 degrees Celsius. IC (KBr) and NMR (dimethylsulfoxide) spectra are consistent with the indicated structure.

For C ₁₂ H ₁₃ F ₂ N ₃ O ₄ S calculated:

H, 3.9; N, 12.6.

found:

42,83% H, 3.92; N, 12.96.

(Dj Preparation of 2- (2,4-difluorophenyl) -1,3-bis (1H-1,2,4-triazol-1-yl) propan-2-ol

0.

cn ₂

N-—

A mixture of 6.7 g (0.02 mol) of 1- [2- (2,4-difluorophenyl) -2,3-epoxypropyl] -1H-1,2,4-triazole methanesulfonate, 2.8 g (0 1,2,4-triazole and 9.1 g (0.066 mol) of anhydrous potassium carbonate are stirred at 90 DEG C. for 4.5 hours in 35 ml of dimethylformamide. The resulting mixture was cooled to room temperature, poured into 170 ml of water, extracted twice with 60 ml of chloroform each, and the extracts were combined and washed twice with 100 ml of water each. The chloroform solution was dried over magnesium sulfate and the solvent was distilled off under reduced pressure. 5.3 g of crude product are obtained as a residue.

This crude product was dissolved in 50 ml of isopropanol and 0.5 g of activated carbon was added. The mixture was filtered and the filtrate was concentrated to a volume of 25 ml. The precipitate formed is filtered off and dried to yield

2.6 g (44%) of the title compound, melting at 139-140 ° C. IR (KBr) and NMR (dimethylsulfoxide) spectra were consistent with the structure.

For C ₁₃ H ₁₂ F ₂ N ₆ O calculated:

% C, 51.0;% H, 3.92;% 27.5%;

found:

% C, 50.85;% H, 3.92;% 27.74.

Claims (2)

Process for the preparation of 2- (2,4-difluoro-phenyl) -1,3-bis (1H-1,2,4-triazol-1-yl) -propan-2-ol of formula I OH N, N-CH-C-CH 2 -CH 2 ^-F (IJ and pharmaceutically acceptable salts thereof), characterized in that 1,2,4-triazole or an acid addition salt thereof in the presence of a base is reacted with a compound of formula II, whereupon optionally the resulting compound of formula I is converted into a pharmaceutically acceptable salt thereof. 2. The process of claim 1, wherein the base is potassium carbonate.