CS228949B2 - 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 antifungal activity and useful for the treatment of fungal infections in animals, including humans.

The novel compound of the present invention is 2- (2,4-difluorophenyl) -1,3-bis (1H-1,2,4-triazol-1-yl) propan-2-ol of Formula I

the invention also includes pharmaceutically acceptable salts of the compound.

British Patent Application No. 2 078 719 A (ICI), published January 13, 82, and European Patent Application No. 0 044 605 (ICI), published February 27, 82, describe compounds corresponding to the general formula

OH

Y = N-CHrC-CH;

i 1 fe i j

R <

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. formula

him formula

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

The above 2,4-dichlorophenyl derivative is teratogenic, whereas the 2,4-difluorophenylanalog of the invention is unexpectedly teratogenic.

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

Teratogenic properties are determined by the following teratological tests.

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

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

Compounds corresponding to the test compound were tested

^c I 'I |

Ø N ~ J

Cl · 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 the meaning of the symbol R

The 2,4-dichlorophenyl group, at a dose of 20 mg / kg body weight, exhibits external malformations, particularly cleft palate. Visceral and skeletal examinations show that this compound is teratogenic at as low a dose as 1 mg / kg, as evidenced by microphthalmia, 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 Compounds Nos. 1 and 9, respectively, 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 formula (I) above, wherein R is a 2,4-difluorophenyl moiety, most surprisingly, does not cause any 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 (teratogenicity and / or embryotoxicity J of those compounds in which R represents 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 preparation or ointment.

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.

The present invention provides a process for the preparation of the novel compound of formula (I) and pharmaceutically acceptable salts thereof, characterized in that at least two molequivalents of 1,2,4-triazole or an acid addition salt thereof are reacted with a compound of formula II in the presence of a base.

in which

Hal is chlorine or bromine, whereupon optionally the resulting compound of formula I is converted to its pharmaceutically acceptable salt.

A preferred base is potassium carbonate or sodium hydride.

The process of the invention is illustrated by the following reaction scheme:

OH

N 'N-Cl-hOCH-N N 1 -. I, * i i f

In the formulas shown in this scheme, Hal is chlorine or bromine.

The intermediate oxirane of formula III may optionally be isolated.

According to a typical embodiment of this reaction, the compound of formula II and 1,2,4-triazole are heated, for example to a temperature of up to 120 ° C, in a suitable solvent, for example in dry N, N-dimethylformamide or tetrahydrofuran, after up to about 24 hours in the presence of a base such as potassium carbonate. In general, an excess of triazole and a base are used. The product of formula I is \

Wg-j

F

F -? Q? - Mgfir

F

O! 1? * Hal-CH CCHX · can be isolated and cleaned as usual.

In general, the process of the invention produces an isomer contaminated product of formula I in which 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.

The starting material of formula (II) may be prepared by conventional methods, for example as follows:

OH

Preferred pharmaceutically acceptable compounds of formula I are acid addition salts. The pharmaceutically acceptable addition salts of the compound of formula I are those derived from strong acids forming non-toxic addition salts containing pharmaceutically acceptable anions 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 antifungal agents useful for combating fungal infections in animals, including humans. For example, they can be used to treat local fungal infections in humans caused, inter alia, by Candida, Trichophyton, Mlcrosporum or Epidermophyton, or by mucosal infections caused by Candida albicans (such as neonatal oral candidiasis and vaginal candidiases). treating systemic fungal infections caused by, for example, Candida albicans, Cryptococcus neoformans, Aspergillus fumigatus, Coccidioides, Paracoccidioides, Histoplasma or Blastomyces.

An 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 certain concentration, are inoculated with a standard culture, such as Candida albicans, and each plate is then incubated at 37 ° C for 48 hours to determine if fungus growth occurred or not from the plates and the appropriate MIC value was recorded. Other microorganisms which may be used include Cryptococcus neoformans, 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 may be performed by intraperitoneal or intraperitoneal administration of mice inoculated with Candida albicans. by intravenous injection or orally administer a series of different doses of the test substance. Untreated mice die within 48 hours. The dose at which the test substance protects 50% of the animals against death 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 antifungal 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 or dyes. The compound of the invention may also be administered by parenteral injection, for example by intravenous, intramuscular 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 ensuring 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. Accordingly, the dosage which will be most suitable for an individual patient and will vary with 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 active ingredient 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

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

t

Of-i

OH i

(i) To a solution of 0.96 g (5 mmol) of 1-bromo-2,4-difluorobenzene in 10 ml of diethyl ether, with stirring at -78 ° C, was added 3.23 ml of a 1.55 M solution of n- butyllithium in hexane (5 mmol). After the addition was complete, the mixture was stirred for 10 minutes, then a solution of 0.63 g (5 mmol) of 1,3-dichloroacetone in 10 ml of diethyl ether was added dropwise over 3 minutes. The mixture was stirred at -78 ° C for 30 minutes, then a solution of 0.33 g of acetic acid in 5 mL of diethyl ether and then 10 mL of water was added at 0 ° C. The organic layer was separated and the aqueous layer was washed once with diethyl ether. The combined ether extracts were dried (MgSO4) and evaporated to a pale yellow oil which was dissolved in 20 mL of DMF. This dimethylformamide solution contains an intermediate corresponding to formula IIB above.

(ii) To the solution prepared in (i) above, 1.72 g (25 mmol) of 1,2,4-triazil and 2.07 g (15 mmol) of anhydrous potassium carbonate were added, and the mixture was heated at 70 for 18 hours. Deň: 32 ° C. The intermediate oxirane derivative of formula III is not isolated. The reaction mixture was cooled, poured into 100 ml of water and extracted twice with ethyl acetate. The combined organic extracts were dried over magnesium sulfate and evaporated to a gummy residue which was chromatographed on silica gel (270-400 mesh) using 3% methanol in methylene chloride as eluent to give 0.40 g (26% calculated on dichloroacetone) of the compound of formula The title compound, as a white solid, melting after crystallization from a mixture of ethyl acetate and hexane at 138-140 ° C.

For C13H12F2N6O calculated:

% H, 3.95;% N, 27.44;

found:

H, 4.05; N, 27.08.

¹ H NMR, IR and mass spectra were consistent with the assigned structure. Chromatography separates the desired product from the undesired 1- [2- (2,4-difluorophenyl) -2-hydroxy-3- (4H-1,2,4-triazol-4-yl) propyl] -1H-1- 2,4-triazole present in the reaction mixture.

Claims (2)

OBJECT OF THE INVENTION Process for the preparation of 2- (2,4-difluorophenyl) -1,3-bis (1H-1,2,4-triazol-1-yl) propan-2-ol of formula I OH and pharmaceutically acceptable salts thereof, characterized in that at least two molequivalents of 1,2,4-triazole or an acid addition salt thereof are reacted in the presence of a base with a compound of formula II in which: Hal is chlorine or bromine, whereupon the optionally formed compound of formula I is converted to its pharmaceutically acceptable salt. 2. The process of claim 1, wherein the base is potassium carbonate.