DK153838B - ANALOGY PROCEDURE FOR PREPARING 2,4-DICHLOR-ALFA (N-IMIDAZOLYLMETHYL) -DIBENZYLETHERS - Google Patents

Description

in

DK 153838 B

The invention relates to an analogous process for the preparation of the novel compounds of formula I as claimed in the preamble of claim 1 or to pharmaceutically acceptable acid addition salts thereof.

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The process according to the invention is characterized by the characterizing part of claim 1.

Preferred pharmaceutically acceptable acid addition salts of the compounds of formula I include those with both inorganic and organic acids such as hydrochloric, nitric, sulfuric, phosphoric, methanesulfonic, succinic, maleic, fumaric, citric and tartaric acids. These salts can be prepared by conventional methods e.g. by adding the desired 15 acid to the base in equimolecular amount, and then recrystallizing the salt thus formed in a suitable solvent.

The compounds of formula I and their salts are important in drugs because of the activity they exhibit against 20 swamp, yeast species and gram positive aerobic and anaerobic bacteria, and this activity is associated with a low toxicity. The compounds prepared according to the invention have been compared with two well-known antimycotic products, clotrimazole, ie. [(imidazol-1-yl) - (o-chlorophenyl) diphenylmethane], and miconazole.

Of particular significance was the comparison between activity and toxicity of the compounds of formula I and miconazole. Miconazole is 2,2 ', 4,4 1-tetrachloro-cc (N-imidazolylmethyl) -dibenzyl ether. In miconazole, both benzyl groups are substituted at the 2- and 4-position with chlorine atoms, whereas the benzyl group in the compounds of formula I is α-unsubstituted and substituted at the 4-position only with a phenyl or phenylthio group. This difference results in a significant reduction in toxicity, which for the compounds of formula I is from 3 to 4 times lower than for miconazole. The antifungal and antibacterial effect is about the same. Conveniently, the compounds of formula I can be used in human therapy

DK 153838B

2 for local treatment of dermatosis, such as trichophytosis and candidosis, and other infections caused by fungi, staphylococci and streptococci. The compounds of formula I may be admixed with pharmaceutically acceptable diluents or carriers to form pharmaceutical compositions such as e.g. powders, ointments, creams, suspensions or dispersions.

Results obtained in biological experiments are listed in Tables I, II and III.

Table I lists the acute toxicity values (LD 50) for compounds of formula I and both of the above-mentioned comparison compounds. The toxicity is indicated in mg / kg administered per os 15 to mice by conventional methods.

Table II lists the minimum inhibitory concentrations (MICs) of compounds of formula I and of both comparison compounds. By MIC is meant the minimum concentration that is capable of inhibiting the growth of fungi and yeasts. The MIC values have been determined by the usual double-se-nutrient-liquid dilution technique.

MIC values for the compounds prepared by the process of the invention and for both comparative compounds against some gram-positive bacteria determined by the conventional dual-series nutrient dilution technique are listed in Table III.

Experimental conditions:

For mushrooms

Medium: Sabouraud liquid pH 5.7 (5 ml per glass)

Inoculum: A ten-day agar culture was washed with a physiological solution containing 10% Tween 80, then filtered through gauze and resuspended in a physiological solution until the solution on a Coleman Jr II spectrophotometer at a wavelength of 650 nm showed a 50 % transparency (T) (0.1 ml

DK 153838 B

3 spore suspension per mL). For Aspergillus niger, after filtration, a 1/10 dilution in physiological solution was prepared. 0.1 ml of this solution constituted inoculum for 5 ml.

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Temperature and incubation time: 25 ° C for 7 days.

For vultures 10 Medium: Saboura liquid pH 5.7 (5 ml per glass)

Inoculum: Yeasts that had been growing in Saboura fluid for 24 hours (Cryptococcus neoformans for 2 days). Cells were separated by centrifugation at 6500 rpm and resuspended in a physiological solution to have a suspension which, on a Colman Jr II spectrofometer at a wavelength of 650 nm, provides a 50% transparency (T). 0.1 ml of this suspension constitutes inoculum for 5 ml.

Temperature and incubation time: 37 ° C for 48 hours.

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For gram-positive bacteria

Medium: Tryptic soy medium pH 7.3 (5 ml per glass)

Inoculum: The day before the study, the microorganisms to be examined were transferred to their respective media. After 25 hours of incubation at 37 ° C, 0.1 ml of a 1: 100 dilute the suspension of each strain was inoculated into 5 ml of a medium containing the compounds to be tested at concentrations of 0.009 to 160 mcg / ml.

Temperature and incubation time: 37 ° C for 18 hours.

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Table I

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DK 153838 B

Acute toxicity (LD50) per os in mice in mg / kg

Formula I Formula I Miconazole Clotrimazole R = C6H5 r = c6h5s 2400 ............................... 3UUU 870 "580.. ..................................

Table II

Antimycotic activity (MIC) in mcg / ml.

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Pathogenic agent Formula I Formula I Micon-Clotri- r = c6h5 RsCgHsS azole mazole u.Albicans R 5 3TJ 5 Γ0 C.Albicans Greensenthal 5 40 5 10 1 C.Albicans 1040 10 80 20 40 C.Albicans 1041 20 80 20 40 C. Neoformans 0.312 0.156 0.078 0.625 T.Mentagroph.2538 0.156 0.156 0.078 0.078 T.Mentagroph.10148 0.625 0.625 0.625 1.25 T.Mentagroph.5865 1.25 1.25 0.31 0.62 T. Verrucosum 10 1 , 25 2.5 1.25 20 T.Rubrum 2121 0.625 0.625 0.312 1.25 M.canis 28 20 2.5 5 2.5 A. Niger 20 10 40 10 P.Chrysogenum 20 5 20 40 E. Floccosum_ 10__5_ 5_ 5_

Table III 25

Antibacterial activity (MIC) in mcg / ml.

Pathogenic agent Formula I Formula I Micona- Clotri- R = C5H5 r = c6r5s 201 mazole 30 S.aureus SG car - U, 039 - U, <J39 - U, 312--0Ϊ3Τ2— S.aureus 10 B 0.039 0.018 0.312 1.25

Size hemolytic 821 0.156 0.156 1.25 2.5 B. subtilis 0.156 0.078 0.625 2.5

Cl.novyi <1.25 5.0 <1.25> 160

Stromhemolvt 203 0.312 0.078 0.625 5 As the solvent of the process according to the invention, aromatic hydrocarbons, dimethylformamide, tetrahydrofuran, hexamethylphosphoramide or dimethylsulfoxide can be used.

Dimethyl sulfoxide is used with particular advantage as it has

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5, the condion station then becomes more complete. This leads to a higher yield and a cleaner product. In this case, it is not necessary to subject the purified base to a purification through a chromatography column, which against such purification is necessary if dimethyl formamide or hexamethylphosphoramide is used as the solvent.

Indeed, a simple filtration of the base solution through a silica gel column is capable of retaining the small amounts of impurities. With compounds of formula I in which R is a phenyl group, filtration is not necessary and crystallization of the nitrate leads to a product sufficiently pure for pharmaceutical use. Along with the aprotic solvents listed above, an alkali metal hydride or amide is used which is capable of forming a salt with the IS hydroxy group in the ethanol derivative.

The condensing solvent may also be an aliphatic alcohol having from 3 to 6 carbon atoms, such as t-butanol, in which case the alkali metal hydride or amide must be replaced by an alkali metal alcoholate, e.g. potassium t-butylate.

It may also be useful to add small amounts of potassium iodide as a catalyst prior to the addition of the halogenobenzyl derivative.

1- (2 ', 4'-dichlorophenyl) -2- (N-imidazolyl) ethanol can be prepared from 2-chloroacetyl-2,4-dichlorobenzene (BeiIstein-Handbuch der Org. Chem. IV ° ed. 7, page 28) by reducing the keto group using sodium borohydride and condensation with imidazole. The reduction and condensation can be carried out in the 30 order you want. The reduction can be carried out in methanol and the condensation can be carried out in dimethyl formamide and methanol in the presence of sodium. The halobenzyl compounds of general formula V are known compounds. The preparation of 4-chloro-methylbiphenyl is described in Chem. Ber. 66B, 351471, 1933, and the preparation of 1-bromomethyl-4-phenylthiobenzene are disclosed in U.S. Patent No. 3,242,193.

The invention is further described in the following Examples, in which Examples 1 to 3 illustrate the method of the invention.

DK 153838B

6 shows the example, and Example 4 shows the preparation of pharmaceutical compositions containing compounds prepared according to the invention. Examples A and B describe the preparation of the starting materials used in Examples 1 to 3.

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Example A

1- (2 ', 4'-dichlorophenyl) -2-chlorethano1.

49.5 g of sodium borohydride are added slowly and in small amounts to a suspension of 233 g of 1- (1'-oxo-21-chloroethyl) -2,4-dichlorobenzene in 1 liter of methanol with stirring and at room temperature. The solution thus prepared was stirred for an additional 2 hours at room temperature and then poured into 1 liter of 15N hydrochloric acid which was cooled with ice. After extraction with ethyl acetate or chloroform, the extract was washed with water, with 1 N sodium hydroxide, then again with water until neutrality and finally with a saturated sodium chloride solution. The extract was dried, the solvent evaporated off and 20 220 g of an oil were obtained. The oil was solid on standing and the solid product melted at 48-51 ° C.

Analysis for CQH70130 C% H% Cl%

Calculated 42.61 3.13 47.17 Found 42.75 3.19 47.43

Example B

1- (21,41-Dichlorophenyl-1-2- (N-imidazolyl) ethanol) 30 g of sodium was added to a solution of 88.5 g of imidazole in 600 ml of methanol and the solvent was evaporated.

The residue was dissolved in 300 ml of dimethylformamide and heated to 115-120 ° C. To the solution thus prepared was added dropwise and with stirring a solution of 225 g of 1- (2 ', 4'-dichlorophenyl) -2-chloroethanol in 400 ml of dimethyl formamide. The mixture was heated to 115-120 ° C and kept at this temperature for 20 minutes, and after cooling

DK 153838 B

7 to 40 ° C, 2500 ml of ice water was added with vigorous stirring. During the stirring for a period of about 2 hours, the product is precipitated and the top liquid is decanted off and an additional 2500 ml of water is added and, after standing, the whole is filtered. The precipitate thus prepared was dried and recrystallized in toluene. 170 g of the desired product were obtained. Melting point 134-135 ° C.

Analysis for CuHiCl 2 O C% H% N% Cl% 10 Calculated 51.38 3.92 10.89 27.58

Found 51.62 3.80 10.73 27.76

Example 1 2,4-Dichloro-4L-phenylthio-α- (N-imidazolyl-methyl 1-di-benzyl-ether (I: R

Method I.

A solution of 2.57 g of 1- (2 ', 4-dichlorophenyl) -2- (N-imidazolyl) ethanol prepared in Example B in 10 ml of hexa-methylphosphoramide was dripped at 25 ° C. to a suspension of 0.52 g of sodium hydride (50% in oil) in 5 ml of hexamethylphosphoramide. When hydrogen evolution had ceased, salt formation was completed by heating for 1 hour to 50 ° C. After cooling to 25 ° C, 2.58 g of 1-chloromethyl-4-phenyl-ylthiobenzene were added. The temperature was set to 50 ° C and kept here for 12 hours. At the end of the reaction, the mixture was poured into 200 ml of water, the product was extracted with diethyl ether, the solvent was evaporated and the residue was purified twice in a silica gel column using ethyl acetate as eluant and examining the various fractions with TLC. The solvent was evaporated and the intermediate fractions provided 2.4 g of the desired base as a yellow oil, showing a single spot on TLC.

DK 153838 B

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Analysis for C24H20N2C120S C% H% N% Cl% s% Calculated 63.30 4.44 6.13 15.57 7.04

Found 63.86 4.24 6.41 15.29 6.97 Method II.

0.66 g of sodium hydride (50% in oil) was added at 20-30 ° C and under nitrogen atmosphere to 3.86 g of 1- (2 ', 4'-dichlorophenyl) -2- (N-imidazolyl) ethanol in ml of dimethyl sulfoxide (dried over 10 calcium hydride).

The mixture was heated with stirring to 50-60 ° C until gas evolution was completed. After cooling to 20-25 ° C, 0.5 g of potassium iodide was added and then slowly a solution of 3.51 g of 1-chloromethyl-4-phenylthiobenzene in 4 ml of dimethyl sulfoxide was added dropwise. The mixture was stirred at 20-25 ° C until addition of 1-chloromethyl-4-phenylthiobenzene was completed. The mixture was then poured into 150 ml of water and extracted with diethyl ether. After drying over anhydrous sodium sulfate 20, an excess of 4N nitric acid in diethyl ether was added to the ethereal solution, and the desired product precipitated as nitrate in the form of an oil which was solid on standing. After standing for 20 hours, the ethereal liquid was decanted off and the residue was recrystallized from ethanol. The nitrate thus obtained, which is not completely pure, was dissolved in water and an excess of sodium carbonate was added to release the base, which was then extracted with ethyl acetate. The base, which was isolated by filtration, was purified in a silica gel column using 30 ethyl acetate as eluant. The combined fractions containing the desired product were evaporated to dryness. The residue was dissolved in diethyl ether, converted again to the nitrate and recrystallized in ethanol. Yield: 3.1 g of a white crystalline powder melting at 134 ° C.

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DK 153838 B

Analysis for C24H20N2Cl2OSHNO3 C% H% N% Cl% S%

Calculated 55.61 4.08 8.11 13.68 6.18

Found 55.32 4.08 8.16 13.56 6.32 5

Example 2.

2,4-ΡΊθή1θΓ-4'-phenyl-g- (N-imidazolvimethyl) -dibenzyl ether (I; R = CgH5)

Method I.

A mixture consisting of 2.06 g of potassium t-butylate in 30 ml; t-butanol was prepared at 20-25 ° C in a nitrogen atmosphere. To this mixture was added 3.86 g of 1- (2 ', 41-dichlorophenyl) -2- (N-imidazolyl) ethanol, prepared according to Example B. This solution was heated under reflux for 1 hour and then cooled to 20-25 ° C. 3.03 g of 4-chloromethyl-biphenyl was added and the solution was again heated under reflux for 5 hours. After cooling to 20-25 ° C, the whole was poured into water and the precipitated base was extracted with ethyl acetate. The extract was washed with water and dried and the solvent was evaporated. The residue was dissolved in diethyl ether (80 ml) and left overnight. The undissolved substances were filtered off and the filtrate treated with nitric acid dissolved in diethyl ether. An oil was solidified on standing. The residue, consisting of 2,4-dichloro-4'-phenyl-α- (N-imidazolylmethyl) -dibenzyl ether nitrate, was recrystallized from ethanol or ethyl acetate. A product, 4.3 g, 30 which was shown to be pure on TLC, melting at 140-141 ° C was obtained.

Analysis for C24H20N2Cl2O.HNO3 C% H% N% C1% Calculated 59.25 4.35 8.64 14.57

Found 59.17 4.14 8.61 14.46

DK 153838B

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Process I (a)

To a solution of 0.37 g of sodium in 20 ml of jv-propanol was added 4.1 g of 1- (2 ', 4'-dichlorophenyl) -2- (N-imidazoly1) ethanol and the mixture was heated under reflux for two hours with stirring. After cooling to room temperature, 0.5 g of potassium iodide and 3.25 g of 4-chloromethylbiphenyl were added with stirring and the mixture was again heated under reflux. At the end of the reaction, the mixture was filtered and washed with ethanol. The filtrate was evaporated to dryness and the residue was dissolved in diethyl ether. The insoluble residue was filtered off and the clear ether solution thus obtained was treated with a mixture of nitric acid and diethyl ether. The 2,4-dichloro-41-phenyl-α- (N-imidazolylmethyl) -dibenzyl ether nitrate thus obtained was recrystallized in ethanol. A product, 2.1 g, was obtained which had the same characteristics as the product prepared according to the above procedure and showed a single spot on TLC.

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Procedure II.

0.66 g of sodium hydride was added under a nitrogen atmosphere and at 20-25 ° C to a solution of 3.86 g of 1- (2 ', 4 * -dichlorophen-25 yl) -2- (N-imidazolyl) -ethanol in 15 ml dimethyl sulfoxide (dried over calcium hydride). The mixture was heated to 50-60 ° C until gas evolution was over. Then the mixture was cooled to 20-25 ° C and 0.5 g of potassium iodide was added and a solution of 3.03 g of 4-chloromethylbiphenyl in 7 ml of dimethyl sulfoxide (dried over calcium hydride) was added thereto. The whole mixture was stirred for approx. 20 hours at 20-25 ° C and then poured into water. The product was extracted with ethyl acetate and then treated as described in Method I. Yield 4.6 g.

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DK 153838 B

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Example 3

Salts of 2,4-dichloro-4-phenylthio-α- (N-imidazolylmethyl) di-benzyl ether were prepared by reacting the free base dissolved in ethanol with an alcoholic solution of the desired acid and subsequently recrystallizing the the salt thus prepared in a suitable solvent. The free base was prepared as described in Example 1, Process I, or by release from the nitrate prepared by Process II, by treatment with sodium carbonate, extraction with diethyl ether and evaporation.

Table IV lists solvents for the recrystallization, elemental analyzes and melting points for some of the 15 salts.

Table V lists some data for some salts of 2,4-dichloro-41-phenyl-α- (N-imidazolylmethyl) dibenzyl ether prepared using the methods described above.

25 30 35

12 DK 153838 B

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DK 153838 B

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Example 4

Pharmaceutical antifungal and antibacterial compositions containing the active compounds of the invention were prepared in concentrations of 0.5 to 5 wt%, preferably from 1 to 3 wt%, in admixture with pharmaceutically acceptable diluents or carriers. Examples of an ointment, a powder, a glycolic solution and a gel are listed below.

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Ointment.

2,4-dichloro-4'-phenyl thi o-α- (N-imidazolylmethyl) dibenzyl ether nitrate 2 g lanolin 20 g vaseline up to 100 g

Glycolic solution.

2,4-dichloro-4'-phenylthio-α- (N-imidazolylmethyl) -dibenzyl ether nitrate 2 g propylene glycol up to 100 ml

Powder.

2,4-dichloro-4'-phenylthio-α- (N-imidazolylmethyl) -dibenzyl ether nitrate 2 g 1 anoly η 1.5 g soybean elec 2 thin talc up to 100 g 35

Claims (2)

5 Carbopol 2 g water 2 g polyethylene glycol up to 100 g triethanolamine up to about pH 3. 10 Patent claims. An Analogous Process for the Preparation of 2,4-Dichloro-α- (N-15-imidazolylmethyl) -di benzyl Eethers of the General Formula I Γ / \ f \ ci - <V Wherein R is a phenyl or phenylthio group or pharmaceutically acceptable acid addition salts thereof, characterized in that 1- (2 ', 4'-dichlorophenyl) -2- (N-imidazolyl) -ethanol at a temperature of from 20 to 100 ° C for from 6 to 36 hours in the presence or absence of potassium iodide as a catalyst in a solvent selected from the group consisting of aromatic hydrocarbons, dimethyl formamide, tetrahydrofuran, hexamethylphosphoramide and dimethylsulfoxide and in the presence of room of an alkali metal hydride or amide or in a solvent consisting of an aliphatic alcohol having from 3 to 6 carbon atoms in the presence of an alkali metal alcoholate is condensed with a halogenobenzyl of the formula V DK 153838 BE-ry-ch 2 x v where R has the meaning given above and X means a chlorine or bromine atom, and the compound of formula I thus prepared is isolated by the usual methods and, if desired, converted to a pharmaceutically acceptable acid additive in t salt. Analogous process according to claim 1, characterized in that the aliphatic alcohol is t.-butanol and the reaction is carried out in the presence of alkali metal t-butylate or the aliphatic alcohol is propenol and the reaction is carried out in the presence of alkali metal n-propylate.