1-(4-Alkyl-2-Aryl-1,3-Dioxolan-2-Ylmethyl)-1h-Imidazoles

In U.S. Pat. Nos. 3,575,999 and 3,717,655 are described some 1-(2-aryl-1,3-dioxolan-2-ylmethyl)imidazoles. The compounds of this invention differ from the foregoing essentially by the nature of the alkyl substituent, present in the 4-position of the dioxolane group.

The invention relates to novel 1-(4-alkyl-2-aryl-2-ylmethyl)-1H-imidazoles having the formula: ##STR1## and the therapeutically acceptable acid addition salts thereof, wherein: R is alkyl having from 2 to about 10 carbon atoms; and

Ar is a member selected from the group consisting of phenyl, substituted phenyl, thienyl, halothienyl and naphthalenyl, and wherein said substituted phenyl is phenyl having from 1 to 3 substituents independently selected from the group consisting of halo, lower alkyl, lower alkyloxy, nitro and cyano.

More particularly "alkyl" as used in the definition of R is meant to include straight and branch chained hydrocarbon radicals having from 2 to about 10 carbon atoms, such as, for example, ethyl, propyl, 1-methylethyl, 1,1-dimethylethyl, butyl, pentyl, hexyl, heptyl, octyl, decyl and the like alkyls; "lower alkyl" as used herein has the meaning of a straight or branch chained alkyl radical having from 1 to about 6 carbon atoms, such as, for example, methyl, ethyl, propyl, 1-methylethyl, 1,1-dimethylethyl, butyl, pentyl, hexyl and the like alkyls; and the term "halo" is generic to halogens of atomic weight less than 127, i.e., fluoro, chloro, bromo and iodo.

The compounds of formula (I) are conveniently prepared by reacting imidazole (II) with an appropriate reactive ester of formula (III) wherein Ar and R are as previously defined and wherein W is a reactive ester function, such as, for example, halo, 4-methylbenzenesulfonate, methanesulfonate and the like. Preferred reactive esters are halides and more particularly bromides and chlorides.

In one method of conducting the reaction between imidazole and (III), imidazole is first transformed into a metal salt thereof by treatment with an appropriate metallating agent such as, for example, a metal alkoxide, e.g., sodium- or potassium methanolate, or a metal hydride such as sodium hydride. The thus obtained metal salt is then reacted with (III) in an appropriate organic solvent, such as, for example, dimethylformamide or dimethylacetamide. A small amount of a metal iodide, such as sodium or potassium iodide may advantageously be added to promote the reaction, especially when the reactive ester is a chloride or bromide.

Alternatively, the reaction of imidazole with the reactive ester (III) may also be carried out without previous salt formation, by bringing the reactants into contact with each other in an appropriate organic solvent such as, for example, dimethylformamide or dimethylacetamide. In these circumstances it is appropriate to use an excess of imidazole or to add to the reaction mixture an appropriate base such as, for example, sodium or potassium carbonate or bicarbonate in order to bind the acid which is liberated during the course of the reaction. The use of an excess of imidazole is however preferred. Further it is advantageous to conduct the reaction in the presence of a metal iodide such as, for example, sodium or potassium iodide.

In each of the above procedures, somewhat elevated temperatures may be employed to enhance the rate of the reaction and most conveniently the reactions are carried out at the reflux temperature of the reaction mixture.

In these and the following preparations the reaction products may be isolated from the medium and, if necessary, further purified according to methodologies generally known in the art, such as, for example, extraction, trituration, crystallization, chromatography, etc.

The foregoing procedures are more fully illustrated by the following schematic representation: ##STR2##

An additional method of preparing the compounds of formula (I) is by the ketalization of an appropriate aroylmethylimidazole of formula (IV) wherein Ar has the same meaning as assigned to it previously with an appropriate diol of formula (V) wherein R is as previously defined.

Said ketalization reaction may be carried out following methodologies analogous to those described in the literature, e.g., for the preparation of 2-bromomethyl-2,4-diphenyl-1,3-dioxolane [Synthesis, 1974 (I), 23].

In a preferred manner of carrying out the reaction both reactants are refluxed together for several hours with azeotropic water removal in an appropriate organic solvent, preferably in the presence of a simple alcohol, such as, for example, ethanol, propanol, butanol, pentanol and the like, and in the presence of an appropriate strong acid such as 4-methylbenzenesulfonic acid. Suitable organic solvents are, for example, aromatic hydrocarbons, such as benzene, methylbenzene, dimethylbenzene and the like and saturated hydrocarbons, such as cyclohexane.

The foregoing reaction may be illustrated as follows: ##STR3##

The imidazole derivatives of formula (I), obtained in base form in the foregoing preparations, may be converted to their therapeutically useful acid addition salts by reaction with an appropriate acid, as, for example, an inorganic acid such as hydrohalic acid, i.e., hydrochloric, hydrobromic or hydroiodic acid; sulfuric, nitric or thiocyanic acid; a phosphoric acid; an organic acid such as acetic, propanoic, hydroxyacetic, .alpha.-hydroxypropanoic, 2-oxopropanoic, ethanedioic, propanedioic, 1,4-butanedioic, (Z)-2-butenedioic, (E)-2-butenedioic, 2-hydroxy-1,4-butanedioic, 2,3-dihydroxy-1,4-butanedioic, 2-hydroxy-1,2,3-propanetricarboxylic, benzoic, 3-phenylpropenoic, .alpha.-hydroxybenzeneacetic, methanesulfonic, ethanesulfonic, 2-hydroxyethanesulfonic, 4-methylbenzenesulfonic, 2-hydroxybenzoic, 4-amino-2-hydroxybenzoic, 2-phenoxybenzoic or 2-acetyloxybenzoic acid. The salts are in turn converted to the corresponding free bases in the usual manner, e.g., by reaction with alkali such as sodium or potassium hydroxide.

The intermediates of formula (III) may be prepared by subjecting an appropriate ketone of formula (VI), wherein Ar and W are as previously defined to a ketalization reaction with an appropriate diol of formula (V) in the same manner as described hereinbefore for the preparation of the compounds (I) starting from (IV) and (V). ##STR4##

Alternatively the intermediates of formula (III) are conveniently prepared by transketalization of a ketal derivative of a ketone of formula (VI) such as, for example, a lower alkyl ketal or a cyclic lower alkylene ketal, with a glycol of formula (V) under conditions similar to those described hereinbefore for the direct ketalization. The lower alkyl ketals and cyclic lower alkylene ketals used herein as starting materials are easily obtained by ketalization of a ketone of formula (VI) with a lower alkanol or alkanediol according to methodologies known in the art. A number of such compounds and methods of preparing the same are described in U.S. Pat. Nos. 3,575,999 and 3,717,655.

The intermediates of formula (III) are deemed to be novel and as useful intermediates herein they constitute an additional feature of this invention.

The precursor glycols of formula (V) are generally known and they may all be prepared according to known procedures as described in the literature.

The precursor arylketones of formula (VI) are also generally known and may be prepared following art-known methodologies. Bromides are, for example, easily obtained by the bromination of the corresponding methyl aryl methanone with bromine.

The aroylmethyl substituted imidazoles of formula (IV), a number of which are described in U.S. Pat. No. 3,717,655 are conveniently prepared by the reaction of (VI) with imidazole in an analogous manner as previously described for the preparation of the compounds (I) starting from imidazole and (III).

From formula (I) it is evident that the compounds of this invention have two asymmetric carbon atoms in their structures, namely those located in the 2- and 4-position of the dioxolane nucleus, and consequently they exist under different stereochemical optical isomeric forms. The stereochemical optical isomeric forms of (I) and the therapeutically active acid addition salts thereof are intended to be within the scope of this invention.

The diastereomeric racemates of (I), denoted as cis and trans forms respectively, according to the rules described in "Naming and Indexing of Chemical Substances for Chemical Abstracts during the 9th Collective Period (1972-1976)", published in C.A. 1972, 76, Index Guide Section IV, p. 85, may be obtained separately by conventional methods. Appropriate methods which may advantageously be employed therefore include, for example, selective crystallization and column-chromatography. For a number of compounds the stereochemical configuration was experimentally determined. In the remaining cases it is conventionally agreed to designate the stereochemical form which is first isolated as "A" and the second as "B", without further reference to the actual stereochemical configuration.

Since the asymmetric carbon atoms are already present in the intermediates (III) it is also possible to separate cis and trans forms, or generally "A" and "B" forms at this stage, whereupon the corresponding forms of (I) may be obtained after reaction of the foregoing with imidazole as previously described. The separation of cis and trans forms of (III) may be performed by conventional methods as described hereinbefore for the separation of the compounds (I) into their cis and trans forms.

It is evident that the cis and trans diastereomeric racemates may be further resolved into their optical isomers, cis(+), cis(-), trans(+) and trans(-) by the application of methodologies known to those skilled in the art.

The compounds of formula (I) and the acid addition salts thereof are useful agents in combatting fungi and bacteria. As such they are valuable in the treatment of human beings, animals and plants suffering from pathogenic microorganisms and in the destruction of microorganisms on materials.

The broad spectrum of antifungal and antibacterial activity of the compounds of formula (I) is clearly illustrated by the experimental data presented hereafter. The compounds in the tables are not listed for the purpose of limiting the invention thereto, but only in order to exemplify the useful properties of all the compounds within the scope of formula (I).

The test for antifungal activity was performed using Sabouraud's liquid medium in test tubes each containing 4.5 ml of liquid medium, autoclaved at 120.degree. C. for 15 minutes. The substances were dissolved in 50% ethanol at a concentration of 20 mg/ml and subsequently diluted with sterile distilled water to a concentration of 10 mg/ml. Successive decimal dilutions were then made with distilled water to give a series of stock solutions. To each tube containing 4.5 ml of Sabouraud's liquid medium was added 0.5 ml of one of the stock solutions to give a concentration of the drug under investigation of 100 .mu.g, 10 .mu.g, 1 .mu.g or 0.1 .mu.g per ml of medium.

Filamentous fungi were incubated at 25.degree. C. for 2-3 weeks. A square block of side 2 mm. was excised and inoculated into the liquid medium. A three-day old culture on Sabouraud's liquid medium was used for yeasts, and the inoculum was 0.05 ml per tube. All the cultures were incubated at 25.degree. C. for 14 days. The final readings were taken after two weeks and are summarized in the Tables I as follows:

In a first screening the drugs under investigation were tested against the following 11 fungi:

1. Microsporum canis (M. c. in the tables)

2. Ctenomyces mentagrophytes (Ct. m. in the tables)

3. Trichophyton rubrum (Tr. r. in the tables)

4. Phialopora verrucosa (Ph. v. in the tables)

5. Cryptococcus neoformans (Cr. n. in the tables)

6. Candida tropicalis (C. tr. in the tables)

7. Candida albicans (C. alb. in the tables)

8. Mucor species (Muc. in the tables)

9. Aspergillus fumigatus (A. f. in the tables)

10. Sporotrichum schenckii (Sp. s. in the tables)

11. Saprolegnia species (Sap. in the tables)

Bactericidal tests were performed on cultures on phenol red dextrose broth Difco medium. The same decimal dilution techniques as described herebefore were used. The inoculum consisted of a platinum loop (5 mm. diameter) from a 24 hour broth culture.

48 Hours after incubation, subcultures were made from each culture and for the assessment of the bactericidal activity of the drugs under investigation the presence or absence of growth after 7 days incubation was scored as described above.

The substances were tested against the following gram-positive bacilli and cocci:

1. Erysipelothrix insidiosa (E. ins. in the table),

2. Staphylococcus hemolyticus (Staph. in the table), and

3. Streptococcus pyogenes (Strept. in the table).

The results are summarized in Table II.

in view of the aforementioned antifungal and antibacterial activities this invention provides valuable compositions comprising the subject 1,3-dioxolan-2-ylmethyl imidazoles (I) or the acid addition salts thereof as the active ingredient in a solvent or a solid, semi-solid or liquid diluent or carrier, and, in addition, it provides an effective method of combatting fungus or bacterial growth by use of an effective anti-fungal or anti-bacterial amount of such ketals (I) or salts thereof. The subject compounds can be used in suitable solvents or diluents, in the form of emulsions, suspensions, dispersions or ointments, on suitable solid or semi-solid carrier substances, in ordinary or synthetic soaps, detergents or dispersion media, if desired, together with other compounds having arachnicidal, insecticidal, fungicidal and/or bactericidal effects, or together with inactive additives.

Solid carrier substances which are suitable for the preparation of compositions in powder form include various inert, porous and pulverous distributing agents of inorganic or organic nature, such as, for example, tricalcium phosphate, calcium carbonate, in the form of prepared chalk or ground limestone, kaolin, bole, bentonite, talcum, kieselguhr and boric acid; powdered cork, sawdust, and other fine pulverous materials of vegetable origin are also suitable carrier substances.

The active ingredient is mixed with these carrier substances, for example, by being ground therewith; alternatively, the inert carrier substance is impregnated with a solution of the active component in a readily volatile solvent and the solvent is thereafter eliminated by heating or by filtering with suction at reduced pressure. By adding wetting and/or dispersing agents, such pulverous preparations can also be made readily wettable with water, so that suspensions are obtained.

Inert solvents used for the production of liquid preparations should preferably not be readily inflammable and should be as far as possible odorless and as far as possible non-toxic to warm-blooded animals or plants in the relevant surroundings. Solvents suitable for this purpose are high-boiling oils, for example, of vegetable origin, and lower-boiling solvents with a flash point of at least 30.degree. C., such as, for example, polyethylene glycols, isopropanol, dimethylsulfoxide, hydrogenated naphthalenes and alkylated naphthalenes. It is, of cours, also possible to use mixtures of solvents. Solutions can be prepared in the usual way, if necessary, with assistance of solution promotors. Other liquid forms which can be used consist of emulsions or suspensions of the active compound in water or suitable inert solvents, or also concentrates for preparing such emulsions, which can be directly adjusted to the required concentration. For this purpose, the active ingredient is, for example, mixed with a dispersing or emulsifying agent. The active component can also be dissolved or dispersed in a suitable inert solvent and mixed simultaneously or subsequently with a dispersing or emulsifying agent.

It is also possible to use semi-solid carrier substances of a cream ointment, paste or waxlike nature, into which the active component can be incorporated, if necessary, with the aid of solution promotors and/or emulsifiers. Vaseline and other cream bases are examples of semi-solid carrier substances.

Furthermore, it is possible for the active component to be used in the form of aerosols. For this purpose, the active component is dissolved or dispersed, if necessary, with the aid of suitable inert solvents as carrier liquids, such as difluorodichloromethane, which at atmospheric pressure boils at a temperature lower than room temperature, or in other volatile solvents. In this way, solutions under pressure are obtained which, when sprayed, yield aerosols which are particularly suitable for controlling or combatting fungi and bacteria, e.g., in closed chambers and storage rooms, and for application to vegetation for eradicating or for preventing infections by fungi or bacteria.

The subject compounds and compositions thereof can be applied by conventional methods. For example, a fungus or bacterial growth or a material to be treated or to be protected against attack by fungus or bacterium can be treated with the subject compounds and the compositions thereof by dusting, sprinkling, spraying, brushing, dipping, smearing, impregnating or other suitable means.

When the subject compounds are employed in combination with suitable carriers, e.g., in solution, suspension, dust, powder, ointment, emulsion, and the like forms, a high activity over a very high range of dilution is observed. For example, concentrations of the active ingredient ranging from 0.1-10 percent by weight, based on the weight of composition employed, have been found effective in combatting fungi or bacteria. Of course, higher concentrations may also be employed as warranted by the particular situation.

The following examples are intended to illustrate, but not to limit, the scope of the present invention. Unless otherwise stated, all parts are by weight.

A mixture of 13.5 parts of 1,2-butanediol, 37.5 parts of 2-bromo-1-(2,4-dichlorophenyl)ethanone, 2 parts of 4-methylbenzenesulfonic acid, 40 parts of butanol and 225 parts of methylbenzene is stirred and refluxed for 24 hours with water-separator. The reaction mixture is cooled, washed twice with a sodium bicarbonate solution, dried, filtered and evaporated. The residue is distilled, yielding 38 parts (80%) of A+B-2-(bromomethyl)-2-(2,4-dichlorophenyl)-4-ethyl-1,3-dioxolane; bp. 125.degree.-130.degree. C. at 0.1 mm. pressure.

Following the procedure of Example I and using equivalent amounts of the appropriate starting materials, the following dioxolanes are prepared:

To a stirred solution of 120 parts of 1-(2,3-dichlorophenyl)-1-ethanone in 240 parts of butanol are added dropwise 101 parts of bromine at room temperature. After stirring for 1 hour at room temperature, there are added successively 42 parts of 1,2-ethanediol, 540 parts of anhydrous benzene and 4 parts of 4-methylbenzenesulfonic acid. The whole is stirred and refluxed overnight with water-separator. The reaction mixture is evaporated and the residue is dissolved in 2,2'-oxybispropane. The solution is washed with a diluted sodium hydroxide solution and three times with water, dried, filtered and evaporated. The residue is distilled, yielding 96.6 parts (49%) of 2-(bromomethyl)-2-(2,3-dichlorophenyl)-1,3-dioxolane; bp. 135.degree.-137.degree. C. at 0.1 mm. pressure.

Following the procedure of Example III and using an equivalent amount of an appropriate 1-aryl-1-ethanone in place of the 1-(2,3-dichlorophenyl)-1-ethanone used therein the following 2-aryl-2-(bromomethyl)-1,3-dioxolanes are prepared:

2-(bromomethyl)-2-(4-chloro-2-methylphenyl)-1,3-dioxolane; and

2-(bromomethyl)-2-(2-chloro-4-methoxyphenyl)-1,3-dioxolane; mp. 53.degree. C.

To a stirred solution of 74.4 parts of 2-bromo-1-(2-naphthalenyl)-1-ethanone in 240 parts of butanol are added successively 3 parts of 4-methylbenzenesulfonic acid and 270 parts of benzene. Then there are added dropwise 28 parts of 1,2-butanediol. Upon completion, stirring is continued overnight at reflux temperature. The reaction mixture is evaporated. The residue is dissolved in 2,2'-oxybispropane and the solution is stirred with a diluted sodium hydroxide solution. The layers are separated and the aqueous phase is extracted with 2,2'-oxybispropane. The extract is neutralized with water, dried, filtered and evaporated. The oily residue is crystallized from methanol. The product is filtered off and recrystallized from methanol, yielding 41 parts of 2-(bromomethyl)-2-(2-naphthalenyl)-1,3-dioxolane; mp. 64.degree. C.

A mixture of 13 parts of 1,2-butanediol, 31.2 parts of 2-(bromomethyl)-2-(2,3-dichlorophenyl)-1,3-dioxolane, 5 parts of 4-methylbenzenesulfonic acid, 40 parts of 1-butanol and 225 parts of dimethylbenzene is stirred and refluxed for 1 week. The reaction mixture is cooled, washed with a potassium carbonate solution, dried, filtered and evaporated. The residue is distilled, yielding 23 parts (67%) of (A+B)-2-(bromomethyl)-2-(2,3-dichlorophenyl)-4-ethyl-1,3-dioxolane; bp. 131.degree.-133.degree. C. at 0.1 mm. pressure.

Following the procedure of Example VI and using equivalent amounts of the appropriate starting materials, the following dioxolanes are prepared:

(A+B)-2-(bromomethyl)-4-ethyl-2-(2,3,4-trichlorophenyl)-1,3-dioxolane; bp. 145.degree. C. at 0.1 mm. pressure;

(A+B)-2-(bromomethyl)-2-(4-chloro-2-methylphenyl)-4-ethyl-1,3-dioxolane; bp. 118.degree. C. at 0.15 mm. pressure;

(A+B)-2-(bromomethyl)-2-(2-chloro-4-methoxyphenyl)-4-ethyl-1,3-dioxolane; bp. 142.degree.-144.degree. C. at 0.3 mm. pressure; and

(A+B)-2-(bromomethyl)-4-ethyl-2-(2-naphthalenyl)-1,3-dioxolane as a residue.

To a stirred and warm solution of 6.5 parts of 1,2-butanediol, 13 parts of 1-(4-chloro-2-methoxyphenyl)ethanone, 40 parts of 1-butanol are added dropwise (slowly) 5.7 parts of bromine at about 40.degree. C. After stirring for 30 minutes, there are added 2 parts of 4-methylbenzenesulfonic acid and 225 parts of methylbenzene and the whole is stirred and refluxed overnight with water-separator. The reaction mixture is cooled, washed with a potassium carbonate solution, dried, filtered and evaporated. The residue is distilled, yielding 17 parts (63%)of (A+B)-2-(bromomethyl)-2-(4-chloro-2-methoxyphenyl)-4-ethyl-1,3-dioxolane; bp. 135.degree.-140.degree. C. at 0.3 mm. pressure.

To a stirred mixture of 9.2 parts of 1,2-butanediol, 22.3 parts of 1-(2,4,5-trichlorophenyl)ethanone and 56 parts of 1-butanol are added dropwise 8.25 parts of bromine at about 40.degree. C. After stirring for 1 hour at room temperature, there are added 2 parts of 4-methylbenzenesulfonic acid and 107 parts of methylbenzene and the whole is stirred and refluxed overnight with water-separator. The reaction mixture is cooled, washed with a potassium carbonate solution, dried, filtered and evaporated. The residue is distilled, yielding 10 parts of (A+B)-2-(bromomethyl)-4-ethyl-2-(2,4,5-trichlorophenyl)-1,3-dioxolane; bp. 145.degree. C. at 0.2 mm. pressure.

16 Parts of (A+B)-2-(bromomethyl)-2-(2,4-dichlorophenyl)-4-ethyl-1,3-dioxolane are separated by column-chromatography over silica gel using a mixture of hexane and trichloromethane (95:5 by volume) as eluent.

The first fraction (A-isomer) is collected and the eluent is evaporated, yielding 5.5 parts of (A)-2-(bromomethyl)-2-(2,4-dichlorophenyl)-4-ethyl-1,3-dioxolane as a residue.

The second fraction (B-isomer) is collected and the eluent is evaporated, yielding 9 parts of (B)-2-(bromomethyl)-2-(2,4-dichlorophenyl)-4-ethyl-1,3-dioxolane as a residue.

To a stirred sodium methoxide solution, prepared starting from 3.8 parts of sodium in 40 parts of methanol, are added 11 parts of 1H-imidazole and 225 parts of N,N-dimethylformamide. The methanol is distilled off till internal temperature of 150.degree. C. Then there are added 19 parts of (A+B)-2-(bromomethyl)-2-(2,4-dichlorophenyl-4-ethyl-1,3-dioxolane and the whole is stirred and refluxed for 1 hour. The reaction mixture is allowed to cool to room temperature and poured onto water. The product is extracted three times with 1,1'-oxybisethane. The combined extracts are washed with water, dried, filtered and evaporated. The residue is purified by column-chromatography over silica gel using a mixture of trichloromethane and 1% of methanol as eluent. The first fraction is collected and the eluent is evaporated. The residue is converted into the nitrate salt in 2,2'-oxybispropane. The salt is filtered off and crystallized from a mixture of 2-propanol and 2,2'-oxybispropane, yielding 12 parts (56%) of (A+B)-1-[2-(2,4-dichlorophenyl)-4-ethyl-1,3-dioxolan-2-ylmethyl]-1H-imidaz ole nitrate; mp. 149.1.degree. C.

To a stirred sodium methoxide solution, prepared starting from 2.8 parts of sodium in 40 parts of methanol, are added 8 parts of 1H-imidazole and 225 parts of N,N-dimethylformamide. The methanol is distilled off till internal temperature of 150.degree. C. Then there are added 30 parts of (A+B)-2-(4-bromo-2-chlorophenyl)-2-(bromomethyl)-4-ethyl-1,3-dioxolane and stirring is continued for 1 hour at reflux temperature. The reaction mixture is cooled and poured onto water. The product is extracted twice with 2,2'-oxybispropane. The combined extracts are washed with water, dried, filtered and evaporated. The residue is purified by column-chromatography over silica gel using a mixture of trichloromethane and 2% of methanol as eluent. The pure fractions are collected and the eluent is evaporated. The residue is converted into the nitrate salt in 2,2'-oxybispropane. The salt is filtered off and crystallized from a mixture of 4-methyl-2-pentanone and 2,2'-oxybispropane, yielding 8.5 parts (26%) of (A+B)-1-[2 -(4-bromo-2-chlorophenyl)-4-ethyl-1,3-dioxolan-2-ylmethyl]-1H-imidazole nitrate; mp. 162.2.degree. C.

Following the procedure of Example XII and using equivalent amounts of the appropriate starting materials, the following imidazole acid addition salts are prepared:

a mixture of 12.5 parts of 1,2-butanediol, 19 parts of 1-(2-chloro-4-fluorophenyl)-2-(1H-imidazol-1-yl)ethanone hydrochloride, 16 parts of 4-methylbenzenesulfonic acid, 40 parts of 1-butanol and 225 parts of dimethylbenzene is stirred and refluxed for 6 days with water-separator. After cooling, the reaction mixture is filtered and the filtrate is washed with a diluted sodium hydroxide solution and with water. After the addition of 2,2'-oxybispropane, the whole is acidified with a nitric acid solution. The formed nitrate salt is filtered off and crystallized from a mixture of 4-methyl-2-pentanone and 2,2'-oxybispropane, yielding 5.7 parts (22%) of (A+B)-1-[2-(2-chloro-4-fluorophenyl)-4-ethyl-1,3-dioxolan-2-ylmethyl]-1H-i midazole nitrate; mp. 132.4.degree. C.

Following the procedure of Example XIV and using equivalent amounts of the appropriate starting materials, the following imidazole acid addition salts are prepared:

(A+B)-1-[2-(4-bromophenyl)-4-ethyl-1,3-dioxolan-2-ylmethyl]-1H-imidazole nitrate; mp. 194.7.degree. C.;

(a+b)-1-[2-(2,4-dibromophenyl)-4-ethyl-1,3-dioxolan-2-ylmethyl]-1H-imidazol e nitrate; mp. 149.7.degree. C.;

(a+b)-1-[4-ethyl-2-(2-thienyl)-1,3-dioxolan-2-ylmethyl]-1H-imidazole nitrate; mp. 135.4.degree. C.; and

(A+B)-1-[2-(5-chloro-2-thienyl)-4-ethyl-1,3-dioxolan-2-ylmethyl]-1H-imidazo le nitrate; mp. 164.3.degree. C.

To a stirred solution methoxide solution, prepared starting from 1.8 parts of sodium in 20 parts of methanol, are added 5.4 parts of 1H-imidazole and 112 parts of N,N-dimethylformamide. The methanol is distilled off till internal temperature of 130.degree. C. Then there are added 9 parts of (B)-2-(bromomethyl)-2-(2,4-dichlorophenyl)-4-ethyl-1,3-dioxolane and the whole is stirred and refluxed for 1 hour. The reaction mixture is cooled and poured onto water. The product is extracted three times with 1,1'-oxybisethane. The combined extracts are washed with water, dried, filtered and evaporated. The residue is purified by column-chromatography over silica gel using a mixture of benzene and ethanol (95:5 by volume) as eluent. The pure fractions are collected and the eluent is evaporated. The residue is converted into the nitrate salt in 2-propanol. The salt is filtered and dried, yielding 3.7 parts (36%) of trans-1-[2-(2,4-dichlorophenyl)-4-ethyl-1,3-dioxolan-2-ylmethyl]-1H-imidaz ole nitrate; mp. 164.degree. C.

Following the procedure of Example XVI there is prepared cis-1-[2-(2,4-dichlorophenyl)-4-ethyl-1,3-dioxolan-2-ylmethyl]-1H-imidazol e nitrate; mp. 160.2.degree. C. by the reaction of imidazole with cis-2-(bromomethyl)-2-(2,4-dichlorophenyl)-4-ethyl-1,3-dioxolane.