CS235971B2 - Fungicide agent and method of effective substances production - Google Patents

Abstract

1. 2-Imidazolylmethyl-2-phenyl-1,3-dioxolanes of the formula (I) see diagramm : EP0080071,P9,F12 in which R represents the groupings see diagramm : EP0080071,P9,F1 and see diagramm : EP0080071,P9,F2 R**1 represents hydrogen or alkyl with 1 to 4 carbon atoms ; R**2 represents hydrogen, alkyl with 1 to 4 carbon atoms or halogenoalkyl with 1 to 2 carbon atoms and 1 to 5 identical or different halogen atoms ; X represents hydrogen, fluorine, chlorine, bromine and alkyl or alkoxy with in each case 1 to 4 carbon atoms ; n represents 1 and Y represents substituted phenyl, possible substituents being : halogen or alkyl with 1 to 4 carbon atoms, and their plant-tolerated acid addition salts and metal salt complexes.

Description

The present invention relates to a fungicidal composition comprising as active

The new 2-imidazzoylmethhl-2-phenyl-1,3-dioxolane component. Part of the invention relates to a process for the preparation of these novel compounds.

It is already known that certain triazolylalkirnoli have fungicidal properties (cf. DE-OS

31 407). Thus, for example, 4-chlorophenyl- (1,2,4-trjazol-1-ylmethil) carbinol can be used for fungal infestation. However, the effect of this substance is not always self-resonant, especially at lower applied quantities.

Partially, it is known that certain iidazooylalkanols have good effects against fungi occurring in human medicine (sov. 7. Med. Chem., 784-791 (1969). Thus, for example, 4-bromophenyl-2-ol may be used for this indication. However, the effect of these compounds against phytopahhogenic fungi is not always well established.

We have now found the new 1-azazyl-2-yl-phenil-1,3-dioxole of formula (I)

(I) in which:

R is a group of formulas

Xn kde

X is hydrogen, halogen, C1 -C4 alkyl, C1 -C4 alkoxy, nitro, or cyano, 1 or 2, and

Y is optionally halogen-substituted phenoxystopine or optionally halogen-substituted phenyl footprint, ^{r 1} is hydrogen or a C 1 to 4 carbon atom;

· ^R represents hydrogen alkytooou quick match with ^1-4 atoms of ^H or L ¹ to halogenalkyžožou stoptou having 1 to 4 carbon atoms, and their addition to the> acid oi! Plant-tolerant and their tommlexes are plant-tolerated metal salts.

The compounds of formula I may exist in various stereoisomeric forms. Preferably, these compounds are present in the form of blends of stereoisomers.

The present invention relates to a fungicidal composition which is characterized in that it contains as active ingredient. e-clips one 22imidazoOyllettyll2 feiyl2 1,3-d0oxžlai general formula 1 or acid addition salt of 2-ilidajažylLmthyl fenill1,3- ^---> dioxžljnž · formula I with an acid or tolerated rostinnami kommlex --ϋdjzažyllettyll2-feiyl-1, 3-DOA ELBOW of formula (I) is a plant-tolerated metal.

According to the invention, the amino-2-phenyl-1,32-dioxolanes of the formula I as well as their acid addition salts and their complexes are prepared by treating the plant-tolerant metal salt by reacting the 1,3-dihydroxy derivative. nu formula II, R = CH ₂ -Z Ο'Ό

(II) in which:

2

R, R and R are as defined above and Z is halogen or a group of the formula

-O-SO ₂ -R ³ , where

R ³ represents a methyl or p-methylphenyl, with imidazoles of formula III (III) wherein

M is hydrogen or an alkali metal, in the presence of a diluent and optionally in the presence of an acid binder, whereupon an acid or a metal salt is optionally added to the compounds of formula I thus obtained;

It has been found that the 2-imidazolyl-2-phenyl-1,3-dioxolanes of the formula I and their plant-tolerated acid addition salts and their metal salt complexes produced by the process according to the invention have potent fungicidal properties.

Surprisingly, the compounds of the invention exhibit better fungicidal activity than 4-chlorophenyl- (1,2,4-triazol-1-ylmethyl) carbinol, 4-bromophenyl- (imidazol-1-ylmethyl) carbinol and 2,4-dichlorophenyl- ( imidazol-1-ylmethyl) carbinol, ie compounds known in the art which are structurally similar substances with the same type of action ·

The 2-imidazolyl-2-phenyl-1,3-dioxolanes according to the invention are generally defined by formula (I). Preferred are those compounds of formula (I) in which:

R is a group of formulas of the four-Y in which

X is hydrogen, fluoro, chloro, bromo and C1-C4alkyl or C1-C4alkoxy, n is 1 and

Y represents an optionally halogen-substituted phenoxy group or an optionally halogen-substituted phenyl group,

R ¹ represents hydrogen or alkyl with 1 to 4 carbon atoms,

R ² represents hydrogen, alkyl having 1 to 4 carbon atoms or halogenoalkyl having 1 to 2 carbon atoms and 1 to 5 identical or different halogen atoms such as fluorine and chlorine atoms ·

Particularly preferred are those compounds of formula I wherein

R is a group of formulas ^C M · ^V B ⁱⁿ which

X is hydrogen, fluoro, chloro or methyl, n is the number 1 and

Y represents an optionally fluorine or chlorine substituted phenoxy or phenyl group,

R ¹ is hydrogen or C 1 -C 4 alkyl;

R is hydrogen, C 1 -C 4 alkyl and fluoro or chloro substituted methyl.

Preferred substances according to the invention are furthermore the acid addition salts of 2-imidazolylmethyl-2-phenyl-1,3-dioxolanes of the formula (I), wherein in the formula (I), R ¹ , R ¹ and R ^{2 are the} radicals mentioned above as preferred for these symbols. Particularly preferred are acid addition salts formed by the addition of a hydrohalic acid such as hydrochloric acid and hydrobromic acid, in particular hydrochloric acid, phosphoric acid, nitric acid, sulfuric acid, mono- and dibasic carboxylic acids and hydroxycarboxylic acids, such as acetic acid acids, maleic acid, succinic acid, fumaric acid, tartaric acid, citric acid, selieylic acid, sorbic acid, lactic acid, as well as sulfonic acids such as p-toluenesulfonic acid and 1,5-naphthalenediulfonic acid.

Preferred compounds of the invention are also 2-imidazolylmethyl-2-phenyl-12 complexes

-1,3-dioxolanes of formula X with a metal salt, wherein in formula 1 R, R and R have the meanings given above as preferred. Particularly preferred are metal salt complexes which contain metal cations IX. to XV. major groups or I. а II. or IV. to VIII. side groups of the Periodic Table of the Elements, examples include copper, zinc, manganese, magnesium, tin, iron and nickel.

The anions of these metal salt complexes are preferably those derived from hydrohalic acids, in particular from hydrochloric acid and hydrobromic acid, from phosphoric acid, nitric acid and sulfuric acid.

If, for example, 2-bromomethyl-2- (4-chloro-2- (4-chloro-2-trifluoromethyl) phenyl-1,3-dioxolane and imidazole are used as starting materials, the reaction according to the invention can be illustrated as follows: by the scheme:

1,3-dioxolane derivatives which are required as starting materials in the process

2 according to the invention are generally defined by formula-II. In this formula, the symbols R, R and R preferably have the meanings which have already been mentioned in the description in relation to the compounds of the general formula 1 according to the invention as being preferred for these symbols. Z is preferably chloro, bromo or -O-SO 4 -R 4 in which R 4 is methyl or p-methylphenyl.

(IV)

The 1,3-dioxolane derivatives of formula (II) have not yet been known. These compounds are obtained by ketoderivatives of the general formula IV

_RC-CH2 -Z

II ^of o

in which

R and Z are as defined above, in reaction with dols of formula V

(V) in which

2

R and R are as defined above, in the presence of an inert organic solvent such as toluene and in the presence of a strong acid catalyst such as p-toluenesulfonic acid at temperatures between 60 and 100, optionally under elevated pressure.

The ketoderivatives of formula (IV) are known compounds (cf., for example, DE-OS 24 31 407) or are obtained in a known manner by reacting the corresponding ketones with, for example, chlorine or bromine in the presence of an inert organic solvent such as ether, chlorinated or of a non-chlorinated hydrocarbon at room temperature or with conventional chlorinating agents such as sulfuryl chloride at a temperature of 20 to 60 ° C. The sulfonic acid derivatives of the compounds of the formula IV can also be prepared by known methods.

The diols of formula V are well known organic chemistry compounds. These compounds are prepared in a manner known per se.

The imidazoles which are used as further starting materials for the process according to the invention are generally defined by formula III. In this formula, M is preferably hydrogen, sodium and potassium.

The imidazoles of formula III are generally known compounds of organic chemistry.

Suitable diluents for the process according to the invention are inert organic solvents. These preferably include amides such as dimethylformamide or dimethylasamide, furthermore dimethylsulfoxide or hexamethylphosphoric triamide.

The process of the invention is optionally carried out in the presence of an acid binding agent. Any customary inorganic or organic acid binding agent such as an alkali metal carbonate such as sodium carbonate, potassium carbonate and sodium bicarbonate, or such as lower tertiary alkylamines, cycloalkylamines or aralkylamines such as triethylamine, N, N-dimethylcyclohexylamine, dicyclchexylamine may be used , N, N-dimethylbenzylamine, pyridine and diazabicyclooctane. Preferably an appropriate excess of imidazole is used.

The reaction temperatures may be within a wide range when carrying out the process of the invention. In general, the reaction is carried out at temperatures between 20 and 150 ° C, preferably between 60 and 150 ° C.

In carrying out the process according to the invention, preferably up to 2 mol of the imidazole III and 1 to 2 mol of the acid binding agent are used per me of the compounds of the formula II. The isolation of the compounds of formula I is carried out in a conventional manner. In many cases, it has proven advantageous to prepare the compounds of formula I in pure form via their salts.

Preference is given to preparing the acid addition salts of the compounds of the formula I with plants which are already mentioned as preferred acids in the description of the acid addition salts of the compounds according to the invention.

These acid addition salts of the compounds of formula (I) may be obtained in a simple manner according to conventional salt-forming methods, for example by dissolving the compound of formula (I) in a suitable inert solvent and adding an acid such as hydrochloric acid. and optionally purified by washing with an inert organic solvent.

For the preparation of the metal salt complexes of the compounds of the formula I, preference is given to salts of those anions and cations which have already been mentioned as advantageous in the description of the more complex compounds of the formula I with the metal salts according to the invention.

Complexes of the compounds of formula I with a metal salt can be obtained in a simple manner by conventional methods, for example by dissolving the metal salt in an alcohol, for example ethanol, and adding this solution to the compound of formula I.

The active compounds according to the invention have a strong microoicidal action and can be used for combating undesirable microorganisms for practical purposes. The active compounds are suitable as plant protection agents.

Plant protection agents are used in plant protection to combat fungi belonging to the classes Plasmodiolhorompete, tornmcetes, Cytridiomyceees, Zyggimcetes, Ascommcetes, Baeidiomyccees, DuVeromyceee 8.

Good tolerability of the active ingredients in concentrations necessary to combat plant diseases by treating aboveground parts of plants, seedlings and seeds, as well as soil.

As plant protection agents, the active compounds according to the invention can be used with particularly good success in combating fungi of the genus Podosplheara levcotticУa, as well as combating cereal diseases such as grass grazing. (Erysiphe graminis) and for the control of Helminthosporium gremin (m). The compounds according to the invention will show; also has a good effect in vitro, particularly against rice plant disease agents.

In the respective applied quantities I will report;)! The compounds of the invention also have the ability to control plant growth.

The active ingredients can be converted into the customary formulations such as solutions, emulsions, wettable powders, suspensions, powders, dusts, foams, pastes, soluble powders, grandates, aerosols, concentrates based on suspensions and emulsions, seed powders , natural and synthetic substances impregnated with active substances, active substances encapsulated in polymeric substances and in seed containers, further with means with flammable additives such as smoke cartridges, jars, spirals and others, and with ULV means for mist dispersion cold and hot.

These compositions are produced in a known manner, for example by reducing the active substances with a filling, i.e. with a liquid. dissolved, gases that. are liquid under pressure and / or solid support! with the aid of surface active agents, i.e. emulsifiers and / or dispersants of oetics and foaming agents. In the case of water ingestion as carrier substances, for example, organic solvents can also be used as auxiliary solvents. , such as xylene, toluene or Olkylnaphthalenes, chlorinated. aromatics or chlorinated aliphatic hydrocarbons, such as .beta.-orbenzenes; c) horethylenes or meethryenechoride, hydrocarbons, such as cyclohexao or paraffins, for example petroleum fractions, alcohols, such as butanol or glycol, and their ethers and esters, ketones, such as acetone The methyl ethyl ketone, methyl isobutyl ketone or cyclohexenone, strongly polar solvents such as dimethylformamide and dimethylene disoxide as well as the liquefied or gaseous liquids are those which are, for example, at ambient temperature and atmospheric pressure such as gaseous gases. aerosol propellants such as halogenated hydrocarbons as well as butane, propane, nitrogen and carbon dioxide; Suitable solid carriers are: for example, natural stone flours such as kaolins, clays, talc, chalk, quartz, attapitite, manganese or diatom and mineral stone flours such as highly dispersed quartz acid, alumina and silica; suitable solid carriers for the granulates are, for example, crushed and fractionated natural minerals, such as limestone, marble, pumice, steloma, dolomite, and synthetic granules of organic and organic flours, and organic mortar greases. such as sawdust, coconut shells, corn flakes and tobacco stems; suitable emulsifiers and foaming agents are, for example: noninogenic and anionic emulsifiers, such as polyoxyethylenes of fatty acids, polyoxides, fatty alcohol ethers, for example, altylarylpilyalytillers, altylsulfonates, allylphioates, sodium oxides. arylsulfins as well as protein hydrolysates; suitable disinfectants are, for example: lignin from sulfuric waste liquors and oil-cellulose.

Adjuvants such as cartilage, natural and powdered, granular or sterile polymers such as gum arabic, polyvitylalkito, polyrioyl acetate may also be used in the compositions.

Dyes, such as inorganic pigments, such as iron (III) oxide, thio (VI) oxide, ferrocyanide and organic dyes, such as dyes, azo-binders, metallic phthalocyanine dyes and trace metals, can be added to the above media. elements, such as iron, manganese, toru, copper, kobbú.tu, · molybdenum and zinc ·

Means of obsíOmu! generally between 0.1 and 95% in the afternoon. Active substance, preferably between 0.5 and 90% by weight of the active substance.

Active substances beneath the invention can be in such compositions Neto ¹ in different · dosage forms příioooy in · combination with simmer active substances such as fungicides, batericidy insecticides, ЮнГО ^ у, ппиоЮ ^ у, herbicides, safeners against · bird repellents, growth agents, plant nutrients and soil improvers,. - · '' ·

The active compounds are applied as such, in the form of compositions or in large-scale dosage forms prepared from such concentrated compositions, such as ready-to-use solutions, curves, suspensions, powders, pastes. and granulates · Aopication is carried out in the usual manner, for example, by watering, dipping, spraying, infusing _/ spraying, in the form of injections, suspended, poured, advised, sprinkling, dry pickling, wet pickling, wet pickling, pickling suspension or incrustation.

When. treatment of plant parts, the concentrations of the active ingredients in the application form may vary in wide dimensions. 1 and 0.000 1% by weight, preferably between 0.5 and 0.001% by weight.

PM seed grinding generally requires 0.001 to 50 g of active ingredient per kg of seed, preferably 0.01 to 10 kg of active ingredient per kg of seed.

In soil treatment, an active compound concentration of from 0.00001 to 0.1% by weight, preferably from 0.0001 to 0.02% by weight, is required in the city where the effect is to be achieved.

The following examples illustrate the preparation and use of the active compounds according to the invention.

Examples I densify the process for producing the active ingredients

Example 1

x HCl

3.0 g (0.011 6 moles) of 2-benzomethyl-2-C4-cyclo-2-trifluoromethyl) phenol-1,3-uioxolane and 2.4 g (0.0334 8 moles) of imazole are heated in 50 ml. dimethylacetamide for 4 days at reflux. After reflection, the reaction mixture was dissolved in water and extracted with ether. The ether phase is washed with water, dried. with sodium sulphate and grind. Ethereal hydrogen chloride was added to the residual oil and crystallized by trituration. There was thus obtained 2- (4-chloro-2-trifluoromethyl) phenoxy-2- (midazol-1-yl) methyl-1,3-dioxolanylmethylamine, m.p. 174-183 ° C.

Production of starting material:

From ^CF 3 ^{C |} - (O \ ^CH 2 - ^Br

M) ^X O

1 g (0.12 ml) of 4-chloro-2-trifluoromethyl-glyphonyl glycol and 9 g (0.15 mol) of glycol are treated with 1.5 g of p-toluenesulfonic acid in 80 ml of toluene in at least 20 ml of butanol for 24 hours. water separators. After cooling, the reaction mixture is washed successively with dilute aqueous sodium hydroxide solution and water, and dried over sodium sulphate. and cheer. 29.6 g (74% of theory) of crude 2-broomethyl-2- (4-chloro-phenylphenyl-1,3-diphxophlan) are obtained as an oil which is used directly for the next reaction.

O

To 22.3 g (0.1 mole) of 4-cis-2-trichloro-5-methyl-acetophenone in 200 ml of chloroform was added 1 ml of acetic acid and the mixture was heated to 40 ° C. At this temperature, 5.1 ml (0.1 ml) of bromine in 50 ml of chloroform are added dropwise. The retention mixture was stirred until gas evolution had ceased. After cooling, the reaction mixture was washed successively with water and aqueous sodium bicarbonate solution, dried over sodium sulphate and dried. 29.4 g (97% of theory) of crude 4-chloro-2-trifluoromethyl-phthalalylbootide are obtained in the form of an oil which is used directly for the next reaction.

The method of Example 1 was also prepared in the following Table. 1 of said compound of formula I

(AND)

TABLE 1

Example No. R R 2 / ^CF 3 c. - <-> - ch ₃ 3 , CF ₃ α- <Ο> H 4 ^c, X2l · c ₂ h ₅ 5 с1 - (^ оУ ~ (оУ ~ H 6 H 7 CH ₃ 8 H

Physical data [temperature ^and melting point (° C), ¹ H-NMR spectrum (deuterated chloroform)]

H viscous oil

NMR: 4.2 (s, 2H), 1.05 (d, 3H), 3.8 (m, 1H)

CHCl 3 NMR: 4.2 (a, 2H), 3.5 (a, 2H)

NMR: 4.2 (s, 2H), 0.9 (t, 3H), 1.4 (m, 2H)

H, m.p. 220 ° C (x HCl) (x HCl)

NMR: 3.05 (s, 2H), 3.75 (m, 2H)

NMR: 4.15 (d, 2H), 8.0 (d, 1H)

CH 2 Cl NMR: 3.75 (d, 2H),

4.0 (d, 2H); 4.25 (s, 2H).

Continuation table

Example face R R ¹ R ² Physical data [Melting point (° C), @ 1 H NMR spectrum (deuterated chloroform)] 9 ^C 2 ^H 5 Η NMR: 0.9 (t, 3H); 1.4 (m, 2H). 4.15 (d, 2H); 8.0 (d, 1H) 10 and <0> <0> СН ₃ Η NMR: 4.1 (d, 2H). 7.95 (d, IH) 1 1 αΗ @ π (θ) - Η CH ₂ C1 NMR: 4.1 (d, 2H). 7.95 (d, IH); 3.7 (d, 2 H) 12 ^c, ^ oXo> - ^С 2 ^Н 5 Η NMR: 4.1 (d, 2H). 0.9 (t, 3 H), 1.4 (m, 2H). 7.95 (d, IH) 13 a-XO ^ o} - СН ₃ СН ₃ NMR: 4.1 (d, 2H), 1.0 (m, 6H), 8.0 (d, 1H) 14 СН ₃ СН ₃ NMR: 4.1 (s, 2H). 1.2 (d, 6H)

сн ₃

NMR: 1.0 (m, 6H), 4.1 (d, 2H), 7.9 Cd, 1H)

The examples illustrate biological activity:

1

In the following examples, the following compounds are used as comparators:

(AND)

Cl

(В) x

(C) χ

Example A

Grass test (Erysiphe graminis f. Sp · hordei) (barley) / protective action solvent: 100 parts by weight of dimethylformamide emulator: 0.35 parts by weight of alkylaryl polyglycol ether

In order to produce a suitable effective. 1 part of the mono-active substance is mixed with the above-mentioned carcass seed and solvent and emulsifier and the concentrate is diluted with water to the desired end.

To test for protective activity, many barley plants are sprayed to the wetting stage with the active preparation. After the spray layer has dried, the plants are dusted with spores of Erysiphe graminis f. days after inoculation, the assessment is carried out ·

A marked superiority in efficiency over the prior art is shown in the prior art. in this test, for example, compounds according to the following Examples: 2 and 4

The results of this test are shown in the table below:

Tabtu.ka A

Test for pacific grass (Erysiphe graminis f · sp · hordei) (barley) / protective effect

Active substance Honccrntrace of the active substance Disease attack in spray suspension % untreated in% hmoOnnotnio control

OH

СН-СН ₂ - | ГТ

Cl

(A) (known)

100.0

0,025

Active substance

Concentration effective. % of substances in the spray suspension in% by weight

Disease attack in% of untreated control

OH Br- / o \ -ch -οη, -αΓΠ \ r / ² \ = ii 0,025 50.0 (B) (known) 0,025 0.0

(2)

0,025

0.0 (4)

Example B

Tnet for PROPERTY (Drechalera graminia) (barley) - seed treatment (syn. Helointhtsptrium gramineuo)

Effective L ^and T are ^alkyl aplitoiji as dry moMďLa · toMdlt was prepared by mixing the respective active ingredient with rock meal to give a finely pulverized snOss which ensures uniform distribution on the seed surface.

For mixing, the infected seed is shaken for 3 minutes with the stirrer in a sealed glass bottle. .

The seed is placed in a sown, wet standard soil in sealed petri dishes, which are kept in a refrigerator at 4 ° C for 10 days. The germination of the barley and possibly the spore of the fungus begin. Then the germinated barley is sown in a number of 2x50. 3 cm deep into the standard soil and the plants were grown in a greenhouse at a temperature of about 18 ° C in suction boxes that stand up daily. 15 hour light.

About 3 weeks after sowing, plants are evaluated for streaking symptoms

In this test, for example, compounds according to the following examples show a clear superiority in efficacy against the prior art: 1 and 2;

The results of this test are shown in Table B below:

Table В

Striping test (Drechslera graminea) (barley) - seed treatment (syn. Helminthosporium gramineum)

Active substance Amount of active substance used in mg / kg of diseased plant seed in $ of total emerging plants not infested

22.9

Cl

OH

200

23.0 (A) (known)

Cl

200

9,2 mm (1)

Cl

200

0.0

CH ₃ (1)

235971.

ExampleC

Test for apple powdery mildew (Podosphaera leucotricha) (apple tree) / protective action solvent: 4.7 parts by weight acetone emulsifier: 0.3 parts by weight alkylaryl polyglycol ether

To obtain a suitable active ingredient, 1 part by weight of active ingredient is mixed with the indicated amounts of solvent and emulsifier and concentrate and diluted with water to the desired concentration.

In order to determine the protective effect, young plants are sprayed with the active product up to the dew point. After the spray layer has dried, the plants are inoculated by dusting with conidia of powdery mildew of Podosphaera leucotricha.

Plants ae are then placed in a greenhouse at 23 ° C and at a relative air humidity of about 70%

In this test, for example, the compounds according to the following examples show a clear superiority in action against the state of the art: 2, 4 and 1.

The results of this test are shown in Table C below:

Table C

Test for apple powdery mildew (Podosphaera leucotricha) (apple tree) / protective effect

Active substance Infestation in% at active substance concentration 0,001%

(C) (known)

(4)

Active substance

Infestation in% at an active compound concentration of 0.001%

Claims (3)

CLAIMS 1. A ringicidal composition comprising as active ingredient at least one 2-imidazolyyrneehl-2-phenyl-1,3-dioxolane of formula I. (I) in which: R is a group of formulas M Έλ where ^Π , X is hydrogen, halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy N is 1, 2 or 4; Y represents optionally halogen-substituted phenoxy group or an optionally halogen substituted phenyl group, ^R1 stands ^for voúí Neto ^^ verifies group having from ^{1 and} 4 carbon ^NHL to ^about R represents hydrogen, a (C1-C4) -alkyl or a (C1-C4) hallialkylalkyl, or a 2-ylidazolylmethyl-2-phenyl-1,3,3-dilolylic acid addition salt of the formula I with a plant-tolerable acid, or a complex 2 The compound of formula (I) with a metal salt which is tolerated by plants. 2. A composition according to claim 1, wherein the active ingredient comprises at least one 2-imidazolylmethyl-22-phenyl-1,3-dilolene of the general formula I, in which the radicals are those in which: X is hydrogen, fluoro, chloro, bromo, (C1-C4) -alkyl or (C1-C4) -alkyl, n = 1a Y represents an optionally halogen-substituted phenoxy group or an optionally halogen-substituted phenyl group, R ¹ is hydrogen or C 1 -C 4 alkyl; R ² represents hydrogen, alkyl having 1 to 4 carbon atoms or haloalkyl It has 1 to 2 carbon atoms and 1 to 5 identical or different halogen atoms, or an acid addition salt thereof or a metal salt complex thereof which are tolerated by plants. A process for the preparation of the active ingredient of the formula I as well as the corresponding acid addition salts of the compounds of the formula I and the metal salt complexes of the compounds of the formula I, characterized in that the 1,3-dioxolane derivatives of the formula II ( In which: 1 2 R, R and R are as defined above and Z is halogen or a group of formula -O-SO ₂ -R ³ , wherein R ³ represents a methyl or p-methylphenyl group, acts imidazoles of the general formula III ^M "O (III) in which M is hydrogen or an alkali metal, in the presence of a diluent and optionally in the presence of an acid binder, whereupon an acid or a metal salt is optionally added to the compounds of formula I thus obtained;