IE47973B1 - 1.1-diphenylethene derivatives,a method for their production,and their use as microbicides - Google Patents

Description

The presenc invention relates to 1.1-diphenylethene derivatives, to their production, and to their use for combating fungi, as well as co microbicidal compositions which contain such compounds as active ingredients.

The new compounds correspond to the'formula I; (R,)m X R (I) in which X is fluorine or chlorine; R is a 1,2,4-triazolyl-l group or imidazolyl-1 group, each of which may or may not be substituted by methyl; while Rg and independently of one another are each a number, determined by m and n respectively, of identical or different substituents from the group halogen, Cg-Cg-alkyl, -CFg or -CM, and m and n independently of one another are each 0, 1, 2 or 3.

Compounds of the formula I can be designated as 1.1diphenyl-2-haloethenes and, depending on the hetarocycle R, are accordingly 1.l-diphenyl-2-halc-2-(1,2,4-triazolyl-l)ethenes and l.l-diphenyl-2-halo-2-(imicazolyl-L)-ethenes. '1 v */ 3 The sales tolerant to plants of the compounds of the formula I with inorganic or organic acids, and also corresponding metal complex salts with Cu salts, Mn salts, Zn salts and Fe salts and other salts, are taken as being embraced by the formula I.

Compounds of the formula I are derived in the majority of cases structurally from the chemical group of DDT analogues, but have no insecticidal action and are readily decomposed under natural conditions .

It has now been found that, surprisingly, compounds having the structure of the formula I have for practical requirements a very favourable microbicidal spectrum for the protection of cultivated plants, without disadvantageous^ affecting them as a result of undesirable secondary effects. Cultivated plants within the scope of the present invention are, for example cereals (wheat, barley, rye, oats and sorghum millets,, maize, rice, vegetables, sugar beet, soya bean, groundnuts, fruit trees, ornamental plants, vines, hops, gourds (cucumbers, pumpkins, melons), solanaceae, such as potatoes, tobacco and tomatoes, as well as banana plants, cocoa and natural rubber plants.

Fungi occurring on plants or parts thereat (fruit, blossom, foliage, stalks, tubers or roots) of the said crops and of related useful crops can be inhibited or destroyed with the active substances of the formula I, and also parts of plants growing subsequently remain protectee against such fungi. Tho active substances are effective against the phytopathogenic fungi belonging to the following classes: Phycomycetes such as Oomvcetes species, Basidiomycetes such as in particular rust fungi (e.g. Puccinia); Fungi imperfecti (e.g. .17 9 7 3 VerticiLlium, Piricularia, Cercospora); especially however against the pathogens of varieties of vine mildew, belonging to the Ascomycetes class, such as Erysiphe and Podosphaera, as well as against Venturia and others. Furthermore, the compounds of the formula I have a systemic action.

They can also be used as dressing agents for the treatment of seed (fruits, tubers and grain), and plant cuttings to protect them from fungus infections, and also against phytopathogenic fungi occurring in the soil.

Preferred compounds of the formula I as plant fungicides are those in which X is fluorine. This group is to be called subgroup Ia.

Further preferred compounds of the formula I are those in which the substituents R^ and R9 occupy one of the ortho- or para-positions of the phenyl rings. When they are derived from the subgroup Ia, such compounds are to be called subgroup lb.

Those compounds of the formula I are particularlypreferred in which R is the unsubstituted 1,2,4-triazolyl-l 2n group, especially those compounds which are derived from the subgroup in and which are here to be called subgroup Ic Active substances especially preferred in the subgroup Ic are those in which in at least two of the four positions 2,4 and 2',4' of both phenyl rings there are 2 halogen atoms from th: group fluorine and chlorine, and in the positions 3,5,6 and 3',5',6' there are hydrogen atoms.

This particularly preferred subgroup is to be called Id.

Very highly effective plant fungicides are, inter alia, the following individual compounds: a) a.,a-bis-(4-chlorophenyl)-£-fluoro-0-(l,2,4-triazolyl-l)e thene, 7 9 7 3 b) α,α-bis-(2-chlorophenyl)-0-fluoro-0-(1,2,4-triazolyl-l) ethene, c) a-phenyl-a-(2,4-dichlorophenyl)-0-fluoro-β-(1,2,4triazolyl-1)-ethene, d) a-(4-fluorophenyl)-a-(2,4-dichlorophenyl)-0-fluoro-0(l,2,-4-triazolyl-l)-ethene, e) a,a-bis-(4-fluorophenyl)-0-fluor0-0-(1,2,4-triazoly1-1)ethene, f) a-(4-chlorophenyl)-a-(2,4-dichlorophenyl)-0-fluoro-0(1,2,4-triazolyl-1)-ethene, g) α,α-bis-(2,4-dichlorophenyl)-0-fluoro-β-(1,2,4-triazolyl1)-ethene, h) α,α-bis-(2-chloro-4-fluorophenyl)-0-£luoro-0-(1,2,4triazolyl-1)-ethene.

These compounds show a particularly strong action in combating varieties of vine mildew. Applied in the customary amounts for fungicide application, compounds of the formula I are tolerant to plants and do not lead to any change in plant growth.

Compounds of the formula I are produced in the first place in the same manner or in a similar manner as DDT and analogues thereof (see e.g. German Patent Specification No. 547,871).

One of the possible known methods for producing symmetrical diphenylethene derivatives comprises condensation of the appropriately substituted benzene derivative with fluoral (or chloral) to give a DDT analogue from which one mol of HX is split off, with a base, to form a DDE analogue II: 7 9 7 3 X - F or Cl (II) · To produce unsymmetrical intermediates of the formula III (III), in which and R„ or m and n are not tbe same, the procedure followed is analogous, and molar amounts of fluoral (or chloral) are condensed to give an intermediate IV which is condensed with a further benzene derivative, and subsequently one mol of HX is split off: III In order to obtain compounds of the formula I, it is possible by using equimolar amounts to exchange one of the two halogen atoms on the double bond of the intermediates IX or III for the heterocycle R, with one mol of HX being simultaneously split off. The reaction can frequently be simplified by performing the splitting-off of HX, to give the intermediates II or III, already in the 7S73 presence of the heterocycle R, so that II or III react in statu nascendi with 1,2,4-triazole or imidazole.

As is known, intermediates of tne formula IV can also be obtained by a Grignard reaction of a benzene derivative appropriately substituted with R^ (or Rg), and further reaction of the resulting phenyl magnesium bromide derivative either with - fluoral or chloral, or - trifluoroacetic acid or trichloroacetic acid, preferably in the form of their respective alkali metal salts, and subsequent catalytic hydrogenation (Hg/Pd) of the resulting trihaloacetophenone V V The product V may also be hydrogenated, instead of catalytically, with NaBH. or LiAlH. to the carbinol IV. 4 There are a number of other processes for producing the α,α —diphenylethane derivatives or α,α—diphenylethene derivatives, which are known in the majority and can be used as intermediates in the processes of the present invention.

The present invention relates to a process for producing compounds of the formula I by reaction of an α,α-diphenylB,β-dihaloethene of the formula III with unsubstituted or methyl-substituted imidazole or 1,2,4-triazole.

High temper itures up to 200°C are required to produce compounds of the formula I in which X is chlorine, in some cases the reaction has to be performed under pressure. Compounds in which X is fluorine can be obtained under milder conditions, e.g. from room temperature 7 9 7 3 up co a maximum of 1OO°C.

Where necessary inert solvents are used. Polar solvents such as glyme (ethylene glycol dimethyl ether), dimethyl sulfoxide, dimethylformamide, dioxane, water and so forth, are preferred. The addition of an inorganic base or of a tertiary amine, besides the basic reactants, is advisable.

With varyingly substituted phenyl rings, a mixture of cis/trans isomers of the formula I is obtained. The pure antipodes have different microbicidal effects.

The production of compounds of the formula I is illustrated in the following Examples. Temperature values throughout are in degrees Centigrade. 7973 Example 1 Production of a-(4-Chlorophenyl)-a-(2,4-dichlorophenyl)-B-fluoro-β-(1,2,4triazolyl-1)-ethene [compound 16] 1 mol (339.5 g) of a-(p-chlorophenyl)-a-(o,p-dichlorophenyl)-B,B,j3-trifluoroethane is placed into 1 litre of glyme (= ethylene glycol dimethyl ether), and 82 g of triazole (= 25£ excess) is added to the solution. 250 mol of 60% KOH solution is added dropwise at 80 - 85° within one hour. The reaction mixture is then held at 80° for 4 hours. After cooling, the two phases are separated, and the organic phase is dried in the customary manner with Na sulfate and concentrated by evaporation to yield a light-coloured oil (320 g), which can be distilled in vacuo (b.p.; 180-185°/0.2 Torr). It is a mixture of the two possible cis-trans isomers. By using ether and cyclohexane, a part of the oil can be caused to crystallise. The crystallised product is one of the two isomers (m.p. = 94 - 95°).

Example 2 Production of ct ,a-8 is - (4-chlorophenyl)-β-fluoro-^-(1,2,4-triazolyl-l)ethene [compound 31 1·) The reaction is performed in a manner analogous to the one described in Example 1. As no geometrical isomers are possible in the case of this compound tne product is obtained immediately in the crystalline form after the organic phase has been evaporated. Recrystallisation from cyclohexane and ether yields the analytically pure compound, m.p. 105-106°.

Example 3 Production of a. ,a-Bis- (4-chlorophenyl) -0-chloro-j3- (imidazolyl-l)-ethene 1 mol (318 g) 7 9 7 3 lation (b.p. 17O-18O°/O.OO5 Torr). The compound can be recrystallisation from cyclohexane, point of 104-105°. obtained pure by It has a melting Example 4 Production of a-(4-Fluorophenyl)-a-(2,4-dichlorophenyl)-0-fluoro-0(l,2,4-triazolyl-l)-ethene (compound 23] a) A spatula tip of iodine is added to 24 g of Mg in 200 ml of diethyl ether, and 175 g (1 mol) of p-fluoro10 chlorobenzene in 800 ml of diethyl ether is added dropwise in such a manner that the exothermically reacting mixture boils under reflux. After 2 hours, the reaction mixture is cooled to 0-10°, and 152 g (1 mol) of anhydrous CF^-COO-K is added. The dispersion obtained is stirred overnight at room temperature, cooled, and 250 ml of 20% hydrochloric acid is added. The ethereal phase is separated, ; washed neutral with water and concentrated by evaporation. Vacuum distillation of the residue yields 91 g (about 50%) of p-fluorotrifluoroacetophenone, b.p. 5O-52°/2O mbars. b) 212 g (1 mcl) of p-fluorotrifluoroacetophenone is dissolved in 1000 ml of ethyl alcohol, 20 g of NaBH^ is added at 0-10°, and the whole is stirred for 2 hours and then for a further 4 hours at room temperature. 500 ml of water is slowly added, and the supernatant clear solution is decanted and concentrated in a rotary evaporator. The residue is dissolved in diethyl ether, the solution is washed with water, dried with sodium sulfate and concentrated by evaporation. The oily residue is fractionated to yield 171 g of p-fluorophenyl-trifluoromethyl carbinol, b.p. 86-9O°C/ mbars. c) 300 ml of 1,3-dichlorobenzene is placed into 1000 ml of concentrated sulfuric acid, and 214 g (1 mol) of the carbinol obtained under b) is added dropwise ar 0-10°. The reaction mixture is stirred overnight at room temperature and is poured onto ice, and 300 ml of dichloromethane is added. The organic phase is washed neutral with water, dried over sodium sulfate and concentrated by evaporation to obtain 260 g of a-(4-fluorophenyl)-a-(2,4-dichlorophenyl)j3,fj,d-trifluoroethane, b.p. 95-lO5°/O.13 mbar. d) 90.4 g (0-28 mol) of the intermediate obtained under c) in 300 ml of glyme with 21.3 g (0-.31 mol) of 1,2,4triazole is heated at 80°C (reflux). A solution of 47 g of KOH in 100 ml of water is added dropwise in the course of 1 hour. The reaction mixture is then refluxed for 6 hours. After cooling, the organic phase is washed with a saturated salt solution and concentrated by evaporation. The viscous residue is distilled under high vacuum: b.p. 200°C/0.015 mbar. Recrystallisation from hexane yields the pure final product, b.p. 70-72°. a, g of finely pulverised KOH is added to the solution at 0-5°. 67 g of imidazole dissolved in 500 ml of dimethylformamide is added dropwise in the course of two hours at 0-5°.

The reaction mixture is held for a further 3 hours at 0-5° and is subsequently allowed to stand at 20° for 12 hours. Three litres of water are then added, and extraction is performed with ether. The ether is evaporated to leave 210 g of the final product as a solid residue which can be recrystallised from ethanol; m.p. 90-91°. 7973 Example 6 a,a.-Diphenyl-)3-fluoro-0-(imidazolyl-l)-ethene [compound 50] mol (236 g ) of trifluorodiphenylethane is dissolved in 1 litre of diglyme [bis-(methoxyethyl) ether], and g of imidazole dissolved in 250 ml of water, and 125 g of KOH dissolved in 250 ml of water are added to this solution. The mixture is heated with stirring for 8 hours to 100-110°. In further processing, the major amount of lo solvent is evaporated off in vacuo, 1 litre of water is added to the residue, and extraction is performed with dichloromethane. The dichloromethane solution is dried with sodium sulfate and concentrated by evaporation The residue is distilled at 0.5 Torr. In this process about 30 g of starting material is recovered as first runnings. The major amount (about 200 g) distills between 140 and 150°/0.55 Torr. On stirring with hexane and some ether, the substance is obtained in crystalline form. The yield after drying in vacuo is 180 g of final product, 2o m.p. 48 - 50°.

Example Ί Production of a,α-Bis-(2,4-dichlorophenyl)-B-fluoro-β-(1,2,4-triazolyl-1)ethene [compound 41 1 mol (374 g) of a,a-bis-(2,4-dichlorophenyl)-B,B,Btrifluoroethane (obtained by condensation of m-dichlorobenzene with fluoral in the presence of concentrated sulfuric acid) is dissolved in 800 ml of glyme. g of 1,2,4-triazole is added with stirring, and then 1q 250 ml of 60% KOH is added dropwise at 80-85°. The reaction mixture is refluxed for about a further 3 hours. After cooling, the aqueous phase is separated and discarded. The organic phase is concentrated by evaporation, and the residue is subjected to molecular distillation under high vacuum. At 180° and 0.1 Torr the substance distills over as colourless oil which solidifies on cooling to form a solid resin. The yield is about 76%. The compound can be crystallised from a mixture of cyclohexane and methanol: m.p. 84 - 86°. 7 9 7 3 In this manner or by one of the above-given methods, the following compounds of the formula are produced; ϋ Comp. No. X r3 *4 *5R6 Physical constant 1 F H H H H m.p. 78-79° 2 F 2-Cl H 2-Cl H m.p. 80-82° 3 F H Cl H Cl m.p. 105-106 JO 4 F 2-Cl Cl 2-Cl Cl m.p. 84-86° 5 F 3-Cl Cl 3-Cl Cl 6 F 2-CH3 Cl 2-CH3 Cl 7 F H ch3 H CH3 b.p. 175%.: 8 F 3-CH3 Cl 3-CH3 Cl 15 9 F 3-CF3 H 3-CF3 H 10 F 3-CF3 Cl 3-CF3 Cl 11 F H F H F m.p. 93-94° 12 F H Br H Br 13 F H CN H CN viscous oil 20 14 F 2-Cl CN 2-Cl CN 15 F 2-CH3 CN 2-CH3 CN 16 F H Cl 2-Cl Cl m.p. 94-95° 17 F 2-C1 H H Cl m.p. 98-100° 7 9 7 3 Comp. No. X r3R4RSR6 Physical constant 18 F H Cl 2-CH3 ch3 b.p. 200°/ 0.13mbar 19 F H Cl 3-CH3 ch3 m.p. 121-125° 20 F H Cl H H b.p. 170°/O.13mbar 21 F H H 2-Cl Cl m.p. 88-89° 22 F H ch3 2-Cl Cl m.p. 143-144’ 23 F H F 2-Cl Cl m.p. 70-72’ 24 F H isoC-H^ 2-Cl Cl 25 F 2-C2Hs Cl 2-C2h5 Cl 26 Cl 2-Cl H 2-Cl H m.p..88-91° 27 Cl H Cl H Cl m.p. 111-113’ 28 Cl 2-Cl Cl 2-Cl Cl b.p. 185°/O.13mbar 29 Cl 3-Cl Cl 3-Cl Cl 30 Cl 2-CH3 Cl 2-CH3 Cl 31 Cl 3-CH3 Cl 3-CH3 Cl 32 Cl 3-CF3 H 3-CF3 H oil 33 Cl 3-CF3 Cl 3-CF3 Cl oil 34 Cl H Br H Br resin 35 Cl H Cl 2-Cl Cl 36 Cl 2-Cl H H Cl 37 Cl H H 2-Cl Cl oil 33 Cl 2-C^ Cl 2-C2H5 Cl oil 39 F 2-C1 F 2-Cl F m.p. 82-85° 40 F E cf3 H F oil 41 F 2-C1 F H F m.p. 190-197°/ 0.5mbar 42 F 2-CF3 Cl H tr viscous 43 F K Cl H cf3 m.p. 99-102° 44 F 2-C1 Cl HCF3 b.p. 161-163°CZ 0.56mbar 45 F 2-C1 Cl H CN b.p. 157-160°/' 0.66mbar 46 F 2-? Cl 2-F Cl m.p. 90-9 3’ J 7 9 7 3 Comp. X No.

R.

Physical constant H 2-C1 2-Cl Cl Cl Cl H 2-C1 2-F m.p. 73-77° m.p. 61-64° viscous are also produced; Comp. No..R3R4R5R6 Physical constant 50 H H H H m.p. 48-50° 51 2-Cl H 2-Cl H m.p. 65-66° 52 H Cl H Cl m.p. 90-91’ 53 2-Cl Cl 2-Cl Cl m.p. 78-80° 54 3-C1 Cl 3-Cl Cl m.p. 105-107’ 55 2-CH3 Cl 2-CH3 Cl 56 H CH3 H H b.p. 145-148°/ 0.13mbar 57 3-CH3 Cl 3-CH3 Cl 58 3-CF3 H 3-CF3 H 59 3-CF3 Cl 3-CF3 Cl 60 H F H F 51 H Br H Br m.p. 98-104° 0 2 H CN H CN 07 3 Comp. No. r3R4RS *6 Physical constant 63 2-Cl CN 2-Cl CN resin 64 2-CH3 CN 2-CH3 CN 65 H Cl 2-Cl Cl 66 2-Cl H H Cl m.p. 84-85* 67 H Cl 2-CH3 ch3 68 H Cl 3-CH3 ch3 69 H Cl H H m.p. 67-69° 70 H H 2-Cl Cl 71 H ch3 2-Cl Cl 72 2-CH3 H H H b.p. 140-150°/ 0.25rabar 73 H c2h5 Hw2n5 oil the to tile above-given methods, polysubstituted compounds of the formula According following are also produced; 7 9 7 3 Comp. No . *3R7R5R6R8 74 2-Cl 6-CH3 2-Cl 4-Cl 6-¾ 75 2-Cl 6-Cl 2-Cl 4-Cl 6-Cl 5 76 2-F 6-F 2-F 4-Cl 6-F 77 2-CH3 6-CH3 2-¾ 4-Cl 6-¾ 78 2-CN 6-Cl 2-CN 4-Cl 6-Cl 79 2-Cl 6-¾ 2-Cl 4-C1 6-C2H, 80 2-Cl H 2-¾ 4-¾ 6-¾ 10 81 H H 2-¾ 4-¾ 6-¾ 82 Ξ H 2-C1 4-ci 5-C1 Physical constant resin oil oil viscous b.p. 240°/ 0.SSmbar m.p. 87-90° b.p. 150-160°/ O.66maar Ο-“3 The compounds of the formula I can be used on their own or together with suitable carriers and/or ocher additives. Suitable carriers and additives can be solid or liquid und correspond Lo the .ui.ibuLunceu common in formulation practice, as e.g. natural or regenerated mineral substances, solvents, dispersing agents, wetting agents, adhesives, thickeners, bonding agents or tertiUsers.

The content of active substance in commercial compositions is between 0.1 and 90%.

For application, the compounds of the formula I can be in the following forms (the weight-percentage figures in brackets signify advantageous amounts of active substance): solid preparations: dusting and strewing powders (up to 10%), granulates, coating granulates, impregnating granulates and homogeneous granulates, pellets (1 to 80%) liquid preparations: a) water-dispersible concentrates of active substance: wettable powders and pastes (25 to 90% in the commercial packing, 0.01 to 15% in ready-for-use solutions); emulsion concentrates and solution concentrates (10 to 50%; 0.01 to 15% in ready-for-use solutions); b) solutions (0.1 to 20%); aerosols The active substances of the formula I of the present invention can be formulated for example as follows: Dusting powders: The following susbstarices are used to produce a) a 5% dust, -and b) a 2% dust; a) 5 95 parts of active substance parts of talcum; b) 2 parts of active substance part of micro dispersed silica acid parts of talcum; The active substances are mixed and comminuted with the carriers, and they can be applied by dusting in this form.

Granulate: The following substances are used to produce a 5% granulate: parts of active substance 0.25 part of epichlorohydrin 0.25 part of cetyl polyglycol ether 3.50 parts of polyethylene glycol 91 parts of kaolin (particle size 0.3 - 0.8 mm).

The active substance is mixed with epichlorohydrin and dissolved in 6 parts of acetone, and the polyethylene glycol and cetyl polyglycol ether are added. The solution obtained is sprayed onto kaolin, and the acetone is evaporated off under vacuum. A microgranulate of this type is advantageously used for combating soil fungi.

Wettable powder: The following constituents are used to produce a) a 70% wettable powder, b) a 40% wettable powder, c) and d) a 25% wettable powder, and e) a 10% wettable powder: a) 70 parts of active substance parts of sodium dibutylnaphthylsulfonate parts of naphthalenesulfonic acid/phenolsulfonic acid/formaldehyde condensate 3:2:1 parts of kaolin parts of Champagne chalk; b) 40 parts of active substance parts of sodium lignosulphonic avid part of sodium dibutylnaphthalenesulfonic acid parts of silicic acid; c) 25 parts of active substance 4.5 parts of calcium lignosulphonate 1.9 parts of Champagne chalk/hydroxy ethyl cellulose mixture (1:1) 1.5 parts of sodium dibutylnaphthalenesulfonate 19.5 parts of silicic acid 19.5 parts of Champagne chalk 28.1 parts of kaolin; d) 25 parts of active substance, 2.5 parts of isooctylphenoxy-polyoxyethylene ethanol 1.7 parts of Champagne chalk/hydroxy ethyl cellulose mixture (1:1) 8.3 parts of sodium aluminium silicate 16.5 parts of diatomite parts of kaolin; e) 10 parts of active substance parts of a mixture of the sodium salts of saturated fatty alcohol sulphonates parts of naphthalenesulfonic acid/formaldehyde condensate parts of kaolin.

The active substances are intimately mixed with the additives in suitable mixers ana ground in appropriate mills and rolls. Wettable powders with excellent wetting and suspension properties are obtained which may be diluted with water to give suspensions of che desired concentration, and these are particularly suitable for leaf application.

Emulsifiable concentrates: The following substances are used to produce a 25% emulsive concentrate: 25 parts of active substance 2.5 parts of epoxidised vegetable oil 10 parts of an alkylarylsulfonate/fatty alcohol polyglycol ether mixture 5 parts of dimethylformamide 1(J 5 7.5 pares of xylene.

Emulsions of the desired concentration can be prepared from these concentrates by dilution with water, and they are particularly suitable for Leaf application.

The concentrations of active substance in the following 15 biological Examples are given in ppm (100 ppm = 0.01%).

Example 8 Action against Cercospora personata (= C- arachidicola) on groundnut plants Three-week old groundnut plants were sprayed with a 2o spray liquor produced from wettable powder of the active substance (200 ppm of active substance). The treated plants were dusted with a conidiospore suspension of the fungus after approx. 12 hours. The infected plants were then incubated for about 24 hours at > 90% relative humidity and were subsequently transferred to a greenhouse at about 22°. The fungus infection was assessed after 12 days.

In comparison with the untreated control plants, plants which have been treated with active substances of the formula I only displayed slight fungus infection or no fungus infection at all. The compounds Nos. 18, 21, 23, 29 and 41 prevented fungus infection even at a concentration of 60 ppm. •47973 ί i.

Example 9 Action against Erysiphe graminis on barley plants Residual protective action Barley plants about 8 cm in heigh', were sprayed with 9 a spray liquor prepared from wettable powder of the active substance (20 ppm of active substance). The treated plants were dusted after 48 hours with conidia of the fungus. The infected barley plants were placed into a greenhouse at about 22°, and the fungus infestation Lu was assessed after 10 days.

The compounds of the formula I are as a rule highly effective against barley mildew. The mildew infection is completely prevented with the compounds Nos. 1, 2, 3, j 4, 7, 11, 16, 17, 18, 20, 21, 22, 23, 39, 41, 82. 5 Example 10 Action against Podosphaera leucotricha on young appletree shoots Residual-protective action Apple-tree cuttings having new shoots about 15 cm long 20 were sprayed with a spray liquor prepared from wettable powder of the active substance (200 ppm of active substance) . The treated plants were infected with a coniiiiospore suspension of the fungus after 24 hours and transferred to a climatic chamber at 70% relative humidity at °. The assessment of the fungus infection was made 12 days after infection. Fungus infection was completely prevented with the active substances Nos. 2, 4, 16, 18, 21, 23, 39, 41. 7 9 7 3 EXAMPLE 11 Action against Venturia inaequalis on young apple-tree shoots Residual protective action i Apple-tree cuttings having new shoots 10-20 cm long were sprayed with a spray liquor prepared from wettable powder of the active substance (200 ppm of the active substance).

The treated plants were infected with a conidiospore suspension of the fungus after 24 hours. The plants were then incubated with 90-100% relative humidity for 5 days and were kept in a green-house at 20-24° for another 10 days.

Scurf infestation was assessed 15 days after the infection.

Fungus infestation was completely prevented with the active substances Nos. 21, 23, 39 and 41.

EXAMPLE 12 Test against seed-borne fungi on cereals Action against delminthosporium gramineum Wheat seeds were contaminated with a spore suspension Of the fungus and dried thereafter. The contaminated seeds were dressed with a suspension produced from wettable powder of 2o the test substance (600 ppm of active substance relative to the weight of the seeds). After two days the seeds were laid out on suitable isinglass dishes, and after another four days the development of the fungus colonies around the seeds was assessed. Number and size of the fungus colonies were taken as a basis for evaluating the test products.

Fungus growth was completely inhibited with the compounds Nos. 11, 16, 21, 32 and 39. 47973 ί Example 13 Action against Pucclnia graminis f. sp. secalls on rye Residual-protective action Rye plants were sprayed, 4 days after sowing, with a spray liquor prepared from wettable powder of the active substance (200 ppm of active substance). The treated plants were infected with an uredo spore suspension of the fungus after 24 hours. After an incubation time of 48 hours at 95 - 100% relative humidity at about 20°, the infected plants were transferred into a greenhouse at about 22°. The development of rust pustules was assessed 12 days after the infection. Compared, with the untreated but infected control plants, tlie compounds of the formula I considerably reduced or completely prevented rust fungus infestation. Plants treated with the active substances Nos. 11, 21, 23, 39 or 41 showed no infection.

Hue to their broad fungus spectrum, compounds of the subgroup Id mentioned in the introduction, e.g. the active substances Nos. 21, 23 and 39, have to be especially men Iioned.

In order to broaden their spectrum of action, compounds of the formula I may be combined with other known fungicides and bactericides, and also with herbicides, insecticides, acaricides, nematocides, plant-growth regulators or fertilisers .

Claims (20)

CLAIMS:

1. A compound of the formula I (Rpm C_ (I) c / \ X R in which X is fluorine or chlorine; R is a 1,2,4triazolyl-l group or imidazolyl-1 group, each of which is unsubstituted or substituted by methyl; whilst Rg and R 2 independently of one another are each a number, determined by m and n respectively, of identical or different substituents from the group: halogen, Cg-C^alfcyl, CFg or -CN; and m and n independently of one another are each 0, 1, 2 or 3.

2. A compound of the formula I according to Claim 1, wherein X is fluorine.

3. A compound of the formula I according to Claim 2, 15 wherein the substituents Rg and R 2 occupy one of the ortho- or para-positions of the phenyl rings.

4. A compound of the formula I according to Claim 2, wherein R is a 1,2,4-triazolyl-l group.

5. A compound of the formula I according to Claim 3, 2o wherein R is a 1,2,4-triazolyl-l group.

6. A compound of the formula I according to Claim 5, wherein in at least two of the four positions 2,4 and 2',4' of both phenyl rings there are 2 halogen atoms from the group fluorine and chlorine, whilst in the 4 7 9 7 3 remaining six positions 3,5,6 and 3',5',6' there are hydrogen atoms.

7. . a-Phenyl-a-(2,4-dichlorophenyl)-B-fluoro-B-(1,2,4triazolyl-l)-ethene according to Claim 6.

8. a-(4-Fluorophenyl)-a-(2,4-dichlorophenyl)-a-fluoro(l,2,4-triazolyl-l)-ethene according to Claim 6.

9. a,a-Bis-(2-chloro-4-fluorophenyl)-0-fluoro-β(l,2,4-triazolyl-l)-ethene according to Claim 6.

10. A process for producing a compound of the formula I (R,)n C — II c / \ (I) in which X is fluorine or chlorine; R is a 1,2,4triazolyl-1 group or imidazolyl-1 group, each of which is unsubstituted or substituted by methyl; whilst and R 3 independently of one another are each a number, determined by m and n respectively, of identical or different substituents from the group: halogen, C^-C.}alkyl, -CF^ or -CN, and m and n independently of one another are each 0, 1, 2 or 3, by reaction of an α,αdipheny 1-/3,/S-dihaloethene of the formula III x x in which Rp R 2 , X, m and n are as defined in the foregoing, 4 7 9 7 3 with unsubstituted or methyl-substituted 1,2,4-triazole or with unsubstituted or methyl-substituted imidazole.

11. A microbicidal composition containing as active substance a compound of the formula I according to 5 Claim 1, together with suitable carriers and/or surfaceactive additives.

12. A composition according to Claim 11 containing a compound of the formula I according to Claim 2.

13. A composition according to Claim 11 containing 10 a compound of the formula I according to Claim 3.

14. A composition according to Claim 11 containing a compound of the formula I according to Claim 4.

15. A composition according to Claim 11 containing a compound of the formula I according to Claim 5. 15

16. A composition according to Claim 11 containing a compound of the formula I according to Claim 6.

17. A composition according to Claim 11 containing the compound a-phenyl-a-(2,4-dichlorophenyl)-0-fluoro-0(1,2,4-triazolyl-l)-ethene. 2o

18. A composition according to Claim 11 containing the compound a-(4-fluorophenyl)-a-(2,4-dichlorophenyl)-βfluoro-(1,2,4-triazolyl-1)-ethene.

19. A composition according to Claim 11 containing the compound α,α-bis-(2-chloro-4-fluorophenyl)-0-fluoro-025 (l,2,4-triazolyl-l)-ethene.

20. A method of combating phytopathogenic fungi and of preventing fungus infection which comprises applying to the locus to be protected a fungicidally effective amount of a compound according to any one of Claims 1 to 9.