DERIVATIVES OF 2,2-DIMETHYL-CYCLOPROPANECARBOXYLIC ACID

Abstract: There are disclosed derivates of 2,2-dimethyl-­ cyclopropanecarboxylic acid, endowed with insecticide and acaricide activity, having general formula: wherein: R is an alkyl, cycloalkyl, alkenyl or alkynyl radical ha­ ving from 1 to 8 carbon atoms, optionally substituted with halogen atoms, or R is an aryl radical optionally substi­ tuted with halogen atoms, alkyl or alkoxyl radicals; Y is O or S; X is H, F, Cl, Br, -CH₃, -CF₃; R₁ represents a group having formula: wherein X₁ = H, F; X₂ = H, -CN, -C ≡ CH; Q = O, CH₂; A = CH or N when X₁ = H, X₂ = CN and Q = O.

Description: The present invention relates to new compounds having insecticide and acaricide activity, which compounds are derivatives of 2,2-dimethyl-cyclopropanecarboxylic acid, furthermore the invention relates to the processes for preparing said compounds. Several compounds are known, belonging to the class of synthetic pyrethroids, which are used for fighting noxious insects both in agrarian and in civil field; among these the most important compounds are derivatives of 2,2-dimethyl-cyclopropanecarboxylic acid such as for instance, permetrina, cypermetrina and deltametrina ("Synthetic Pyrethroids", A.C.S. Symposium Series 42,1977) or the compounds disclosed in DE-A-2 907 609, EP-A-121 847 and EP-A-20954. These and the other synthetic pyrethroids, more in used, show, however, an important limit concerning the low activity explicated against acari. We have now found some pyrethroids which, besides having a high insecticide activity, have a good acaricide activity as well. Therefore an object of the present invention concerns the derivatives of 2,2-dimethyl-cyclopropane carboxylic acid having general formula: wherein: R represents an optionally halogen-substituted alkyl, cycloalkyl, alkenyl or alkynyl group containing from 1 to 8 carbon atoms, or an aryl group, optionally substituted with halogen, alkyl or alkoxyl radicals; Y represents O or S; X represents H, F, Cl, Br, -CH₃ or -CF₃; R₁ represents a group having formula: wherein X₁ is H or F; X₂ is H, -CN or -C ≡ CH; Q is O or CH₂, or the group and then X is chloro and R-Y- is 2,2,2-trifluoroethoxy or 2,2,3,3,3-pentafluoropropoxy-. Such products show, besides a high activity against noxious insects both in agrarian and in civil field (Hemiptera, Lepidoptera, Coleoptera, Diptera and Blaptoidea ), also a good acaricide activity, higher than the one of the known pyrethroids. The preparation of the compounds of formula (I) is carried out by esterification of a carboxylic acid or of an acylic derivative thereof of formula (II): with an alcohol of formula R₁-OH, wherein R, Y, X and R₁ have the meanings given hereinbefore, an R₂ represents OH, Cl, or a C₁-C₄ alkoxy radical. The esterification reaction may be carried out according to different techniques, which are usually used in the organic chemistry practice. Preferably, an acid having formula (II) (R₂=OH) is converted into acyl chloride by means of a suitable agent such as for instance oxalyl chloride, thionyl chloride, phosphorus pentachloride and the like, in an inert solvent at a temperature ranging between room temperature and reflux temperature and then it is reacted with an equivalent of alcohol of formula R₁-OH in an anhydrous inert organic solvent at room temperature in the presence of an organic base, preferably pyridine or triethylamine. The alcohols having formula R₁-OH are known compounds, which are generally used for the synthesis of synthetic pyrethroids. The compounds having the general formula (II) are new, and, as such, they form another object of the present invention. The compounds haying general formula (II), when R₂ is OH or a C₁-C₄ alkoxy group, may be prepared by a process, and this forms a further object of the present invention, consisting in reacting a metal salt of formula RY⁻ -M⁺ (V) with a difluoro olefin of formula (VI): in the presence of an organic solvent at a temperature ranging from -78°C to the boiling temperature of the solvent, according to the following reaction scheme: wherein R, Y, X have the meanings specified hereinbefore, R₂ is OH or a C₁-C₄ alkoxy group, M is selected from Na, K and Li; and A represents H or an acylic or sulfonic group; selected pereferably from CH₃CO, CH₃SO₂, CF₃SO₂, CH₃-C₆H₄-SO₂. The following solvents may be suitable to be used in the reaction: linear or cyclic ethers, such as diethylether, tetrahydrofuran, dioxane, diglyme; the aprotic dipolar solvents such as N,N-dimethylformamide, dimethylsulfoxide, sulfolane, hexamethylphosphorotriamide; the nitrogenated heterocyclic solvents such as pyridine, picoline; optionally use may be made, as solvent, of the protic RYH compound corresponding to metal salt (II) employed in the reaction. Such solvents are used alone or mixed together; preferably use is made of the following solvents: tetrahydrofuran, dimethylformamide, dioxane, hexamethylphosphorotriamide and pyridine. The preferred reaction temperature ranges between: -30° and 25°C. The reactants are used in substantially stoichiometric ratios. The compounds having formula (VI): are known products or, anyhow, they may be obtained by processes described in literature, such as for instance Tetrahedron Letters 27, 3655 (1986). The operating way may vary according to the employed compounds and, anyhow, it does not represent any critical factor. A preferred embodiment of carrying out the process, consists in adding the compound of formula (VI), dissolved in the selected solvent, to a suspension of metal salt RYM in the reaction solvent; according an alternative embodiment metal salt RYM may be added, in the solid form or in suspension, to the solution of the compound of formula (VI). Moreover the compounds having general formula (II) may be prepared by adjusting a few usual synthetic methods of the pyrethroid chemistry starting from polyfluorohalogenated ethers having formula (III): wherein X and Y have the same meanings as recorded in general formula (I), whereas Z and Z' are halogen atoms, which may be the same or different. Preferably when X = H, -CH₃ or -CF₃, Z and Z' represent Cl, Br or I; when X = F, Z = Z' = Br or Cl, or Z = F and Z' = I; when X = Cl, Z and Z' may be Br or Cl; when X = Br, Z = Z' = Br. The compounds having formula (III) are known products or, anyhow, they may be obtained by processes disclosed in literature such as, for instance, in Angew. Chem. Int. Ed. Engl. 24 (1985) 871, in U.S. patent No 3388078 (C.A.69: 28654a), in J. Org. Chem. 50 (1985), 4047-4051. The compounds having general formula (II) may be prepared preferably according to one of the methods illustrated hereinafter. Method A According to a process similar to the one disclosed in DOS 2539895 (1976) and in Bull. Chem. Soc. Jpn. 52,1511 (1979), a compound of formula (III) is added to ethyl ester of 3,3-dimethyl-pentenoic acid in the presence of a suitable promoter of radicalic reactions (step 1A); the thus obtained adduct is cyclized and (step 2A) further dehydrohalogenated (step 3A) by treatment with bases to yield a compound having general formula (II) with R₂ = C₂H₅ Method B By operating likewise as disclosed in European patent application No 187674 a compound of formula (III) is reacted with caronaldehyde (ethyl-2,2-dimethyl-3-formyl-cyclopropanecarboxylate) in the presence of metals such as zinc or magnesium (step 1B); by subsequent dehydroxyhalogenation of carbinol of formula (IV), for instance by acetylation, and subsequent treatment with Zn (step 2B), a compound of general formula (II) is obtained wherein R₂ = C₂H₅. Method C By operating likewise as disclosed, for instance, in J. A. C. S., 101 5853 (1979) a compound of formula (III) is added to acrylic acid in the presence of promoters of radicalic reactions (step 1C); the obtained adduct is turned into acyl chloride (step 2C), that is reacted with triethylamine and isobutylene (step 3C); the obtained intermediate is isomerized by means of catalytic amounts of triethylamine (step 4C) to yield a 4-halo-cyclobutanone, that undergoes easily Favorskii rearrangement by treatment with a base at room temperature (step 5C). A further basic treatment yields a product having formula (II) with R₂ = H (step 6C). The application of methods A and C generally leads to compounds of formula (II) having prevailingly cis configuration with respect to cyclopropane whereas, by applying method B to a mixture of caronaldehyde in 1/1 cis/trans isomeric ratio, the trans-isomers are prevailingly obtained. The compounds having general formula (I) may be as isomer mixtures. The separation of the mixtures into their components may be carried out according to known chemical techniques, such as column chromatography or thin layer chromatography. The isolation and use of any steric and/or configurational isomer, as well as the direct use of the mixtures that may be obtained by preparing the compounds and the use of the mixtures coming from an incomplete separation of the isomers fall within the spirit of the present invention. As above mentioned, the compounds having formula (I) are endowed with a high insecticide activity. Their characterization consists in having a wide action spectrum against insects belonging to different families such as Lepidoptera, Diptera, Coleoptera, Aphides and the like and furthermore in having a satisfactory acaricide activity. On account of their positive characteristics the compounds of formula (I) may be used in protecting cultivations of agrarian interest and meanwhile in protecting from noxious insects environments frequented by men, domestic animals and breeding cattle. For the practical uses both in agriculture and in other fields, the compounds of the invention may be used usefully in the form of suitable compositions. These compositions contain, besides one or more components of formula (I), as active principle, inert solid carriers (for instance kaolin, silica, talc, attapulgite, diatom earth and the like) or liquid carriers (organic solvents, vegetable or mineral oils, water and mixtures thereof) and optionally other additives of common use in the formulation field such as surfactants, suspending agents, dispersing agents, and wetting agents. For particular application needs or in order to widen the action spectrum of the compositions, other active ingredients, such as for instance other insecticides or acaricides, herbicides, fungicides or fertilizers, may be added to the compositions described hereinbefore. The application doses vary, as a function of different factors, such as the kind and degree of infestation, the kind of composition that has been used, climatic and environmental factors. For practical uses in agriculture, doses of a compound of formula (I) ranging from 10 to 500 g/ha give satisfactory results. The following examples will be given in order to better illustrate the invention. EXAMPLE 1 Synthesis of trans-α-cyano-m-phenoxybenzyl 2,2-dimethyl-3-[2-chloro-2-(methoxydifluoromethyl) ethenyl]-cyclopropane carboxylate (compound No 1). 1.5 g of trans-2,2-dimethyl-3-[2-chloro-2-(methoxydifluoromethyl)vinyl]-cyclopropane carboxylic acid, whose preparation will be disclosed in next example 6, were dissolved in 15 ml of benzene. 3.5 g of oxalyl chloride were added dropwise to the solution. The whole was kept under stirring at room temperature over 3 hours in an inert atmosphere and then the solvent was evaporated at reduced pressure; the residue, after having been treated with anhydrous ether, was dripped into a solution of 2.25 g of α-cyano-m-phenoxybenzylalcohol in 3 cc. of pyridine and 20 cc. of anhydrous ether. The whole was kept under stirring overnight, the precipitate was filtered and the filtrate after having been washed with HCl at 1%, with bicarbonate and with brine, was dehydrated and dried. A raw oil (3.5 g) was obtained, that was analysed by silica gel chromatography to yield 2.1 g of pure product. N.M.R. (CDCl₃) δ=1.15-1.3 (m. 6H); 1.75 (d.1H); 2.3-2.55 (dd. 1H); 3.6 (s. 3H); 6.05 (d. 1H); 6.35 (d. 1H); 6.85-7.5 (m. 9H). Mass: 461 (M+, 0.1%),209 (100%), 208, 181, 81 (CF₂OCH₃). EXAMPLE 2 Synthesis of cis-α-cyano-m-phenoxybenzyl-2,2-dimethyl-3-[2-chloro-2-p-chlorophenoxydifluoromethyl)vinyl]-cyclopropanecarboxylate (compound No 2). 1.5 g of cis-2,2-dimethyl-3-[2-chloro-2-(p-chlorophenoxydifluoromethyl)vinyl]-cyclopropane carboxylic acid, whose preparation will be disclosed in next example 7, were dissolved in 15 cc. of benzene. 2.5 cc. of oxalyl chloride were added. The whole was kept under stirring at room temperature over 3 hours and then the solvent was evaporated at the rotavapor apparatus; the residue, after having been treated with anhydrous ether, was dripped into a solution of 2 g of α-cyano-m-phenoxy-benzylalcohol in 3 cc of pyridine and 20 cc of anhydrous ether. The whole was kept under stirring overnight, the precipitate was filtered and the filtrate,after having been washed with HCl at 1%, with bicarbonate and with brine, was dehydrated and dried. A raw oil (3 g)was obtained, that was analysed by silica gel chromatography to yield 1.9 g. of pure product. N.M.R. (CDCl₃)δ:1.25 (bs. 6H); 1.6-2.35 (m. 2H); 6.2 (d. 1H); 7.5-6.6 (m. 14H). EXAMPLE 3 Synthesis of trans-α-cyano-m-phenoxybenzyl-2,2-dimethyl-3-[2-chloro-2-(p-chlorophenoxydifluoromethyl)vinyl]-cyclopropane carboxylate (compound No 3). 1.8 g of trans-2,2-dimethyl-3-[2-chloro-2-(p-chlorophenoxydifluoromethyl)vinyl]-cyclopropane carboxylic acid, whose preparation will be disclosed in next example 8, were dissolved in 15 cc. of benzene. 2.5 cc. of oxalyl chloride were added. The whole was kept under stirring at room temperature over 3 hours and then the solvent was evaporated at the rotavapor apparatus; the residue, after having been treated with anhydrous ether, was dripped into a solution of 2 g of α-cyano-m-phenoxy-benzylalcohol in 3 cc. of pyridine and 20 cc. of anhydrous ether. The whole was kept under stirring overnight, the precipitate was filtered and the filtrate,after having been washed with HCl at 1%, with bicarbonate and with brine, was dehydrated and dried. A raw oil (3 g) was obtained, that was analysed by silica gel chromatography to yield 1.9 g of pure product. N.M.R. (CDCl₃)δ: 1.32-1.13 (m. 6H); 1.7 (d. 1H); 2.4 (dd 1H); 6.0 (d. 1H); 6.18 (d. 1H); 7.5-6.6 (m. 13H). EXAMPLE 4 Synthesis of cis- α-cyano-m-phenoxybenzyl-2,2-dimethyl-3-[2-chloro-2-(p-ethoxyphenoxydifluoromethyl)vinyl]-cyclopropanecarboxylate (Compound No 4). 1.5 g of cis-2,2-dimethyl-3-[2-chloro-2-(p-ethoxy-phenoxydifluoromethyl)vinyl]-cyclopropane carboxylic acid, that will be disclosed in next example 9, were dissolved in 15 ml of benzene, then 3.5 g of thionyl chloride were added. The whole was kept under stirring at 80°C over 2 hours and then one evaporated at reduced pressure; the residue, after having been treated with anhydrous ether, was dripped into a solution of 2.25 g of m-phenoxybenzaldehyde-cyanohydrin in 3 cc. of triethylamine and 20 cc of anhydrous ether. The whole was kept under stirring overnight, the precipitate was filtered and the filtrate, after having been washed with HCl at 1%, with bicarbonate and with brine, was dehydrated and dried. A raw oil (3.2 g.) was obtained, that was analysed by silica gel chromatography to yield 2 g. of pure product. N.M.R. (CDCl₃) δ: 1.1-1.4 (m. 9H); 2.3-1.8 (m. 2H); 3.86 (q. 2H); 6.15 (d. 1H); 7.5-6.6 (m. 14H). EXAMPLE 5 By following procedures similar to the ones disclosed in the preceding examples, the following compounds, as isomeric mixtures, were prepared, starting from 2,2-dimethyl-3-[2-bromo-2-(methoxydifluoromethyl)ethenyl]-cyclopropanecarboxylic acid: α-cyano-3-phenoxybenzyl-2,2-dimethyl-3-[2-bromo-2-(methoxydifluoromethyl)ethenyl]-cyclopropane carboxylate (compound No 5); starting from 2,2-dimethyl-3-[2-chloro-2-(ethylthiodifluoromethyl)ethenyl]-cyclopropane carboxylic acid: α-cyano-3-phenoxybenzyl-2,2-dimethyl-3-[2-chloro-2-(ethylthiodifluoromethyl)ethenyl]-cyclopropane carboxylate (compound No 6); 3-phenoxybenzyl-2,2-dimethyl-3-[2-chloro-2-(ethylthiodifluoromethyl)ethenyl]-cyclopropane carboxylate (compound No 7); starting from 2,2-dimethyl-3-[2-chloro-2-(2,2,2-trifluoroethoxy-difluoromethyl)ethenyl]-cyclopropane carboxylic acid: 3-phenoxybenzyl-2,2-dimethyl-3-(2-chloro-2-(2,2,2-trifluoroethoxy-difluoromethyl)ethenyl]-cyclopropane carboxylate (compound No 8); α-cyano-3-phenoxybenzyl-2,2-dimethyl-3-(2-chloro-2-(2,2,2-trifluoroethoxy-difluoromethyl)ethenyl]-cyclopropane carboxylate (compound No 9); 3-phenoxy-4-fluorobenzyl-2,2-dimethyl-3-(2-chloro-2-(2,2,2-trifluoroethoxy-difluoromethyl)ethenyl]-cyclopropane carboxylate (compound No 10); α-(cyano-3-phenoxy-4-fluorobenzyl-2,2-dimethyl-3-[2-chloro-2-(2,2,2-trifluoroethoxy -difluoromethyl) ethenyl]-cyclopropane carboxylate (compound No 11); 3-benzyl-benzyl-2,2-dimethyl-3-[2-chloro-2-(2,2,2-trifluoroethoxy -difluoromethyl) ethenyl]-cyclopropane carboxylate (compound No 12); α-cyano-3-(2-pyridyloxy)-benzyl-2,2-dimethyl -3-[2-chloro-2-(2,2,2-trifluoroethoxy -difluoromethyl) ethenyl]-cyclopropane carboxylate (compound No 13); starting from 2,2-dimethyl-3-[2-fluoro-2-(2,2,2-trifluoroethoxy -difluoromethyl) ethenyl]-cyclopropane carboxylic acid: α- cyano-3-phenoxybenzyl-2,2-dimethyl-3-[2-fluoro-2-(2,2,2-trifluoroethoxy -difluoromethyl) ethenyl]-cyclopropane carboxylate (compound No 14); starting from 2,2-dimethyl-3-[2-chloro-2-(2,2,3,3-tetrafluoropropoxy -difluoromethyl) ethenyl]-cyclopropane carboxylic acid: α-cyano-3-phenoxybenzyl-2,2-dimethyl-3-[2-chloro-2-(2,2, 3,3-tetrafluoropropoxy -difluoromethyl) ethenyl]-cyclopropane carboxylate (compound No 15); starting from 2,2-dimethyl-3-[2-chloro-2-(2,2,3,3,3-pentafluoropropoxy -difluoromethyl) ethenyl]-cyclopropane carboxylic acid: 3-benzyl-benzyl-2,2-dimethyl-3-[2-chloro-2-(2,2,3,3,3-pentafluoropropoxy -difluoromethyl) ethenyl]-cyclopropanecarboxylate (compound No 16); α-cyano-3-(2-pyridyloxy)-benzyl-2,2-dimethyl-3-[2-chloro-2-(2,2,3,3,3-pentafluoropropoxy -difluoromethyl) ethenyl]-cyclopropane carboxylate (compound No 17); α-ethenyl-3-phenoxy-benzyl-2,2-dimethyl-3-[2-chloro-2-(2,2,3,3,3-pentafluoropropoxy -difluoromethyl) ethenyl]-cyclopropane carboxylate (compound No 18); EXAMPLE 6 Synthesis of trans-2,2-dimethyl-3-[2-chloro-2-methoxydifluoromethyl)vinyl]-cyclopropanecarboxylic acid. Step 1B - 100 cc. of anhydrous DMF, 8.5 g of a 1:1 mixture of cis/trans caronaldehyde (0.05 moles), 3.5 g of Zn were fed into a 3 neck flask equipped with a cooler and magnetic stirrer, under nitrogen. Then 12 g of CH₃OCF₂CCl₃ were dripped under stirring into the mixture. The mixture was kept at 40 degrees over two hours and then cooled to room temperature and the reaction was stopped by means of HCl at 10%; one extracted with ether (3x100 cc.), the extract was washed with a solution saturated with bicarbonate and with water and salt, dehydrated and dried. One obtained 14 g of a yellow oil containing ethyl 2,2-dimethyl-3-[(1-hydroxy-2,2-dichloro-3,3-difluoro-3-methoxy) propyl]-cyclopropanecarboxylate, that were used without any further purification. Step 2B - 14 g of raw product obtained at step 1B were dissolved in 30 cc. of anhydrous DMF and 10 cc. of pyridine. 10 cc. of acetic anhydride were dripped into the mixture, that was brought to 60 degrees over 3 hours. The carbynol conversion was checked by a monitor through G.L.C. When the conversion was over, 8 cc of glacial acetic acid and 4 g of Zn were added to the mixture, that was kept at 60 degrees over further 2 hours. At the end the mixture was cooled, diluted with water and extracted several times by means of ether; the ethereal extracts were collected, washed with bicarbonate and saturated brine, dehydrated and dried. 6 g of a raw product were obtained, that were analysed by silica gel chromatography (hexane/ether 9/1) to yield 3.9 g of traps-ethyl-2,2-dimethyl-3-[2-chloro-2-(methoxy difluoromethyl)vinyl]-cyclopropane carboxylate. N.M.R.: (CDCl₃) δ: 1,1-1,4 (m. 9H); 1,8 (d. 1H); 2,4 (dd. 1H); 3,6 (s.3H); 3,9 (q. 2H); 6.05 (d. 1H). Hydrolysis 3.9 g of the product coming from step 2B were dissolved in 30 cc. of ethanol at 95% containing 1.68 g of KOH. The resulting solution was kept under stirring at 60 degrees over 2 hours. The mixture was evaporated at reduced pressure, treated with ether and washed with soda at 10% . Then the aqueous extract was washed with ether again and successively acidified with HCl at 10%. The acid solution was extracted with ether several times, the extracts were collected, washed with saturated brine, dehydrated with sodium and dried at the rotavapor apparatus. 3.3 g of product were obtained. N.M.R. : (CDCl₃) δ: 1,2-1,35 (s. 6H); 1,8 (d. 1H); 2,4 (dd. 1H); 3,6 (s. 3H); 6.03 (d. 1H); 9,7 (bs. 1H). EXAMPLE 7 Synthesis of cis-2,2-dimethyl-3-[2-chloro-2-(p-chlorophenoxydifluoromethyl)vinyl]-cyclopropane carboxylic acid. Step 1A - 7.4 g of 1-(p-chlorophenoxy)-1,1-difluoro-2,2,2-trichloroethane, 3,9 g of ethyl-3,3-dimethylpentenoate, 30 cc. of CH₃CN, 1 g of CuCl, 1.5 g of dipyridyl were fed into a three neck flask under nitrogen. The whole was kept under magnetic stirring at 80 degrees over 4 hours. At the end the mixture was cooled, diluted with ether, the insoluble salts were filtered, one washed with diluted HCl and then with bicarbonate and saturated brine. One dehydrated and one dried. One obtained 10.55 g of an oil containing ethyl-3,3-dimethyl-4,6,6-trichloro-7,7-difluoro-7-(p-chlorophenoxy)heptanoate, that was used without any purification at the next step. Step 2A - The raw product prepared at step 1A was dripped into a solution of 4.1 g of sodium ethylate in 125cc. of anhydrous ethanol. The mixture was stirred over two hours at room temperature, afterwards the solvent was evaporated at reduced pressure; one acidified with HCl at 5% and one extracted with ether several times; the organic extracts, after having been collected, were washed with bicarbonate and with water and salt, dehydrated, dried and analysed by silica gel chromatography to yield 4.2 g of ethyl 2,2-dimethyl-3-[(2,2-dichloro-3,3-difluoro-3-p-chlorophenoxy)propyl]cyclopropanecarboxylate. N.M.R. (CDCl₃) δ :1,1-1,35 (m. 9H); 1,65-2,2 (m. 2H); 3,15-3,3 (m. 2H); 4,02 (q. 2H); 7,0-7,4 (m. 4H). Step 3A - The product obtained at step 3A was dissolved in 50 cc. of anhydrous DMF. 3.2 g of DBU (diazabicycloundecene) were added to the solution and the whole was brought to 100 degrees over 4 hours. At the end the solution was cooled, acidified with HCl at 10% and extracted with ether several times. The ethereal extracts were washed repeatedly with water, then dehydrated, dried and analysed by silica gel chromatography to yield 2.7 g of cis-ethyl 2,2-dimethyl-3-[2-chloro-2-(p-chlorophenoxydifluoromethyl) vinyl]cyclopropane carboxylate. N.M.R. (CDCl₃) δ: 1.15-1.4 (m. 9H); 1.65-2.4 (m.2H); 4.05 (q. 2H); 6.8 (d. 1H); 7.0-7.35 (m. 4H). Hydrolysis 2.7 g of the product obtained at step 3A were dissolved in 30 cc of ethanol at 95% containing 1.38 g of KOH. The resulting solution was kept under stirring at 60 degrees over 2 hours. The mixture was evaporated at reduced pressure, treated with ether and washed with soda at 10%. The aqueous extract was washed with ether again and then acidified with HCl at 10%. The acid solution was extracted with ether several times, the extracts were collected, washed with saturated brine, dehydrated with sodium sulphate and dried at the rotavapor apparatus. 2.2 g of acid were obtained. EXAMPLE 8 Synthesis of trans-2,2-dimethyl-3-[2-chloro-2-(p-chlorophenoxy-difluoromethyl)vinyl]-cyclopropane carboxylic acid. Step 1B - 50 cc. of anhydrous DMF, 4.25 g of caronaldehyde (mixture 1:1 cis:trans) (0.025 moles), 1.75 g of Zn were fed into a 3 neck flask equipped with a cooler and magnetic stirrer, under nitrogen atmosphere. Then 10 g of 1-(p-chlorophenoxy)-1,1-difluoro-2,2,2-trichloroethane were dripped into the mixture, under stirring. The mixture was kept at 40 degrees over two hours, afterwards it was cooled to room temperature and the reaction was stopped by means of HCl at 10%. One extracted with ether (3x70 cc.); the extract was washed with a solution saturated with bicarbonate and with water and salt, dehydrated and dried. One obtained 11 g of a yellow oil containing ethyl-2,2-dimethyl-3-[(1-hydroxy-2,2-dichloro-3,3-difluoro-3-p-chlorophenoxy)propyl]cyclopropane carboxylate. Step 2B - 11 g of the product coming from step 1B were dissolved in 20 cc. of anhydrous DMF and 5 cc of pyridine. 5 cc of acetic anhydride were dripped into the mixture, that was brought to 60 degrees over 3 hours. The carbinol conversion was checked by means of a monitor through G.L.C. When the conversion was over, 4 cc. of glacial acetic acid and 2 g of Zn were added to the mixture, that was kept at 60 degrees over further 2 hours. At the end the mixture was cooled, diluted with water and extracted with ether several times; the ethereal extracts were collected, washed with bicarbonate and with water and salt, dehydrated and dried. 5 g of raw product were obtained, that were analysed by silica gel chromatography to yield 3.1 g of traps-ethyl-2,2-dimethyl-3-[2-chloro-2-(p-chlorophenoxy-difluoromethyl)vinyl]-cyclopropane carboxylate. N.M.R. (CDCl₃) δ:1.0-1.3 (m. 9H); 1.6 (d. 1H); 2.3 (dd. 1H); 4.02 (q. 2H); 6.05 (d. 1H); 7.15 (q. 4H). Hydrolysis 3.1 g (0.0082 moles) of ester coming from step 2B were dissolved in 30 cc. of ethanol at 95% containing 1.05 g of KOH. The resulting solution was kept under stirring at 60 degrees over 2 hours. The mixture was evaporated at reduced pressure, treated with ether and washed with soda at 10%. Then the aqueous extract was washed with ether again and acidified with HCl at 10%. The acid solution was extracted with ether several times, the extracts were collected, washed with saturated brine, dehydrated with sodium sulfate and dried at the rotavapor apparatus. 2.7 g of acid were obtained. EXAMPLE 9 Synthesys of cis-2,2-dimethyl-3-[2-chloro-2-(p-ethoxyphenoxy-difluoromethyl)vinyl]-cyclopropane carboxylic acid. Step 1A - 60 cc. of acetonitrile, 6 g (19.6 millimoles) of 1-(p-ethoxyphenoxy)-1,1-difluoro-2,2,2-trichloroethane, 4.6 g (29.5 millimoles) of ethyl 3,3-dimethyl-4-pentenoate, 0.2 g (2 millimoles) of anhydrous CuCl and 0.3 g (2 millimoles) of dipyridyl were fed, according to the indicated order, into a 3 neck flask, under nitrogen head. The mixture was kept under magnetic stirring at 80 degrees over 4 hours. At the end the mixture was cooled, diluted with water and the insoluble salts were filtered; the filtrate was washed with diluted HCl and then with bicarbonate and with saturated brine, dehydrated and dried. One obtained 9.14 g of an oil containing ethyl-3,3-dimethyl-4,6,6-trichloro-7,7-difluoro-7-(p-ethoxy-phenoxy) heptanoate, that was used without any purification at next step. Step 2A - 100 ml of anhydrous ethanol, 3.4 g of sodium ethylate and 9.14 g of the raw product coming from step 1A were fed into a three neck flask under nitrogen. The mixture was stirred over two hours at room temperature, afterwards the solvent was evaporated at reduced pressure; one acidified with HCl at 5% and one extracted with ether several times; the organic extracts, after having been collected, were washed with bicarbonate and with water and salt, dehydrated and dried. One obtained 6.3 g of a raw oil containing ethyl-2,2-dimethyl-3-[2,2-dichloro-3,3-difluoro-3-(p-ethoxy-phenoxy)propyl]-cyclopropane carboxylate, that was used without any further treatment at next step. Step 3A - The product obtained at step 2A was dissolved in 50 cc. of anhydrous D.M.F. 3.2 g of DBU (diazabicycloundecene) were added to the solution and the whole was brought to 100 degrees over 4 hours. At the end the solution was cooled, acidified with HCl at 10% and extracted with ether several times. The ethereal extracts were washed with water repeatedly, then dehydrated, dried and analysed by silica gel chromatography to yield 1.8 g of cis-ethyl-2,2-dimethyl-3-[2-chloro-2-(p-ethoxy-phenoxy difluoromethyl)vinyl]cyclopropane carboxylate. N.M.R. (CDCl₃) δ :1.1-1.5 (m. 12H); 1.7-2.4 (m. 2H); 3.7-4.2 (m. 4H); 6.6-7.15 (m. 5H). Hydrolysis 1.8 g of the product obtained at step 3A were dissolved in 30 cc. of ethanol at 95%. containing 0.55 g of ground KOH. The resulting solution was kept under stirring at 60 degrees over 2 hours. The mixture was evaporated at reduced pressure, treated with ether and washed with soda at 10%. Then the aqueous extract was washed with ether again and acidified with HCl at 10%. The acid solution was extracted with ether several times, the extracts were collected, washed with saturated brine, dehydrated with sodium sulfate and dried at the rotavapor.apparatus. 2.2 g. of acid were obtained. EXAMPLE 10 Synthesis of trans-ethyl-2,2-dimethyl-3[2-chloro-2-(2,2,2-trifluoroethoxy -difluoromethyl) ethenyl]-cyclopropanecarboxylate. 20 cc of anhydrous THF and 480 mg of a suspension containing 50% of NaH in vaseline oil (10 mmoles) were loaded into a 3 neck flask equipped with a dropping funnel and magnetic stirrer . 1 g (10 mmoles) of 2,2,2-trifluoroethanol was added cautiously to the suspension, while keeping the temperature at 20°C. After a few minutes, the solution, when got limpid, was cooled down to -30°C and a solution of 3.1 g (10 mmoles) of trans-ethyl-2,2-dimethyl-3-[1-acetoxy-2-chloro-3,3-difluoro - 2-propenyl]-cyclopropane carboxylate was added dropwise to the cooled solution. After 15 minutes at -30°C the reaction was stopped by means of 30 cc of a saturated solution of NH₄Cl; the mixture was extracted with ether, rinsed with a solution saturated with bicarbonate, rinsed with brine, dehydrated and dried. After a quick silica gel chromatography 3 g. of product (1) (86%) were obtained. N.M.R. (CDCl₃) 1.2-1,35 (m. 9H); 1.75 (d. 1H); 2.4 (dd. 1H); 4.15 (q. 2H); 4.2 (q. 2H); 6.15 (d. 1H). EXAMPLE 11 Synthesis of trans-ethyl-2,2-dimethyl-3-[2-chloro-2-(2,2,3,3-tetrafluoropropoxy -difluoromethyl) ethenyl]-cyclopropane carboxylate. 20 cc of anhydrous THF and 480 mg of a suspension containing 50% of NaH in vaseline oil (10 mmoles) were loaded into a 3 neck flask equipped with a dropping funnel and magnetic stirrer. 1.32 g (10 mmoles) of 2,2,3,3-tetrafluoropropanol were added cautiously to the suspension, while keeping the temperature at 20°C. After a few minutes, the solution, when got limpid, was cooled down to -30°C and a solution of 3.1 g (10 mmoles) of trans-ethyl-2,2-dimethyl-3-[(1-acetoxy-2-chloro-3,3-difluoro) 2-propenyl]cyclopropane carboxylate was added dropwise to the cooled solution. After 10 minutes at -30°C the reaction was stopped by means of 30 cc of a solution saturated with NH₄Cl; the mixture was extracted with ether, rinsed with a solution saturated with bicarbonate, rinsed with brine, dehydrated and dried. After a quick silica gel chromatography 3.2 g of product (2) (84%) were obtained. N.M.R. (CDCl₃) 1.2-1.35 (m. 9H); 1.75 (d. 1H); 2.4 (dd. 1H); 4.2 (q. 2H); 4.2 (t. 2H); 5.95 (tt. 1H); 6.15 (d. 1H). EXAMPLE 12 Synthesis of trans-ethyl 2,2-dimethyl-3-[2-chloro-2-(methoxydifluoromethyl) ethenyl]-cyclopropane carboxylate. 20 cc of anhydrous THF and 3.1 g (10 mmoles) of transethyl 2,2-dimethyl-3-[(1-acetoxy-2-chloro-3,3-difluoro)-2-propenyl]-cyclopropane carboxylate were loaded into a 3 neck flask equipped with a dropping funnel and magnetic stirrer. The mixture was cooled down to -30°C and 540 mg (10 mmoles) of CH₃ONa were added gradually in parts. After 30 minutes at -30°C the reaction was stopped by means of a solution saturated with NH₄Cl; the resulting mixture was extracted with ether, rinsed with a solution saturated with bicarbonate and with brine, dehydrated and dried. After silica gel chromatography 2.6 g of product (3) (92%) were obtained. N.M.R. (CDCl₃) 1.1-1.4 (m. 9H); 1.8 (d. 1H); 2.4 (dd. 1H); 3.6 (s. 3H); 3.9 (q. 2H); 6.05 (d. 1H). EXAMPLE 13 Synthesis of traps-ethyl 2,2-dimethyl-3-[2-chloro-2-(1,1,1,3,3,3-hexafluoro-2-propyloxy -difluoromethyl)ethenyl]-cyclopropane carboxylate. 20 cc. of anhydrous THF and 480 mg of a suspension containing 50% of NaH in vaseline oil (10 mmoles) were loaded into a 3 neck flask equipped with a dropping funnel and magnetic stirrer. 1.68 g (10 mmoles) of 1,1,1,3,3,3-hexafluoro-2-propanol were added cautiously to the suspension, while keeping the temperature at 20°C. After a few minutes 3.1 g (10 mmoles) of traps-ethyl-2,2,-dimethyl-3-[(1-acetoxy-2-chloro-3,3-difluoro)2-propenyl]-cyclopropane carboxylate were dripped at room temperature. The mixture was stirred at room temperature over 2 hours. The reaction was stopped by means of 30 cc of a solution saturated with NH₄Cl; the mixture was extracted with ether, rinsed with a solution saturated with bicarbonate and with brine, dehydrated and dried. After silica gel chromatography 3.6 g of product (86%) were obtained. EXAMPLE 14 Synthesis of trans-ethyl 2,2-dimethyl-3-[2-chloro-2-(isopropylthio-difluoromethyl)ethenyl]-cyclopropane carboxylate. 20 cc of anhydrous THF and 480 mg of a suspension containing 50% of NaH in vaseline oil (10 mmoles) were loaded into a 3 neck flask equipped with dropping funnel and magnetic stirrer. 0.76 g (10 mmoles) of isopropanethiol were added cautiously to the suspension, while keeping the temperature at 20°C. After a few minutes 3.1 g (10 mmoles) of trans-ethyl-2,2-dimethyl-3-[(1-acetoxy-2-chloro-3,3-difluoro)-2-propenyl]-cyclopropane carboxylate were dripped at room temperature. The mixture was stirred at room temperature over 2 hours. The reaction was stopped by means of 30 cc of a solution saturated with NH₄Cl; the mixture was extracted with ether, rinsed with a solution saturated with bicarbonate and with brine, dehydrated and dried. After silica gel chromatography 2.8 g of product (86%) were obtained. EXAMPLE 15 Synthesis of traps-ethyl 2,2-dimethyl-3-[2-fluoro-2-(2,2,2-trifluoroethoxy -difluoromethyl)ethenyl]-cyclopropanecarboxylate. 20 cc of anhydrous THF and 480 mg of a suspension containing 50% of NaH in vaseline oil (10 mmoles) were loaded into a 3 neck flask equipped with dropping funnel and magnetic stirrer. 1 g (10 mmoles) of 2,2,2-trifluoroethanol was added to the suspension cautiously, while keeping the temperature at 20°C. After a few minutes the solution, when get limpid, was cooled down to -30°C and a solution of 2.95 g (10 mmoles) of trans-ethyl-2,2-dimethyl-3-[(1-acetoxy-2-fluoro-3,3-difluoro)-2-propenyl]-cyclopropane carboxylate was dripped into the cooled solution. After 15 minutes at -30°C the reaction was stopped by means of 30 cc of a solution saturated with NH₄Cl; the mixture was extracted with ether, rinsed with a solution saturated with bicarbonate and with brine, dehydrated and dried. After a quick silica gel chromatography 2.9 g product(1)(87%) were obtained. N.M.R. (CDCl₃): 1.05-1.3 (m. 9H), 1.55 (d. 1H), 2.2 (dd. 1H), 3.85-4.3 (m. 4H), 5.15 (dd. 1H). EXAMPLE 16 Determination of the insecticide and acaricide activity. A. Insecticide activity against Macrosiphum euphorbiae (aphides). Small plants of potato grown in pots, were infested with adult females of aphis and, after a few hours, sprinkled with a water-acetone (acetone 10% by volume) suspension of the product being tested. 24 hours after the treatment, the percentage of the aphis mortality was determined, in comparison with the one of aphides infesting small plants, only treated with an aqueous solution containing 10% of acetone. B. Insecticide activity against Leptinotarsa decemlineata (coleoptera). Small plants of potato grown in pots were infested with coleopter larvae being 4 days of age. Then the small plants were sprinkled with a water-acetone (acetone 10% by volume) dispersion containing the product being tested. The percentage of the larva mortality was evaluated 48 hours after the treatment, in comparison with the one of larvae infesting small plants, only sprinkled with an aqueous solution of acetone at 10%. C. Insecticide activity against Aedes aegypti (Diptera) Dipter larvae being 4 days of age were brought in vessels containing 300 ml of an aqueous solution at 1% of acetone, containing the product being tested. After 48 hours the percentage of the larva mortality was determined, in comparison with the one of larvae brought in an aqueous solution, that only contained acetone at 1%. D. Acaricide activity against Tetranychus Urticae Adults Small disks, obtained from bean leaves, were infested with adult acari and then sprinkled with a water-acetone (acetone 10% by volume) solution containing the product being tested. The mortality percentage was determined 24 hours after the treatment, in comparison with the one of acari infesting small disks, that had been only sprinkled with an aqueous solution containing 10% of acetone. Eggs Small disks, obtained from bean leaves, were infested with acarus eggs and then sprinkled with a water-acetone solution containing the product being tested. The percentage of unopened eggs was evaluated 7 days after the treatment, in comparison with the one of eggs, that had been only treated with water-acetone mixture. By operating according to the above described conditions, the compounds of the invention were tested in order to determine both the insecticide and acaricide activity. The insecticide activity was evaluated, according to the percentage of insect morality at different doses of active compound, and was expressed according to the following scale of values: 5 = complete activity mortality above 90% 4 = high activity mortality ranging from 80 to 90% 3 = fairly good activity mortality ranging from 60 to 79% 2 = middling activity mortality ranging from 40 to 59% 1 = scanty activity mortality ranging from 20 to 39% 0 = negligible activity mortality ranging from 0 to 19% The results of the carried out tests are recorded in Table 1.

Claims: Pyrethroids of general formula (I): wherein: R represents an optionally halogen-substituted alkyl, cycloalkyl, alkenyl or alkynyl group containing from 1 to 8 carbon atoms, or an aryl group optionally substituted with halogen, alkyl or alkoxy radicals; Y represents 0 or S; X represents H, F, Cl, Br, -CH₃ or -CF₃; R₁ represents a group having formula: wherein X₁ is H or F; X₂ is H, -CN or -C ≡ CH; Q is O or CH₂, or the group and then X is chloro and R-Y- is 2,2,2-trifluoroethoxy or 2,2,3,3,3 - pentafluoropropoxy-. Compounds according to claim 1, namely: trans-α-cyano-m-phenoxybenzyl-2,2-dimethyl-3-[2-chloro-2-(methoxydifluoro methyl)ethenyl]cyclopropane carboxylate; 3-phenoxybenzyl-2,2-dimethyl-3-[2-chloro-2-(2,2,2-trifluoroethoxy-difluoromethyl)-ethenyl]-cyclopropane carboxylate; α-cyano-3-phenoxybenzyl-2,2-dimethyl-3-[2-chloro-2-(2,2,2-trifluoroethoxy-difluoromethyl)-ethenyl]-cyclopropane carboxylate; 3-phenoxy-4-fluorobenzyl-2,2-dimethyl-3-[2-chloro-2-(2,2,2-trifluoroethoxy-difluoromethyl)-ethenyl]-cyclopropane carboxylate; α-cyano-3-phenoxy-4-fluorobenzyl-2,2-dimethyl-3-[2-chloro-2-(2,2,2-trifluoroethoxy-difluoromethyl)-ethenyl] cyclopropane carboxylate; α-cyano-3-phenoxybenzyl-2,2-dimethyl-3-[2-fluoro-2-(2, 2,2-trifluoroethoxy-difluoromethyl)-ethenyl]-cyclopropane carboxylate; and α-cyano-3-phenoxybenzyl-2,2-dimethyl-3-[2-chloro-2-(2, 2,3,3-tetrafluoropropoxy-difluoromethyl)-ethenyl]-cyclopropane carboxylate. Process for preparing the compounds of formula (I) according to claim 1, consisting in esterifying a carboxylic acid or an acylic derivative thereof of formula (II): with an alcohol of formula R₁-OH, wherein R, Y, X and R₁ have the meanings given in claim 1, and R₂ represents OH, Cl, or a C₁-C₄ alkoxy radical, said esterification being carried out at room temperature in an inert organic solvent and in the presence of an organic base. Process according to claim 3, wherein R₂ is Cl and the organic base is selected from pyridine and triethylamine. Compounds having the general formula (II): wherein R, Y and X have the meanings specified in claim 1, and R₂ represents OH, Cl or a C₁-C₄ alkoxy group. Process for preparing the compounds having formula (II) according to claim 5, wherein R₂ is OH or a C₁-C₄ alkoxy group, consisting in reacting a metal salt of formula RY-M (V) with a difluoroolefin of formula (VI): wherein R, Y, X have the meanings specified hereinbefore, R₂ is OH or a C₁-C₄ alkoxy group, M is selected from Na, K and Li; and A represents H or an acylic or sulfonic group; said reaction being carried out in the presence of an organic solvent and at a temperature ranging from -78°C to the boiling temperature of the solvent. Process according to claim 6, wherein A is selected from CH₃CO, CH₃SO₂, CF₃SO₂ and CH₃-C₆H₄-SO₂. Method of controlling infestations by noxious insects and acari, consisting in distributing in the infested area an effective amount of one or more compounds according to claims 1 and 2, together with inert solid or liquid carriers and optionally other additives. Insecticide and acaricide compositions containing, as active ingredient, one or more compounds as defined in claims 1 and 2, together with inert solid or liquid carriers and optionally other additives.

Inventors: BETTARINI, FRANCO, DR., CAPRIOLI, VINCENZO, DR., CAPUZZI, LUIGI, DR., CASTORO, PAOLO, MASSARDO, PIETRO, DR.
Applicants: MONTEDISON S.P.A.
Application year: 1987
Main classification: C07C69
IPC codes: C07D213, A01N53