GB2055822A - Carboxylic ester compounds for use as insecticides - Google Patents

Abstract

Novel carboxylic esters of formula (I), <IMAGE> wherein X is a chlorine, bromine or fluorine atom, are effective in the control of insects. They can be produced by reacting a carboxylic acid of formula (II), <IMAGE> or a reactive derivative thereof, with an alcohol or a reactive derivative of the formula (III), <IMAGE> wherein A is a hydroxyl group or a tosyloxy group.

Description

SPECIFICATION Carboxylic ester compounds for use as insecticides The present invention relates to new carboxylic esters of the formula (I),

wherein Xis a chlorine, bromine or fluorine atom, their production, and insecticides of low toxicity and rapid effect containing the esters as an active ingredient.

Since many of infectious diseases are carried by insects, exterminating these insects is very effective in preventing the diseases from spreading, and using insecticides is the most effective means for achieving this object. Consequently, the role of insecticides in maintaining a high living standard of mankind is very great.

Many superior insecticides have so far been invented in order to achieve this object and used in various fields with good results. Organochlorine insecticides such as BHC and DDT and organophosphorus insecticides were however markedly limited in use, because they generated insects resistant thereto and caused various problems such as enviromental pollution and toxicity to organisms out of target. Also, with new insecticides substituted for the above ones, this problem of resistant insects is now becoming serious in various fields. Under these circumstances, the development of novel and more superior insecticides is eagerly desired.Hereupon, the followings may be said about properties essential to insecticides: High insecticidal activity and knockdown effect are of course necessary, but in addition to this, a low toxicity to organisms out of target such as mammals, no persistency and little enviromental pollution are strongly demanded at present. Natural pyrethrin is low in toxicity to mammals and easily decomposable in outdoor conditions, so that it possesses a part of the aforesaid properties essential to insecticides. But its insecticidal activity is relatively low as compared with the organophosphates and carbamates, and besides it is too rapidly decomposed to keep a residual effect, and it is expensive ["Advantages and Disadvantages of Pyrethrum" in "Pyrethrum" (J.E. Casida, Academic Press, New York and London, 1973) pp 307 - 311].

The inventors have extensively studied to develop compounds which make up for the drawbacks of natural pyrethrin and which are superiorto insecticides now in practical use. As a result, it was found that the present compounds of the formula (I) have the characteristics: (1 ) Markedly rapid effect (nock-down effect) and high insecticial activity.

(2) Relatively low toxicity to mammals.

(3) Excellent insecticidal activity against insects resistant to organophosphates and carbamates.

(4) Can be produced at a relatively low cost.

The inventors thus attained to the present invention.

The compounds of the present invention are included, in a broad sense, in the scope of Published Unexamined Japanese Patent Application No. 47531/1974. In the patent application, however, there is no specific description on the compounds and, as a matter of course, no reference is made to the physical properties; synthetic examples and insecticidal activity of the compounds.

The present invention was the first to find that the present compounds of the formula (I) have a remarkably higher knock-down effect than any compound in the patent application concerned with the present compounds. Consequently, it has a greater significance.

The compounds of the present invention are obtained by reacting a carboxylic acid of the formula (II),

wherein X is as defined above, or its reactive derivative with an alcohol or its reactive derivative of the formula (ill),

wherein A is a hydroxyl group or a tosyloxy group, in the presence of a suitable solvent, reaction assistant and catalyst if necessary. The reactive derivative of the carboxylic acid of the formula (II) referred to herein includes for example acid halides, each anhydrides, lower alkyl esters, alkali metal salts amd organic tertiary base salts. The reactive derivative of the alcohol of the formula (Ill) includes for example compounds obtained by replacing the hydroxyl group of the alcohol with a halogen atom or a tosyloxy group.

The carboxylic esters of the formula (I) have isomeric forms, i.e. geometrical isomers (cis and trans isomers) based on the steric configuration of the carboxylic acid moiety and optical isomers based on the asymmetric carbon atoms of the carboxylic acid and alcohol moieties. All these isomers are also of course included in the scope of the present invention.

The method for producing the carboxylic esters of the present invention will be summarized in that the carboxylic ester of the formula (I) is produced by reacting a carboxylic acid of the formula (II),

wherein Xis as defined above, or its reactive derivative, with an alcohol or its reactive derivative of the formula (Ill),

wherein A is a hydroxyl group or a toxyloxy group. Further, the above-mentioned reactive derivative of the carboxylic acid is an acid halide (acid chloride or acid bromide) or acid anhydride when A in the formula (III) is hydroxyl group and is an alkali metal salt of the acid when A in the formula (III) is tosyloxy group.That is: Synthesis A: Reaction between alcohol and carboxylic halide The objective of the ester of the formua (I) is obtained by reacting an alcohol of the formula (III'),

with a carboxylic halide (chloride or bromide), preferably carboxylic chloride, of the formula (II),

wherein Xis as defined above, at -30" to 1 00 C for 0.5 to 20 hours in an inert solvent (e.g. benzene, toluene, hexane, ether) in the presence of a base (e.g. pyridine, triethylamine).

The base is usually employed in an amount of 1.0 to 3.0 moles based on 1 mole of the alcohol of the formula (III'). And, the amount of the carboxylic halide of the formula (II) used is 1.0 to 1.5 moles based on 1 mole of the alcohol of the formula (III').

Synthesis B: Reaction between alcohol and carboxylic anhydride The objective ester of the formula (I) is obtained by reacting an alcohol of the formula (III'),

with a carboxylic anhydride of the formula (II),

wherein X is as defined above, at -20" to 1 00"C for 1 to 20 hours in an inert solvent (e.g. benzene, toluene, hexane, acetone) in the presence of a base (e.g. pyridine, triethylamine).

The base is usually employed in an amount of 1.0 to 3.0 moles based on 1 mole of the alcohol of the formula (III'). And, the amount of the carboxylic anhydride of the formula (II) used is 1.0 to 1.5 mols based on 1 mole of the alcohol of the formula (Ill').

Synthesis C: Dehydration reaction between alcohol and carboxylic acid The objective ester of the formula (I) is obtained by reacting an alcohol of the formula-(lll')

with a carboxylic acid of the formula (II),

wherein X is as defined above, at 0 to 1 50"C for 0.5 to 10 hours in an inert solvent (e.g. benzene, toluene, ether, acetone) in the presence of a dehydrating agent )e.g. dicyclohexylcarbodiimide).

The dehydrating agent is usually employed in an amount og 1.0 to 2.0 moles based on 1 mole of the alcohol of the formula (III'). And, the amount of the carboxylic acid of the formula (II) used is 1.0 to 1.5 moles based on 1 mole of the alcohol of the formula (III').

Synthesis D: Reaction between alcohol tosylate and carboxylic acid salt The objective ester of the formula (I) is obtained by reacting an alcohol tosylate of the formula (Ill),

wherein A is a tosyloxy group, with an alkali metal salt of carboxylic acid represented by the formula (IV),

wherein X is as defined above and M is a sodium or potassium atom, at 0" to 1 50"C for 0.5 to 10 hours in an inert solvent (e.g. benzene, toluene, acetone, dimethyl-formamide, dimethyl sulfoxide).

The amount of the alkali metal salt of carboxylic acid represented by the formula (IV) used is 1.0 to 1.5 mols based on 1 mole of the alcohol tosylate of the formula (III).

The carboxylic esters of the formula (I) obtained by the foregoing methods may be purified by chromatography or distillation if necessary.

The present invention will be illustrated in detail with reference to the following examples, which are not however to be interpreted as limiting the invention thereto.

Example 1 (+)-2-Methyl-3-2'-propynyl-cyclopent-2-en-4-on-l-ol (3.0 g) and pyridine (2.4 g) were dissolved in toluene (50 ml), and (t)-2,2-dimethyl-3-cis-2',2'-dichlorovinylcyclopropanecarboxylic anhydride (8.0 g) was added, followed by stirring at 40"C for 24 hours. The reaction solution was poured into an aqueous hydrochloric acid solution and separated into aqueous and toluene layers. The toluene layer was washed with a 5 % aqueous potassium carbonate solution and then with an aqueous sodium chloride solution, and the solvent was removed by evaporation to obtain 6.6 g of a pale yellow oil.This oil was purified by chromatography on silica gel (developing solvent, n-hexane/ethyl acetate mixture) to obtain 4.1 g of (+)-2-methyl-3-2'-propynyi- cyclopent-2-en-4-on-l-yl (± )-2,2-dimethyl-3-cis-2',2'-dichlorovinylcyclopropanecarboxylate (Compound A).

Refractive index 1.5310 C).

Example 2 (I)-2-Methyl-3-2'-prnpyl nyl-cyclopent-2-en-4-on-1 ol tosylate (3.0 g) was dissolved in dimethylformamide (50 ml), and potassium (+)-2,2-dimethyl-3-trans-2',2'-dichiorovinylcycíopropanecarboxyíate (2.5 g) was added, followed by stirring at 60"C for 15 hours. The reaction solution was poured into an aqueous hydrochloric acid solution and extracted with ethyl acetate. The ethyl acetate layer was washed with a 5 % aqueous potassium carbonate solution and then with an aqueous sodium chloride solution, and the solent was removed by evaporation to obtain 2.8 g of a pale yellow oil.This oil was purified by chromatography on silica gel (developing solvent, n-hexane/ethyl acetate mixture) to obtain 2.1 g of (+)-2-methyl-3-2'-propynyl- cyclopent-2-en-4-on-l-yl (+)-2,2-dimethyl-3-trans-2',2'-dichlornvinylcycloprnpanecarboxylate (Compound B).

Refractive index 1.5282 (22.5"C).

Example 3 (I)-2-Methyl-3-2'-prnpynyl-cydopent-2-enA-on-l-ol (320 mg) and pyridine (240 mg) were dissolved in toluene (10 ml), and (+)-2,2-dimethyl-3-trans-2',2'-difluorovinylcyclopropanecarboxylic acid chloride (420 mg) was added dropwise, followed by stirring at room temperature for 5 hours. The reaction solution was poured into an aqueous hydrochloric acid solution and separated into aqueous and toluene layers. The toluene layer was washed with an aqueous sodium hydrogen carbonate solution and then with an aqueous sodium chloride solution, and the solvent was removed by evaporation to obtain 680 mg of a pale yellow oil.

This oil was purified by chromatography on silica gel (developing solvent, n-hexane/ethyl acetate mixture) to obtain 450 mg of Z(+ )-2-methyl-3-2'-pro pynyl-cyclopent-2-en-4-on-l-yl (+)-2,2-dimethyl-3-trans-2',2'- difluorovinylcyclopropanecarboxylate (Compound C).

Refractive index 1.4921 (25.0"C).

Example 4 (*)-2-Methy-3-2'-propynyl-cyclopent-2-en-4-on-l-ol (150 mg) was dissolved in toluene )10 ml),. and (+)-2,2-dimethyl-3-cis-2',2'-dibromovinylcyclopropane-carboxylic acid (300 mg) and dicyclohexylcarbodiimide (400 mg) were added, followed by stirring at room temperature for 5 hours. The reaction solution was poured into an aqueous hydrochloric acid solution and separated into aqueous and toluene layers. The toluene layer was washed with an aqueous sodium hydrogen carbonate solution and then with an aqueous sodium chiroide solution, and the solentwas removed by evaporation to obtain 410 mg of a pale yellow oil.

This oil was purified by chromatography on silica gel (developing solvent, n-hexane/ethyl acetate mixture) to obtain 320 mg of (~)-2-methy-3-2'-propynylcyclopent-2-en-4-on-l-yl (+)-2,2-dimethyl-3-cis-2',2'-dibromo- vinylcyclopropanecarboxylate (Compound D).

Refractive index 1.5621 (22.5"C).

Example 5 (+)-2-Methyl-3-2'-propynyl-cyclopent-2-en-4-ol-l-ol (150 mg) and pyridine (120 mg) were dissolved in toluene (10 ml), and (I)-2,2-dimethyl-3-cis-2',2'-dichlornvinylcycloprnpanecarboxylic acid chloride (220 mg) was added dropwise, followed by stirring at room temperature for 5 hours. The reaction solution was poured into a 5% aqueous hydrochloric acid solution and separated into aqueous and toluene layers. The toluene layers was washed with an aqueous sodium hydrogen carbonate solution and then with an aqueous sodium chloride solution, and the solvent was removed by evaporation to obtain 320 mg of a pale yellow oil.This oil was purified by chromatography on silica gel (developing solvent, n-hexane/ethyl acetate mixture) to obtain 270 mg of (+)-2-methyl-3-2'-propynyl-cyclopent-2-en-4-on-l-yi (+)-2,2-dimethyl-3-cis-2'-2' dichlorovinylcyclopropanecarboxylate (Compound E).

Refractive index 1.5298 (24.0"C).

Example 6 (~)-2-Methyl-3-2'-propynyl-cyclopent-2-en-4-on-l-ol (1.50 g) and pyridine (1.20 g) were dissolved in toluene (30 ml), and (+)-2,2-dimethyl-3-cis, trans-2',2'-dichlorovinylcyclopropanecarboxylic acid chloride (2.28 g) was added dropwise, followed by stirring at 20"C for 5 hours, The reaction solution was poured into a 5% aqueous hydrochloric acid solution and separated into aqueous and toluene layers. The toluene layer was washed with an aqueous sodium hydrogen carbonate solution and then with an aqueous sodium chloride solution, and dried over magnesium sulfate.The solvent was removed by evaporation, and the residue was purified by chromatography on silica gel (developing solvent, n-hexane/ethyl acetate mixture) to obtain 2.50 g of (j)-2-methyl-3-2'-prnpynylcyclopent-2-en-4-on-l-yl (+)-2,2-dimethyl-3-cis, trans-2',2'dichlorovinylcyclopropanecarboxylate (Compound F).

Refractive index 1.5290 (22.5"C.

The present compounds of the formula (I) have a very rapid effect on harmful insanitary insects such as flies, mosquitoes and cockroaches, and besides they are very useful for controlling insects harmful to agricultural crops such as planthoppers, leafhoppers, armyworms and cutworms, diamond-back moth (Plutellxylostella), tortorixes, aphids, stem borers as well as insects harmful to stored cereals such as indian meal moth (Plodia interpunctefla) and rice weevils (Sitophilus zeamais) and animal-parasitic lice and ticks.

Also, they are effective for controlling other harmful insects. Further, the compounds of the present invention have not only an effect to known down insects to death but also repellency, an effect to repel insects from their host plants.

The excellent properties of the carobyxlic ester of the formula (I) are the more remarkable with (I)-2-methyl-3-2'-propynyl-cyclopent-2-en-4-on-l-yl(t-2,2-dimethyl-3-cis,trans-2',2'.

dichlorovinylcyclopropanecarboxylate, (+)-2-methy-3-2'-prnpynyl-cyclopent-2-enA-on-l-yl-(+)-2,2 dimethyl-3-trans-2',2'-difluoro-vinylcyclopropanecarboxylate and )-2-methyl-3-2'-propynyl-cyclopent-2- en-4-on-l-yl (+)-2,2-dimethyl-3-cis-2',2'-dibrnmovinylcycloprnpanecarboxylate.

The compounds of the present invention can practically be used for these objects in various preparation forms.

In order to make it clearer that the compounds of the present invention are excellent, typical experimental examples will be given below. The compounds of the formula (I) other than those described in the examples have also the same tendency.

Test Example 1 0.1 Part of each of the present compounds and reference compounds was dissolved in deodarized kerosene and made up to a total weight of 100 parts with kerosene to obtain an oil spray of each compound.

Ten northern house mosquito female adults (Culexpipienspallens) and ten housefly adults (Musca domestica) were liberated in a (70 cm)3 glass chamber. and 0.7 ml of the above oil spray was sprayed into the chamber. Thereafter, the number of knocked-down insects was counted with the lapse of time, and the value of KT50 was obtained from the average knock-down ratio of three replications according to the Finney's method.After 10 minutes, the tests insects were collected and given a 5 % sugar water, and after 24 hours, the dead and alive were counted.

Northern house mosquito female I Housefly adult Test compound i adult KT50 Mortality KT50 Mortality (sec) (%) (see) (%) Present compound A 89 97 | 86 67 Present compound B 81 100 l 80 50 Present compound C 44 100 | 40 80 Present compound D 100 100 l 95 50 Present compound E 59 100 l 63 90 Present coaipound. F 85 100 l 83 60 ni -. 120 90 130 J II 120 90 130 40 j *2 -- oc Scx 300 83 1 530 30 oc 1 *3 1180 77 ?600 oc OICI > cl r 0 C1 4/ < OC C1 *3 450 90 > 600 o ci ) rice > C1 c1 L-3"'-"' Tet"anitbr1n *11 160 80 360 20 PyreLt.riri t4 320 73 > 600 No LruLnitiL > 600 o > 600 0

(Note) *1 Compound described in J. Econ. Ento., 54, 1250 (1961).

*2 Compound described in Chemical Listy, 52, 688 (1958).

*3 Compound described in Published Unexamined Japanese Patent Application No. 47531/1974.

*4 Commercial chemical Test Example 2 A 0.1 % oil spray of each of the present compounds and the reference compound was prepared using deodorized kerosene as solvent.

Ten German cockroach adults (Blattella germanica) were liberated in a glass Petri dish of 10 cm in diameter of which the inside wall was coated thinly with vaseline, and the dish was covered with a 50-mesh nylon gauze. Thereafter, 0.6 ml of the oil spray was sprayed 50 cm apart from the dish by means of a glass atomizer, and the number of knocked-down insects was counted after 5, 10 and 20 minutes.

Knock-down ratio(%) Test compound After After After 5 min. 10 min. 20 min.

Present compound A 93 100 100 Present compound B 90 100 100 PresentcompoundC 100 100 100 PresentcompoundD 97 100 100 Presentcompound E 100 100 100 Present Compound F 90 100 100 Allethrin 0 30 60 In producing an insecticide an acaricide using the present compounds (I), the compounds may be formulated, like the conventional pyrethroids, into optional preparation forms using diluents for the common insecticides according to the methods well known to those skilled in the art. The preparation forms include for example oil sprays, emulsifiable concentrates, dusts, aerosols, wettable powders, granules, mosquito coils, heating or non-heating fumigants, baits of powder form or solid form containing attractants and other optional forms.

Further, a stronger insecticidal activity can be developed by blending two or more of these compounds.

Also, the insecticidal activity of the present compounds can be increased by blending with synergists for pyrethroids or other well-known effective synergists for Allethrin and Pyrethrin. The synergists for pyrethroids include for example a-[2-(2-butoxyethoxy)ethoxy]-4,5-methylene-dioxy-2-propyltoluene (hereinafter referred to as piperonylbutoxide), 1 ,2-methylenedioxy-4-[2-(octyl-sulfinyl)propyl]benzene (hereinafter referred to as sulfoxide), 4-(3,4-methylenedioxyphenyl)-5-methyl-1 3-dioxane (hereinafter referred to as sulfoxane), N-(2-ethylhexyl)-bicyclo[2,2,1 jhepta-5-ene-2,3-dicarboximide (hereinafter referred to as MGK-264), octachlorodipropyl ether (hereinafter referred to as S-421) and isobornylthiocyanoacetate (hereinafter refered to as Thanite).

In general, carboxylic esters tend to be inferior in resistance to light, heat and oxidation, and therefore compositions of more stable effect can be obtained by adding a proper amount of stabilizers. The stabilizers include for example antioxidants and ultraviolet absorbers such as phenol derivatives (e.g. BHT, BHA), bisphenol derivatives, arylamines (e.g. phenyl-a-naphthylamine, phenyl-p-naphthylamine, condensation products of phenetidine and acetone), and benzo-phenone compounds.

Further, multi-purpose compositions of excellent efficacy can be produced by mixing with other active ingredients for example Allethrin, N-(chrysanthemoxymethyl)-3,4,5,6-tetrahydrophthalimide (hereinafter referred to as tetramethrin), 5-benzyl-3-furylmethyl chrysanthemate (hereinafter referred to as resmethrin), 3-phenoxybenzyl chrysanthemate (hereinafter referred to as phenothrin), 4-propargylfurfuryl chrysanthemate, 2-methyl-5-propargyl-3-furylmethyl ch rysanthemate, d-trans or di-cis trans isomers of these chrysanthemates, pyrethrum extracts, d-trans or d-cis;trans chrysanthemic esters of d-allethrolone; 3-phenyloxybenzyl 2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropanecarboxylate, a-cyano-3-phenoxybenzyl 2',2'-dimethyl-3'-(2,2-dichlorovinyl)-cyclopropanecarboxylate, a-cyano-3-phenoxybenzyl 2',2',3',3'tetramethylcyclopropanecarboxylate, a-cyano-3-phenoxybenzyl 2-(4-chlorophenyl)isovalerate and other well-known cyclopropa necarboxylic esters; organophosphorous insecticides such as 0,0-dimethyl 0-(3methyl-4-nitrophenyl)-phosphorothioate (hereinafter referred to as fenitrothion), 0,0-dimethyl 0-4-cyanophenylphosphorothioate (hereinafter referred to as Cyanophos),0,0-dimethyl 0-(2,2dichlorovinyl)phosphate (hereinafter referred to as Dichlorvos);Baycid, Vinyphate, Malathion, Salithion, Papthion, Dipterex and Diazinon; carbamate insecticides such as 1-naphthyl N-methyl-carbamate, 3,4dimethylphenyi N-methylcarbamate, 3-methyiphenyl N-methylcarbamate, 2-isopropoxyphenyl Nmethylcarbamate S-methyl-N-(methylcarbamoyloxy)-thioacetoimidate; N'-(2-methyl-4-chlorophenyl)-N,Ndimethylformamidine; 1,3-bis)carbamoylthio)-2-(N,N-dimethyl-amino)propane hydrochloride; other insecticides, microbial pesticides such as fungicides, nematocides, acaracides, plant growth regulators, B.T. and B.M., insect hormone compounds, herbicides, fertilizers and other agricultural chemicals. Further, a synergistic effect can be expected by such mixing.

The foregoing preparations generally contain 0.01 to 80% by weight, preferably 0.05 to 60 % by weight, of the active ingredient (including other ingredients mixed). Since, however, the amount and concentration of the active ingredient depend upon the preparation forms, application time, application techniques, application sites, diseases and crops, they may properly be increased or decreased irrespective of the aforesaid ranges.

Next, the preparation examples for the present insecticids and acaricides will be shown.

Preparation Example 1 0.2 Part of each of the present compounds (A) to (F) is dissolved in kerosene and made up to 100 parts with kerosene to obtain the oil spray of each compound.

Preparation Example 2 To 0.05 part of the present compound (A) is added 0.25 part of piperonylbutoxide, and the mixture is dissolved in kerosene and made up to 100 parts with kerosene to obtain an oil spary.

Preparation Example 3 To 20 parts of each of the present compounds (A) to (F) are added 15 parts of Sorpol 3005X (a registered trade mark of Toho Kagaku Co.) and 65 parts ofxylene, and the mixture is well stirred to make a solution.

Thus, the emulsifiable concentrate of each compound is obtained.

Preparation Example 4 To 60 parts of each of the present compounds (A) to (F) are added 10 parts of Sorpol 3005X (a registered trade mark of Toho Kagaku Co.) and 30 parts ofxylene, and the mixture is well stirred to make a solution.

Thus, the emulsifiable concentrate of each compound is obtained.

Preparation Example 5 To 10 parts of each of the present compounds (B) and (D) are added 20 parts of S-421, 15 parts of Sorpol 3005X (same as above) and 55 parts of xyiene, and the mixture is well stirred to make a solution. Thus, the emulsifiable concentrate of each compound is obtained.

Preparation Example 6 0.1 Part of the present compound (C), 0.2 part of resmethrin, 7 parts of xylene and 7.7 parts of deodorized kerosene are well mixed to make a solution. The solution is filled in an aerosol container. After attaching a valve portion to the container, 85 parts of a propellant (liquefied petroleum gas) is charged therein under pressure through the valve to obtain an aerosol.

Preparation Example 7 0.3 Part of the present compound (E), 0.1 part of 3-phenoxybenzyl d-cis.trans-chrysanthemate, 7 parts of xylene and 7.6 parts of deodorized kerosene are well mixed to make a solution. The solution is filled in an aerosol container, and an aerosol is obtained in the same manner as in Preparation Example 6.

Preparation Example 8 To 0.15 g of each of the present compounds (C) and (E) is added 0.2 g of the d-trans chrysanthemic ester of Allethrin, and the mixture is dissolved in 20 ml of methanol. The solution is uniformly mixed, with stirring, with 99.65 g of a mosquitor coil carrier containing Tabu powder, Pyrethrum marc and wood powder in a ratio of : 5:1, and then methanol is evaporated. To the residue is added 150 ml of water, and the mixture is well kneaded, shaped into a mosquito coil and dried. Thus, the mosquito coil of each compound is obtained.

Preparation Example 9 To 0.02 g of the present compound (A) are added 0.05 g of 5-propargylfurfuryl dl-cis.trans-chrysanthemate and 0.1 g of BHT, and the mixture is dissolved in a suitable amount of chloroform. The solution is uniformly adsorbed in a filter paper of 3.5 cm x 1.5 cm x 0.3 cm (thick). Thus, a fibrous fumigant for heating on a hot plate is obtained.

Preparation Example 10 To 20 parts of each of the present compounds (B) and (D) are added 10 parts of fenitrothion (same as above) and 5 parts of Sorpol SM-200 (a registered trade mark of Toho Kagaku Co.), followed by thorough mixing. The mixture is then mixed with 65 parts of 300-mesh diatomaceous earth while being well stirred in a mortar. Thus, the wettable powder of each compound is obtained.

Preparation Example ii To 1 part of the present compound (A) is added 2 parts of 3-methylphenyl N-methylcarbamate, and the mixture is dissolved in 20 parts of acetone. The solution is then well mixed with 97 parts of 300-mesh talc while being stirred well in a mortar, and then acetone is removed by evaporation to obtain a dust.

Preparation Example 12 To 3 parts of each of the present compounds (A) and (B) are added 5 parts of Toyolignin CT (a registered trade mark of Toyo Spinning Co.) and 92 parts of GSM Clay (a registered trade mark of Zieklite Mining Co.), and the mixture is well mxed while being stirred in a mortar.

Then, the mixture is well mixed with water of 10 % based thereon, granulated by means of a granulator and air-dried. Thus, the granule of each compound is obtained.

Preparation Example 13 0.1 Part of the present compound (D), 0.2 part of the d-cis.trans acid isomer of Fenothrin, 11.7 parts of deodorized kerosene and 1 part of Atmos 300, an emulsifier, (a registered trade mark of Atlas Chemical Co.) are mixed, and then emulsified with addition of 50 parts of pure water. The emulsion is then filled in an aerosol container together with 35 parts of a 3:1 mixture of deodorized butane and deodorized propane to obtain a water-base aerosol.

Next, the insecticidal effect of the esters of the present invention will be illustrated in more detail with reference to the following application examples.

Test Example 3 Five millimeters of each of the oil sprays obtained in Preparation Examples 1 and 2 was sprayed according to the Campbell's turntable method [Soap and Sanitary Chemicals, Vol. 14, No. 6, 119(1938)] using about 100 housefly adults (Musca domestica) per group. The housefly adults were exposed to the descending mist for 10 minutes. By the next day, more than 80 % of the houseflies could be killed in any case.

Test Example 4 The emulsifiable concentrate obtained in Preparation Example 3 was diluted 100,000 times with water.

Two hundred milliliters of the solution was placed in a 300-ml glass beaker, and 30 full grown larvae of northern house mosquito (Culex pipiens pallens) were liberated therein. By the next day, more than 90 % of the larvae could be killed in any case.

Test Example 5 The insecticidal activity on housefly adults (Musca domestica) of each aerosol obtained in Preparation Examples 6, 7, and 13 was tested by the aerosol test method (Soap and Chemical Specialities, Blue Book, 1965) using a (6 ft)3 Peet Grady's chamber. As a result, with any areosol, more than 80 % of the flies could be knocked down 15 minutes after spraying, and more than 70 % of the flies could be killed by the next day.

Test Example 6 About 50 northern house mosquito female adults (Culexpipienspallens) were liberated in a (70 cm)3 glass chamber in which a batter-type small electric fan (wing diameter, 13 cm) was placed and driven.

0.1 Gram of each of the mosquitor coils obtained in Preparation Example 8 was ignited at one end and placed at the center of the bottom of the chamber. With any mosquito coil, more than 90 % of the adults could be knocked down within 20 minutes, and more than 80 % of the adults could be killed by the next day.

Test Example 7 About 50 housefly adults (Musca domestica) were liberated in a (70 cm)3 glass chamber in which a battery-type small electric fan (wing diameter, 13 cm) was placed and driven.

The heating fumigant obtained in Preparation Example 9 was placed on a hot plate in the chamber and fumigated. More than 90 % of the adults could be knocked down within 20 minutes.

Test Example 8 About 20 rice seedlings were grown up to a 3-to 4-leaf stage in a flower pot of 10cm in diameter, and the dust obtained in Preparation Example 11 was dusted at a rate of 3 kg/10 are by means of a Bel jar duster.

After dusting, the pot was covered with a wire net, and 20 to 30 green rice leafhopper adults (Nephotettix cincticeps) were libereated therein. The dead and alive after 24 hours were observed, and as a result the mortality was more than 80 oil.

Test Example 9 Ten liters of water was placed in a 14-liter polypropylene bucket, and 1 g of each fo the granules obtained in Preparation Example 12 was added thereto. After one day, about 100 full grown larvae of northern house mosquito (Culex pipiens pollens) were liberated in the water. The dead and alive were observed, and as a result more than 90 % of the larvae could be killed within 24 hours in any case.

Claims (8)

1. Acompound oftheformula:

wherein Xis a chlorine, bromine or fluorine atom.

2. (+ )-2-Methyl-3-2'-propynyl-cyclopent-2-en-4-on-l-yl (+ )-2,2-dimethyl-3-cis,trans-2',2'-d i- chlorovinylcyclopyopanecarboxylate.

3. (+ )-2-Methyl-3-2'-propynyl-cyclopent-2-en-4-on-l-yl (+)-2,2-dimethyl-3-trans-2',2'- difl uorovinylcyclopropanecarboxylate.

4. (± )-2-Methyl-3-2'-propynyl-cyclopent-2-en-4-on-l-yl (+ )-2,2-dimethyl-3-cis.2',2'-dibromovinyl- cyclopropanecarboxylate.

5. A process for producing a compound as claimed in claim 1, which comprises reacting a carboxylic acid oftheformula (II),

wherein X is as defined in claim 1, or a reactive derivative thereof, with an alcohol of the formula (III'),

or a reactive derivative thereof.

6. A process according to claim 5 substantially as described with reference to any one of Examples 1 to 6.

7. An insecticidal composition which comprises as an active ingredient an insecticidally effective amount of a compound as claimed in any one of claims 1 to 4, and an inert carrier.

8. A method for controlling an insect which comprises applying to the insect an insecticidally effective amount of a compound as claimed in any one of claims 1 to 4.