IL28102A - Alkynyl phosphonate synergists for insecticidal chrysanthemumates - Google Patents

Description

ALKY YL PHOSPHONATE SYNERGISTS FOR INSECTICIDAL CHRYSANTHEMUMATES m 'j>9 ni¾»ya tmacna 'a» ^s maiam This invention relates to novel compositions for the control of insects and acarids and in particular to such pesticidal compositions containing pyrethrins, allethrin, or related insecticidal cyclopropanecarboxylic acid esters, in combination with certain mono(alkyl or alkenyl )mono-uu-alkynyl aryl- and aralkylphosphonates as synergists for insecticidal activity.

Among the most widely used insecticides today are the pyrethrins, the active principle of pyrethrum flowers ( Chrysanthemum cinerariaef lium) , which have a high order of insecticidal activity and a low mammalian toxicity. The relatively high cost and the uncertain supply of pyrethrins have encouraged attempts to prepare synthetic insecticides which retain the desirable properties of pyrethrins. It has long been known that synthetic products having a basic structural similarity to pyrethrins in that they are esters of 2, 2-dimethyl-3-(2-methylpropenyl)cyclopropanecarboxylic acid (which is also known as chrysanthemumic acid and will be so referred to herein) exhibit insecticidal activity of a significant order.

The wide market which pyrethrins and related synthetic insecticides enjoy today is due primarily to the discovery of certain additives which enhance the activity of these insecticides. These additives, commonly called synergists, are agents which may or may not themselves exhibit insecticidal activity, but which when combined with pyrethrins or related compounds produce new insecticides, having an effectiveness significantly greater than the sum of the effectiveness of the components when used separately. A great deal of time and effort has been devoted to the search for effective synergists. One of the most effectively and most widely used of the pyrethrins synergists is the compound piperonyl butoxide, which is described in synergistic combination with pyrethrins in Wachs U. S. Patent 2, 550, 737.

Unfortunately, it has been found that many compounds which are excellent synergists for pyrethrins are not nearly as effective when used with allethrin or other synthetic cyclo-propanecarboxylic acid esters.

It has now been found that chemical compounds of the class of certain mono(alkyl) or alkenyl)mono- ^alkynyl aryl-and aralkylphosphonates are effective synergists for the insecticidal activity of esters of cyclopropanecarboxylic acids such as the chrysanthemumates. These synergistic phosphonates have the structural formula: wherein j is an alkyl or alkenyl group of fromone to about twenty carbon atoms, straight or branched chain; R2 is an alkylene group of one to six carbon atoms, straight or branched chain; R is hydrogen or methyl; n is an integer from 0 to 3 inclusive; Ar is a phenyl, or, thienyl, radical; Y is halogen; m is an integer from 0 to 2 inclusive. When n is 2 or 3, the R groups may be the same or different. Similarly, when m is 2, the Y groups may be the same or different.

Particularly preferred are those compounds represented by the following formulae: wherein Ra. is an alkyl or alkenyl group of from one to about six carbon atoms; Ra is an alkylene group of from one to four carbon atoms; Y is chlorine or fluorine; and m is an integer from 0 to 2 inclusive.

Of the natural and synthetic esters of cyclopropanecar-boxylic acids the best known members , preferred for use herein because of their general insecticidal activity and availability, are the esters of "chrysanthemumic acid, which have the general structure: and wherein the radical Ri can be any of the very large number of radicals which have been found to form insecticidal chrysanthemumates . For example, this class of esters includes the pyrethrins, allethrin (5-allyl-2-methyl-4-oxo-2-cyclopentenyl chrysanthemumate ) and related insecticides as described by Schechter and La Forge in U. S. Patent 2,661,374; cyclethrin (3-(2-cyclopentenyl)-2-methyl-4-oxo-2-cyclopentenyl chrysanthemumate) as described by Guest and Stansbury in U. S. Patent 2,891,888; furethrin ( furfuryl- -methyl-4-oxo-2-cyclopentenyl chrysanthemumate ) as descri¬ 230 bed in National Distillers Products British Patent 678,3 $; barthrin (6-chloropiperonyl chrysanthemumate) and its bromo analog, as described by Barthel et al in U. S. Patent 2,886,485; dimethrin (2,4-dimethylbenzyl chrysanthemumate) and the 5,4-dimethyl isomer, as described by Barthel in U. S. Patent 2,857.»309; compounds of the classes of (cyclo-hexene-l,2-dicarboximido )methyl chrysanthemumates as described In Belgian Patent 646,399 and cyclohexadiene-1,2-dicarboximido chrysanthemumates as described in Belgian Patent 651*737* both to the Sumitomo Chemical Company, Ltd.; and related compounds such as phthalimidoalkyl and substituted phthalimidoalkyl chrysanthemumates as described in Sumitomo Belgian Patent 63 *902. Other insecticidal esters of chrysanthemumic acid also form synergistic combinations with the phosphonates of this invention.

The preparation of the phosphonates of this invention and their synergistic insecticidal properties are illustrated in the following examples, which are not intended to be limitative of the variety of procedures which are applicable to the synthesis of mono(alkyl or alkenyl) mono-uu-alkynyl phosphonates , or of the many insecticidal combinations in which they are effective. In these examples, all temperatures are in degrees centigrade.

EXAMPLE 1 Preparation of Butyl 3-Butynyl Phenylphosphonate The starting material, butyl phenylphosphonochlori-date, was prepared from dichlorophenylphosphine as follows: To a cold, stirred solution of 30.0 g of butanol and 4l„4 g of triethylamine in about 300 ml of ethyl ether was added dropwise a solution of 34.6 g of dichlorophenylphosphine in about 200 ml of ethyl ether while the temperature was maintained below 0°. When addition was completed, the mixture was allowed to warm to room temperature . Stirring was continued overnight. The mixture was filtered, and the filtrate was concentrated under reduced pressure. The residual oil was distilled under reduced pressure to give 39.5 g of dlbutyl phenylphosphonite , b.p. l20-131°/ca 1.0 mm. Chlorine gas was bubbled into 38. g of dibutyl phenylphosphonite for about three hours. The mixture was warmed to 50° under aspirator vacuum to remove butyl chloride, the residual colorless oil was dissolved in 100 ml of benzene, washed with 1 sodium hydroxide and with water, dried over magnesium sulfate, and the dried solution concentrated under reduced pressure to give 30.6 g of pale yellow butyl phenylphosphonochloridate .

A solution of 15.6 g of butyl phenylphosphonochloridate in 15 ml of benzene was added dropwise with stirring to a cold solution of 5.2 g of 3-butyn-l-ol and 7.5 g of tri-ethylamine in 5 ml of benzene while the temperature of the mixture was kept below 10°. When addition was complete, the mixture was slowly warmed to approximately 50° at which temperature it was stirred for one hour, then allowed to stand overnight at room temperature . The mixture was filtered, and the filtrate was washed with dilute hydrochloric acid, dilute sodium hydroxide, and water. The washed filtrate was dried over magnesium sulfate and concentrated under reduced pressure. The residue was distilled under reduced pressure to give 10.1 g of colorless butyl 3-butynyl phenylphosphonate . The stem and pot temperatures were 91-106° and 130-l l° respectively with the pressure at 2 microns.

Analysis: Calc'd for C14H19O3P: C 6l. l; H 7.53; Found: C 6l.6l; H 7.55.

EXAMPLE 2 The Synergistic Activity of Butyl 3-Butynyl Phenylphosphonate The synergistic insecticidal activity of butyl 3-butynyl phenylphosphonate in combination with representative chrysan-themumates was determined by the following procedure: The test compound and the chrysanthemumate were dissolved in 0 parts by volume of acetone, which was then made up to 100 parts by volume by addition of water. A group of 30 to 40 houseflies (Musca Domestica L.), immobilized under carbon dioxide, was placed on a moist filter paper on a Buchner funnel attached to a vacuum source. Twenty-five ml of test solution was poured over the immobilized flies, this being sufficient volume that all flies were completely immersed. Vacuum was then applied to remove the test solution, and the flies were transferred to holding cages lined with absorbent paper.

Mortality counts were made after 24 hours. Results are shown in Table 1. In this and subsequent tables, the amounts of the test ingredients are stated in concentration terms of mg per 100 ml of test solution.

Table 1 Synergistic Compositions of Butyl 3-Butynyl Phenylphosphonate Mortality of Chrysanthemumate mg Synergist mg House Allethrin 10 50 100$ none 50 38$ none 3 (l-Cyclohexene-1,2- 10 0 100$ dicarboximido)methyl none 50 38$ chrysanthemumate 10 none 28$ The results in Table 1 illustrate the synergistic interaction of a phosphonate of this invention with two different synthetic chrysanthemumates .

EXAMPLE The synergistic activity of butyl 3-butynyl phenyl-phosphonate with a variety of chrysanthemumate esters was evaluated against house lies by the following procedure: About one microliter of a solution containing the indicated amount of the test materials in 100 ml of acetone was applied topically to each of 35 to 5 three- to four-day-old house-flies in one to four replicates. After 24 hours the mortality was determined by physical counting of the dead and living flies , and the percent kill was calculated. Results are shown in Table 2.

Table 2 Compositions of Butyl 3-Butynyl Phenylphosphonate and Chrysanthemumates Mortality of Chrysanthemumate mg Synergist mg Housefl: Allethrin Pyrethrins 14.4 72 82 none 72 14.4 none 8 ( l-Cyclohexene-1,2 14.4 72 100$ dicarboximido )methyl none 72 2$ chrysanthemumate 14.4 none 1 The results shown in Table 2 are illustrative of the eral synergistic interaction between an alkyl uu-alkynyl phenylphosphonate of this invention and chrysanthemumates . Even at dosages of 72 mg this phosphonate itself was essentially inactive, yet a consistent and substantial synergistic effect was observed in combinations with chrysanthemumates which themselves produced negligible kill of houseflies under these test conditions.

EXAMPLE Preparation of Propyl 2-Propynyl Phenylphosphonate Propyl phenylphosphinate used in the preparation of this synergist was prepared by the method of Kosolapoff, J.A.C.S.72, 292 (1950). Phenylphosphonous dichloride, 126.1 g, was added dropwise with stirring and cooling to 127 g propyl alcohol over a period of 30 minutes. The reaction mixture was allowed to warm to room temperature.

After stirring at room temperature for two hours, the re-action mixture was warmed to 40-50° and stirred for one hour. Excess propyl alcohol was removed under reduced pressure (hot water bath), and the residual oil was vacuum distilled. The major cut, propyl phenylphosphinate, boiled at 103° at 3 mm. Hg. ng5 1.51 0. The total yield was 88 g of clear, colorless oil, identified by infrared spectral analysis.

A solution of 10.8 g propyl phenylphosphinate in 0 ml benzene was added dropwise to a chilled, stirred solution of 3.7 g 2-propyn-l-ol, 12.8 g bromotrichloromethane, and 7.1 g triethylamine in 100 ml benzene. During this addition the temperature was kept below 35° . When addition was complete, the reaction mixture was warmed to room temperature, and stirring was continued for 15 hours. Precipitated triethylammonium bromide was removed by filtration and the filtrate washed successively with dilute hydrochloric acid, dilute sodium hydroxide, and water. The washed organic layer was dried over magnesium sulfate, and after removal of the drying agent, stripped of solvent under reduced pressure, leaving 13.1 g of light yellow oil. The product was distilled (diffusion) with a bath temperature of 109-118° at Ο.ΐμ Hg. giving 10.4 g of propyl 2-propynyl phenylphosphonate as a clear, colorless oil.

Analysis: Calc'd for Ci2Hi503P: 0 60.50; H 6.35; E 13.00 Found: C 60.52; H 6.53; P 13.15 EXAMPLE 5 The Synergistic Activity of Propyl 2-Propynyl Phenylphos- phonate The synergistic insecticidal activity of propyl 2-propynyl phenylphosphonate in combination with allethrin, pyrethrins, and ( 1-cyclohexene-l,2-dicarboximido )methyl chrysanthemumate was determined by the test procedure of Example 2. Results are shown in Table 3.

Table 3 Compositions of Propyl 2-Propynyl Phenylphosphonate and Chrysanthemumates Mortality of Chrysanthemumate mg Synergist mg Houseflies Allethrin 10 50 100 none 50 0 none 8$ Pyrethrins 10 50 100 none 50 0 none 3$ (l-Cyclohexene-1,2- 10 50 100$ dicarboximido )methyl none 50 0 chrysanthemumate 10 none 12$ Table 3 shows that propyl 2-propynyl phenylphosphonate, itself inactive at the dosage used, is an effective synergist for a variety of chrysanthemumates .

EXAMPLE 6 The synergistic activity of propyl 2-propynyl phenylphosphonate with a variety of chrysanthemumate esters against houseflies was further demonstrated using the test procedure of Example 3. Results are shown in Table 4.

Table 4 Compositions of Propyl 2-Propynyl Phenylphosphonat and Chrysanthemumates Mortality of Chrysanthemumate mg Synergist mg Houseflies Allethrin 14.4 72 71¾ none 72 14.4 none 10 Pyrethrins ( l-Cyclohexene-1,2- 14.4 72 100 dicarboximido )methyl none 72 4 chrysanthemumate 14.4 none 7 EXAMPLE 7 Preparation of Ethyl 4-Pentynyl Phenylphosphonate Following the procedure described in Example 1, 5.85 g 4-pentyn-l-ol was reacted with 11.3 g ethyl phenylphos-phonochloridate The final product, ethyl 4-pentynyl phenylphosphonate, distilled (diffusion system) at a bath temperature of 120-130° at 0.1 mm Hg.

Analysis: 'Calc'd for C13H17O3P: C 61.90; H 6.79; P 12.28 Found: C 61.65; H 7.04; P 12.17 EXAMPLE 8 Preparation of n-Butyl 3-Butynyl 2-Thienylphosphonate Following the procedure described in Example 4, 4.0 g of 3- utyn-l-ol was reacted with 10.3 g of n-butyl 2-thienylphosphinate . The product, n-butyl 3-hutynyl 2-thienylphosphonate, was distilled in short path diffusion apparatus at 0.5μ Hg. with a pot temperature of 128-140°.

Analysis: Calc'd for C12H17O3PS: C 52.93; H 6.29; p 11.37 Found : C 53.22; H 6.46; P 11.48 EXAMPLE 9 Preparation of n-Octadecyl 5-Butynyl Phenylphosphonate Following the procedure of Example 4, 12.6 g 3-butynyl phenylphosphinate was reacted with 17.4 g n-octadecanol .

The product, n-octadecyl 3-butynyl phenylphosphonate, re-crystallized from hexane, was a waxy solid, partially molten at room temperature.

Analysis: Calc'd for Cj»H4703P: C 2.69 H 10.24; P 6.69 Found: C 72.74; H 10.53; P 6.58 EXAMPLES 10 TO 27 Following the general procedures exemplified above, a large number of compounds of this class are readily synthesized. The synergistic activity of typical phosphonates of this invention, in combination with typical and useful chrysanthemumates, is further illustrated in Table 5.

These results were obtained following the procedure described in Example 2.

Table 5 Synergistic Insecticidal Compositions Mortality Chrysanthemumate mg Phosphonate mg of Houseflie (l-Cyclohexene-1,2- 10 Methyl 2-propynyl 50 100 dicarboximido )methyl none phenylphosphonate 50 0 chrysanthemumate 10 none 11$ Pyrethrins 10 Methyl 3-butynyl 50 100$ none pheny1phosphonate 50 20$ none 3$ Allethrin 10 Ethyl 3-butynyl 50 100$ none phenylphosphonate 50 36$ none 8$ Allethrin 10 Ethyl 4-pentynyl 50 79$ none phenylphosphonate 50 0 none 8$ Table 5. (continued) Mortality Chrysanthemumate mg Phosphonate mg of Housefl Pyrethrins 10 Ethyl 3-butynyl 50 100 none benzylphosphonate 50 7$ none 3$ Pyrethrins 10 Ethyl 4-pentynyl 50 100$ none benzylphosphonate 50 38$ none 3$ Allethrin 10 Ethyl 3-butynyl 50 100$ none 4-fluorobenzyl- 50 8$ phosphonate none 8$ ( l-Cyclohexene-1,2- 10 n-Propyl 3-butynyl 50 100$ dicarboximido )methyl none phenylphosphonate 50 12$ chrysanthemumate 10 none 12$ Pyrethrins 10 n-Propyl 4- 50 100$ none pentynyl phenyl50 3$ phosphonate none 3$ Allethrin 10 i-Propyl 2- 50 100$ none propynyl phenyl50 0 phosphonate none 33$ ( 1-Cyclohexene-l , 2- 10 2-Propenyl 2- 50 100$ dicarboximido )methyl none propynyl phenyl50 3$ chrysanthemumate 10 phosphonate none 11$ Pyrethrins 10 2-Propenyl 3- 50 95$ none butynyl phenyl50 0 phosphonate none ii (l-Cyclohexene-1,2- 10 n-Butyl 3-butynyl 50 100$ dicarboximido )methyl none 2-thienylphosphon- 50 26$ chrysanthemumate 10 ate none 24$ (l-Cyclohexene-1 , 2- 10 n-Pentyl 2- 50 100$ dicarboximido )methyl none propynyl phenyl50 19$ chrysanthemumate 10 phosphonate none 28$ Allethrin 10 n-Pentyl 3-butynyl 50 100$ none phenylphosphonate 50 0 none 39$ ( l-Cyclohexene-1,2- 10 n-Pentyl 4- 50 100$ dicarboximido )methyl none pentynyl phenyl50 0 chrysanthemumate 10 phosphonate none 28$ Allethrin 10 n-Dodecyl 3- 50 84$ none : butynyl phenyl50 3$ phosphonate none 33$ Allethrin 10 n-0ctadecyl 3- 50 93$ none butynyl phenyl50 10$ EXAMPLE 28 The synergistic activity of the phosphonates of this invention with chrysanthemumates over a wide range of chrysanthemumate to synergist ratios was demonstrated "by a series of tests carried out by the method described in Example 2. Results for two different chrysanthemumate-synergist combinations are shown in Table 6.

Table 6 Compositions With Different Chrysanthemumate to Synergist Ratios Ratio Mortality of themumate{A ) trig. Synergist (B) A :B Houseflies ComposiComposition I tion II none 9$ 13$ 10 1:2 83$ 61$ 25 1:5 100 78$ 50 1:10 100$ 97$ 100 1:20 100$ 100$ 250 1:50 100$ 100$ none 100 - 8$ 23 none 250 - 3$ 41$ Composition I: Chrysanthemumate - ( l-cyclohexene-l,2-di- carboximido )methyl chrysanthemumate Synergist- propyl 2-propynyl phenyl- phosphonate Composition II: Chrysanthemumate - allethrin Synergist- butyl 3-but nyl phenyl- phosphonate The results in Table 6 illustrate the marked synergistic interaction found over a wide range of ratios.

EXAMPLE 29 The effectiveness of the synergistic compositions of this invention is strikingly shown in aerosol formulations, as illustrated in the following example: Aerosol formulations were prepared containing a typical insecticidal chrysanthemumate, both with and without the synergist, in this example butyl 3-butynyl phenylphosphonate, as follows: With Without Synergist Synergist ( 1-Cyclohexene-l,2-di- carboximido)methyl chrysanthemumate (90 active) 0.140 g 0.l4o g Butyl 3-butynyl phenylphosphonate Ο.625 g none Heavy aromatic naphtha 6.00 g 6.00 g Purified kerosene 3. g 3.86 g Trichloromonofluoromethane 20.00 g 20.00 g Dichlorodifluoromethane 20.00 g 20.00 g A group of 200 to 300 houseflles was introduced into a 216 cu. ft. test chamber, prepared according to the specifications of the Chemical Specialties Manufacturers Association (Soap and Chemical Specialties, I96I Blue Book, p. 244). Measured amounts of the aerosol formulations were introduced into the chamber. Results, shown in Table 7, are the a er-ages of nine replicates for the composition containing the synergist and of two replicates for the composition containing the chrysanthemumate alone.

Table 7 Aerosol Formulations Average Dose Knockdown Mortality Composition (g/lOOO ft? ) 15 minutes 24 hours With Synergist 5.15 g 84 71$ Without Synergist 2.92 g 8 $ 14$ It is of particular interest to note that butyl 3-tmtynyl phenylphosphonate enhanced to a marked extent the percent kill obtained with this chrysanthemumate, which by itself exhibited excellent knockdown of houseflies, but very poor . permanent effectiveness.

In addition to the specific phosphonates exemplified herein, similar synergistic behavior characterizes the other members of the class described, including but not limited to the following: 1-Ethylbutyl 5-hexynyl ( 4-chlorobenzyl)phosphonate; methyl l-methyl-3-butynyl ( 3-chlorobenzyl )phosphonate i-propyl 3-butynyl ( 4-bromo-benzyl)phosphonate; 2-pentenyl 1, l-dimethyl-3-t>utynyl benzylphosphonate ; 2 , 4-dimethylpentyl 3-t>utynyl (l-phenyj-propyl )phosphonate j 2-propenyl 2-ethyl-3-butynyl (2-phenyl-propyl )phosphonate ; 2-methylbutyl 3-b'utynyl ( 4-iodobenzyl ) phosphonate; methyl 3-Tnethyl- -pentynyl ( 2 , 3-dichloro- ye/44n U t> bttcW iMiUk n-propyl ( 2-methyl-3-butynyl) (3-fluorobenzyl)phosphonatej iH l ' &-l hittyifll (£l-bbMiI j3l)-l I n-hexyl l-ethyl-2-propynyl ( 4-chlorobenzyl)phosphonate; and the like .

The novel synergists of this invention may be prepared by adaptation of the synthetic procedures illustrated above, i.e., from suitable phosphonochloridates or phos-phinates as well as by other known procedures. These procedures are well described in the chemical literature, for example by Kosalopoff, J.A.C.S. 72 , 92 ( 1950 ) ; Hudson et al. J. Chem. Soc., 1859 ( i960 ) ; Harman et al, U. S.Patent 2,659,714; Ben ov et al. J. Chem. Soc, 4750 (196 ); and Cherbuliez et al. Helv. Chlm. Acta, 46, 2464 (1965).

The novel synergists described herein have a degree of effectiveness not shared by certain closely related compounds. The nature and location of the unsaturated linkage has been found to have a marked effect on the synergistic effectiveness of this class of compounds. For example, reduction of the acetylenic linkage to an olefinic or a saturated linkage diminishes the synergistic activity.

Displacement of the acetylenic linkage from the terminal position also decreases the activity.

The synergistic compositions of this invention may be employed to control a variety of crop pests and household pests. These compositions are not usually applied full strength, but are generally incorporated with the adjuvants and carriers normally employed for facilitating dispersion of active ingredients for insecticidal applications, recognizing the accepted fact that the formulation and mode of application may affect the activity of a material. Striking results are obtained when these compositions are applied as space sprays and aerosol sprays, for example, or are formulated into any of the diluted and extended types of formulations used in insecticidal practice, including dusts, wettable powders, emulsifiable concentrates, solutions, granulars, baits, and the like, for application to foliage, within enclosed areas, to surfaces, and wherever insect control is desired.

These synergistic compositions may be made into liquid concentrates by solution or emulsification in suitable liquids, and into solid concentrates by admixing the active components with talc, clays , and other solid carriers used in the insecticide art. Such concentrates normally contain about 5-80 of the toxic composition, and the rest inert material which includes dispersing- agents , emulsifying agentsj and wetting agents. For practical application, the concentrates are normally diluted with water or other liquid for liquid sprays, with liquefied propellants for aerosols, or with additional solid carrier for application as a dust or granular formulation. Baits , are usually prepared "by mixing such concentrates with a suitable insect food, such as mixtures of cornmeal and sugar, and insect attractants may also be present. The concentration of the active ingredients in the diluted formulations, as generally applied for control of insects, is normally in the range of about 0.001$ to about 5 . Many variations of spraying and dusting compositions are well known in the art, as are the techniques for formulating and applying these compositions.

Employing the synergistic pesticidal compositions described herein, enhanced control is obtained of both crop and household pests, including insects and acarids against which the cyclopropanecarboxylates are themselves effective, but at higher concentrations. This includes flying and crawling pests of the orders Coleoptera (beetles), Hemiptera (true bugs), Homoptera (aphids), Diptera (flies), Orthoptera (roaches), Acarina (mites and ticks), and Lepidoptera (butterflies and moths including their larvae). Because of the low mammalian toxicity of these compositions, they are preferred compositions for use in control of pests in an environment inhabited by man and animals, including control of flies, mosquitoes, ants, roaches, moths, ticks, and the like, as well as in uses such as packaging, food and grain protection, and garden, pet, and livestock uses.

The relative amounts of synergist and chrysanthemumate employed are not critical, in that a relatively minor amount, e.g., less than one part of synergist per part of chrysanthemumate, is effective in imparting a "beneficial effect to the combination. Prom practical considerations, it is preferred to use larger amounts of synergist, for example, from two to fifty parts of synergist per part of cyclopropanecarboxylate . Even larger proportions of synergist may be employed without detriment, whether or not the optimum synergistic proportions have been achieved. It is clear that effective amounts of synergist should be employed in the compositions, that the components should be present in synergistic proportions, and that effective amounts of the compositions, to control the particular insect pests in the environment of infestation, should be applied.

Claims (23)

28102/2

1. Compounds of the formula wherein Rj Is alkyl or alkenyl of one to twenty carbon atoms; R2 is alkylene of one to six carbon atoms; R is hydrogen or methyl; n is an integer of 0 to S inclusive; Ar radical; Y is halogen and m is an integer of O to 2 inclusive, When n is 2 or 3 the R groups may' be the same or different; when/^ft is 2 the Y groups may be the same or different.

2. Compounds of the formula wherein i is alkyl or alkenyl of one to six carbon atoms and R2 is alkylene of one to four carbon atoms.

3. The compound n- ropyl 2-propynyl phenylphos-phonate.

4. The compound n-butyl 3-butynyl phenylphosphonate.

5. The compound methyl 2-propynyl phenylphosphonate.

6. Pesticidal compositions comprising a combination of a chrysanthemumate and, in synergistic proportions therewith, compound of claim 1.

7. Pesticidal compositions comprising a combination ©f a chrysanthemumate and, in synergistic proportions therewith, a compound of claim 2.

8. Pesticidal compositions of claims 6 and 7 wherein said chrysanthemumate is allethrin.

9» Pesticidal compositions of claims 6 and 7 wherein said chrysanthemumate is pyrethrin^.

10. Besticidal compositions of claims 6 and 7 wherein said chrysanthemumate is (1-cyclohexene-l, 2-dicarboximido)-methyl 2, 2-dimethyl-3-(2-methyl-l-pr©penyl)cycl©propanecarboxylate.

11. The method of controlling insect and acarid pests which comprises applying thereto an effective amount of a composition comprising a chrysanthemumate and, in synergistic proportions therewith, a compound of claim 1,

12. The method of controlling insect and acarid pests which comprises applying thereto an effective amount of a composition comprising a chrysanthemumate and, in synergistic proportions therewith, a compound of claim 2.

13. A method of enhancing the insecticidal and acarididal properties of a chrysanthemumate by incorporating in a composition containing said chrysanthemumate a synergistic proportion ©f a compound ©f claim J.

14. A method of enhancing the insecticidal and acaricidal properties of a chrysanthemumate by incorporating in a composition containing said chrysanthemumate a synergistic proportion ©f a compound ©f claim 2.

15. A process for preparing a synergistic insecticidal and acaricidal compound ©f claim ¾. characterized in that a phosphon©- chloridate of the formula wherein Z is chlorine or bromine and Rj, R, Y, n, m , and Ar are as defined in Claim 1, is reacted with an alkynol of the formula HC≤.C-R2 -OH wherein 2 is as defined in Claim 1 or a salt thereof.

16. A process for preparing a synergistic insecticidal and acaricidal compound of the formula wherein Rj is alkyl or alkenyl of one to six carbon atoms and R2 is alkylene of one to four carbon atoms, characterized in that a phosph halidate of the formula wherein Z is chlorine orl bromine and Rj is as defined above, is reacted with an alkynol of the formula HC=C-R -OH wherein 2 is as defined above, or a salt thereof, to form a synergistic insecticidal and acaricidal compound of the formula shown above.

17. A process for preparing a synergistic insecticidal and acaricidal compound of claim 1, characterized in that a hydrogen phosphinate of the formulate wherein R^, R, Ar, Y, n and m are as defined in claim 1 is reacted with an alkynol of the formula HCsC-R2-OH wherein Rg is as defined in claim 1, in the presence of tri- chloromethyl^romide or carbon tetrachloride and a strong base.

18. A process for preparing a synergistic insecticidal and acaricidal compound of claim 2, characterized in that a hydrogen phosphinate of the formula wherein R^ is as defined in Claim 2, is reacted with an alkynol of the formula HCSC-R2-OH wherein 2 is as defined in Claim 2, in the presence of trichloro- methy] bromide or carbon tetrachloride and a strong base.

19. Synergistic insecticidal and acaricidal. compounds according to claims 1 -5 substantially as hereinbefore described.

20. Pesticidal compositions according to claims 6-10 substantially as hereinbefore described.

21. A method of controlling insect and acarid pests according to claims 11 and 12 substantially as hereinbefore described.

22. A method of enhancing the insecticidal and acaricidal properties of a chrysanthemumate according to claims 13 and 14, substantially as hereinbefore described.

23. A process for preparing a synergistic insecticidal and acari