US2431844A - Pyrethrin synergist - Google Patents

Description

Patented Dec. 2, 1947 UNITED STATES PATENT OFFICE PYRETHRIN SYNERGIST Martin E. Synerholm, Hastings on Hudson, N. Y., assignor to Boyce Thompson Institute for Plant Research, Inc., a corporation of New York No Drawing. Application August a, 1944, Serial No. 547.982

3 Claims. (Cl. 167-24) those comprising pyrethrin, or the like, are very efiicient in combating insect pests, such as flies, moths, or mosquitoes.

I have discovered a class of esters of piperic acid, prepared by known methods of esterification, and having the formulae where R is represented by a radical of the group consisting of ethyl, n-propyl, isopropyl, n-butyl, allyl, benzyl, cinnamyl, and tetrahydrofuriuryl, which'are suitable for insecticidal purposes. The com unds are exceptional synergistic agents in compositions comprising pyrethrin in a spray medium, advantageously in a mutual solvent. Spray compositions comprising one or more of the compounds and pyrethrin in a hydrocarbon or mineral oil, such as odorless kerosene or naphtha are especially effective insecticides.

The aforementioned compounds increase the toxic effect of pyrethrin to a very marked extent and when they are incorporated in a suitable spraying medium with pyrethrin or like extracts the resulting composition has more killing effect against such insects as the ordinary housefly than the combined eifects of the pyrethrin and the compound when used alone. The invention provides an improved insecticidal composition comprising one or more piperic acid esters of the group consisting of where R. is a radical of the group consisting of ethyl, n-propyl, iso-propyl, n-butyl, allyl, benzyl, cinnamyl. and tetrahydrofurfuryl, and pyrethrin in a liquid spray medium, for example, of hydrocarbon character. such as odorless kerosene or naphtha.

The synergistic effect of the compounds is shown in the following table in which the results were obtained by the Standard Feet-Grady metha 2 ad with five-day old flies as described on pages 92 to 98 of Pyrethrum Flowers by C. B. Gnadinger, 1936 edition, with compositions comprising compounds represented by the formulae in which the various compounds are identified by the radical R, and 0.025 gm. pyrethrins per 100 ml. of odorless kerosene:

O'II Ad] 1? Grams per Per Cent at R 100 ml. Kill g? Ethyl 0.5 91 50 0.25 68 46 B-Bromoethyl 0.5 87 5c 82 n-Propyl 0. 5 98 76 0.25 91 58 86 0.125 77 56 72 Iso-propyl 0. 5 100 58 98 0. 125 65 51 65 .B 1 2'3 8% i8 romoiso to y p p 0.5 92 47 93 0. 25 84 46 85 0. 05 38 46 43 o-Chlorophenyl I 0. l 63 46 65 0.05 62 41 47 n-Butyl 0. 5 98 68 94 0.25 94 68 '85 0.125 90 68 79 2-nitroisobutyl 0.5 60 36 73 0. 25 71 47 73 n-Amyl 0.5 95 72 0.25 81* 53 Ally] 1.0 93 5 it 2% 0.25 35 0.1 44 50 0.05 32 46 Cinnamyl 1.0 65 47 0.25 66 56 Benzyl 0.5 95 58 0.25 82 56 Tetrahydroiuriuryl. 0. 25 94 58 0. 06 66 5s Bornyl 1.0 97 49 0.5 79 47 Compounds used without pyrethrins Grams Per Per Cent OTI Adjusted R per m0 Ccnt Knock Per Cent Per Cent ml. Kill down Kill Kill o-Chlorophenyl 0. 05 0 70 40 0 Allyl 0.1 22 91 51 21 Tetrahydrofurfuryl 0. 1 17 90 46 19 I claim:

1. An insecticidal composition comprising pys'sasssesasaess rethrin and a compound represented by the formulae REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Gertler et al Aug. 10, 1943 OTHER REFERENCES Number Beilstein, 1934, 4th ed., vol. 19, page 282. (Copy in Scientific Lib.)

Harvill et al., Contributions from Boyce Thompson Institute, vol. 13, No. 2, 1943, pgs. 87 to 91.

Roark, Chemical and Engineering News; Sept. 10, 1944, pg. 1467. (Copy in Lib.)