- Chiral stability of synthetic pyrethroid insecticides
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Synthetic pyrethroids are chiral compounds consisting of multiple stereoisomers. Evaluation of enantioselectivity in environmental fate and ecotoxicity requires analytical methods that preserve stereoisomer integrity during analysis. In this study, we characterized the stability of stereoisomers from four commonly used pyrethroids, cis-bifenthrin (cis-BF), permethrin (PM), cypermethrin (CP), and cyfluthrin (CF), during gas chromatography (GC) analysis and sample preparation. Stereoisomers of cis-BF and PM were found to be stable, but those of CP and CF were unstable, under heat or in water. Isomer conversion occurred only at the aC in CP or CF, causing the analyte stereoisomer to convert to an epimer. At a GC inlet temperature of 260°C, about 9% conversion occurred for CP and CF. In organic solvents and sterile water, stereoisomers of cis-BF and PM were stable, but slow isomer conversion was observed for CP and CF in water at ambient temperature. However, isomer conversion for CP and CF was relatively insignificant (2-3%) when the GC inlet temperature was kept at ≤ 180°C or when on-column injection was used. Isomer conversion at the αC in water suggests that abiotic processes may also contribute to enantioselectivity observed in the environment for pyrethroids with the asymmetric αC.
- Liu, Weiping,Qin, Sujie,Gan, Jianying
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p. 3814 - 3820
(2007/10/03)
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- Secondary battery with a radical compound active material
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A radical compound may be used as an active material for an anode layer 2 to provide a novel stable secondary battery with a higher energy density and a larger capacity. The radical compound used has, for example, a spin concentration of 1021 spins/g or more.
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- Wood preservatives
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Wood preservatives having biocidal properties which include quaternary ammonium compounds of general formula (I): wherein R1 is a C8-18-alkyl group or an optionally substituted benzyl group, R2 is a C8-18-alkyl group, R3 is a C1-4-alkyl group or a group of the formula —[CH2—CH2—O]n—H, R4 is a C1-4-alkyl group, n is a number from 0.5 to 8, preferably from 1 to 5, and A?is the anion of an organic carboxylic acid which contains 2 to 12 C atoms and carries at least one hydroxyl, amino or sulfonic acid group. The wood preservatives also penetrate deeply into the wood without the use of pressure, and have only a mild corrosive action on metals. Furthermore, a process for treating timbers with these compositions, concentrates for the preparation thereof, the use of new and known quaternary ammonium compounds in wood preservatives and new quaternary ammonium compounds and their use as biocides.
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- Fungicidal active compound combinations
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The present application relates to new active compound combinations composed, on the one hand, of prior art compounds metaconazole, 5-[(4-chlorophenyl)methyl]-2,2-dimethyl-1-(1H-1,2,4-triazol-1-yl-methyl)cyclopentanol and imidacloprid, 1-[(6-chloro-3-pyridinyl)-methyl]-4,5-dihydro-N-nitro-1H-imidazole-2-amine, and, on the other hand, of other prior-art active compounds, the combinations being extremely suitable for the protection of wood products.
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- Anti-fouling compositions
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An anti-fouling composition comprising a carrier, and a binder, the improvement which comprises an effective amount of at least one insecticide. The composition is applied to the surfaces of articles which come into contact with seawater or brackish water, especially wood. Other conventional anti-fouling agents may also be present.
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- Para-hydroxyphenylacetic acid for reducing the repellency of insecticides
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The present invention relates to the new use of p-hydroxyphenylacetic acid, by itself or in a mixture with other chemical compounds, for reducing the repellency of insecticides in the control of cockroaches, and to cockroach control compositions which comprise these mixtures, details being found in the description.
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- Methods and agents for combating cockroaches
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The present invention relates to the use of compounds of the general formula I STR1 in which R1 represents C1 -C5 -alkyl or hydroxy-C1 -C5 -alkyl; R2 represents C1 -C5 -alkyl; and m represents an integer from 10 to 20, for combating cockroaches.
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- Conversion of pyrethroid isomers to move active species
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Crystallizable pyrethroid isomers or enantiomer pairs are converted to more pesticidally active isomers by contacting a hydrocarbon slurry of the starting isomers with a base and a catalyst, the catalyst being substantially soluble in the slurry and selected from a quaternary ammonium compound, a quaternary phosphonium compound and a crown ether, agitating the slurry while maintaining a temperature effective for conversion, and recovering the resulting isomers. The tendency to form benzoin ester by-product is reduced by including in the slurry a weak base, an aldehyde scavenger such as a metabisulfite, and/or a tetraalkyl (C1 -C5) ammonium halide catalyst dissolved in an aprotic solvent such as an organic nitrile. The process typically is effective for enriching cypermethrin, cyfluthrin and (cyano (3-phenoxyphenyl)methyl 3-(2,2-dibromoethenyl)-2,2-dimethylcyclopropanecarboxylate in the more active species.
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- Long-acting pyrethrum/pyrethroid based pesticides with silicone stabilizers
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Pesticidal compositions based on nontoxic, naturally unstable insecticides (pyrethrum, synthetic pyrethroids and mixtures thereof) include a liquid alkyl aryl silicone polymer which stabilizes the insecticide to provide an extended effective killing life. The compositions additionally include a synergist to provide an immediate killing action and an antioxidant to protect the insecticide against destruction by oxygen. Ultraviolet protectants and insect repellents may also be included. Applications include control of insect pests to animals and plants and general purpose insect control. Exemplary formulations are given for compositions to be applied as sprays, dips, powdered or dusts, foggers and shampoos.
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- Baits for combating vermin
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An insecticidal bait comprising an insecticidally effective amount of (a) α-cyano-3-phenoxy-4-fluorobenzyl 2,2-dimethyl-3-(β,β-dichlorovinyl)-cyclopropanecarboxylate of the formula STR1 and (b) an insect attracting amount of at least one ingestion attractant. It may also contain additional insecticides, a grinding auxiliary, carrier, adhesive or swelling agent. Surprisingly the principal active ingredient does not repel insects, as do other pyrethroid-like insecticides in baits.
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- Oil-in-water emulsions, and their use
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Novel oil-in-water emulsions, which contain (a) 0.1 to 80% by weight of at least one sparingly water-soluble active compound (as herein defined) selected from agrochemical active compounds, active compounds for combating pests in the domestic field and hygiene field and/or pharmacologically active compounds, (b) 1 to 20% by weight of at least one alkylaryl polyglycol ether of the general formula STR1 wherein R1 represents a hydrogen atom or an alkyl group having 1 to 16 carbon atoms, R3 represents a hydrogen atom or a methyl group, m is 1, 2 or 3, and n is an integer from 10 to 50, if appropriate in a mixture with an alkylarylsulphonic acid salt of the general formula STR2 wherein R3 represents an alkyl group having 8 to 35 carbon atoms and Me≈ represents an alkali metal cation, an equivalent of an alkaline earth metal cation or a cation of the general formula STR3 wherein R', R", R'" and RIV independently of one another represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a hydroxyalkyl group having 1 to 4 carbon atoms, (c) water, (d) if necessary, 1 to 30% by weight of at least one poorly water-miscible organic solvent and/or a solubilizer, and (e) if appropriate 0.05 to 15% by weight of one or more additives, the sum of the components being 100% by weight in each case, a process for the preparation of these emulsions and their use in the field appropriate to the active compound.
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- Combating arthropods with stereoisomers of 2,2-dimethyl-3-(2,2-dichlorovinyl)-cyclopropane-1-carboxylic acid α-c
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An arthropodicidally active substantially pure stereoisomer of 2,2-dimethyl-3-(2,2-dichlorovinyl)-cyclopropane-1-carboxylic acid α-cyano-3-phenoxy-4-fluoro-benzyl ester of the formula STR1 selected from the group consisting of ester in which the asymmetric C atoms , , and α have the following configuration: ______________________________________ Absolute configuration at the centerIsomer 1 3 α______________________________________a R R Rb R R Sc R S Rd R S Se S S Sf S S Rg S R Sh S R R,______________________________________ and diastereomeric mixtures of (1R)-cis- and (1R)-trans-2,2-dimethyl-3-(2,2-dichlorovinyl)-cyclopropane-1-carboxylic acid (R,S)-α-cyano-3-phenoxy-4-fluoro-benzyl esters of the formula STR2
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