- Photodecarboxylation of cyanohydrin esters. Models for pyrethroid photodecomposition
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Benzyl esters in which the α position has been substituted with a cyano group give upon irradiation in either methanol or hexane products resulting from photoelimination of carbon dioxide. The relative amount of photoeliminated product formed is dependent upon intermediate free radical stability. The α substituted and unsubstituted esters examined may serve as models for photodecomposition studies of pyrethroid insecticide chemicals in organic solvents.
- Holmstead,Fullmer
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- Production method of fenvalerate
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The invention discloses a production method of fenvalerate. The production method comprises the following steps: (1) selecting a methyl oleate solvent, butyryl chloride, malathion, 3-phenoxybenzaldehyde, sodium cyanide, triethylamine (mole) and an emulsifier as raw materials, firstly adding sodium cyanide into a reaction kettle, and starting to cool till the temperature is 8 DEG C or below; (2) sequentially adding the methyl oleate solvent, butyryl chloride, malathion, 3-phenoxybenzaldehyde, sodium cyanide, molar triethylamine and the emulsifier into the reaction kettle in the step (1), then dropwise adding a stabilizing and antifreezing agent, starting reaction, controlling the reaction temperature to range from 5 DEG C below zero to 80 DEG C, and after adding, stirring and preserving heat for 2-4 h. The production method has the characteristics of high yield, high product purity, low cost, mild reaction condition, simple operation and the like, and is applicable to industrial production.
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Paragraph 0011-0019
(2017/10/05)
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- Method for fighting against arthropods destructive of crops and compositions therefor
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The present invention relates to processes for controlling arthropods, particularly processes for controlling insects and especially processes for controlling insects which ravage crops, particularly rice crops or market-garden crops; as well as to processes for protecting crops, particularly rice crops or market-garden crops; as well as to processes directed towards improving the yield of the treated crops; as well as to compositions or products which may be used in such processes.
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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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- Macrocyclic plant acaricides
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Compounds of the formula I STR1 in which either R is methyl and there is a double bond in the 9,10-position, or in which R is hydrogen and there is a single bond in the 9,10-position, are highly active against Acarina which damage plants.
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- Insecticidal resin coating film
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An insecticidal resin coating film comprising a combination of an acrylonitrile and/or methacrylonitrile copolymer resin and an insecticidal component selected from the group consisting of specified compounds exhibits an insecticidal effect, since the compound is kept on the surface of the coating film in a state capable of exhibiting its insecticidal effect for a long period of time.
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- Preparation of cyanomethyl esters
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Cyanomethyl esters are prepared by reacting a carboxylic acid halide with an alpha-hydroxynitrile, a molar excess of a hydrogen halide acceptor and a catalytic amount of a tertiary-aminopyridine or N-methylimidazole.
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- Process for preparation of an S-alpha-cyano S-alpha-isopropylphenylacetate
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A method of preparing an "A-alpha" single stereoisomer of an S-alpha-cyano-3-phenoxybenzyl S-alpha-isopropylphenylacetate by precipitation from a solution of an "alpha" diastereoisomer pair, S-alpha-cyano-3-phenoxybenzyl R,S-alpha-isopropylphenylacetate, and optional hydrolysis of the mother liquor and recycle of the components thereof. The phenylacetate "alpha" is prepared from the S-alpha-cyano-3-phenoxybenzyl alcohol and racemic alpha-isopropylphenylacetic acid or reactive derivative thereof.
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- Crystal of enantiomer pair of phenylacetic acid ester derivative and process for obtaining a mixture of stereoisomers of the derivative
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A crystal of an enantiomer pair of stereoisomers of α-cyano-3-phenoxybenzyl 2-(4-chlorophenyl)isovalerate (general name: fenvalerate) comprising (S)-α-cyano-3-phenoxybenzyl (S)-2-(4-chlorophenyl)isovalerate and an enantiomer thereof, which has the crystal characteristics as specified in the specification, is disclosed. A process for preparing the enantiomer pair or the fenvalerate rich in the enantiomer pair by depositing the above-described crystal from a solution of a racemate of fenvalerate is also disclosed. A process for preparing the enantiomer pair by depositing the crystal from a solution of the fenvalerate rich in the enantiomer pair is further disclosed.
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- Carboxamidoesters
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Esters of formula: STR1 wherein R is either (a) or a group of formula: STR2 where X is methyl, chlorine or bromine, or (b) a group of formula: STR3 where Y is methyl or chlorine and n is one or two, and R2 is alkyl or 2 to 4 carbon atoms; and R1 is phenoxy or 2,2-dichlorovinyloxy.
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- Method for preparing optically active carboxylic acid esters
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A method for preparing an optically active carboxylic acid ester of the formula (I): STR1 wherein X is a hydrogen atom or a fluorine atom, and * indicates an asymmetric carbon atom, which is an Aα-isomer having an (S)-configuration on both the acid and alcohol moieties, or rich in said Aα-isomer, which method comprises crystallizing said Aα-isomer from a solution of an A-isomer of the formula (I) having an (S)-configuration on the acid moiety in the presence of a crystal that is of substantially pure Aα-isomer and in the presence or absence of a basic catalyst.
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- Preparation of α-cyanobenzyl esters
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New α-halobenzyl esters, intermediates for α-cyanobenzyl pyrethroid esters, are prepared by treating a benzaldehyde derivative with a pyrethroid acid halide. The resulting α-halobenzyl ester is treated with a water-soluble compound capable of generating cyanide ions (CN-) to give the corresponding α-cyanobenzyl esters.
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- Preparation of esters
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Certain alpha-cyano esters are prepared by reacting an acyl halide with an aldehyde in a substantially water-immiscible aprotic solvent and an aqueous solution of water-soluble cyanide salt in the presence of an amine or cryptate rate-promoting agent.
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- Preparation of esters
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Certain alpha-cyano esters are prepared by reacting an acyl halide with an aldehyde in a substantially water-immiscible aprotic solvent and an aqueous solution of water-soluble cyanide salt in the presence of an amphoteric surfactant rate-promoting agent.
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- Process for the preparation of esters
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Novel esters in the form of their stereoisomers and mixtures of stereoisomers of the formula STR1 wherein X is selected from the group consisting of fluorine, chlorine and bromine R1 is selected from the group consisting of STR2 Y1 and Y2 may both be methyl and when Y1 is hydrogen, Y2 is selected from the group consisting of STR3 and Y3 and Y4 are individually selected from the group consisting of fluorine, bromine and chlorine or the group consisting of hydrogen and methyl, Z is selected from the group consisting of hydrogen, fluorine, chlorine, bromine, alkyl of 1 to 4 carbon atoms and alkoxy of 1 to 4 carbon atoms, and when Y2 is STR4 R2 is selected from the group consisting of STR5 A is selected from the group consisting of STR6 and when Y2 is --CHBr--CCl2 Br, R2 is m-phenoxy-phenyl and when R1 is R1 ' and Y2 is STR7 the said acid moiety may be in the cis or trans form or mixtures thereof or optically active isomeric form or racemic mixtures thereof and when R1 is R1 ", the said acid moiety is optically active isomeric form or racemic mixtures thereof and the compounds may be in one of two diastereoisomeric forms due to the existence of the asymetrical carbon atoms to which X is attached having insecticidal activity and their preparation.
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- Preparation of esters
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α-cyano esters are prepared by reacting an acyl halide with an aldehyde in a homogeneous mixture of substantially water-miscible aprotic solvent and an aqueous solution of water-soluble cyanide salt.
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- Preparation of esters
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Certain alpha-cyano esters are prepared by reacting an acyl halide with an aldehyde in a substantially water-immiscible aprotic solvent and an aqueous solution of water-soluble cyanide salt in the presence of an amine or cryptate rate-promoting agent.
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- Preparation of esters
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Certain alpha-cyano esters are prepared by reacting an acyl halide with an aldehyde in a substantially water-immiscible aprotic solvent and an aqueous solution of water-soluble cyanide salt in the presence of an amphoteric surfactant rate-promoting agent.
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- Method for controlling wood-damaging insects
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A method for controlling insects harmful to wood comprising contacting the insect with a composition comprising a carboxylate of the formula: STR1 as an active ingredient.
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- Method for preparing a mixture of stereoisomers of α-cyano-3-phenoxybenzyl 2-(4-substituted-phenyl)isovalerates
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A method for preparing α-cyano-3-phenoxybenzyl 2-(4-substituted-phenyl)isovalerates which consist substantially of or are rich in the enantiomer pair (S)-α-cyano-3-phenoxybenzyl (S)-2-(4-substituted-phenyl)isovalerate and (R)-α-cyano-3-phenoxybenzyl (R)-2-(4-substituted-phenyl)isovalerate.
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- Method for preparing a mixture of stereoisomers of α-cyano-3-phenoxybenzyl 2-(4-chlorophenyl)isovalerate
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An α-cyano-3-phenoxybenzyl 2-(4-chlorophenyl)isovalerate which consists substantially of or is rich in (S)-α-cyano-3-phenoxybenzyl (S)-2-(4-chlorophenyl)isovalerate and (R)-α-cyano-3-phenoxybenzyl (R)-2-(4-chlorophenyl)isovalerate. A method for preparing the same and an insecticidal and acaricidal composition.
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- Preparation of cyanoesters
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A process for the preparation of certain cyano substituted esters and optical isomers thereof useful as insecticides by dehydration of the precursor carboxamido esters.
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- Pesticidal α-cyanobenzyl ester enantiomer pair
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An enantiomer pair consisting of S-α-cyano-3-phenoxybenzyl S-α-isopropyl-p-chlorophenylacetate and R-α-cyano-3-phenoxybenzyl R-α-isopropyl-p-chlorophenylacetate, said pair substantially free of other stereoisomers is a highly active pesticide.
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- Preparation of esters
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Certain carboxylic acid esters also containing a cyano group are prepared by reacting an acid halide, an aldehyde and a water-soluble cyanide in the presence of a water-immiscible aprotic solvent and surface-active agent as catalyst.
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- Preparation of esters
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Certain carboxylic acid esters also containing a cyano group are prepared by reacting an acid halide, an aldehyde and a water-soluble cyanide in the presence of one or more water-immiscible (cyclo)alkane solvents.
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- Preparation of phenoxybenzyl esters
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Phenoxybenzyl esters are prepared by neutralizing an aqueous solution of a carboxylic acid and contacting the neutralized solution with a solution of phenoxybenzyl halide in a water-immiscible base in the presence of a phase transfer catalyst.
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