- Synthesis and stereostructure-activity relationship of novel pyrethroids possessing two asymmetric centers on a cyclopropane ring
-
2-Methylcyclopropane pyrethroid insecticides bearing chiral cyanohydrin esters or chiral ethers and two asymmetric centers on the cyclopropane ring, were synthesized. These compounds were designed using a “reverse connection approach” between the isopropyl group in Fenvalerate, and between two dimethyl groups in an Etofenprox analogue (the methyl, ethyl form), respectively. These syntheses were achieved by accessible ring opening reactions of commercially available (±)-, (R)-, and (S)-propylene oxides using 4-chlorobenzyl cyanide anion as the crucial step, giving good overall yield of the product with >98% ee. The insecticidal activity against the common mosquito (Culex pipiens pallens) was assessed for pairs of achiral diastereomeric (1R*,2S*)-, (1R*,2R*)-cyanohydrin esters, and (1R*,2S*)-, (1R*,2R*)-ethers; only the (1R*,2R*)-ether was significantly effective. For the enantiomeric (1S,2S)-ether and (1R,2R)-ether, the activity was clearly centered on the (1R,2R)-ether. The present stereostructure?activity relationship revealed that (i) cyanohydrin esters derived from fenvalerate were unexpectedly inactive, whereas ethers derived from etofenprox were active, and (ii) apparent chiral discrimination between the (1S,2S)-ether and the (1R,2R)-ether was observed. During the present synthetic study, we performed alternative convergent syntheses of Etofenprox and novel 4-EtO-type (1S,2S)- and (1R,2R)-pyrethroids from the corresponding parent 4-Cl-type pyrethroids, by utilizing a recently-developed hydroxylation cross-coupling reaction.
- Taniguchi, Takashi,Taketomo, Yasuaki,Moriyama, Mizuki,Matsuo, Noritada,Tanabe, Yoo
-
supporting information
(2019/03/26)
-
- Preparation method of ethofenprox
-
The invention relates to the field of preparation of compounds, and concretely relates to a preparation method of ethofenprox. The ethofenprox has a structure represented by formula I shown in the description. The method comprises the following steps: 1, synthesizing an intermediate m-phenoxybenzyl chlorosulfite (II); and 2, carrying out an etherification reaction on 2-(4-ethoxyphenyl)-2-methylpropanol (III) and the m-phenoxybenzyl chlorosulfite (II) to generate the ethofenprox. The preparation method of ethofenprox is different from Williamson ether synthesis method in present technologies, effectively reduces the generation of byproducts in the reaction process, and has a higher yield than present industrial routes in the whole preparation process, so the preparation method provided by the invention is suitable for industrial production.
- -
-
Paragraph 0034; 0036; 0037; 0039; 0040; 0042;
(2017/08/27)
-
- Synthesis of ethophenprox
-
An ethophenprox synthesis from easily available p-nitroneophyl chloride was developed. The reduction of the latter to aniline derivative followed by Sandmayer's and Claisen's reactions furnished p-ethoxyneophyl chloride that by condensation with 3-phenoxybenzyl alcohol in the presence KOH in DMSO yielded ethophenprox.
- Rakhimov,Galin,Tomilov,Le
-
p. 1629 - 1634
(2007/10/03)
-
- Synthesis of ethophenprox analogs
-
The synthesis of ethophenprox analogs was performed by condensation of alcohols with benzyl halides under conditions of the phase transfer catalysis. The ultrasonic irradiation was shown to accelerate the reaction and to increase the yield of ethers. The trends in fragmentation of new generation pyrethroids under the electron impact were established. Insecticidal activity of the compounds obtained was evaluated.
- Galin,Rakhimov,Vyrypaev,Bogdanov,Amirkhanov,Furlei,Tolstikov
-
p. 826 - 835
(2007/10/03)
-
- Halogen alkenyl azolyl microbicides
-
Novel halogenoalkenyl-azolyl derivatives of the formula STR1 in which R1 represents optionally substituted alkyl, optionally substituted alkenyl, optionally substituted cycloalkyl, optionally substituted aryl or represents optionally substituted heteroaryl, R2 represents alkyl, halogenoalkyl, 1-hydroxyalkyl, 2-hydroxyalkyl, 1-hydroxyhalogenalkyl, 1-alkenyl or 2-alkenyl, X1 represents fluorine, chlorine, bromine or iodine, X2 represents fluorine, chlorine, bromine or iodine, and Y represents nitrogen or a CH group, and addition products thereof with acids or metal salts are very active as microbicides in plant protection and in the protection of materials.
- -
-
-
- Pesticidal composition containing a microencapsulated organo-phosphorus or carbamate in a pyrethroid dispersion
-
An insecticidal and/or acaricidal and/or nematicidal composition having a rapid efficacy and residual activity which comprises a mixture of a poorly water-soluble organophosphorus insecticide and/or acaricide and/or nematicide and/or a poorly water-soluble carbamate insecticide and/or acaricide which have been microencapsulated in water-insoluble polymer coatings with a dispersing agent used in forming a microcapsule part, with a poorly water-soluble pyrethroid insecticide and/or acaricide emulsified or suspended in water with the above-mentioned dispersing agent used in forming a flowable part.
- -
-
-
- Insecticidal resin coating film
-
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.
- -
-
-
