Conversion of pyrethroid isomers to move active species

Details Conversion of pyrethroid isomers to move active species Conversion of pyrethroid isomers to move active species

1988-05-23

1991-03-05

Brust, Joseph Paul

Organic compounds -- part of the class 532-570 series

Organic compounds

Nitriles

558355, 558407, 560124, C07C25332, C07C25334, C07C25531, C07C25539

Patent

active

049979701

ABSTRACT:
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 (C.sub.1 -C.sub.5) 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.

REFERENCES:
patent: 4213916 (1980-07-01), Davies et al.
patent: 4287208 (1981-09-01), Fuchs et al.
patent: 4308279 (1981-12-01), Smeltz
patent: 4427598 (1984-01-01), Mason et al.
patent: 4512931 (1985-04-01), Robson
patent: 4544508 (1985-10-01), Fuchs et al.
patent: 4544510 (1985-10-01), van Berkel et al.
patent: 4656303 (1987-04-01), Kurono et al.
patent: 4670464 (1987-06-01), Doyle et al.
patent: 4681969 (1987-07-01), Williams et al.
patent: 4733001 (1988-03-01), Suzuki et al.
patent: 4782174 (1988-11-01), Fuchs et al.
patent: 4845126 (1989-07-01), Hidasi et al.
Merch Index, 10th Edition, Compound 7050, p. 1033 (1983).
Aldrich Catalog Handbook of Fine Chemicals (1986), p. 39.

Affiliated with

Also associated with

Rating

Conversion of pyrethroid isomers to move active species does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Conversion of pyrethroid isomers to move active species, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Conversion of pyrethroid isomers to move active species will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-498198