| 摘要 |
In the prodn. of 2,2-dimethyl-3- (fluoro-substd. 2-chloro- vinyl)- cyclopropanecarboxylic acid esters (I), HCl is eliminated from 2,2-dimethyl-3 -(fluoro-substd. 2,2-dichloroethyl)- cyclopropanecarboxylic acid esters (II) in a polar aprotic diluent in the presence of either (a) alkali carbonates and quat. ammonium or phosphonium salts or (b) potassium fluoride (where R1 is F, or CF3; and R2 is lower alkyl or the residue of an alcohol utilizable in pyrethroids). The starting esters (II) are new when R1 is CF3. The prods. are pesticides or intermediates for pesticides. High yields of (75-85%) can be obtd. |
