GB1070950A - Halo-substituted diphenyl-cyclopropanes and their use in combatting insect pests - Google Patents

Abstract

The invention comprises compounds of the formula <FORM:1070950/C2/1> in which R and R1 are the same or different and are Cl, Br or F. They may be prepared by reacting a 1,1-di-(p-halophenyl)-ethylene of formula <FORM:1070950/C2/2> in a medium which generates dichlorcarbene (CCl2) or which contains a dichloromethylene transfer agent. For example, the 1,1-di-(p-halophenyl)-ethylene may be reacted with phenyl(trichloromethyl)-mercury or phenyl-(bromodichloromethyl)-mercury. Alternatively they may be produced by reacting 1,1-di-(p-chloro-phenyl)ethylene with, for example, chloroform or bromodichloromethane, in the presence of a base, e.g. potassium tert.-butoxide, butyl lithium, methyl lithium and sodium hydride, to give 1-(4-chlorophenyl)-1-(41-chlorophenyl)-2,2 -dichlorocyclopropane.ALSO:Compounds of the general formula <FORM:1070950/A5-A6/1> in which R and R\sv are the same or different and chlorine, bromine or fluorine are used in combatting insect pests. The compounds may be used (a) in the form of solutions, emulsions or suspensions in, for example, isopropyl ether, a ketone, a chlorinated hydrocarbon, a liquid alkane, an aromatic hydrocarbon, a petroleum fraction or an olefin dimer or trimer; as a solid with a solid extending agent, e.g. tricalcium phosphate, calcium phosphate, calcium carbonate, kaolin, bole, kieselguhr, talc, bentonite, fuller's earth, pyrophillite, diatomaceous earth, calcined magnesia, volcanic ash, sulphur, powdered cork, powdered wood and powdered walnut shells; and (c) an aerosol. The emulsions and suspensions may also contain non-ionic surfactants.