Cyclopropyl dihalo phosphites

摘要

Process for the preparation of novel trihalomethyl carbonates of the general formula:

wherein R<1> represents an optionally-substituted cyclopropyl or an optionally-substituted alkyl group, R<1> a methyl group or a hydrogen atom or R<1> and R<2>, together with the carbon atom to which they are attached jointly form a cycloalkyl group, each Hal is a chlorine or bromine atom and M represents an alkali metal atom, wherein a carbonyl compound of the general formula:

wherein R<1> and R<2> have the same meaning as in formula I, is reacted under substantially anhydrous conditions with a trihaloacetate of the general formula:

Hal3C - @ - O - M (III)
wherein Hal and M have the above-mentioned meaning, in the presence of a highly polar, aprotic inert solvent. The trihalomethyl carbonates are useful as intermediates in the manufacture of pyrethroid insecticides.