Method of preparing tetrahalobenzene compounds, chemical intermediates used therein and certain of the compounds themselves

摘要

Tetrahalobenzene compounds of the formula (I): <IMAGE> (I) in which X is independently chloro or, preferably, fluoro and Y is hydrogen or -N+R3A- in which each R is independently C1-4 alkyl and A is a radical capable of forming an anion A-, are prepared by (a) alkylating a compound of formula (II): <IMAGE> (II) or a salt thereof, to form a compound of formula (III): <IMAGE> (III) (b) treating the compound of formula (III) with a quaternizing agent of formula RA to form a compound of formula (IV): <IMAGE> (IV) and (c) partially or completely reductively cleaving the compound of formula (IV) to replace one or both -N+R3A- groups by hydrogen. Compounds (I), in which Y is -N+R3A-, (III) and (IV) are novel. Compound (I) is useful in the synthesis of insecticides.