Patent ID: 8334417

Claim:
A process for preparing a compound of formula (II) in which X is chlorine or bromine, R 1 , R 2 and R 3 are the same or different and are independently hydrogen, halogen, C 1 -C 6 -alkyl, C 1 -C 6 -haloalkyl, C 2 -C 6 -alkenyl, C 2 -C 6 -alkynyl, optionally substituted C 3 -C 6 -cycloalkyl or C 4 -C 6 -cycloalkenyl, C 1 -C 6 -alkoxy, C 1 -C 6 -haloalkoxy, optionally substituted phenyl, phenoxy, heterocyclyl or hetaryl, or cyano, C 1 -C 6 -alkylamino or di(C 1 -C 6 -alkyl)amino, R 4 is halogen, C 1 -C 6 -alkyl, C 1 -C 6 -haloalkyl, C 2 -C 6 -alkynyl, C 2 -C 6 alkynyl, optionally substituted C 3 -C 6 -cycloalkyl or C 4 -C 6 -cycloalkenyl, C 1 -C 6 -alkoxy, C 1 -C 6 -haloalkoxy, optionally substituted phenyl, phenoxy, heterocyclyl or hetaryl, or cyano, C 1 -C 6 -alkylamino or di(C 1 -C 6 -alkyl)amino, and n is 0, 1 or 2, characterized in that a compound of the formula (I): in which R 1 , R 2 , R 3 , R 4 and n are each as defined above, is diazotized by means of sodium nitrite or potassium nitrite in the presence of aqueous hydrochloric acid or hydrobromic acid, and then converted by addition of a substoichiometric amount of an iron(II) or iron(III) compound and optionally additional amounts of hydrogen chloride or hydrogen bromide or an alkali metal or alkaline earth metal chloride or bromide.