Syngenta Participations Ag

Thomas Klatt

Helmars Smits

Paul Knochel

Matthias Becker

The invention relates to a process for the preparation of compound of formula (I) wherein Ris halogen and Ris halogen or hydrogen; comprising a) reacting the compound of formula (II) in an aprotic organic solvent in the presence of an aprotic polar co-solvent with a magnesium amide base followed by a halogenating agent, to the compound of formula I wherein Ris halogen and Ris hydrogen, and b) reacting the compound of formula (I), wherein Ris chloro and Ris hydrogen, in an aprotic organic solvent in the presence of an aprotic polar co-solvent with a magnesium amide base followed by a halogenating agent to a compound of formula I, wherein Ris chloro and Ris halogen. 

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Munich, Germany

Thomas Klatt