Process for preparing chlorinated 4,5-difluorobenzoic acids, -benzoic acid derivatives and -benzaldehyde

摘要

The present invention relates to a process for the preparation of compounds of the formula IMAGE in which R1 represents -CN, -COOH, -COOR', where R' denotes an organic radical having 1 to 6 carbon atoms, -CONH2, -COCl or -CHO and R2 represents H or Cl, by reacting a compound of the formula IMAGE in which R1 has the abovementioned meaning and R3 represents H or Cl, with a chlorinating agent at -10 to 200@C in the presence of a chlorination catalyst.