3 - bromine - 4 - fluorbenzonitril and processes for the manufacture of a replaced: 3 - bromine - 4 - fluorbenzols

摘要

Substituted bromofluorobenzene, wherein the fluorine is in para-position and the bromine in meta-position to another substituent, is prepared by direct bromination of the corresponding fluorobenzene derivative. Bromination is advantageously carried out in the presence of a catalyst, preferably a metal or metal salt. The elementary bromine is used in an amount of 0.9 to 1.3 mols per mol of fluorobenzene derivative and the reaction temperature is between 20 DEG and 200 DEG C. The bromofluorobenzene derivatives are suitable for the synthesis of medicaments and plant protective agents.