Hoechst Aktiengesellschaft

Lothar Schulz

Hans-Jurgen Arpe

Konrad Baessler

Kurt C Habig

Heinz Schutte

Nitrosation agent(s), contained as by-products in nitrated aromatic compounds after nitration with nitric acid or nitration acid, are removed by a water treatment, wherein the water is distilled off at least partially in vapor form, advantageously under reduced pressure. In the further reaction of the nitrocompounds treated in this manner undesired nitrosamines are practically not formed. The process is especially suitable for the manufacture of 4-di-n-propylamino-3,5-dinitrobenzotrifluoride (Trifluralin), a valuable herbicide, substantially free from nitrosamine(s).

Method for removing nitrosation agent(s) from a nitrated aromatic

A process for the preparation of bromine and hydrogen bromide, which comprises reacting ammonium bromide with an oxygen containing gas at temperatures of from 200.degree. to 800.degree. C in the presence of oxidation catalysts is disclosed. Catalysts based on platinum group metals favor formation of HBr. Most other metal catalysts cause chiefly formation of bromine.

Process for the preparation of bromine and hydrogen bromide from

A process for the preparation of bromine and hydrogen bromide, which comprises reacting ammonium bromide with an oxygen containing gas at temperatures of from 200.degree. to 800.degree. C. in the presence of oxidation catalysts is disclosed. Catalysts based on platinum group metals favor formation of HBr. Most other metal catalysts cause chiefly formation of bromine.

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Bad Soden am Taunus, Germany

Lothar Schulz