Abstract: The invention relates to a process for the preparation of nitrated aromatic compounds by the mixed acid process, in which water is removed from the reaction mass by passing an inert gas through it.

Abstract: A process provided for the production of 2-nitrobenzaldehyde from 2-nitrotoluene, in which 2-nitrotoluene is converted, by bromination by a radical mechanism, to 2-nitrobenzyl bromide in the form of a bromination oil containing 20 to 50% or more of 2-nitrobenzyl bromide, and the bromination oil is oxidized directly with a mixture of dimethylsulphoxide and sodium bicarbonate in a weight ratio of 3:1 to 10:1 at temperatures of up to 100.degree. C. and the 2-nitrobenzaldehyde is subsequently isolated via the bisulphite adduct, to give 2-nitrobenzaldehyde in high purity and high yield. The process also has the advantage of a very short reaction time. The 2-nitrobenzaldehyde produced is an important intermediate, for example in the production of pharmaceutically active 1,4-dihydropyridines.

Abstract: A process for preparing bentotrifluoride or its derivatives by contacting benzotrichloride or its derivatives corresponding thereto with hydrogen fluoride in a gaseous phase, characterized in that the contact is carried out in the presence of aluminum fluoride and, if desired, of chlorine.

Abstract: This invention relates to a novel process for the direct trifluoromethylation of aromatic compounds via carbon tetrachloride and hydrogen fluoride in the presence of strong Bronsted or Lewis acids which give an acidic reaction (increase in concentration of H.sub.2 F.sup.+ ions) in anhydrous hydrogen fluoride.