Bayer Aktiengesellschaft

Wolf Mehl

Helmut Fiege

Heinz U Blank

Franz-Josef Mais

Klaus-Christian Paetz

Ingo Janisch

Wolfgang Scheinert

Andreas Groschl

Dieter Brueck

Process for preparing haloaromatic amines by catalytic hydrogenation of the corresponding halonitroaromatic compounds, characterized in that iron-containing Raney nickel is used as catalyst, where the haloaromatic amines prepared can be used for the synthesis of photographic couplers which are useful in photographic emulsions or elements.

Hydrogenation of halonitroaromatic compounds

A first alkanol having from 1 to 3 carbon atoms can be separated off from other organic compounds of higher carbon number from the group comprising other alcohols, polyalcohols, ethers, oxo compounds, esters of carboxylic acids and of carbonic acid, haloaliphatics, amines, amides, hydrocarbons, carboxylic acids and nitriles, which in each case have at least 1 carbon atom more than the first alkanol, where in the case of halogenoaliphatics, halogen substituents are counted as further carbon atoms, by permeation on membranes, if a water content from 1 to 30% by weight, preferably from 5 to 15% by weight, based on the amount of mixture and water, is maintained.

Process for separating off alkanols from other organic compounds of

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Koln, Germany

Wolf Mehl