Bayer Aktiengesellschaft

Alfred Nierth

Heinrich Konigshofen

Hans Muller

Marko Zlokarnik

Reinhard Preuss

Dieter W Bruck

Bernhard Scherhag

Heinz Klose

Salvatore Sabia

Hans-Jorg Uhlmann

Diarylguanidines can be isolated from the crude melt from the reaction of arylamines and cyanogen chloride in excellent quality and yield by dissolving the hot melt in water, extracting this solution with at least one polar, water-insoluble, organic compound, and precipitating from the purified aqueous solution the diarylguanidine by adding alkali metal hydroxide.

Process for isolating diarylguanidines

Diaryl guanidines can be obtained in a high degree of purity and in high yields from the crude melt obtained from the reaction of arylamines and cyanogen chloride by dissolving the hot melt in water, extracting this solution with a mixture of at least one water insoluble, apolar hydrocarbon and at least one polar organic compound and precipitating the diaryl guanidine from the purified, aqueous solution by the addition of alkali metal hydroxide.

Process for the isolation of diaryl guanidines

An improved process for the production of cyanogen chloride is disclosed according to which liquid hydrocyanic acid and gaseous chlorine are reacted in an aqueous medium. The liquid hydrocyanic acid and chlorine are introduced into a column-shaped reactor via at least one two-component nozzle. The reaction mixture is removed at the head of the column-shaped reactor. Preferably, the hydrocyanic acid is in liquid form and the chlorine is in gaseous form. By the process disclosed, quantitative yields of cyanogen chloride are obtained separately from aqueous solutions of hydrochloric acid of a strength suitable for commercial use.

Process for the production of cyanogen chloride from hydrocyanic acid

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Dormagen, Germany

Alfred Nierth