2,2-Bis(4-aminocyclohexyl)propane can be obtained by amination of the corresponding bishydroxy compound in the liquid phase under pressure. Product yields of ca. 90% are obtained over hydrogenation catalysts containing palladium, ruthenium or cobalt, manganese, and phosphoric acid. Alternatively, hydrogenation of the condensation product of aniline and acetone, bisaniline A, furnishes the same compound. The industrial product is a mixture of three stereoisomers. Concentration of the trans,trans isomer by treating the isomer mixture with phosphoric acid under reduced pressure at 230 ℃ or by recrystallization from branched octanes is important because polymerization of the pure isomer gives polyamides of better quality.
