Catalytic hydrogenation of di (4-aminophenyl) methane
AssigneeMobay Chemical Corporation
InventorGary F. Allen
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Abstract
The present invention relates to an improved process for the catalytic hydrogenation of di(4-aminophenyl) methane to a liquid di(4-aminocyclohexyl) methane mixture containing from 15 to 40% by weight of the trans, trans isomer. The invention resides in the use of a ruthenium-on-alumina catalyst, the use of an aliphatic alcohol during hydrogenation and the use of ammonia during hydrogenation, with the hydrogenation being conducted under specific process conditions. The hydrogenation reaction is conducted for no more than about sixty minutes at a temperature of from 150.degree. to 217.degree. C. and at a hydrogen pressure of at least 500 psi.
Claims15
A process for the catalytic hydrogenation of di(4-aminophenyl)methane to a liquid di(4-aminocyclohexyl)methane containing from 15% to 40% by weight of the trans, trans isomer comprising hydrogenating di(4-aminophenyl)methane in the presence of (i) a ruthenium-on-alumina catalyst (ii) at least 25% by weight of an aliphatic alcohol selected from the group consisting of methanol, ethanol, n-propanol, and isopropanol, based on the weight of the total weight of the di(4-aminophenyl)methane and the alcohol, and (iii) ammonia, the amount of ammonia present being such that the molar ratio of ammonia to di(4-aminophenyl)methane is from 0.5:1 to 10:1, the hydrogenation being conducted at a hydrogen pressure of at least 500 psi, at a temperature of from 150.degree. C. to 217.degree. C., and for a time not exceeding 60 minutes.
The process of claim 4 wherein the pressure is at least 1500 psi.
A process for the catalytic hydrogenation of di(4-aminophenyl)methane to a liquid di(4-aminocyclohexyl)methane containing from 15% to 40% by weight of the trans, trans isomer comprising hydrogenating di(4-aminophenyl)methane in the presence of (i) a ruthenium-on-alumina catalyst, (ii) at least 25% by weight of an aliphatic alcohol, based on the weight of the total weight of the di(4-aminophenyl)methane and the alcohol, and (iii) ammonia, the amount of ammonia present being such that the mol ratio of ammonia to di(4-aminophenyl)methane is from 0.5:1 to 10:1, the hydrogenation being conducted at a hydrogen pressure of from about 1500 to 4000 psi, at a temperature of from 150.degree. C. to 217.degree. C., and for a time not exceeding sixty minutes.
Dependencies are inferred from the claim text.