Organic compounds -- part of the class 532-570 series – Organic compounds – Amino nitrogen containing
Reexamination Certificate
2006-08-15
2006-08-15
Davis, Brian (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Amino nitrogen containing
Reexamination Certificate
active
07091384
ABSTRACT:
The invention relates to a process for increasing the selectivity of the hydrogenation of 4,4′-diaminodiphenylmethane (4,4′-MDA) to diaminodicyclohexylmethane (4,4′-HMDA) by catalytic hydrogenation of a mixture containing 4,4′-MDA as the main component and its mono-N-methyl derivative as a secondary component. According to the invention, the hydrogenation is terminated before a conversion of 4,4′-MDA to 4,4′-HMDA of 99% is achieved. Under these conditions, a substantially smaller proportion of the N-methyl-4,4′-MDA is hydrogenated to N-methyl-4,4-HMDA.
REFERENCES:
patent: 5360934 (1994-11-01), Vedage et al.
patent: 0 231 788 (1987-08-01), None
patent: 0 324 190 (1989-07-01), None
patent: 0 392 435 (1990-10-01), None
patent: 0 476 359 (1992-03-01), None
patent: 0 639 403 (1995-02-01), None
Haas Thomas
Hofen Willi
Jaeger Bernd
Lettmann Christian
Lotz Joerg
Davis Brian
Degussa - AG
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
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