4-aminopiperidine prepn - using rhodium or ruthenium catalyst

摘要

4-Aminopiperidines of formula (I):- (where R = H, halogen, lower alkyl, -COOMe, -SO3Me, or -P(O)(OMe)2 where Me is a cation) are prepd. by single stage hydrogenation in aq. or organic media of -4-nitro-pyridine-N-oxides of formula:- using rhodium or ruthenium catalysts. (I) are used in prepn. of (co)polyamides, polyamide-imides and similar polymers.