Preparation of 4-amino-2,2,6,6-tetramethylpiperidine (TAD) via 2,2,6,6-tetramethyl-4-[(2,2,6,6-tetramethyl-4-piperidylidene) amino]piperidine as intermediate

摘要

A description is given, as an alternative to known processes, of a process for preparing 4-amino-2,2,6,6-tetramethylpiperidine (TAD) of the formula (I) <IMAGE> (I) which comprises the steps of reacting without catalysis, in a first step, 2,2,6,6-tetramethylpiperidine-4-one(TAA) of the formula II <IMAGE> (II) with TAD to form 2,2,6,6-tetramethyl4[(2,2,6,6tetramethyl-4-piperidylidene)- amino]piperidine (imine III) of the formula III belowstep, the imine (III) with ammonia and hydrogen in the presence of a hydrogenation catalyst to give 2 mol equivalents of TAD.