Process for the manufacture of aza-spirodecanes

Claim 1

A process for the manufacture of aza-spirodecanes of the formula (I) ##STR12## in which X and Y, being different, each are ##STR13## R 1 is hydrogen or C 1 -C 12 -alkyl R 2 and R 3 , either are identical and represent each hydrogen or a C 1 -C 5 -alkyl group R 4 being a methyl group in this case, or R 2 is hydrogen or C 1 -C 5 -alkyl, and R 3 and R 4 , together with the carbon atoms to which they are linked, form a C 5 - or C 6 -cycloalkyl group, or a group of the formula ##STR14## R 5 and R 6 being identical or different, each are hydrogen, C 1 -C 30 alkyl, a phenyl or naphthyl group being unsubstituted or substituted by chlorine or C 1 -C 4 -alkyl, or a phenylalkyl group being unsubstituted or substituted by C 1 -C 4 -alkyl; or R 5 and R 6 , together with the carbon atom linked to them are a C 5 -C 18 -cycloalkyl group being unsubstituted or substituted by up to four C 1 -C 4 -alkyl groups, or a group of the formula ##STR15## which comprises reacting a polyalkyl-piperidone-4-cyanohydrine of the formula (II) ##STR16## with an aldehyde or ketone of the formula (III) ##STR17## or reacting a polyalkyl-piperidone-4 of the formula (IV) ##STR18## with an aldehyde- or ketone-cyanohydrine of the formula (V) ##STR19## at a temperature of from 20° to 120° C. in the presence of an aliphatic carboxylic acid liquid at room temperature as solvent, and in the presence of an inorganic protonic acid; the carbonyl compounds (III) and (IV), respectively, being used in a 1- to 3-fold molar amount relative to the cyanohydrines (II) and (V), respectively, and the amount of protonic acid being chosen in such a manner that the piperidone-cyanohydrines (II) and the piperidones (IV), respectively, are present as salts, while the 0.5 to 2-fold molar amount relative to the cyanohydrine to be converted is present in addition, and by subsequently liberating the free base from the protonic acid salt of the intended azaspirodecane so obtained by treatment with a stronger base.