Patent ID: 7321042

Claim:
A process for preparing N-substituted 3β-aminonortropanes of formula I or an acid addition salt thereof, wherein R 1 denotes an optionally substituted group selected from the group consisting of C 1 -C 8 -alkyl, C 2 -C 8 -alkenyl, C 3 -C 8 -cycloalkyl and C 6 -C 10 -aryl-C 1 -C 8 -alkyl, wherein either (a) a corresponding 3-oxonortropane of formula IIA is reacted with an arylmethylamine of formula IIIA H 2 N—CH 2 —Ar (IIIA) wherein Ar denotes an optionally substituted phenyl group or an optionally substituted 5- or 6-membered heteroaromatic group with at least one heteroatom selected from the group N, O and S; or (b) a corresponding 3α-aminonortropane of formula IIB is reacted with an arylaldehyde of formula IIIB O═CH—Ar (IIIB); converting the resulting imine of formulae IVA prepared in option (a) or IVB prepared in option (b) to the thermodynamically stable compound of formula V in the presence of a base which is then hydrolysed in the presence of an acid to obtain the compound of formula I, which may be optionally converted into an acid addition salt.