Enantiomerically enriched 1-phenylethylamines

Process for preparing enantiomerically enriched compounds of the formula (I)

• in which
• * marks a stereogenic carbon atom,
• n is 1, 2 or 3,
• m is an integer in the range from 0 to (5-n) and
• R1 is in each case independently selected from the radicals:
• C1-C12-alkyl, C1-C12-alkoxy, C1-C1-2-alkylthio, C5-C14-aryl, C5-C14-aryloxy, C6-C15-arylalkyl, C6-C15-arylalkoxy, chlorine, fluorine, cyano, free or protected formyl, free or protected hydroxyl, free or protected mercapto, C1-C12-haloalkyl, C1-C12-haloalkylthio, C1-C12-haloalkoxy and radicals of the formulae (IIa) and (IIb)
• A-B-D-E (IIa)
• A-E (IIb)
• in which
• A is absent or is a C1-C8-alkylene, C1-C8-alkenylene or C1-C8-haloalkylene radical and
• B is absent or oxygen, sulphur or NR2 where
• R2 is hydrogen, C1-C8-alkyl, C6-C15-arylalkyl or C5-C14-aryl and
• D is a carbonyl group and
• E is OR3 or N(R4)2
• where
• R3 is C1-C8-alkyl, C6-C15-arylalkyl or C5-C14-aryl and
• R4 is in each case independently hydrogen, C1-C8-alkyl, C6-C15-arylalkyl or C6-C14-aryl, or N(R4)2 together is a cyclic amino radical having 4 to 12 carbon atoms,
• comprising,
• * in a step A), reacting
• compounds of the formula (III)
• with compounds of the formula (IVa) or (IVb)
• R5O—NH2 (IVa)
• R5O—NH2.HX (IVb)
• in which
• R5 is hydrogen or C1-C12-alkyl and
• X is an anion
• to initially give compounds of the formula (V)
• and,
• in a step B), reducing
• the compounds of the formula (V)
• in an organic solvent
• with a complex borohydride and
• an acid
• to racemic compounds of the formula (Ia)
• and,
• in a step C), enriching
• the racemic compounds of the formula (Ia) enantiomerically with the aid of enantiomerically enriched acids.