Patent ID: 6849760

Claim:
A method for purifying a diastereomer, said method comprising (a) preparing an organic acid salt or an inorganic acid salt of an amino compound having the formula wherein R 1 represents alkyl, aryl, cycloalkyl, cycloalkylalkyl or aralkyl radicals, which are optionally substituted with alkyl, halogen, NO 2 , OR 9 or SR 9 radicals, where R 9 represents hydrogen, alkyl, aryl or aralkyl radicals; R 3 represents hydrogen, alkyl, alkenyl, alkynyl, hydroxyalkyl, alkoxyalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heteroaryl, heterocycloalkylalkyl, aryl, aralkyl, heteroaralkyl, aminoalkyl or N-mono- or N,N-disubstituted aminoalkyl radicals, wherein said N-mono- or N,N-disubstituted aminoalkyl radicals are substituted with alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl, or heterocycloalkylalkyl radicals, or wherein said N,N-disubstituted aminoalkyl radical is substituted with substituents that, together with the nitrogen atom to which they are bonded, form heterocycloalkyl or heteroaryl radicals; and P 1 and P 2 are each independently hydrogen, acyl, aralkyl, silyl, aralkoxycarbonyl, alkoxycarbonyl, alkylcarbonyl, aralkylcarbonyl, arylcarbonyl or cycloalkenylalkyl radicals; or P 1 and P 2 together with the nitrogen atom to which they are bonded form a heterocyclic ring system; and (b) precipitating or crystallizing said organic acid salt or said inorganic acid salt from a solution.