| abstract |
The pure enantiomeric form of a compound of the formula <IMAGE> wherein Y is OH, R<1>COO, R<2>R<3>NCOO- or R<4>O where R<1> is an aliphatic hydrocarbon residue having 1-17 carbon atoms, a phenyl, 2,6-dimethylphenyl or 3- or 4-hydroxyphenyl group or a 3-or 4-alkanoyloxyphenyl group of formula <IMAGE> wherein R<5> is an alkyl group having 1-6 carbon atoms, or R<1> is a group <IMAGE> wherein R<6> is hydrogen, an alkyl group having 1 to 5 carbon atoms or a phenyl group, R<7> is hydrogen, an alkyl group having 1 to 5 carbon atoms or an acyl group and R<8> is hydrogen or an alkyl group having 1 to 5 carbon atoms, R<2> is hydrogen, an alkyl group having 1-5 carbon atoms, a phenethyl, benzyl or phenyl group which may be mono- or disubstituted in the aromatic part with a methyl, methoxy, hydroxy, nitro or cyano group or a halogen, R<3> is H, an alkyl group having 1 to 5 carbon atoms or a phenyl group or R<2> and R<3> together with the nitrogen atom to which they are linked form a 5, 6 or 7 membered ring optionally containing 1 to 3 double bonds and/or 1 or 2 further heteroatoms selected from N, O and S, and R<4> is an allyl or benzyl group, said enantiomer having the same absolute configuration at the asymmetric carbon atom (*) as that of the (-)-enantiomer of the compound of formula I wherein Y is OH, and being in the form of a base or a pharmaceutically acceptable acid addition salt thereof. The enantiomers are useful in the treatment of central nervous system disorders. |