Patent ID: 7105698

Claim:
A process for separating the R(−)-5-[2-[[2-(2-ethoxyphenoxy)ethyl]amino]propyl]-2-methoxybenzenesulfonamide enantiomer [R(−)-I]or S(+)-[2-[[2-(2-ethoxyphenoxy)ethyl]amino]propyl]-2-methoxybenzenesulfonamide enantiomer [S(+)-I] from a mixture of said R(−)-I and S(+)-I enantiomers, comprising: (a) placing a mixture containing the R(−)-I and S(+)-I enantiomers in contact, in a solvent, with an optically active organic acid selected from the group consisting of (−)-N-(3,5-dinitrobenzoyl)-α-phenyl-glycine, (+)-N-(3,5-dinitrobenzoyl)-α-phenyl-glycine, and non-racemic mixtures thereof, to form diastereoisomeric salts with said R(−)-I and S(+)-I enantiomers, wherein said diastereoisomeric salts have different solubility in said solvent and can be separated by crystallization; (b) separating the diastereoisomeric salt mixture enriched in the diastereoisomeric salt of the R(−)-I or S(+)-I enantiomer formed in step (a); and (c) releasing the diastereoisomeric salt mixture separated in step (b) to obtain the R(−)-I or S(+)-I enantiomer or a mixture enriched in one of them.