A practical resolution of 1-phenyl-2-(4-methylphenyl) ethylamine 1 for obtaining (R)-and (S)- enantiomers by a dielectrically controlled resolution (DCR) method using a single resolving agent,(S)-mandelic acid 2, has been studied. The configuration of the excess enantiomer 1 in the less-soluble diastereomeric salt was found to vary depending on the solvent controlled by adjusting the solvent dielectric constant ε and the water content of the ...