Abstract: Racemic R, S-α-phenylethylamine was resolved by R (-) thiazolidine-2-thione-4-carboxylic acid R (-)TTCAas a new resolving agent, R (-)TTCA·S (-) α phenylethylamine salt [α]_D²⁰=-53.14°, optically active R (+)-α-phenylethylamine(94.45% e.e.) and S(-)-α-phenylethylamine(82.1% e.e.) were obtained. R (-) TTCAas a new resolving agent has not been reported. The optimized configuration and electronic structures of Rand S α phenylethylamines have been studied using quantum chemistry PM3 method. The crystal structures of R (-) TTCA·S (-)-α-phenylethylamine salt(R-S configuration) and R (-) TTCA·R (+)-α-phenylethylamine salt (R-R configuration) have been established by X-ray diffraction. They crystallize in a monoclinic system. Space group is P2₁. The cell parameters of R-S configuration were obtained: a=1.3878(2) nm, b=0.66405(10) nm, c=1.5800(2) nm; β=90.844(10)°, Z=4. Those of R-R configuration were also obtained: a=1.0806(2) nm, b=0.58480(12) nm, c=1.2188(2) nm, β=110.38(3)°, V=0.7220 nm³, Z=2. There exist intermolecular hydrogen bonds in crystals of R-S configuration and R-R configuration. The hydrogen bond number in unit cell of R-S configuration is two times that of R-R configuration. Thus R-S configuration was formed faster than R-R configuration in solution reaction process, we can resolve R, S-α-phenylethylamine by using R (-)TTCA.

Key words: R (-)Thiazolidine-2-thione-4-carboxylic acid, Resolution, R,S-α-Phenylethylamine, Crystal structure, Electronic structure