STUDIES ON THE RESOLUTION OF RACEMIC ALPHA-PHENYLETHYLAMINE BY A NEW RESOLVING AGENT (R)THIAZOLIDINE-2-THIONE-4-CARBOXYLIC ACID

Racemic R,S-alpha-phenylethylamine was resolved by R(-) thiazolidine-2 -thione-4-carboxylic acid [R(-)TTCA] as a new resolving agent, R(-)TTC A . S (-)-alpha-phenylethylamine salt [alpha](D)(20) = -53.14 degrees, optically active R (+) -alpha-phenylethylamine (94.45% e.e.) and S(-) -alpha-phenylethylamine (82.1% e.e.) were obtained. R(-) TTCA as a new resolving agent has not been reported,; The optimized configuration a nd electronic structures of R- and S-alpha-phenylethylamines have been studied using quantum chemistry PM3 method. The crystal structures of R(-) TTCA S(-)-a-phenylethylamine salt(R-S configuration) and R(-) TT CA . R(+) -alpha-phenylethylamine salt (R-R configuration) have been e stablished by X-ray diffraction. They crystallize in a monoclinic syst em. Space group is P2(1). The cell parameters of R-S configuration wer e obtained: a = 1.387 8(2) nm, b = 0.664 05(10) nm, c = 1.580 0(2) nm; beta = 90.844(10)degrees, Z=4. Those of R-li configuration were also obtained: a = 1.080 6(2) nm, b = 0.584 80(12) nm, c = 1.218 8(2) nm, b eta = 110.38(3)degrees, V = 0. 722 0 nm(3), Z = 2. There exist intermo lecular hydrogen bonds in crystals of R-S configuration and R-R config uration. The hydrogen bond number in unit cell of R-S configuration is two times that of R-R configuration. Thus R-S configuration was forme d faster than R-R configuration in solution reaction process, we can r esolve R,S-a-phenylethylamine by using R(-)TTCA.