Study of diastereomeric thioureas formed with a new chiral derivatizing agent.

(1S,2S)-1,3-Diacetoxy-1-(4-nitrophenyl)-2-propyl isothiocyanate ((S,S)-DANI) was recently introduced as a new chiral derivatizing agent for the enantioseparation of amino compounds. In the present study, diastereomeric derivatives of racemic amino acids were formed with (S,S)-DANI. The thioureas produced were distinguished by means of infrared spectroscopy, theoretical calculations and high-performance liquid chromatography. The differences observed between the corresponding diastereomers by the independent methods are considered to prove the applicability of the new reagent in the field of enantiomer separation.