Synthesis of Chiral Amino Alcohols from L-Leucine and Their Chiral Recognition of Enantiomers of Ibuprofen and Mandelic Acid

Chiral amino alcohol polydentate ligand was derived from 5,N,N-tri-methyl-2-amino benzalde- hyde and chiral amino alcohol by condensation and reduction. Thus the former was obtained by methylation and formylation of p-methyl aniline, the latter was prepared by esterification and Grignard reaction of L-leucine. The products were characterized by IR, 1 H NMR and MS techniques. The chiral amino alcohol and the chiral amino alcohol polydentate ligand were evaluated as chiral solvating agent for chiral carboxylic acid such as ibuprofen and mandelic acid. In the presence of an equimolar amount of guest and host, the chemical shift non-equivalences (ΔΔδ) of the methyl proton of (CH3)CHCOOH in racemic ibuprofen and α-H in racemic mandelic acid are 11.2 and 9.2 Hz, respectively.