ALPHA-AMINO-ALPHA-TRIFLUOROMETHYL-PHENYLACETONITRILE - A POTENTIAL REAGENT FOR F-19 NMR DETERMINATION OF ENANTIOMERIC PURITY OF ACIDS

Alpha-Amino-alpha-trifluoromethyl-phenylacetonitrile, PhC(CF3)(CN)NH2,2, in which the amino group is located on a crowded, chiral, quaternary carbon center, has been studied as a potential reagent for the F-19 NMR determination of enantiomeric purity of chiral acids by conversion to their corresponding diastereomeric amides. The differences in the F-19 NMR chemical shifts (DELTAdelta) of the R,R/S,S versus R,S/S,R diastereomeric amides (8a-j) prepared from amine 2 and ten chiral acids range up to 0.266 ppm. Eight of the ten examples have DELTAdelta in excess of the useful minimum of 0.02 ppm. These values are not notably superior to those of other known reagents.