N-ALKYLOXYCARBONYL ISOBUTYLAMIDES AS READILY PREPARED DIAMIDE DERIVATIVES OF AMINO-ACIDS FOR SEPARATION OF ENANTIOMERIC ISOMERS BY CHIRAL PHASE CAPILLARY GAS-CHROMATOGRAPHY

Amino acid diamide derivatives of N-alkyloxycarbonyl isobutylamides have been prepared from corresponding N-alkyloxycarbonyl 2,2,2-trifluoroethyl esters and provided for use in separation of enantiomeric isomers by chiral phase capillary gas chromatography. The substitution reaction of 2,2,2-trifluoroethyl ester with isobutylamine was found to proceed almost completely within 5 min at room temperature. All the diamide derivatives prepared have increased the separation factor including Pro.