Methods for the isolation and characterization of constituents of natural products: V. Separation of 2,6-dinitrophenylhydrazone pyruvamides into classes and resolution of the individual members

Abstract

Class separation of the 2,6-dinitrophenylhydrazone derivatives of n-aliphatic primary and symmetrical secondary aliphatic amines is described. Both quantitative column adsorption and qualitative thin-layer adsorption Chromatographic procedures are presented. In both procedures the classes are cleanly separated and they can also be distinguished readily by color; the secondary amine derivatives are green and the primary amine derivatives are violet during chromatography. Approximately 0.2 μmole of a derivative is easily seen in the column procedure whereas 1.8 × 10 −4 μmole of a primary derivative and 5.4 × 10 −4 μmole of a secondary amine derivative can be followed in the thin-layer procedure. Methods for the separation of a homologous series of the primary amine derivatives and a partial series of secondary amine derivatives by thin-layer partition chromatography is also described. Approximately 1.5 × 10 −4 μmoles of derivative can be utilized in this procedure. Reversed-phase separation of the higher primary amine derivatives by thin-layer chromatography is also presented.