NMR-SPECTROSCOPY OF DERIVATIVES OF 2,4-DI CHLOROPHENOXYACETYL HYDRAZIDE

Derivatives of 2,4-dichlorphenoxyacetyl-hydrazides were prepared by re action of the hydrazides with different aldehydes. NMR-spectroscopic i nvestigations of these compounds show the existence of rotamers result ing from a nitrogen-carbonyl bond rotation. Contrary to substituted di thiocarbacinic acid derivatives no E/Z-isomerism relative to the C=N d ouble bond could be demonstrated. In order to prove the structures we utilized chemical shift differences in the H-1-, C-13- and N-15-NMR-sp ectra, NH and CH coupling constants and NOE-difference measurements. T he barriers of rotation were determined by NMR-measurements at various temperatures and line shape analysis using the computer program D-NMR 3.