NMR-spektroskopische Untersuchungen an Derivaten des 2,4-Dichlorphenoxyessigsäurehydrazids

Summary

Derivatives of 2,4-dichlorphenoxyacetyl-hydrazides were prepared by reaction of the hydrazides with different aldehydes. NMR-spectroscopic investigations of these compounds show the existence of rotamers resulting from a nitrogen-carbonyl bond rotation. Contrary to substituted dithiocarbacinic acid derivatives noE/Z-isomerism relative to the C=N double bond could be demonstrated. In order to prove the structures we utilized chemical shift differences in the¹H-,¹³C- and¹⁵N-NMR-spectra, NH and CH coupling constants and NOE-difference measurements. The barriers of rotation were determined by NMR-measurements at various temperatures and line shape analysis using the computer program D-NMR 3.