C-13-NMR AND N-15-NMR SPECTRA OF PHENYLAZOACETOACETAMIDES AND SIMILAR COMPOUNDS

The **1**3C- and **1**5N-NMR spectra of phenylazoacetoacetamides (1) and similar compounds and their **1**5N-isotopomers have been measured and the carbon and nitrogen signals have been assigned. The compounds exist in their hydrazone forms. Based on the stereospecific behavior of the coupling constants **2J(**1**5N**1**3C) a strong predominance of (Z)-isomer has been found for the compounds 1 in C**2HCl//3 or in left bracket **2**,H//6 right bracket DMSO solutions. In some cases (E)-isomers ( less than equivalent to 5%) have been observed.