Abstract
Structures of Levene's 5-phenylhydrazinouracil derivatives (VIII) and 5, 6-diphenyl-hydrazinouridine (III) formed by reactions of 5-hydroxyuracil derivatives and brominated uridine with phenylhydrazine, were revised to 5-oxo-5, 6-dihydrouracil phenylhydrazone derivatives (XI) and 5-oxo-6-phenylhydrazino-5, 6-dihydrouridine phenylhydrazone (IIa), respectively, by means of physical analyses. These resolutions were substantiated by the separation of optical active isomers of compound IIa and by proving the existence of syn- and anti-isomers with the compounds of XI type, except 5-oxo-5, 6-dihydrouridine phenylhydrazone (VII).
