Solvent-dependent conformational system in hydroxyureas detected by NMR spectroscopy

The proton magnetic resonance spectra of the antileukemia agent hydroxyurea and substituted hydroxyureas in several solvents were recorded and correlated with structural features. Solvent-dependent differences in conformational preferences due to effects on internal hydrogen bonding, a temperature-dependent conformational feature, anthe exchangeability of protons with deuterium oxide and acetone-d6 were observed. The conformational features consistent with the spectral data are discussed.