5-Benzyluracil and its derivatives

5-(Hydroxybenzyl)uracils are obtained by condensation of 5-hydroxymethyluracil (I) with phenols in the presence of CF₃COOH [1]. However, the activity of CF₃COOH is insufficient for aromatic compounds that do not contain electron-donor substituents. Thus, according to PMR data, the reaction between equivalent amounts of I and C₆H₆ in CF₃COOH is complete only after 3 days. However, benzene derivatives containing electron-acceptor substituents are practically unreactive. Anhydrous HP, in which even benzotrifluoride reacts, is a considerably more efficient agent.