Reaction of 5,7-Dihydroxycoumarins with Pyrimidines

Abstract

The study of 5,7-dihydroxycoumarins as nucleophilic agents in the S_N^H reaction with pyrimidines showed that the reaction does not stop at the stage of formation of σ^H-adduct as intermediate in the S_N^H mechanism but proceeds further with annulation of the 1,3,5-oxadiazocine ring in moderate to excellent yields. The structures of the obtained compounds were confirmed by NMR spectroscopy and X-ray diffraction. A primary in vitro assessment of their antitumor activity was performed.