Preparation of Pyrimidinophanes from Pyrimidine Bases

Article abstract of DOI:10.1246/bcsj.69.3239

Treatment of pyrimidine bases such as uracil, thymine, and 5-fluorouracil with X(CH₂)_nX (X=I or Br; n=4-12) gave three types of pyrimidinophanes. When the numbers of carbon atoms of X(CH₂)_nX are odd numbers (n=5, 7, 9, 11), three structures of pyrimidinophanes could be differentiated on the basis of the ¹³C NMR and mass spectra. Treatment of pyrimidinophanes with 1,4-naphthoquinone or maleimides in the presence of palladium(II) acetate gave the coupling products. Reaction of pyrimidinophanes with NaNO₂ in the presence of palladium(II) acetate led to the nitration.