Photochemical synthesis of naphthocyclobuta-pyrimidines via 1,2-cycloaddition of 6-chloro-1,3-dimethyluracil with naphthalenes

摘要

UV-Irradiation of a solution of 6-chloro-1,3-dimethyluracil (6-CIDMU) and naphthalene ina non-polar solvent (cyclohexane) afforded 6-(1-naphthyluracil) as the sole product. In contrast, irradiation of a solution of 6-CIDMU and naphthalene in a polar medium in the absence of TFA effected 1,2-cycloaddition to give naphthocyclobutapyrimidines in moderate yields. This photocycloaddition reaction also proceeds in non-polar solvents in the presence of TFA.