Regioselective Bromination of a Thymine-Acridine Conjugate by N-BromosuccinimideSynthetic Communications
AbstractA thymine and acridine conjugate (1), containing a benzylic carbon of thymine and an electron-rich aromatic ring (acridine) within the same molecule, was synthesized. Treatment of 1 with N-bromosuccinimide (NBS) in anhydrous chloroform in the presence of azobisisobutylnitrile produced a dibromo-substituted thymine-acridine conjugate (7) as a major product, in which the bromination was only observed on the acridine ring. Nuclear Overhauser effect (NOE) difference spectroscopy revealed that the actual bromination substitution was on C-2 and C-7 of acridine. Our results suggest that electrophilic aromatic substitution, not the expected benzylic radical reaction, takes place predominantly even when 1 is subjected to the NBS reaction condition, which favors radical processes. In addition, such selectivity is clearly solvent dependent.
Citation InformationWanbo Liu, Engelbert Navarro, Andreas H. Franz and Liang Xue. "Regioselective Bromination of a Thymine-Acridine Conjugate by N-Bromosuccinimide" Synthetic Communications Vol. 40 Iss. 8 (2010) p. 1192 - 1201 ISSN: 0039-7911
Available at: http://works.bepress.com/andreas-franz/44/