NMR and X-ray structural studies on 3-benzyl-8-bromoadenine

摘要

8-Bromoadenine was benzylated in the presence of base to give a mixture of two regioisomers. One was easily recognized as 9-benzyl-8-bromoadenine, but the other structure could not be determined with absolute certainty by NMR. Therefore, X-ray crystallography was used to prove that the benzyl group was attached to N-3. Furthermore, it is shown that the 3-benzyl adenine derivative exists as the amine tautomer both in the crystalline state as well as in solution (DMSO-d_6), with restricted rotation around the N ~6-C6 bond.