反应详情

A mixture of 2-chloro-N6 -(3-iodobenzyl)adenine (0.84 g, 2.18 mmol), ammonium sulfate (catalytic amount), and HMDS (20 ml) was refluxed for 5 h under nitrogen to provide the silylated derivative. The clear solution was concentrated to dryness in vacuo with exclusion of moisture and the residue was dissolved in dry dichloroethane (6 ml). A solution of 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranoside (Janssen Chimica Chemical Co., 1 g, 1.98 mmol) in dry dichloroethane (12 ml) and TMSOTf (0.42 ml, 2.18 mmol) was added, and the reaction mixture was stirred for 20 min at room temperature and refluxed for 14 h under nitrogen. After a workup similar to that for the compound of Example 55, the residue was purified on a silica gel column chromatography (Hx-EtOAc, 2:1) to yield 2-chloro-N6 -(3-iodobenzyl)-9-[2,3,5-tri-O-benzoyl-β-D-ribofuranosyl]-adenine [Rf =0.11 (Hx-EtOAc, 3:1), 1.495 g, 91%] as a colorless foam. 1 H NMR (CDCl3) d 4.69-4.92 (m, 5H, CH2, H-4', H-5'), 6.15 (m, 3H, H-2', H-3', NH), 6.45 (d, J=4.3 Hz, 1H, H-1'), 7.07 (pseudo t, 1H, Bn), 7.31-8.10 (m, 20H, Ar).

1. temperaturewas refluxed for 5 h under nitrogen
2. customto provide the silylated derivative
3. concentrationThe clear solution was concentrated to dryness in vacuo with exclusion of moisture
4. dissolutionthe residue was dissolved in dry dichloroethane (6 ml)
5. temperaturerefluxed for 14 h under nitrogen
6. customAfter a workup similar to that for the compound of Example 55, the residue was purified on a silica gel column chromatography (Hx-EtOAc, 2:1)