Hexamethyldisilazane → 2-chloro-N6-(3-iodobenzyl)-9-[2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl]-adenine

Beteiligte Stoffe

Reaktionsschritte

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).

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