反应详情

Hydrazine hydrate (1.4 mL, 28.7 mmol) was added to a solution of 1-(2-O-acetyl-3,5-di-O-benzoyl-β-L-xylofuranosyl)uracil 10 [Ref.: Gosselin, G.; Bergogne, M.-C.; Imbach, J.-L., “Synthesis and Antiviral Evaluation of β-L-Xylofuranosyl Nucleosides of the Five Naturally Occuring Nucleic Acid Bases”, Journal of Heterocyclic Chemistry, 1993, 30 (Oct.-Nov.), 1229-1233] (4.79 g, 9.68 mmol) in pyridine (60 mL) and acetic acid (15 mL). The solution was stirred overnight at room temperature. Acetone was added (35 mL) and the mixture was stirred for 30 min. The reaction mixture was evaporated under reduced pressure. The resulting residue was purified by silica gel column chromatography [eluent: stepwise gradient of methanol (0-4%) in dichloromethane to give 11 (3.0 g, 68%) which was crystallized from cyclohexane/dichloromethane: mp=111-114° C.; 1H-NMR (DMSO-d6): δ 11.35 (br s, 1H, NH), 7.9-7.4 (m, 11H, 2 C6H5CO, H-6), 6.38 (d, 1H, OH-2′, JOH-2′=4.2 Hz), 5.77 (d, 1H, H-1′, J1′-2′=1.9 Hz), 5.55 (d, 1H, H-5, J5-6=8 Hz), 5.54 (dd, 1H, H-3′, J3′-2′=3.9 Hz and J3′-4′=1.8 Hz), 4.8 (m, 1H, H-4′), 4.7 (m, 2H, H-5′ and H-5″), 4.3 (m, 1H, H-2′); MS: FAB>0 (matrix GT) m/z 453 (M+H)+, 105 (C6H5CO)+; FAB<0 (matrix GT) m/z 451 (M−H)−, 121 (C6H5CO2)−, 111 (B)−; Anal. Calcd for C23H20N2O8.H2O: C, 58.09; H, 4.76; N, 5.96. Found: C, 57.71; H, 4.42; N, 5.70.

1. stirringthe mixture was stirred for 30 min
2. customThe reaction mixture was evaporated under reduced pressure
3. customThe resulting residue was purified by silica gel column chromatography [eluent