反应详情

A solution of 1-(3,5-di-O-benzoyl-β-L-xylofuranosyl)-uracil (6a) (1.4 g: 3.21 mmol) in ammoniacal methanol (previously saturated at 10° C. and hermetically closed) (90 ml) is stirred for two days at room temperature. The solution is evaporated several times with methanol under reduced pressure. The crude material obtained is dissolved in water and the resulting solution is washed several times with chloroform. The aqueous phase is evaporated and the residue is directly crystallized from methanol to give 0.6 g (yield 82%) of pure 7a: m.p.: 165-167° C.; 1H NMR (DMSO-d6), δ ppm=11.23 (s, 1H, 3-NH), 7.92 (d, 1H H-6; J=8.1 Hz), 6.04 (dd, 1H, H-1′; J=2.0 and 8.3 Hz), 5.26 (d, H, H-5; J=8.1 Hz), 5.26 (d, 1H, OH-3′; J=3.2 Hz), 4.69 (t, 1H, OH-5′; J=5.3 Hz), 4.20 (m, 1H, H-3′), 3.81 (m, 1H, H-4′), 3.80-3.60 (m, 2H, H-5′ and 5″), 2.6-2.5 (m, 1H, H-2′, partially obscured by DMSO-d5), 1.85 (dd, 1H, H-2″; J=2.0 and 14.7 Hz); mass spectra (matrix: glycerol-thioglycerol: 50:50, v/v): FAB>0 321 [M+glycerol+H]+, 229 [M+H]+, 117 [s]+ and 113 [BH2]+; FAB<0 227 [M−H]−.

1. customThe solution is evaporated several times with methanol under reduced pressure
2. customThe crude material obtained
3. washthe resulting solution is washed several times with chloroform
4. customThe aqueous phase is evaporated
5. customthe residue is directly crystallized from methanol