7-Amino-1-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)-1,3-aza-phospholo[4,5-d]pyrimidine → 7-Amino-1-(beta-D-ribofuranosyl)-1,3-azaphospholo-[4,5-d]pyrimidine

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Reaction Steps

A mixture of 7-Amino-1-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)-1,3-azaphospholo[4,5-d]pyrimidine (compound 21 , R=2,3,5-tri-O-benzoyl-β-ribofuranose, 0.45 g, 0.75 mmol) and methanolic ammonia (100 mL, saturated at 0° C.) was stirred at room temperature for 20 h and the methanolic ammonia was evaporated under reduced pressure. The residue was triturated with methanol (10 mL) and the product was collected by filtration. The filtrate was evaporated and the residue was purified by chromatography over a silica gel column. The column was flash eluted with dichloromethane containing 0-20% methanol. The appropriate fractions containing the pure product were collected and evaporated to give a total yield of 0.18 g (84%) of the title compound, mp 220-222° C. Ir (KBr): ν700 (=P-C), 1205 (-P=CH), and 2930-3470 (NH2, OH) cm-1. Uv (pH 1): λmax254 nm (ε23,400), 284 (15,600), and 314 (5600); (MeOH): λmax266 nm (ε32,900), and 340 (2100); (pH 11): 266 nm (ε36,050), and 338 (3250). 31 p nmr (DMSO-d6): δ 62.50; 1H nmr (DMSO-d6): δ3.73(dd,2H, C5'H2), 3.98 (m, 1 H, C4'H), 4.10 (br s, 1 H, C3'H), 4.28 (m, 1 H, C2'H), 5.24 (br s, 2 H, 2OH), 5.63 (br s, 1 H, OH), 5.70 (d, 1 H, C1'H), 8.24 (s, 2 H, NH2), 8.86 (d, 1 H, C5H), and 8.83 (d, 1 H, J =58.8 Hz, C2H). Anal. Calcd. for C10H13N4O4P.0.25 CH2Cl2 :C, 40.30; H, 4.45; N, 18.35. Found: C, 40.40; H, 4.15; N, 18.54.

Provenance & Evidence