反应详情

To a solution of (R)—N-benzyl-1-(2,2-dimethyl-1,3-dioxolan-4-yl)methanamine (0.372 g, 1.682 mmol) and 5-(benzyloxymethyl)-4-methoxy-5H-pyrrolo[3,2-d]pyrimidine-7-carbaldehyde (0.5 g, 1.682 mmol) in 1,2-dichloroethane (30 ml) was added sodium triacetoxyborohydride (0.463 g, 2.186 mmol) and anhydrous MgSO4 (1 g). The mixture was stirred for 6 h. Tlc (EtOAc-hexanes, 8:2) showed the reaction essentially over. After diluting with CH2Cl2 the mixture was washed with aqueous sat. NaHCO3, brine, dried and the solvent evaporated. The residue was chromatographed (EtOAc-hex, 1:1, uv and molybdate) to give (R)—N-benzyl-1-(5-(benzyloxymethyl)-4-methoxy-5H-pyrrolo[3,2-d]pyrimidin-7-yl)-N-((2,2-dimethyl-1,3-dioxolan-4-yl)methyl)methanamine (0.631 g, 1.255 mmol, 74.7% yield) as a colourless gum. [α]D21 −21.9 (c, 0.905, MeOH). 1H NMR (CDCl3, 300 MHz), 5 ppm, 8.55 (s, 1H), 7.41 (s, 1H), 7.37-7.18 (m, 10H), 5.73 (s, 2H), 4.46 (s, 2H), 4.38-4.29 (m, 1H), 4.10, (s, 3H), 4.05-3.98 (m, 2H), 3.79 (d, 1H, J 13.9 Hz), 3.63 (d, 1H, J 13.9 Hz), 3.53, (t, 1H, J 7.9 Hz), 2.73 (dd, 1H, J 13.3, 5.9 Hz), 2.64 (dd, 1H, J 13.3, 5.9 Hz), 1.32 (s, 6H). 13C NMR (CDCl3, 75.5 MHz), δ ppm, 156.2 (C), 150.7 (C), 150.0 (CH), 139.6 (C), 136.9 (C), 132.2 (CH), 128.8 (CH), 128.4 (CH), 128.2 (CH), 128.0 (CH), 127.7 (CH), 126.9 (CH), 115.7 (C), 114.7 (C), 109.0 (C), 77.0 (CH2), 74.7 (CH2), 70.1 (CH2), 68.4 (CH2), 59.2 (CH2), 56.2 (CH2) 53.5 (CH3), 47.8 (CH2), 26.8 (CH3), 25.6 (CH3). +ESMS Found 503.2643 (M+H)+ C29H35N4O4 requires 503.2658.

1. customthe reaction essentially over
2. washwas washed with aqueous sat. NaHCO3, brine
3. customdried
4. customthe solvent evaporated
5. customThe residue was chromatographed (EtOAc-hex, 1:1, uv and molybdate)