2-Methylamino-6,7-diphenyl-1-ß-D-ribofuranosyl-4(3H)pteridinone (45). A solution of 37 (0.158 mg, 0.2 mmol) in abs. THF was cooled to -15°C, then methanolic CH3NH2 (5%, 2 ml) added and kept in the icebox for 1 day. It was evaporated, the residue dissolved in abs. MeOH (10 ml), 1 N CH3ONa (0.2 ml) added and stirred at rt for 1 day. The solution was acidified by AcOH to pH 5, evaporated and purified on a preparative thick layer silica gel plate (40 x 20 x 0.2 cm) with CHCl3/MeOH (4:1) to give after recrystallization from EtOH/H2O (2:3) 62 mg (70%) of 45. M.p. 189°C (decomp.). 1H-NMR ((D6)DMSO): 8.02 (bs, 1 H, NH); 7.40-7.20 (m, 10 H, arom. H); 6.98 (d, 1 H, H-C(1')); 5.02 (bs, 1 H, 5'-OH); 5.40 (d, ,1 H, 2'-OH); 5.21 (d, 1 H, 3'-OH); 4.52 (dd, 1 H; H-C(2')); 4.15 (m, 1 H, H-C(3')); 4.05 (m, 1 NH, H-C(4')); 3.72 (m, 2 H, H-C(5')); 2.91 (s, 3 H, H3C-NH). Anal. Calc. for C24H23N5O5 x 0.5 H2O (470.4): C, 61.16; H, 5.14; N, 14.88. Found: C, 60.84; H, 5.02; N, 14.82.
2-Ethylamino-6,7-diphenyl-1-ß-D-ribofuranosyl-4(3H)pteridinone (46). Analogous to the preceding procedure with 37 (0.158 g, 0.2 mmol) and C2H5NH2-gas for 3 days in the icebox. Treatment with CH3ONa and purification on a silica gel plate to give after recrystallization from EtOH/H2O (2:3) 65 mg (78%) of 46. Mp. 177°C. 1H-NMR ((D6)DMSO): 8.07 (bs, 1 H, NH); 7.50-7.30 (m, 10 H, arom. H); 6.95 (d, 1 H, H-C(1')); 5.89 (t, 1 H, 5’-OH); 5.46 (d, 1 H, 2’-OH); 5.24 (d, 1 H, 3’-OH); 4.52 (dd, 1 H; H-C(2')); 4.14 (m, 1 H, H-C(3')); 4.03 (m, 1 NH, H-C(4')); 3.71 (m, 2 H, H-C(5')); 3.45 (q, 2 H, NCH2CH3);); 1.29 (t, 3 H, NCH2CH3). Anal. Calc. for C25H25N5O5 x H2O (493.5): C, 60.84; H, 5.51; N, 14.09. Found: C, 60.58; H, 5.32; N, 13.61.
2-Ethanolamino-6,7-diphenyl-1-ß-D-ribofuranosyl-4(3H)pteridinone (47). Analogous to the preceding procedure with 37 (0.158 g, 0.2 mmol) and methanolic ethanolamine (10%, 3 ml) for 2 days in the icebox. Treatment with CH3ONa and purification on a silica gel plate gave after recrystallization from EtOH/H2O (2:3) 65 mg (66%) of 47. M.p. 177°. 1H-NMR ((D6)DMSO): 7.98 (bs, 1 H, NH); 7.50-7.30 (m, 10 H, arom. H); 6.96 (d, 1 H, H-C(1')); 5.78 (t, 1 OH, 5’-OH); 5.38 (d, 1 H,2’-OH); 5.21 (d, 1 H, 3’-OH); 4.87 (t, 1 H, CH2CH2OH); 4.56 (dd, 1 H; H-C(2')); 4.14 (m, 1 H, H-C(3')); 4.01 (m, 1 NH, H-C(4')); 3.71 (m, 2 H, H-C(5')); 3.55 (bs, 2 H, CH2CH2OH); 3.41 (m, 2 H, HOCH2CH2N). Anal. Calc. for C25H25N5O6 (491.5): C, 61.09; H, 5.13; N, 14.26. Found: C, 60.60; H, 5.36; N, 14.16.
2-Isopropylamino-6,7-diphenyl-1-ß-D-ribofuranosyl-4(3H)pteridinone (48). Analogous to the preceding procedure with 37 (0.158 g, 0.2 mmol) and methanolic isopropylamine (10%, 3 ml) for 2 days in the icebox. Treatment with CH3ONa and purification on a silica gel plate gave after recrystallization from EtOH/H2O (2:3) 31 mg (32%) of 48. M.p. 190°. 1H-NMR ((D6)DMSO): 7.85 (bs, 1 H, NH); 7.50-7.30 (m, 10 H, arom. H); 6.93 (d, 1 H, H-C(1')); 5.75 (t, 1 H, 5’-OH); 5.45 (d, 1 H, 2’-OH); 5.23 (d, 1 H, 3’-OH); 4.46 (m, 2 H; H-C(2'), Me2CH); 4.15 (m, 1 H, H-C(3')); 3.98 (m, 1 NH, H-C(4')); 3.71 (bs, 2 H, H-C(5')); 1.25 (d, 6 H, (H3C)2CH). Anal. Calc. for C26H27N5O5 x H2O (507.5): C, 61.43; H, 5.41; N, 13.45. Found: C, 61.04; H, 5.75; N, 13.79.
2-n-Butylamino-6,7-diphenyl-1-ß-D-ribofuranosyl-4(3H)pteridinone (49). Analogous to the preceding procedure with 37 (0.158 g, 0.2 mmol) and methanolic n-butylamine (10%, 3 ml) for 2 days in the icebox. Treatment with CH3ONa and purification on a silica gel plate gave after
