Reaction Steps
A solution of 0.363 g (0.852 mmole) of 76 in 10 mL of NH3 /MeOH was stirred in a pressure bottle at room temperature for 5 hr. The reaction mixture was evaporated and coevaporated with MeOH (3×, bath temperature <40° C.), The residue was recrystallized from MeOH/Et2O to give 0.203 g (2 crops, 79%) of 78 as beige crystals. MP ~154° C. (dec.), MS (El) m/e 299.0675 (10%, M+ =299.0673), 1H NMR (DMSO-d6): d 7.56 (d, 1, 7-H, J7-6 =8.5 Hz), 6.73 (d, 1, 4-H, J4-6 =2.0 Hz), 6.57 (dd, 1, 6-H), 5.77 (d, 1, 1'-H, J1'-2' =7 5 Hz), 5.39 (d, 1, 2'-OH, J2'-2'OH =6.5 Hz), 5.18 (d, 1, 3'-OH, J3'-3'OH =4.5 Hz), 5.11 (t, 1, 5'-OH, J5'-5'OH =5.0 Hz), 4.90 (s, 2, 5-NH2), 4.44 (m, 1, 2'-H, J2'-3' =6.0 Hz), 4.09 (m, 1, 3'-H, J3'-4' =2.5 Hz), 3.91 (m, 1, 4'-H, J4'-5' =3.5 Hz), 3.65 ("t", 2, 5'-H), 13C NMR (DMSO-d6): d 144.82 (C5), 142.77 (C3a), 138.25 (C2), 125.13 (C7a), 112.67 (C7), 112.22 (C6), 101.83 (C4), 88.81 (C1'), 85.48 (C4'), 70.89 (C2'), 69.61 (C3'), 61.31 (C5').
