Methanol → 6-N-(4-Monomethoxytrityl)-9-(3,5-di-O-benzoyl-2-deoxy-beta-L-threo-pentofuranosyl)adenine

Temperature

60 °C

To a solution of compound 4 (0.88 g, 1.92 mmol) in dry pyridine (40 mL) was added 4-monomethoxytrityl chloride (1.18 g, 3.84 mmol). The mixture was stirred at 60° C. for 24 h. After addition of methanol (5 mL), the solution was concentrated to dryness, the residue was dissolved in dichloromethane (50 mL) and washed successively with water (30 mL), aqueous saturated NaHCO3 (30 mL) and water (30 mL). The organic layer was dried, filtered, concentrated and co-evaporated with toluene to give pure 5 (1.01 g, 72%) as a foam: 1H NMR (CDCl3): δ 2.9-3.0 (m, 2H, H-2′ and H-2″), 3.62 (s, 3H, OCH3), 4.6-4.8 (m, 3H, H-4′, H-5′ and H-5″), 5.85 (pt, 1H, H-3″), 6.44 (dd, 1H, H-1′, J1′,2′=3.1 Hz, J1′,2″=7.3 Hz), 6.9 (br s, 1H, NH-6), 6.7-6.8 and 7.2-7.4 (2m, 24H, 2 benzoyls and MMTr), 7.97 and 8.13 (2s, 2H, H-2 and H-8); ms: matri G/T, (FAB+) m/z 732 [M+H]+, (FAB−) m/z 730 [M−H]31 ; UV (95% ethanol): λmax 274 nm (ε 12100), 225 nm (ε 24200), λmin 250 nm (ε 5900); [α]D20=−16 (c 1.12, DMSO).

1. concentrationthe solution was concentrated to dryness
2. dissolutionthe residue was dissolved in dichloromethane (50 mL)
3. washwashed successively with water (30 mL), aqueous saturated NaHCO3 (30 mL) and water (30 mL)
4. customThe organic layer was dried
5. filtrationfiltered
6. concentrationconcentrated

ORD record

ord-54d55db3e03e4eb1bb2f1cd338a2ca94

Source dataset

uspto-grants-2003_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06569837B1