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: matrix G/T, (FAB+) m/z 732 [M+H]+, (FAB−) m/z 730 [M−H]−; 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-e099c76f4fa5478b9aaffd2c5f0ce60e

Source dataset

uspto-grants-2007_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07304043B2