Methanol → HCID 131723305, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 9 (520 mg, 1.19 mmol) in anhydrous dimethylformamide (12 mL) was added lithium azide moistened with 10% methanol (300 mg, 5.31 mmol). The reaction mixture was stirred at 100° C. during 2.5 h, and then cooled to room temperature, poured onto ice/water (200 mL) and extracted with chloroform (3×100 mL). Combined extracts were washed with saturated aqueous sodium hydrogen carbonate solution (2×100 mL), with water (5×100 mL), and then dried over sodium sulphate and evaporated under reduced pressure. The residue was purified by silica gel column chromatography [eluent : methanol (4%) in chloroform] to give pure 10 (327 mg, 72%), which was crystallized from a diethyl ether/methanol mixture: mp 146-147° C.; UV (ethanol): λmax 243 nm (ε 8700), 283 nm (ε8400), λmin 226 nm (ε 7200), 264 nm (ε 6700); 1H NMR (DMSO-d6): δ 7.90 (d, 1H, H-6, J6-F5=7.0 Hz), 7.8-7.5 (br d, 2H, NH2), 6.0 (m, 1H, H-1′), 4.3 (m, 1H, H-3′), 3.9-3.7 (m, 3H, H-4′, H-5′ and H″-5), 2.4-2.2 (m, 2H, H-2′ and H-2″), 0.87 (s, 9H, (CH3)3C—Si), 0.05 (s, 6H, (CH3)2Si); MS (matrix GT): FAB>0 m/z 769 (2M+H)+, 385 (M+H)+, 130 (BH2)+; FAB<0 m/z 383 (M−H)−; [α]D20=−67 (c, 0.96 DMSO).

Provenance & Evidence