Methanol → HCID 131723529, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 20 (442 mg, 1.01 mmol) in anhydrous dilmethylformamide (12 mL) was added lithium azide moistened with 10% methanol (265 mg, 4.87 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 a 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 21 (291 mg, 75% yield) as a white solid: mnp 147-148° C.; UV (ethanol): λmax 242 nm (ε7700), 283 nm (ε7400), λmin 226 nm (ε6600), 264 nm (ε5800); 1H NMR (DMSO-d6): δ8.05 (d, 1H, H-6, J6-F5=7.0 Hz), 7.9-7.4 (br d, 2H, NH2), 5.7 (br s, 1H, H-1′), 4.37 (d, 1H, H-2′, J2′-3′=5.5 Hz), 4.3 (m, 1H, H-4′), 4. (m, 1H, H-5′), 3.7 (m, 1H,H-5″), 2.0 (m, 1H, H-3′), 1.8 (m, 1H, H-3″), 0.88 (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 1151 (3M−H)−, 767 (2M−H)−, 383 (M−H)−, 128 (B)−; [α]D20=+25 (c, 0.95 DMSO).

Provenance & Evidence