Methanol → HCID 87970440, compound

Participants

Reaction Conditions

Reaction Steps

A suspension of 19 (1.70 g, 4.73 mmol) in dry pyridine (80 mL) was stirred under argon and cooled to 0° C. Methanesulfonyl chloride (MsCl, 1.21 mL, 15.6 mmol) was added dropwise and the reaction mixture stirred at 0° C. for 5 h. Then the mixture was poured onto ice/water (300 mL) and extracted with chloroform (3×300 mL). Combined extracts were washed with a 5% aqueous sodium hydrogen carbonate solution (300 mL), with water (2×300 mL) and then dried over sodium sulphate and evaporated under reduced pressure. The resulting residue was purified by silica gel column chromatography [eluent: stepwise gradient of methanol (8-12%) in toluene] to give pure 20 (1.41 g, 68% yield) as a white solid: mp 75-76° C.; UV (ethanol): λmax 243 nm (ε 8100), 282 nm (ε 7300), λmin 225 nm (ε 6000), 265 nm (ε 6000); 1H NMR (DMSO-d6): δ 7.9-7.6 (br d, 2H, NH2), 7.85 (d, 1H, H-6, J6-F5=7.0 Hz), 6.08 (dd, 1H, H-1′, J1′-2′=5.2 Hz and J1′-F5=1.6 Hz), 5.4 (m, 1H, H-2′), 4.1 (m, 1H, H-4′), 3.9 (m, 1H, H-5′), 3.7 (m, 1H, H-5″), 3.11 (s, 3H, CH3SO2), 2.47 (m, 1H, H-3′), 2.0 (m, 1H, H-2″), 0.85 (s, 9H, (CH3)3C—Si), 0.05 (s, 6H, (CH3)2Si); MS (matrix GT): FAB>0 m/z 1312 (3M+H)+, 875 (2M+H)+, 438 (M+H)+, 309 (S)+, 130 (BH2)+; FAB<0 m/z 1310 (2M−H)−, 873 (2M−H)−, 436 (M−H)−, 128 (B)−, 95 (CH3SO3)−; [α]D20=−84 (c, 0.84 DMSO).

Provenance & Evidence