Trimethylsilyl triflate → HCID 54258191, compound

Participants

Reaction Steps

As per General Procedure III. 5,6-difluoro-1H-benzimidazole (1.0 g, 6.5 mmol), N,O-bis(trimethlsilyl)acetamide (1.6 ml, 6.5 mmol), in 50 ml 1,2-dichloroethane (Aldrich Sure Seal, Milwaukee) were heated at 85° C. for 2.5 h under a nitrogen atmosphere then allowed to cool to rt. Trimethylsilyl trifluoromethanesulfonate (1.4 ml, 7.2 mmol) and 2.0 g (6.3 mmol) solid 1,2,3,4-tetra-O-acetyl-b-D-ribopyranose (beta-D-ribopyranose 1,2,3,4-tetraacetate, Aldrich, Milwaukee) was added and the mixture was heated in an oil bath at 85° C. for 24 h under a nitrogen atmosphere. The reaction was then poured into 7% aqueous sodium bicarbonate and extracted with dichloromethane. The organic layer was dried with magnesium sulfate (anhyd), filtered, and evaporated. The crude residue was purified on a silica gel column (2.5×20 cm, 230-400 mesh) with CH2Cl2 and an increasing gradient of methanol from 0.5 to 2% to provide the title compound as a white foam (1.1 g, 2.6 mmol, 40%); MS (API+): m/z (rel. intensity) 524 (0.10, M+1); 1H NMR (DMSO-d6) δ8.47 (s,1H), 8.20-8.16 (m, 1H), 7.76-7.71 (m, 1H), 6.02-6.00 (d, 1H, J=9.5 Hz), 5.75-5.69 (m, 2H), 5.53-5.40 (m, 1H), 4.05-3.94 (m, 1H), 2.22 (s, 3H), 2.00 (s, 3H), 1.73 (s, 3H).

Provenance & Evidence