Trimethylsilyl triflate → 1-(2-c-Methyl-2,3,5-tri-o-benzoyl-beta-d-ribofuranosyl)imidazo[4,5-d]pyridazin-4-one

Participants

Reaction Conditions

Reaction Steps

To a suspension of imidazo[4,5-d]pyridazine (3.48 g, 25.5 mmol) [for preparation see Journal of Heterocyclic Chemistry, 1969, Vol 6, 93] in dry acetonitrile (35 mL) was added 1,2,3,5-tetra-O-benzoyl-2-C-methyl-β-D-ribofuranose (14.48 g, 25.0 mmol) at 20° C. and stirred for 15 mn. DBU (11.5 mL, 76.3 mmol) was added at 0° C. and the solution was stirred for 15 mn at 0° C. TMSOTf (24.7 mL, 127.8 mmol) was added at 0° C. and the mixture was heated at 80° C. for 20 hours. The reaction mixture was poured into an aqueous solution of sodium hydrogenocarbonate and extracted by ethyl acetate. The organic layer was evaporated to dryness to give a yellow powder. The crude product was purified on silica gel using dichloromethane/methanol (99.3/0.7) as eluant to give a slight yellow powder which was crystallized from isopropanol to give the title compound (2.45 g) as a white powder.

Provenance & Evidence