Chlorotrimethylsilane → HCID 136352430, compound

Participants

Reaction Steps

5-Aminothiazolo[4,5-d]pyrimidine-2,7(6H)-dione 32 (400 mg, 2.71 mmol) was suspended in acetonitrile (16 mL) and hexamethyldisilazane (0.96 mL), and trimethylchlorosilane (0.55 mL) and trimethylsilyl triflate (0.9 mL) added. The mixture was stirred under reflux for 3.5 h. A solution of trimethylsilyl triflate (0.45 mL) in acetonitrile (1.0 mL) was added dropwise and stirring and heating was continued for additional 30 min. A slurry of 1-O-acetyl-2,3,5-O-tribenzoyl-L-ribofuranose (1.22 g, 2.28 mmol) in acetonitrile (4.1 mL) was added and the mixture stirred under reflux for 30 min. The reaction mixture was cooled and slowly poured into a vigorously stirred mixture of sodium bicarbonate (2.81 g) and water (96 mL), which produced a stick solid. Ethyl acetate was added, the mixture stirred until the solid dissolved. The aqueous layer was extracted with ethyl acetate twice and the combined organic layer washed with sodium bicarbonate, dried (Na2SO4), and concentrated. The crude was purified by chromatography on silica with 5%Et3N and 5% ethanol in methylene chloride to give 1.10 g of 5-amino-3-(2′,3′,5′-O-tribenzoyl-β-L-ribofuranosyl)thiazolo[4,5-d]pyrimidine-2,7(6H)-dione 33 as a white solid.

Provenance & Evidence