Trifluoroacetic anhydride → 1-ethyl-7-methyl-3-(4-{[tris(1-methylethyl)silyl]oxy}phenyl)-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-one 4-oxide

Participants

Reaction Steps

Trifluoroacetic anhydride (3.92 mL) was added to a suspension of 1-ethyl-7-methyl-3-(4-{[tris(1-methylethyl)silyl]oxy}phenyl)-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-one (4 g) and urea hydrogen peroxide (2.74 g) in EtOAc (20 mL) at 0° C. The mixture was stirred at room temperature under a dry atmosphere (CaCl2 tube) overnight. The mixture was neutralized with sat. NaHCO3 at 0° C. and extracted with EtOAc. The organic layer was separated, washed with water and brine, dried over MgSO4 and concentrated in vacuo. The residue was purified by column chromatography (NH silica gel, eluted with 0%-100% EtOAc in hexane) to give 1-ethyl-7-methyl-3-(4-{[tris(1-methylethyl)silyl]oxy}phenyl)-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-one 4-oxide (250 mg) as colorless crystals.

Provenance & Evidence