Sodium Pyrosulfite → N-{[6-bromo-2-oxo-4-(trifluoromethyl)-1,4-dihydro-2H-3,1-benzoxazin-4-yl]methyl}-4-fluorobenzamide

Participants

Reaction Steps

While stirring a solution of N-{[6-bromo-1-(4-methoxybenzyl)-2-oxo-4-(trifluoromethyl)-1,4-dihydro-2H-3,1-benzoxazin-4-yl]methyl}-4-fluorobenzamide (13.0 g, 22.9 mmol) in acetonitrile (50 mL), an aqueous solution (25 mL) of cerium ammonium nitrate (37.7 g, 68.7 mmol) was added dropwise thereto at room temperature. The reaction solution was stirred at room temperature for 4 hours. Sodium pyrosulfite was added to the reaction solution, and the solution was stirred for 30 minutes and then diluted with ethyl acetate, and the organic layer was separated. The organic layer was washed sequentially with water and saturated brine and then dried over magnesium sulfate. After the drying agent was removed by filtration, the solvent was evaporated under reduced pressure. The resulting residue was crystallized from ethyl acetate-heptane, whereby the objective compound (6.7 g of primary crystal, 2.5 g of secondary crystal, 9.2 g in total, 90%) was obtained as a white solid.

Provenance & Evidence