Sodium Bicarbonate → HCID 10814962, compound

Participants

Reaction Steps

2-[(1R,2S)-2-(2,4-Difluorophenyl)-2-hydroxy-3-(isopropoxydimethylsilyl)-1-methylpropyl]-4-[4-(2,2,3,3-tetrafluoropropoxy)phenyl]-3(2H,4H)-1,2,4-triazolone (11 g) was dissolved in a mixture of methanol and tetrahydrofuran (1:1, 90 ml), to which 19.2 ml of 30% aqueous hydrogen peroxide and 1.57 g of sodium hydrogencarbonate were added. Then, the mixture was heated at 70° to 80° C. for 90 minutes. The reaction solution was cooled and extracted with a mixture of 500 ml of ethyl acetate and 100 ml of diisopropyl ether. The extract was washed with 100 ml of water, an aqueous solution of Na2S2O3 (50 ml×2) and 50 ml of an aqueous solution of sodium chloride successively, and dried over magnesium sulfate. After the solvent was distilled off under reduced pressure, the residue was recrystallized from 50 ml of diisopropyl ether to give 8.27 g of 2-[(1R,2S)-2-(2,4-difluorophenyl)-2,3-dihydroxy-1-methylpropyl]-4-[4-(2,2,3,3-tetrafluoropropoxy)phenyl]-3(2H,4H)-1,2,4-triazolone as colorless prisms. The mother liquor of recrystallization was submitted to silica gel chromatography (silica gel: 40 g, eluent; hexane:ethyl acetate=1:1). The resultant was recrystallized from diisopropyl ether to give 0.33 g of the above compound (total yield: 93.7%).

Provenance & Evidence