Trifluoroacetic acid → HCID 5278921, compound

Participants

Reaction Steps

790 mg of (R)-2-methyl-2-(4′-(4-tert-butoxycarbonylpiperazin-1-yl)biphenyl-4-yloxymethyl)-6-nitro-2,3-dihydroimidazo[2,1-b]oxazole was dissolved in 10 ml of trifluoroacetic acid and 5 ml of dichloromethane, followed by stirring at room temperature overnight. Thereafter, the reaction solution was concentrated under a reduced pressure, and then, 6 ml of dichloromethane and 6 ml of triethylamine were added thereto. The mixture was stirred at room temperature for 5 minutes, and it was then concentrated under a reduced pressure. The residue was dissolved in 15 ml of DMF, and then, 0.4 ml of 4-trifluoromethylbenzaldehyde and 625 mg of triacetoxy sodium borohydride were added thereto while cooled by ice, followed by stirring at room temperature overnight. Thereafter, water was added to the reaction solution, the mixture was stirred, and the insoluble precipitate was removed by filtration. The filtrate was washed with water and then dissolved in dichloromethane. The obtained solution was washed with a saturated aqueous solution of sodium chloride, and then dried over sodium sulfate. The sodium sulfate was filtered, and the filtrate was concentrated under a reduced pressure. The residue was purified by silica gel column chromatography (dichloromethane:methanol=20:1). The resultant product was then recrystallized from a mixed solvent consisting of dichloromethane and ethyl acetate to obtain 585 mg (yield: 60.5%) of light yellow powders, (R)-2-methyl-6-nitro-2-(4′-(4-(4-trifluoromethylbenzyl)piperazin-1-yl)biphenyl-4-yloxymethyl)-2,3-dihydroimidazo[2,1-b]oxazole.

Provenance & Evidence