Pyridine → Tert-butyl 2-[(tert-butoxycarbonyl)oxy]-6-[({2'-[(hydroxyimino)methyl]-4'-[(methoxycarbonyl)methyl]-1,1'-biphenyl-4-yl}oxy)methyl]-3-(trifluoromethyl)benzoate

Participants

Reaction Steps

Pyridine (49 μl, 0.62 mmol) and hydroxylamine hydrochloride (42 mg, 0.62 mmol) were added to a solution of tert-butyl 2-[(tert-butoxycarbonyl)oxy]-6-[({2′-formyl-4′-[(methoxycarbonyl)methyl]-1,1′-biphenyl-4-yl}oxy)methyl]-3-(trifluoromethyl)benzoate (198 mg, 0.307 mmol) obtained in Example (45-2) in ethanol (4 ml), and the mixture was stirred at room temperature for 4 hours. The reaction mixture was diluted with ethyl acetate, successively washed with water and a saturated aqueous NaCl solution and dried with anhydrous sodium sulfate. The residue obtained by removing the solvent under reduced pressure was subjected to silica gel preparative thin layer chromatography (developing solvent: n-hexane/ethyl acetate=2/1) to give crude tert-butyl 2-[(tert-butoxycarbonyl)oxy]-6-[({2′-[(hydroxyimino)methyl]-4′-[(methoxycarbonyl)methyl]-1,1′-biphenyl-4-yl}oxy)methyl]-3-(trifluoromethyl)benzoate (170 mg).

Provenance & Evidence