[(6-{(4S)-4-[(tert-Butoxycarbonyl)amino]-2-oxopyrrolidin-1-yl}-2-nitropyridin-3-yl)oxy]acetic acid ethyl ester → [(3S)-5-Oxo-1-(3-oxo-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazin-6-yl)pyrrolidin-3-yl]carbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

Reduced iron (150 mg, 2.69 mmol) was added to a solution of [(6-{(4S)-4-[(tert-butoxycarbonyl)amino]-2-oxopyrrolidin-1-yl}-2-nitropyridin-3-yl)oxy]acetic acid ethyl ester (380 mg, 0.895 mmol) in acetic acid (3.8 ml) and the mixture was stirred at 85° C. for 1.5 hours. After cooling, the insoluble material was removed by filtration and the filtrate was concentrated under reduced pressure. The residue was dissolved in dichloromethane, a saturated sodium hydrogen carbonate aqueous solution was added thereto and the mixture was stirred for 10 minutes. The solvent was removed under reduced pressure and the obtained residue was purified by silica gel column chromatography (chloroform/methanol) to yield 305 mg (98%) of the title compound in the form of a colorless solid.

Provenance & Evidence