Sulfuric Acid → 6-[(4R)-4-Amino-2-oxopyrrolidin-1-yl]-2H-1,4-benzoxazin-3(4H)-one

Participants

Reaction Conditions

Reaction Steps

A solution of {(3R)-1-[4-(methoxymethyl)-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-6-yl]-5-oxopyrrolidin-3-yl}carbamic acid tert-butyl ester (120 mg, 0.31 mmol) in methanol (2 ml) was cooled in an ice bath. Lithium chloride (80 mg, 0.92 mmol) and concentrated sulfuric acid (0.5 ml) were added thereto, and the mixture was then stirred at 80° C. for 2 hours. After cooling, the reaction solution was neutralized with a saturated sodium hydrogen carbonate aqueous solution and the solvent was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (NH silica gel, chloroform/methanol) to yield 58 mg (75%) of the title compound in the form of a colorless solid.

Provenance & Evidence