Sulfuric Acid → HCID 59002890, compound

Participants

Reaction Steps

To a suspension of ethyl (3S)-8-amino-9,10-difluoro-2,3-dihydro-7-oxo-3-phenylmethyl-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylate (100 mg, 0.250 mmol) in a mixture of AcOH (0.6 mL) and water (0.5 mL), was added H2SO4 (0.1 mL), the whole mixture was heated under reflux for 3 h. The reaction mixture was poured into ice-water and the resulting precipitates were collected by filtration. The filtered precipitates were suspended in water, filtered, and dried in vacuo to give (3S)-8-amino-9,10-difluoro-2,3-dihydro-7-oxo-3-phenylmethyl-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid (88.0 mg, 95%) as a yellow powder.

Provenance & Evidence