Hydrochloric Acid → Ethyl 1-cyclopropyl-6,7-difluoro-1,2,3,4-tetrahydro-8-methoxy-5-nitro-4-oxo-2-phenylquinoline-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of ethyl 1-cyclopropyl-6,7-difluoro-1,4-dihydro-8-methoxy-5-nitro-4-oxoquinoline-3-carboxylate (3.00 g, 8.15 mmol) and cuprous iodide (467 mg, 2.45 mmol) in THF (80 mL), 2 M phenylmagnesium bromide in THF (6.10 mL, 12.2 mmol) was added under argon atmosphere at −78° C. After stirred at −78° C. for 1 h and at room temperature for 2 h, the reaction mixture was poured into ice-water (400 mL) and concentrated HCl (40 mL) was added to stirred for 30 min. The crude product was extracted with EtOAc, washed with saturated aq. NaHCO3 and brine, dried over MgSO4 and the solvent was removed in vacuo. The crude product was purified by column chromatography (Hexane:EtOAc 40:1→10:1) to yield ethyl 1-cyclopropyl-6,7-difluoro-1,2,3,4-tetrahydro-8-methoxy-5-nitro-4-oxo-2-phenylquinoline-3-carboxylate (3.09 g, 85%) as a yellow solid.

Provenance & Evidence