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

HRID 561146Notes

Reaction equation

[CH:1]1([N:4]2[C:13]3[C:8](=[C:9]([N+:18]([O-:20])=[O:19])[C:10]([F:17])=[C:11]([F:16])[C:12]=3[O:14][CH3:15])[C:7](=[O:21])[C:6]([C:22]([O:24][CH2:25][CH3:26])=[O:23])=[CH:5]2)[CH2:3][CH2:2]1.Cl.[CH2:28]1COCC1>C[Mg]Cl>[CH:1]1([N:4]2[C:13]3[C:8](=[C:9]([N+:18]([O-:20])=[O:19])[C:10]([F:17])=[C:11]([F:16])[C:12]=3[O:14][CH3:15])[C:7](=[O:21])[CH:6]([C:22]([O:24][CH2:25][CH3:26])=[O:23])[CH:5]2[CH3:28])[CH2:2][CH2:3]1

Participants

Conditions

Temperature: -78 °C

Procedure

To a stirred solution of ethyl 1-cyclopropyl-6,7-difluoro-1,4-dihydro-8-methoxy-5-nitro-4-oxoquinoline-3-carboxylate (2.50 g, 6.79 mmol) and cuprous iodide (389 mg, 2.04 mmol) in THF (70 mL), 3 M methylmagnesium chloride in THF (3.40 mL, 10.2 mmol) was added under argon atmosphere at −78° C. After stirred at −78° C. for 1 h and at room temperature for 1 h, the reaction mixture was poured into ice-water (300 mL) and concentrated HCl (30 mL) was added to stirred for 30 min. The crude product was extracted with EtOAc, washed with brine, dried over MgSO4 and the solvent was removed in vacuo. The crude product was purified by column chromatography (Hexane:EtOAc 20:1→5:1) to yield ethyl 1-cyclopropyl-6,7-difluoro-1,2,3,4-tetrahydro-8-methoxy-2-methyl-5-nitro-4-oxoquinoline-3-carboxylate (1.44 g, 55%) as a yellow solid.

Workup

additionwas added
stirringto stirred for 30 min
extractionThe crude product was extracted with EtOAc
washwashed with brine
dry with materialdried over MgSO4
customthe solvent was removed in vacuo
customThe crude product was purified by column chromatography (Hexane:EtOAc 20:1→5:1)

Sources & evidence

ORD record: ord-94f0ffc81e3045b58b6fbfa2d8edb824
Source dataset: uspto-grants-2011_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08063221B2

Reaction notes

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