Triethyl Phosphate → Ethyl 1-ethyl-7,8-dimethoxy-4-oxo-1,4-dihydroquinoline-3-carboxylate

HRID 525949Notes

Reaction equation

[CH3:1][O:2][C:3]1[C:12]([O:13][CH3:14])=[C:11]2[C:6]([C:7](=[O:20])[C:8]([C:15]([O:17][CH2:18][CH3:19])=[O:16])=[CH:9][NH:10]2)=[CH:5][CH:4]=1.C(=O)([O-])[O-].[K+].[K+].P(OCC)(OCC)(O[CH2:30][CH3:31])=O>O>[CH2:30]([N:10]1[C:11]2[C:6](=[CH:5][CH:4]=[C:3]([O:2][CH3:1])[C:12]=2[O:13][CH3:14])[C:7](=[O:20])[C:8]([C:15]([O:17][CH2:18][CH3:19])=[O:16])=[CH:9]1)[CH3:31]

Participants

Conditions

Temperature: 120 °C

Procedure

A mixture of ethyl 7,8-dimethoxy-4-oxo-1,4-dihydroquinoline-3-carboxylate (40 g, 144 mmol) and potassium carbonate (29.9 g, 216 mmol) in triethyl phosphate (123 ml, 721 mmol) was stirred at 120° C. for 24 h. LCMS indicated completion of the reaction. The reaction mixture was cooled down to rt and diluted with water, extracted with DCM, dried over sodium sulfate and evaporated in vacuo. The crude material was recrystallized in EtOH, the precipitate was collected by filtration, washed by cold EtOH and dried in air to afford ethyl 1-ethyl-7,8-dimethoxy-4-oxo-1,4-dihydroquinoline-3-carboxylate (26 g, 85 mmol, 59.0% yield) as a yellow solid. LCMS: (M+H)+: 306.2.

Workup

customcompletion of the reaction
temperatureThe reaction mixture was cooled down to rt
extractionextracted with DCM
dry with materialdried over sodium sulfate
customevaporated in vacuo
customThe crude material was recrystallized in EtOH
filtrationthe precipitate was collected by filtration
washwashed by cold EtOH
customdried in air

Sources & evidence

ORD record: ord-7090ebedfdb8456c86d6328edb9893ff
Source dataset: uspto-grants-2016_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09340556B2

Reaction notes

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