Diisopropylethylamine → methyl 3-[(2S)-4-[(tert-butoxy)carbonyl]-2-methylpiperazin-1-yl]-2-oxo-1,2-dihydroquinoxaline-6-carboxylate

HRID 1403569Notes

Reaction equation

Cl[C:2]1[C:3](=[O:16])[NH:4][C:5]2[C:10]([N:11]=1)=[CH:9][C:8]([C:12]([O:14][CH3:15])=[O:13])=[CH:7][CH:6]=2.[C:17]([O:21][C:22]([N:24]1[CH2:29][CH2:28][NH:27][C@@H:26]([CH3:30])[CH2:25]1)=[O:23])([CH3:20])([CH3:19])[CH3:18].CCN(C(C)C)C(C)C>CS(C)=O.O>[C:17]([O:21][C:22]([N:24]1[CH2:29][CH2:28][N:27]([C:2]2[C:3](=[O:16])[NH:4][C:5]3[C:10]([N:11]=2)=[CH:9][C:8]([C:12]([O:14][CH3:15])=[O:13])=[CH:7][CH:6]=3)[C@@H:26]([CH3:30])[CH2:25]1)=[O:23])([CH3:20])([CH3:18])[CH3:19]

Participants

Conditions

Temperature: 80 °C

Procedure

To a solution of methyl 3-chloro-2-oxo-1,2-dihydroquinoxaline-6-carboxylate (1.0 g, crude) in DMSO (10 mL) was added tert-butyl-(3S)-3-methylpiperazine-1-carboxylate (1.0 g, 4.99 mmol) and DIEA (1.0 g, 7.74 mmol). The resulting solution was stirred overnight at 80° C. in an oil bath and then diluted with water (100 mL), extracted with ethyl acetate (4×40 mL) and the organic layers combined and dried over anhydrous magnesium sulfate. The solids were filtered out and filtrate was concentrated in vacuo to give a residue, which was purified by a silica gel column chromatography (2% ethyl acetate in petroleum ether) to afford methyl 3-[(2S)-4-[(tert-butoxy)carbonyl]-2-methylpiperazin-1-yl]-2-oxo-1,2-dihydroquinoxaline-6-carboxylate as a light yellow solid (310 mg).

Workup

extractionextracted with ethyl acetate (4×40 mL)
dry with materialdried over anhydrous magnesium sulfate
filtrationThe solids were filtered out
concentrationfiltrate was concentrated in vacuo
customto give a residue, which
customwas purified by a silica gel column chromatography (2% ethyl acetate in petroleum ether)

Sources & evidence

ORD record: ord-e1ed6a86760f463babc6b68807936441
Source dataset: uspto-grants-2014_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08912188B2

Reaction notes

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