[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[N:8]([C:12](=[O:14])[CH3:13])[C@@H:7]([CH3:15])[CH2:6][NH:5]2.C(N(CC)C(C)C)(C)C.[O:25]1[CH:29]=[CH:28][CH:27]=[C:26]1[C:30](Cl)=[O:31]>ClCCCl>[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[N:8]([C:12](=[O:14])[CH3:13])[C@@H:7]([CH3:15])[CH2:6][N:5]2[C:30]([C:26]1[O:25][CH:29]=[CH:28][CH:27]=1)=[O:31]A 100 mL round bottomed flask fitted with a nitrogen inlet was charged with (S)-1-(6-bromo-2-methyl-3,4-dihydroquinoxaline-1(2H)-yl)ethanone (0.500 g, 1.858 mmol), 1,2-dichloroethane (20 mL), N,N-diisopropylethylamine (1.0 mL, 5.73 mmol), and furan-2-carbonyl chloride (0.366 mL, 3.72 mmol). The reaction mixture was heated to 50° C. for 2 h with magnetic stirring. After for 2 h, the reaction was washed with 1 N aqueous sodium hydroxide solution (15 mL). The organic layer was removed and set aside. The aqueous layer was washed with 1,2-dichloroethane (20 mL) and the organic layers were combined and concentrated under reduced pressure. The crude product was purified by column chromatography on silica gel (eluting with 2:1 hexanes-ethyl acetate) to afford (S)-1-(6-bromo-4-(furan-2-carbonyl)-2-methyl-3,4-dihydroquinoxaline-1(2H)-yl)ethanone (0.58 g, 86% yield) as a viscous yellow oil. MS (ESI, pos. ion) m/z 417 [M+1]+.
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