[Na].[C:2]([NH:5][CH:6]([C:12]#[N:13])[C:7]([O:9][CH2:10][CH3:11])=[O:8])(=[O:4])[CH3:3].Br[CH:15]1[CH2:22][C:21]2[C:16]1=[CH:17][CH:18]=[CH:19][CH:20]=2>C(O)C>[C:2]([NH:5][C:6]([CH:15]1[CH2:22][C:21]2[C:16]1=[CH:17][CH:18]=[CH:19][CH:20]=2)([C:12]#[N:13])[C:7]([O:9][CH2:10][CH3:11])=[O:8])(=[O:4])[CH3:3]Sodium (464 mg, 20.2 mmol, 1.2 eq.) was allowed to react with absolute ethanol (40 mL, 0.42 M); to the resulting mixture was added ethyl 2-(acetylamino)-2-cyanoacetate (3.44 g, 20.2 mmol, 1.2 eq.). After 20 minutes at 60° C., 7-bromobicyclo[4.2.0]octa-1,3,5-triene (3.092 g, 16.89 mmol, 1 eq.) was added and the reaction mixture was heated at reflux overnight, then filtered and concentrated in vacuo. The residue was diluted with water and extracted with ethyl acetate. The organic layer was washed with brine, dried over sodium sulfate, filtered, and concentrated in vacuo to give a dark oil, which was purified by silica gel chromatography (Gradient: 0% to 50% ethyl acetate in heptane) to give #99 (4.38 g) as a yellow gum. LC-MS: m/z 273.2 [M+H+], retention time=2.36 minutes.
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