Ethyl bromoacetate → ethyl (2,4-dioxo-2H-3,1-benzoxazin-1(4H)-yl)acetate

Reaction equation

[C:1]12[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=1)[NH:6][C:5](=[O:12])[O:4][C:2]2=[O:3].[H-].[Na+].Br[CH2:16][C:17]([O:19][CH2:20][CH3:21])=[O:18]>CN(C)C=O>[O:12]=[C:5]1[N:6]([CH2:16][C:17]([O:19][CH2:20][CH3:21])=[O:18])[C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][C:1]=2[C:2](=[O:3])[O:4]1

Participants

Procedure

Isatoic anhydride (10 g, 1 equiv) in dimethylformamide (30 ml) was added dropwise to a suspension of sodium hydride (2.45 g, 60% in mineral oil, 1 equiv) in dimethylformamide (70 ml) at room temperature. The reaction was stirred for 1 hour prior to the addition of ethyl bromoacetate (6.8 ml, 1 equiv) and the resulting mixture stirred for 16 hours. Solvent evaporated, the residue suspended in water and the solid collected. The title compound was obtained by crystallisation from ethyl acetate, (10.5 g). 1H-NMR (CDCl3) δ 1.29 (3H, t), 4.27 (2H, q), 4.82 (2H, s), 6.96 (1H, d), 7.33 (1H, t), 7.74 (1H, dt), 8.19 (1H, dd).