Sodium Carbonate → 5-Bromo-3-methyl-indol-2-one

Beteiligte Stoffe

Reaktionsschritte

Under an atmosphere of nitrogen, bromine (0.96 g, 6.0 mmol) in acetic acid (5 cm3). was added drop wise to a solution of 3-methyl-2-indolinone (0.8749 g, 6.0 mmol) (Kende, et al, Synth. Commun., 12, 1, 1982) and sodium acetate (0.50 g, 6.0 mmol) in acetic acid (10 cm3). The reaction was stirred at room temperature for 3.5 h. Saturated sodium carbonate was added to quench the reaction. The water layer was extracted EtOAc (×3), dried (MgSO4), filtered, and evaporated to give the title compound (1.26 g, 93%), Mp=119-120° C.; 1H NMR (DMSO) δ 1.32 (d, 3H, J=7.66 Hz), 3.45 (q, 1H, J=7.62 Hz), 6.77 (d, 1H, J=8.23 Hz), 7.46 (s, 1H), 7.36-7.33 (m, 1H), 10.4 (s, 1H); IR (KBr) 3200, 1725 cm−1; MS (EI) m/z 224/226 (M−H)−; CHN calculated for C9H8BrNO: C, 47.82; H, 3.57; N, 6.20; Found: C, 47.44; H, 3.42; N, 6.04.

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