反应详情

To a solution of 2-methylindole (0.500 g, 3.81 mmol) in THF (30 mL) was added 2,5-dichloro-1,4-benzoquinone (1.35 g, 7.62 mmol) at room temperature. To this mixture was added concentrated HCl (12 N, 0.38 mL, 4.57 mmol) dropwise. After the reaction mixture was stirred for 5 hours (5 h–12 h) at room temperature, DDQ (1.73 g, 7.62 mmol) was added. After stirring for 3 hours (3 h–12 h) at room temperature, the mixture was diluted with EtOAc (100 mL). The organic solution was washed with saturated NaHCO3 (3×100 mL) and brine (100 mL), and dried over Na2SO4. The residue was concentrated and purified by flash column chromatography using 15% EtOAc in hexane as eluent to afford pure 2,5-dichloro-3-(2-methyl-1H-indol-3-yl)-[1,4]benzoquinone (1.13 g, 97%) as a blue solid. Melting point 158–159° C. Rf=0.35 (3:7, EtOAc/hexane). 1H NMR (CDCl3) δ 8.40 (bs, NH), 7.24–7.11 (m, 5H), 2.26 (s, 3H). 1H NMR (d6-acetone): δ 10.60 (1H, br s), 7.39 (1H, s), 7.36 (1H, d, J=7.8 Hz), 7.24 (1H, d, J=7.8 Hz), 7.10 (1H, t, J=7.8 Hz), 7.01 (1H, t, J=7.8 Hz). 13C NMR (CDCl3) δ 177.7, 176.6, 144.3, 139.8, 139.3, 136.9, 135.1, 133.1, 126.6, 122.0, 120.5, 119.6, 110.8, 104.8, 13.9. IR (KBr): 3388, 3061, 1676, 1566, 1459, 1250, 1032, 749 cm−1. Anal. Calcd. for C15H9Cl2NO2: C, 58.85; H, 2.96; Cl, 23.16; N, 4.58. Found: C, 58.85; H, 2.96; Cl, 23.16; N, 4.58. HRMS (EI) Calcd. For C15H9Cl2NO2 [M+]: 305.0010. Found: 305.0002.

1. stirringAfter stirring for 3 hours (3 h–12 h) at room temperature
2. washThe organic solution was washed with saturated NaHCO3 (3×100 mL) and brine (100 mL)
3. dry with materialdried over Na2SO4
4. concentrationThe residue was concentrated
5. custompurified by flash column chromatography