反应详情

To a solution of methyl 2-aminothiophene-3-carboxylate (2.0 g, 12.7 mmol) in dichloromethane (40 mL) and glacial acetic acid (0.72 mL) were added isobutyraldehyde (0.87 g, 12.1 mmol) and sodium triacetoxyborohydride (4.0 g, 18.9 mmol). The reaction mixture was stirred for 18 h at room temperature and concentrated. The residue was dissolved in ethyl acetate, washed with aqueous sodium bicarbonate solution and with water, dried over anhydrous sodium sulfate and concentrated. The residual oil was purified on a silica gel flash chromatography column eluted with 5% ethyl acetate-hexane to afford the title compound as a slightly yellow oil (2.19 g, 81% yield). 1H NMR (400 MHz, CDCl3): δ 7.00 (d, 1 H), 6.18 (d, 1 H), 3.80 (s, 3 H), 3.20 (m, 2 H), 1.68 (m, 1 H), 1.00 (d, 6 H).

1. concentrationconcentrated
2. dissolutionThe residue was dissolved in ethyl acetate
3. washwashed with aqueous sodium bicarbonate solution and with water
4. dry with materialdried over anhydrous sodium sulfate
5. concentrationconcentrated
6. customThe residual oil was purified on a silica gel flash chromatography column
7. washeluted with 5% ethyl acetate-hexane