反应详情

To a solution of 7-methyl-1H-indazole-5-carbaldehyde (5.0 g, 31.25 mmol) and N-methyl-dicyclohexylamine (13.5 mL, 62.35 mmol) in dry tetrahydrofuran (120 mL) at 0° C., was added 2-(trimethylsilyl)ethoxymethyl chloride (6.65 mL, 39.5 mmol). The ice-bath was removed and stirring continued for 5 h. The reaction mixture was diluted with ethyl acetate, washed with water (2×), brine (2×), dried over sodium sulfate, and concentrated in vacuo. Column chromatography afforded 8.5 g (93%). 1H-NMR (400 MHz, CDCl3) δ 12.3 (br., 1H), 8.13 (s, 1H), 7.88 (s, 1H), 7.42 (s, 1H), 6.12 (d, J=7.0 Hz, 1H), 5.31 (d, J=7.0 Hz, 1H), 3.80 (s, 3H), 2.60 (s, 3H).

1. customThe ice-bath was removed
2. additionThe reaction mixture was diluted with ethyl acetate
3. washwashed with water (2×), brine (2×)
4. dry with materialdried over sodium sulfate
5. concentrationconcentrated in vacuo
6. customColumn chromatography afforded 8.5 g (93%)