N-Methyl dicyclohexylamine → 5-Chloro-2-((2-(trimethylsilyl)ethoxy)methyl)-2H-indazole-7-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

5-Chloro-1H-indazole-7-carbaldehyde (5.6 g, 31.0 mmol) and N-methyldicyclohexylamine (9 mL, 41.9 mmol) were suspended in tetrahydrofuran (100 mL), cooled to 0° C., and treated with (2-(chloromethoxy)ethyl)trimethylsilane (8.3 mL, 46.5 mmol). Cooling was removed and stirring continued for 4 h. The reaction was poured into ethyl acetate, washed with water (3×), 1 M potassium bisulfate (2×), brine (2×), dried over sodium sulfate, and concentrated. Column chromatography on silica gel (25% ethyl acetate/hexanes) gave 5.6 g (58%) as a faint yellow oil. 1H-NMR (CDCl3, 300 MHz) δ 10.50 (s, 1H), 8.21 (s, 1H), 7.94 (d, J=2.2 Hz, 1H), 7.82 (d, J=1.8 Hz, 1H), 5.78 (s, 2H), 3.62-3.67 (m, 2H), 0.90-0.96 (m, 2H), 0.05 (s, 9H). Mass spec.: 332.98 (MNa)+.

Provenance & Evidence