Tetrahydrofuran → 5-chloro-7-formyl-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-indole-3-carbonitrile

Participants

Reaction Steps

Osmium tetroxide (0.1 mL, 0.013 mmol) (4% in water) was added to a solution of 5-chloro-1-((2-(trimethylsilyl)ethoxy)methyl)-7-vinyl-1H-indole-3-carbonitrile (385 mg, 1.157 mmol) and NMO (271 mg, 2.313 mmol) in Acetone (20 mL) and Water (5 mL). The reaction was stirred at ambient temperature for 2 hours and then THF (10 mL) and sodium periodate (742 mg, 3.47 mmol) were added. The reaction was stirred for 1 hour, and precipitate formed. The solvent was evaporated and the residue was taken up in water (100 mL) and extracted with ethyl acetate (3×20 mL). The organic layers were dried with MgSO4 and evaporated. The residue was purified by chromatography on SiO2 with 10% to 15% ethyl acetate/hexanes to give 5-chloro-7-formyl-1-((2-(trimethylsilyl)ethoxy)methyl)-1H-indole-3-carbonitrile (310 mg, 0.926 mmol, 80% yield) as a white solid. 1H-NMR (CDCl3, 400 MHz) δ 10.22 (s, 1H), 8.0 (d, J=2.0 Hz, 1H), 7.84 (d, J=2.0 Hz, 1H), 7.79 (s, 1H), 5.80 (s, 2H), 3.43 (app T, J=8.2 Hz, 2H), 0.84 (app t, J=8.2 Hz, 2H), −0.07 (s, 9H). LC (HPLC method 4): tR=3.68 min.

Provenance & Evidence