Tetrabutylammonium Fluoride → HCID 59129375, compound

Participants

Reaction Steps

A solution of 5-{2-[2-(tert-butyl-dimethyl-silanyloxy)-ethylamino]-5-nitro-phenyl}-3,3-dimethyl-pent-4-ynoic acid ethyl ester (600 mg, 1.34 mmol) and PdCl2(650 mg) in CH3CN (30 mL) was heated at reflux overnight. The resulting mixture was extracted with EtOAc (30 mL×3). The combined organic extracts were dried over anhydrous Na2SO4 and evaporated under vacuum. The residue was dissolved in THF (20 mL) and TBAF (780 mg, 3.0 mmol) was added. The mixture was stirred at room temperature for 1 h, the solvent was removed under vacuum, and the residue was purified by chromatography on silica gel (10% ethyl acetate/petroleum) to afford 3-[1-(2-hydroxy-ethyl)-5-nitro-1H-indol-2-yl]-3-methyl-butyric acid ethyl ester (270 mg, 60%). 1H NMR (300 MHz, CDCl3) δ 8.45 (d, J=2.1 Hz, 1H), 8.05 (dd, J=2.1, 9.0 Hz, 1H), 6.36 (d, J=9.0 Hz, 1H), 6.48 (s, 1H), 4.46 (t, J=6.6 Hz, 2H), 4.00-3.91 (m, 4H), 2.76 (s, 2H), 1.61 (s, 6H), 0.99 (t, J=7.2 Hz, 1H), 0.85 (s, 9H), 0.03 (s, 6H).

Provenance & Evidence