反应详情

Diisopropyl azodicarboxylate (0.15 ml, 0.75 mmol) was added to an anhydrous tetrahydrofuran (THF) solution (2.5 ml) of 5-hydroxy-1-(toluene-4-sulfonyl)-1H-indole-2-carboxylic acid ethyl ester (175 mg, 0.48 mmol), triphenylphosphine (197 mg, 0.75 mmol), and 2-propanol (0.2 ml, 4.0 mmol), and stirred at room temperature for one hour. The reaction mixture was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography to give 5-isopropoxy-1-(toluene-4-sulfonyl)-1H-indole-2-carboxylic acid ethyl ester as a colorless gum-like material (166.7 mg, 87%).

1. concentrationThe reaction mixture was concentrated under reduced pressure
2. customThe resulting residue was purified by silica gel column chromatography