Toluene → tert-butyl 5-(hydroxymethyl)-1H-indole-1-carboxylate

Participants

Reaction Steps

To a solution of N-tert-butoxycarbonylindole-5-carboxylic acid methyl ester (23.6 g, 85.7 mmol) in dry tetrahydrofuran (225 mL) at −78° C. was added 1.5 M DIBALH in toluene (171 mL, 257 mmol). After 2 h, the reaction mixture was quenched by the slow addition of methanol (45 mL), water (60 mL), and saturated aqueous NH4Cl (30 mL). The cold bath was removed and after stirring for an additional 1 h, the reaction mixture was filtered over Celite. The Celite cake was washed with tetrahydrofuran and the filtrate was concentrated to remove the more volatile tetrahydrofuran. The biphasic mixture was extracted with ethyl acetate. The combined organic layers were washed with water and the aqueous layer back extracted with ethyl acetate. The combined organic layers were washed with brine, dried over magnesium sulfate, and concentrated to afford N-tert-butoxycarbonylindol-5-yl methanol (21.2 g).

Provenance & Evidence