Ethanol → Ethyl indole-5-carboxylate

Participants

Reaction Steps

Combine 5-carboxyindole (4.8 g, 29.8 mmol) in 150 mL THF and carbonyldiimidazole (9.7 g, 59.6 mmol) and stir overnight at ambient temperature. Treat the reaction mixture with 25 mL EtOH and 1.2 g (29.8 mmol) of a 60% oil dispersion of NaH and stir for 2 hours. Concentration under vacuum gives a residue. Partition the residue between 150 mL EtOAc and 100 mL brine. Separate the layers, dry the organic layer over MgSO4, filter, and concentrated to an oil. Chromatograph on silica gel eluting with 1% MeOH in CHCl3 to give 7.2 g of an oil. Crystallize the oil from toluene gives the title compound: Analysis for C11H11NO2: calcd: C, 69.83; H, 5.86; N, 7.40; found: C, 69.82; H, 5.90; N, 7.38; ISMS 190 (M+1).

Provenance & Evidence