Tetrahydrofuran → 1-tert-butyl 2-ethyl 5-(2-methoxyethoxy)-7-nitro-1H-indole-1,2-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

To a mixture of ethyl 5-(2-methoxyethoxy)-7-nitro-1H-indole-2-carboxylate (3.08 g), t-butyl bicarbonate (4.37 g) and tetrahydrofuran (100 mL) was added N,N-dimethyl-4-aminopyridine (122 mg), and the mixture was stirred at 50° C. for 4 hr. The reaction mixture was diluted with ethyl acetate and water, and the organic layer was washed successively with 10% aqueous citric acid solution, aqueous sodium bicarbonate solution and saturated brine, dried over anhydrous sodium sulfate, and filtered, and the filtrate was concentrated under reduced pressure. The residue was subjected to basic silica gel column chromatography to give the title compound (3.93 g, yield 96%) as a yellow oil from a fraction eluted with ethyl acetate-hexane (2:3, volume ratio).

Provenance & Evidence