Ethyl Acetate → methyl 2-{6,6-dimethyl-1-[2-(trimethylsilyl)ethoxymethyl]-4,5,6,7-tetrahydro-1H-indazol-3-yl}-1-[2-(trimethylsilyl)ethoxymethyl]-1H-indole-6-carboxylate

Participants

Reaction Steps

Under an argon atmosphere, to a solution of methyl 2-(6,6-dimethyl-4,5,6,7-tetrahydro-1H-indazol-3-yl)indole-6-carboxylate (23 g, 71 mmol) in N,N-dimethylformamide (230 ml) was added sodium hydride (6.3 g, 157 mmol) in portions of about 500 mg at an inside temperature of −10° C., and the mixture was stirred for 30 min. Then, 2-(trimethylsilyl)ethoxymethyl chloride (26 g, 157 mmol) was added dropwise over 15 min, and the mixture was further stirred for 2 hr. To the reaction mixture were added ethyl acetate and water, and the organic layer was separated. Then, the organic layer was washed successively with water and saturated brine, and dried over sodium sulfate. Sodium sulfate was removed by filtration, and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel chromatography to give the title compound (33 g, yield 80%).

Provenance & Evidence