Tetrabutylammonium Fluoride → benzyl N-{2-(6,6-dimethyl-4,5,6,7-tetrahydro-1H-indazol-3-yl)-1H-indol-6-yl}-N-methylcarbamate

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Reaction Conditions

Reaction Steps

A solution of benzyl N-(2-{6,6-dimethyl-1-[2-(trimethylsilyl)ethoxymethyl]-4,5,6,7-tetrahydro-1H-indazol-3-yl}-1-[2-(trimethylsilyl)ethoxymethyl]-1H-indol-6-yl)-N-methylcarbamate (13 g, 19 mmol) obtained in Example 1, Step 6, in N,N-dimethylformamide (102 ml) was added to tetrabutylammonium fluoride (93 ml, 93 mmol) concentrated in advance under reduced pressure, and then ethylenediamine (19 ml) was added. The mixture was stirred with heating at 90° C. for 7 hr. After cooling, water and ethyl acetate were added, and the organic layer was separated. Then, the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed successively with water, 10% aqueous citric acid solution 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 (7.2 g, yield 91%).

Provenance & Evidence