Sulfuric acid magnesium salt (1:1) → (4aR,8aS)-3,3-dimethyl-1-(1-(triisopropylsilyl)-1H-indol-6-yl)decahydroquinoxaline

Participants

Reaction Steps

A toluene (8 mL) suspension of (4aS,8aR)-2,2-dimethyldecahydroquinoxaline (337 mg, 2.00 mmol), 6-bromo-1-(triisopropylsilyl)-1H-indole (846 mg, 2.40 mmol), sodium tert-butoxide (269 mg, 2.80 mmol), palladium (II) acetate (22.5 mg, 0.0902 mmol), and tri-tert -butylphosphine tetrafluoroborate (29.1 mg, 0.101 mmol) was stirred for 5 hours under reflux in a nitrogen atmosphere. The reaction mixture was cooled to room temperature. Then, water (0.5 mL) and ethyl acetate (10 mL) were added thereto, and the mixture was stirred, followed by addition of magnesium sulfate. Insoluble matter was filtered through celite, and the filtrate was then concentrated under reduced pressure. The obtained residue was purified by NH-silica gel column chromatography (n-hexane:ethyl acetate) to obtain colorless, amorphous (4aR,8aS)-3,3-dimethyl-1-(1-(triisopropylsilyl)-1H-indol-6-yl)decahydroquinoxaline (0.75 g, yield; 85%).

Provenance & Evidence