2-Bromobutane → 9-(Butan-2-yl)-9H-carbazole

Participants

Reaction Steps

25 g (0.15 mol) of carbazole and 33 g (0.24 mol) 2-bromo-butane were dissolved in 250 ml acetone. 14 g (40 mmol) tetrabutylammonium hydrogen sulfate was added, followed by the addition of 18.6 g (0.285 mol) potassium hydroxide (88%). The reaction mixture was refluxed for 10 hours. After 10 hours, an additional 4 g (30 mmol) 2-bromo-butane and 2 g (31 mmol) potassium hydroxide (88%) were added and the reaction was allowed to continue at reflux temperature for 16 hours. The precipitated salts were removed by filtration and the solvent was evaporated under reduced pressure. The residue was redissolved in 200 ml methyl tert.butyl ether and extracted with 100 ml 1M Na2CO3 and 100 ml water. The organic fraction was isolated, dried over MgSO4 and evaporated under reduced pressure. N-sec.butyl-carbazole was isolated by preparative column chromatography on a Prochrom LC80 column, using Kromasil Si60 10 μm and n. hexane/methylene chloride 93/7 as eluent. 8.7 g (26%) of N-sec.butyl carbazole was isolated.

Provenance & Evidence