Dimethyl Sulfoxide → 9-(1-Propen-1-yl)-9H-carbazole

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Reaction Steps

Into a 100 mL round bottom flask fitted with a magnetic stirrer, reflux condenser and nitrogen inlet were placed 2.07 g (0.01 mole) of 9-allyl carbazole, 1.12 g (0.01 mole) of potassium t-butoxide and 10 mL of DMSO. The reaction mixture was stirred for 20 minutes at room temperature and then was heated to 120° C. and kept at that temperature for two hours. TLC on silica gel was used to monitor the reaction. After cooling to room temperature, the reaction mixture was poured into 20 mL of distilled water and extracted with ethyl ether. The organic layer was washed with distilled water to remove DMSO, then anhydrous sodium sulfate was added and the mixture stirred for an hour. Thereafter, the sodium sulfate was removed by filtration and a rotary evaporator was used to remove the solvent. 9-(1-Propenyl)carbazole was isolated in 63% yield (1.3 g) as a pale yellow viscous liquid. 1H NMR (300 MHz, CDCl3) showed that the product was consisted of approximately a 1:2 ratio of cis and trans 9-(1-propenyl)carbazole isomers.

Provenance & Evidence