Carbazole → 9-(oxiran-2-ylmethyl)-9H-carbazole

Participants

Reaction Steps

Powdered potassium hydroxide (3.36 g, 60 mmol) was added to a solution of carbazole (8.36 g, 50 mmol) in anhydrous N,N-dimethylformamide (50 mL) and stirred at ambient temperature for 1 hour. The reaction mixture was cooled in an ice bath and epibromohydrin (10.3 mL, 125 mmol) was added. The ice bath was removed and the reaction was stirred at room temperature for 20 hours. The mixture was partitioned between ethyl acetate and water. The organic layer was washed successively with water and saturated aqueous sodium chloride solutions, dried (anhydrous sodium sulfate), filtered, and concentrated. The crude material was triturated with hexanes, and recrystallized from ethyl acetate/hexanes to yield the desired product as white needles (6.41 g, 58% yield). A second crop of crystals was crystallized from the mother liquor to give additional product (1.2 g, 11%). 1H NMR (CDCl3, 300 MHz) δ 8.11-8.08 (m, 2H), 7.46-7.44 (m, 4H), 7.28-7.25 (m, 2H), 4.68-4.62 (dd, 1H, J=3.1, 15.8 Hz) 4.45-4.38 (dd, 1H, J=4.8, 15.9 Hz), 3.37 (m, 1H), 2.84-2.81 (dd, 1H, J=4.2, 4.3 Hz), 2.60-2.57 (dd, 1H, J=2.5, 5.0 Hz). HPLC analysis: (C18, 5-95% acetonitrile in H2O+0.1% trifluoroacetic acid over 20 min: detention time, % area at 254 nm): 7.83 min, 98.7%.

Provenance & Evidence