Potassium Hydroxide → 4,5-Difluoro-9-(oxiran-2-ylmethyl)-9H-carbazole

Reaction equation

[F:1][C:2]1[C:14]2[C:13]3[C:8](=[CH:9][CH:10]=[CH:11][C:12]=3[F:15])[NH:7][C:6]=2[CH:5]=[CH:4][CH:3]=1.[OH-].[K+].[CH2:18]([CH:20]1[O:22][CH2:21]1)Br>CN(C)C=O>[F:1][C:2]1[C:14]2[C:13]3[C:8](=[CH:9][CH:10]=[CH:11][C:12]=3[F:15])[N:7]([CH2:18][CH:20]3[CH2:21][O:22]3)[C:6]=2[CH:5]=[CH:4][CH:3]=1

Participants

Procedure

To a stirred solution of 4,5-difluoro-9H-carbazole (0.270 g, 1.3 mmol) in N,N-dimethylformamide (5 mL) at 0° C. was added 85% potassium hydroxide (0.105 g, 1.6 mmol) and the mixture was stirred for 1 hr. Epibromohydrin (0.220 mL, 2.7 mmol) was added and the mixture was slowly warmed to room temperature and stirred for 4 hrs. The mixture was partitioned between water and ethyl acetate. The organic layer was washed with saturated aqueous sodium chloride, dried (anhydrous sodium sulfate), filtered, and concentrated in vacuo. The residue was purified by silica gel chromatography (10-50% methylene chloride/hexanes) to afford the desired product as a white solid (0.315 g, 91%). 1H NMR (300 MHz, CDCl3) δ 7.45 (tt, 2H, J=8.1, 2.4 Hz), 7.25 (d, 2H, J=8.1 Hz), 6.99 (dt, 2H, J=9.9, 4.2 Hz), 4.68 (dd, 1H, J=15.9, 3.0 Hz), 4.38 (dd, 1H, J=15.9, 5.1 Hz), 3.37 (m, 1H), 2.85 (t, 1H, J=4.5 Hz), 2.57 (dd, 1H, J=4.5, 2.4 Hz).