Hydrochloric Acid → 6-Bromo-2,3,4,9-tetrahydro-1H-carbazol-1-one

Participants

Reaction Conditions

Reaction Steps

4-Bromophenyl hydrazine hydrochloride (0.3 g, 1.3 mmol) in MeOH (3 mL) was heated to 60° C. and 1,2-cyclohexanedione (0.16 g, 1.4 mmol), dissolved in AcOH (4 mL) and conc. HCl (1.5 mL) were added while maintaining the temperature at 60° C. After the addition was completed, the reaction mixture was cooled to room temperature and stirred for 12 h during time a solid precipitated out. The mixture was basified with aq NaHCO3 and extracted with EtOAc (3×25 mL). The combined organic extracts were washed with water, dried over Na2SO4 and concentrated in vacuo to give the crude product which was purified by column chromatography to give the title compound as a pale yellow solid (0.080 g, 22%). 1H NMR (500 MHz, CDCl3, δ in ppm) 8.8 (bs, 1H), 7.8 (s, 1H), 7.43 (dd, J=10.0, 2.0 Hz, 1H), 7.24 (d, J=9.5 Hz, 1H), 2.98 (t, J=8.0 Hz, 2H), 2.63 (t, 8.0 Hz, 2H), 2.24 (m, 2H).

Provenance & Evidence