Hydrochloric Acid → 6-Bromo-1,2,3,4-tetrahydrocarbazole

Participants

Reaction Conditions

Reaction Steps

A 250-mL round-bottomed flask was charged with 1-(4-bromophenyl)-2-cyclohexylidenehydrazine (11 g, 41.35 mmol, 1.00 equiv) and conc. HCl (150 mL). The resulting mixture was heated to 60° C. in an oil bath for 4 hours. The reaction progress was monitored by TLC (EtOAc:PE=1:1). Upon completion, the reaction mixture was cooled down to room temperature. The pH was adjusted to 8 with aqueous sodium hydroxide. The resulting mixture was then extracted with ethyl acetate (5×100 mL). The combined organic layers were dried over anhydrous sodium sulfate, filtered off and concentrated on a rotary evaporator. The residue was purified by a silica gel column chromatography eluted with ethyl acetate/petroleum ether (1/10) affording 3-bromo-6,7,8,9-tetrahydro-5H-carbazole as yellow solid (10 g, 97%).

Provenance & Evidence