1,3-Cyclohexanedione → 6-Chloro-4-oxo-1,2,3,4-tetrahydrocarbazole

Participants

Reaction Conditions

Reaction Steps

A suspension of p-chlorophenylhydrazine hydrochloride (8.06 g, 45 mmol) in water is added over a 10 min. period to a solution of 1,3-cyclohexanedione (5.05 g, 45 mmol) in water, stirred for 16 h and filtered. The filtercake is washed with water and air-dried. The thus-obtained cyclohexane-1,3-dione mono-(4-chlorophenyl)-hydrazone (45 mmol th.) is dissolved in trifluoroacetic acid (TFA) (30 mL), heated at 80° C. for 16 h, cooled to room temperature, poured into ice-water and filtered. The filtercake is air-dried and recrystallized from ethanol/water to afford the title product as a tan solid, 4.2 g (42% yield) identified by NMR and mass spectral analyses.

Provenance & Evidence