2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 3-Bromo-9-methoxy-6,6-dimethyl-5,6-dihydro-benzo[b]carbazol-11-one

Participants

Reaction Conditions

Reaction Steps

6-Methoxy-1,1-dimethyl-3,4-dihydro-1H-naphthalen-2-one (Compound J2, 2.15 g, 10.5 mmol) and 3-bromophenylhydrazine hydrochloric acid salt (3.11 g, 1.3 eq.) were dissolved in acetic acid (12 mL), and stirred at 100° C. for 2.5 hr under nitrogen atmosphere. After cooling, the reaction solution was added with ethyl acetate, washed with water, saturated aqueous solution of sodium hydrogen carbonate, and saturated brine, and dried over magnesium sulfate. After the filtration, it was concentrated under reduced pressure. The resulting residues were dissolved in THF (30 mL) and water (3 mL), added with DDQ (5.96 g, 2.5 eq.) at 0° C., and then stirred at room temperature overnight. The reaction solution was added with MTBE, washed with 0.5 N aqueous solution of sodium hydroxide and saturated brine, and dried over magnesium sulfate. After filtration and the concentration under reduced pressure, the resulting residues were washed with MTBE to obtain the title compound (brown solid, 1.80 g, 46%).

Provenance & Evidence