2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 3-Chloro-8-methoxy-2,6,6-trimethyl-5,6-dihydro-benzo[b]carbazol-11-one

Participants

Reaction Steps

7-Methoxy-1,1-dimethyl-3,4-dihydro-1H-naphthalen-2-one (Compound A2, 99.1 mg, 0.485 mmol) and (3-chloro-4-methyl-phenyl)hydrazine hydrochloric acid salt (100.4 mg, 1.1 eq.) were dissolved in TFA (1 mL) and the mixture was irradiated with microwave at 80° C. for 10 min 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 filtration and concentration under reduced pressure, the residues obtained therefrom were dissolved in THF (2 mL) and water (0.2 mL), added with DDQ (125.7 mg, 1.1 eq.), and stirred at room temperature overnight. The reaction solution was added with the mixture solvent of hexane and ethyl acetate, and the starting-point components were removed by dry type silica gel column. The eluent was concentrated under reduced pressure, and the resulting residues were purified by preparative TLC (methanol/dichloromethane) to obtain the title compound (19.4 mg, 12%).

Provenance & Evidence