A suspension of sodium hydride (60%, 0.013 g) in N,N-dimethylformamide (3 ml) was added with ethyl 4-[(6a-methyl-5,6,6a,7,8,9-hexahydro-4H-2-phenalenyl)amino]benzoate (0.055 g) dissolved in N,N-dimethylformamide (2 ml), and the mixture was stirred at room temperature for 15 minutes. The reaction mixture was added with bromoethane (0.025 ml), the mixture was stirred overnight at room temperature, and then added with saturated aqueous ammonium chloride, and the mixture was extracted with diethyl ether. The organic layer was washed successively with water and saturated brine, and dried over anhydrous sodium sulfate. The organic layer was concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (developing solvent: ethyl acetate:n-hexane=1:50) to obtain the title compound (0.058 g, yield: 98%).
