Methyl Methacrylate → 10-bromo-2-methoxy-5-methyl-4H-pyrido [3,2,1-jk]carbazole-4-one

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Reaction Steps

3-bromo-6-methoxycarbazole (20 g) produced in Example 1, step 1 was dissolved in anhydrous tetrahydrofuran (200 ml), and to the solution were added methyl methacrylate (77.6 ml), then Triton B (0.7 ml). The mixture was heated under reflux in an argon atmosphere for 2 hours, and the solvent was evaporated under reduced pressure. The resulting residue was suspended in methanol (60 ml), and sodium hydroxide (6.4 g) dissolved in water (80 ml) was added dropwise at room temperature, and the mixture was stirred at room temperature for 12 hours. The solvent was evaporated under reduced pressure, and water and ether were added for phase separation. The aqueous layer was rendered acidic by addition of 4N hydrochloric acid, and ethyl acetate was added for further phase separation. The ethyl acetate layer was washed with water and saturated aqueous solution of sodium chloride, dried over anhydrous sodium sulfate, and the solvent was evaporated under reduced pressure. The residual crude crystals were washed with hexane and ether and recovered by filtration to obtain the title compound (25.0 g, 95%).

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