A solution of [(2R)-8-methyl-2,3-dihydro[1,4]dioxino[2,3-f]quinolin-2-yl]methyl 4-bromobenzenesulfonate (2.0 g, 4.44 mmol), 3-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indole (1.01 g, 5.09 mmol) and diisopropylethyl amine (0.86 g, 6.65 mmol) in DMSO (10 mL) was heated to 80–83° C. After 10 h, the reaction mixture was cooled to 65–70° C. before CH3OH (3 mL) was added. The resulted suspension was cooled to room temperature, filtered, washed with CH3OH and dried in a vacuum oven to give 1.3 g (71%) of the title compound as a yellow solid.
