A solution of 6-methoxy-7-(morpholinomethyl)benzofuran-3(2H)-one (0.079 g, 0.300 mmol) in methanol (1.2 mL) was added with 1H-indole-3-carboxaldehyde (0.0523 g, 0.300 mmol) and piperidine (0.00255 g, 0.0300 mmol), and the mixture was stirred at 60° C. for 2 hours. The reaction mixture was concentrated, and the residue was purified by silica gel column chromatography (chloroform/methanol) to obtain an orange crude product as a solid. This solid was suspended in ethyl acetate and thereby washed to obtain the objective (Z)-2-[(1H-indol-3-yl)methylene]-6-methoxy-7-(morpholinomethyl)benzofuran-3(2H)-one (0.0128 g, 10%).
