To the solution of 5-phenyl-1H-indole-7-carboxamide (3.11 g, 12 mmol) in methanol (100 mL) was added benzyl piperidone (7.4 g, 36 mmol), followed by 156 mL of NaOMe (0.5 M in MeOH). The reaction mixture was then heated at 80° C. overnight. The solution was cooled to ambient temperature and the solvent removed under reduced pressure, and the resulting residue redisolved in a bilayer of ethyl acetate and 5% sodium hydroxide solution. The organic phase washed with brine, dried over potassium carbonate, and the solvent removed under reduced pressure. The residue was purified by silica gel chromatography (CH2Cl2:MeOH:NH4OH=96:3:1) to provide the desired product (2.66 g, 51%).
