To a solution of 1-(2-aminoethyl)-5-(diphenylmethyl)-2(1H)-pyridinone (75.0 mg), a mixture of indole-4-carboxylic acid (39.7 mg), HOBt (36.6 mg) and DMF (3.0 mL) was added WSCD. HCl (52.0 mg) at ambient temperature and the mixture was stirred at the same temperature for 18 hours. The resulting mixture was diluted with water (10.0 mL) and extracted with EtOAc (15 mL). The organic layer was washed successively with 1M HCl aqueous solution, saturated NaHCO3 aqueous solution and brine, dried over anhydrous MgSO4, filtered and evaporated in vacuo. The residue was purified by preparative thin-layer chromatography (chloroform:MeOH=90:10) to afford N-{2-[5-(diphenylmethyl)-2-oxo-1(2H)-pyridinyl]ethyl}-1H-indole-4-carboxamide (65 mg) as a yellow amorphous powder.
