To a solution of acetamide (91.5 mg, 1.54 mmol in dry THF (10 mL) was added 1.0M lithium bis(trimethylsilyl)amide (LHMDS) (1.2 mL, 1.54 mmol) at −78° C. and the mixture was stirred for 45 min at −78° C. and 10 min at −10° C. Again the reaction was cooled back to −78° C. To the mixture at −78° C. was added 3-(3-iodo-1-tosyl-1H-indol-5-yl)-5-(trichloromethyl)-1,2,4-oxadiazole (600 mg, 1.03 mmol) and the reaction was stirred at RT for 12 h. The solvent was then removed in vacuo and the residue was diluted with water (10 mL) and extracted with EtOAc (2×20 mL). The combined organic layers were dried over anhydrous Na2SO4, and concentrated in vacuo. The residue was purified with basic alumina column chromatography (eluent: 35% EtOAc in petroleum ether) to give N-(3-(3-iodo-1-tosyl-1H-indol-5-yl)-1,2,4-oxadiazol-5-yl)acetamide (300 mg, 55.5%) as an off brown solid. MS (ESI, pos. ion) m/z: 523.0 (M+1); 1H-NMR (400 MHz, DMSO-d6): δ 12.22 (brs, 1H), 8.22 (s, 1H), 8.15 (d, J=8.8 Hz, 1H), 8.02-7.90 (m, 4H), 7.44 (d, J=8.0 Hz, 2H), 2.33 (m, 3H), 2.19 (s, 3H).
