EDCI (153 mg) and HOBT (132 mg) were added to a solution of 6-[(1-methylethyl)oxy]-5-(trifluoromethyl)-3-pyridinecarboxylic acid (100 mg) in THF (2.5 mL). The mixture was stirred at room temperature for 0.5 hour, followed by addition of ethyl 3-{7-[(Z)-(hydroxyamino)(imino)methyl]-1H-indol-3-yl}propanoate (D35) (165 mg) in THF (2.5 mL). The resulting mixture was stirred at room temperature for 1 hour, followed by addition of TBAF (418 mg). The reaction vessel was sealed and the reaction mixture was stirred at 120° C. in the microwave for 1.5 h. THF was removed. The residue was dissolved in EtOAc. The organic solution was washed with saturated aqueous sodium bicarbonate solution. The organic solution was dried over anhydrous sodium sulfate. The dried solution was concentrated. The residue was purified by column chromatography to afford ethyl 3-(7-{5-[6-[(1-methylethyl)oxy]-5-(trifluoromethyl)-3-pyridinyl]-1,2,4-oxadiazol-3-yl}-1H-indol-3-yl)propanoate (D37) (83 mg) as a white solid. δH (CDCl3, 400 MHz): 1.24 (3H, t), 1.45 (6H, d), 2.74 (2H, t), 3.17 (2H, t), 4.15 (2H, q), 5.58 (1H, m), 7.19 (1H, d), 7.29 (1H, d), 7.82 (1H, d), 8.12 (1H, dd), 8.64 (1H, d), 9.17 (1H, d), 9.55 (1H, s); MS (ES): C24H23F3N4O4 requires 488; found 489.2 (M+H+).
