1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → Ethyl 3-[7-(5-{5-chloro-6-[(1-methylethyl)oxy]-3-pyridinyl}-1,2,4-oxadiazol-3-yl)-1H-indol-3-yl]propanoate

Participants

Reaction Steps

EDCI (189 mg) and HOBT (162 mg) were added to a solution of 5-chloro-6-[(1-methylethyl)oxy]-3-pyridinecarboxylic acid (105 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) (200 mg) in THF (2.5 mL). The resulting mixture was stirred for 1 hour, followed by addition of TBAF (512 mg). The reaction vessel was sealed and stirred at 120° C. in the microwave for 1.5 hour. 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-{5-chloro-6-[(1-methylethyl)oxy]-3-pyridinyl}-1,2,4-oxadiazol-3-yl)-1H-indol-3-yl]propanoate (D36) (180 mg) as a white solid. δH (DMSO-d6, 400 MHz): 1.16 (3H, t), 1.40 (6H, d), 2.71 (2H, t), 3.03 (2H, t), 4.06 (2H, q), 5.46 (1H, m), 7.22 (1H, t), 7.28 (1H, d), 7.83 (1H, d), 7.94 (1H, d), 8.76 (1H, d), 9.06 (1H, d), 10.91 (1H, s);

Provenance & Evidence