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

Participants

Reaction Steps

EDCI (289 mg) and HOBT (220 mg) were added to a solution of 6-[(1-methylethyl)oxy]-5-(methyloxy)-3-pyridinecarboxylic acid (152 mg) in THF (3 mL) at RT. The resulting solution was stirred for 30 mins. Ethyl 3-{7-[(Z)-(hydroxyamino)(imino)methyl]-1H-indol-3-yl}propanoate (D35) (250 mg) in THF (3 mL) was added and the reaction mixture was stirred at RT for 2 hours. TBAF (910 mg) was then added. The reaction vessel was sealed and heated in Biotage Initiator using initial normal to 120° C. for 90 mins. After cooling, the reaction was quenched with water, and extracted with EtOAc for 3 times. The combined organic solution was washed with brine, dried over anhydrous sodium sulfate. The dried solution was concentrated. The residue was purified by column chromatography (20% EtOAc in hexane) to afford ethyl 3-(7-{5-[6-[(1-methylethyl)oxy]-5-(methyloxy)-3-pyridinyl]-1,2,4-oxadiazol-3-yl}-1H-indol-3-yl)propanoate (D38) (286 mg) as a pale yellow solid. MS (ES): C24H26N4O5 requires 450; found 451.2 (M+H+).

Provenance & Evidence