1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → methyl 3-(7-{5-[3-chloro-4,5-bis(ethyloxy)phenyl]-1,2,4-oxadiazol-3-yl}-1H-indol-3-yl)propanoate

Beteiligte Stoffe

Reaktionsschritte

To a solution of 3-chloro-4,5-bis(ethyloxy)benzoic acid (D69) (184 mg) in tetrahydrofuran (10 mL) stirred at room temperature was added EDCI (192 mg) and HOBT (153 mg). The reaction mixture was stirred for 2 h, followed by addition of methyl 3-{7-[(Z)-(hydroxyamino)(imino)methyl]-1H-indol-3-yl}propanoate (D35) (131 mg). The reaction mixture was stirred at 60° C. for another 2 h, and then TBAF (523 mg) was added. The reaction vessel was sealed and heated in Biotage Initiator using initial normal to 130° C. for 3 h. After cooling the reaction, the solvent was removed. Water (10 mL) and ethyl acetate (30 mL) was added, the organic layer was separated and the solvent was evaporated off. The residue was purified by Mass Directed Auto Prep to afford methyl 3-(7-{5-[3-chloro-4,5-bis(ethyloxy)phenyl]-1,2,4-oxadiazol-3-yl}-1H-indol-3-yl)propanoate (D70) (25 mg) as a white solid. δH (CDCl3, 400 MHz): 1.46 (3H, t), 1.55 (3H, m), 2.78 (2H, t), 3.18 (2H, t), 3.70 (3H, s), 4.22-4.28 (4H, m), 7.21 (1H, d), 7.29 (1H, t), 7.67 (1H, d), 7.81 (1H, t), 7.93 (1H, d), 8.13 (1H, d), 9.60 (1H, s).

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