4-Oxobutanoic acid → 4-(5-(1-(Benzo[d][1,3]dioxol-5-yl)cyclopropanecarboxamido)-2-tert-butylindolin-1-yl)butanoic acid

Participants

Reaction Steps

To a solution of 1-(benzo[d][1,3]dioxol-5-yl)-N-(2-tert-butylindolin-5-yl)cyclopropanecarboxamide (350 mg, 0.93 mmol, 1 eq) in anhydrous methanol (6.5 mL) and AcOH (65 μL) was added 4-oxobutanoic acid (15% in water, 710 mg, 1.0 mmol) at room temperature. After 20 min of stirring, NaBH3CN (130 mg, 2.0 mmol) was added in one portion and the reaction mixture was stirred for another 4 h at room temperature. The reaction mixture was quenched by addition of AcOH (0.5 mL) at 0° C. and the solvent was removed under reduced pressure. The residue was purified by column chromatography on silica gel (5-75% ethyl acetate/hexanes) to give 4-(5-(1-(benzo[d][1,3]dioxol-5-yl)cyclopropanecarboxamido)-2-tert-butylindolin-1-yl)butanoic acid (130 mg, 30%).

Provenance & Evidence