Ethylamine → 2-oxo-2,3-dihydro-1H-indole-4-carboxylic acid ethylamide

Participants

Reaction Steps

Ethylamine (2.1 mL of 2.0M solution in tetrahydrofuran, 4.2 mmol) was added dropwise to a suspension of 4-carboxy-2-oxindole (380 mg, 2.1 mmol) in dimethylformamide (8 mL), followed by 4-dimethylaminopyridine (385 mg, 3.15 mmol) and PyBOP (2.185 g, 4.2 mmol). The mixture was stirred at room temperature for 6 hrs. The reaction was concentrated. The residue was dissolved in dichloromethane, washed with saturated sodium bicarbonate and brine, dried, concentrated and recrystallized to give 280 mg (65%) of 2-oxo-2,3-dihydro-1H-indole-4-carboxylic acid ethylamide.

Provenance & Evidence