Methyl 2,3-dihydro-2-oxo-1H-indole-5-carboxylate → methyl (3E)-3-(4-bromo-5,5-dimethylfuran-2(5H)-ylidene)-2-oxoindoline-5-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a 0° C. stirred solution of methyl oxindole-5-carboxylate (421 mg, 2.2 mmol) and 4-bromo-5,5-dimethylfuran-2(5H)-one (382 mg, 2.0 mmol) in THF (10 mL), was added 1M LiHMDS/THF solution (4.4 mL, 4.4 mmol) under nitrogen. The mixture was stirred at 0° C. for 80 min, quenched with 2.5M H2SO4 (3 mL), and poured into 100 mL of water. The precipitates were filtered, washed with water, and dried in vacuo to give methyl (3E)-3-(4-bromo-5,5-dimethylfuran-2(5H)-ylidene)-2-oxoindoline-5-carboxylate as yellow solid. Yield: 408 mg, 56%.

Herkunft & Nachweise