Hydrochloric Acid → (3E)-3-(4-bromo-5,5-dimethylfuran-2(5H)-ylidene)-6-fluoro-1,3-dihydro-2H-indol-2-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 6-fluorooxindole (3 g, 20 mmol) in THF (50 mL) at 0° C., was added 40 mL of 1M LHMDS in THF. The reaction mixture was stirred at 0° C. for 15 minutes. A solution of 4-bromo-5,5-dimethyl-5H-furan-2-one (5) (1.91 g, 10 mmol) in 5 mL of THF was added to the above reaction mixture. The reaction was stirred at 0° C. for further 30 minutes and then at room temperature for 2.5 hrs. To the reaction, 80 mL of 2M HCl was added. The resulting mixture was stirred at 50-55° C. for one hour, cooled down to room temperature, poured to 1000 mL of water and was stirred at room temperature for one hour. The precipitates formed were collected and washed with water, dried in vacuum to give the title compound as a yellow solid product (2.4 g, yield: 74%).

Provenance & Evidence