Hydrochloric Acid → 5-fluoro-1,3-dihydro-2H-indol-2-one

Participants

Reaction Conditions

Reaction Steps

Into a 10-L four necked round-bottomed flask equipped with a mechanical stirrer, a thermometer pocket, and a reflux condenser were charged 5-fluoro-isatin (0.3 Kg; 1.81 mole) and 90% hydrazine hydrate. (1.5 Lt) and stirred well for 30 minutes. The temperature of the reaction mixture was raised to 100-110° C. and maintained for 1 hour and the temperature further raised to 125-130° C. and maintained for 4 hours. The progress of the reaction was monitored by TLC. After completion of reaction, the reaction mixture was cooled to 25-30° C. and diluted with water. The pH was adjusted with conc. HCl to 3.0. The solution was stirred at 25-30° C. for 4 hours. The product was isolated by filtration and washed with ice water. The product was dried at 60° C.

Provenance & Evidence