To a reflux apparatus add 3.15 g of potassium hydroxide, 3.15 g of isatin and 15 mL of ethanol with stirring, then add 4.4 mL of cyclohexanone and reflux gently for 24h. Then distill the ethanol off and add 10 mL of water to the mixture, filter, wash the solution with 10 mL of hexane. Precipitate the crude product out from the solution with about 3.5 mL of acetic acid to make it acidic, filter and pour the damp product into a beaker. To the beaker add 30 mL of water and 15 mL of ethanol to recrystallize the product.
The solution prior to reflux and distillation
Refluxing the solution for 24h and then distillation of the solution
The crude product precipitated from the solution
The pure recrystallized product