Reaction #6455

Reaction equation

sodium bicarbonate

5-methylisatin

sodium hydride

acetic anhydride

→

1-acetyl-5-methylisatin

Yield 47.6%

Solvents

toluene

Conditions

Workup

1. 1
   workup.STIRRINGWhile stirring under ice cooling
2. 2
   Temperatureby heating at 80° C. for further an hour
3. 3
   workup.STIRRINGwith stirring
4. 4
   OtherAfter completion of the reaction
5. 5
   FiltrationThe crystals were filtered
6. 6
   Washwashed with water
7. 7
   Otherdried

Procedure

With stirring at 0° C., 8.06 g (50.0 mmols) of 5-methylisatin was added by small portions to a solution of 2.00 g (50.0 mmols) of sodium hydride in toluene. While stirring under ice cooling, 4.7 ml (50.0 mmols) of acetic anhydride was dropwise added to the mixture followed by heating at 80° C. for further an hour with stirring. After completion of the reaction, an aqueous saturated sodium bicarbonate solution was added to the reaction mixture. The crystals were filtered, washed with water and dried to give 4.84 g (yield, 47%) of 1-acetyl-5-methylisatin.

Source