Reaction #43546

Reaction equation

water

5-Fluoro-1H-indole-2,3-dione

sodium hydride

p-methoxybenzyl chloride

→

5-Fluoro-1-(4-methoxy-benzyl)-1H-indole-2,3-dione

Yield 80.0%

Solvents

DMF

DMF

ethyl acetate hexane

Conditions

Workup

1. 1
   workup.STIRRINGThe solution was then stirred ca 2 hours
2. 2
   Extractionfollowed by extraction into ethyl acetate
3. 3
   WashThe organic layer was washed twice with water
4. 4
   Dryingdried over MgSO4

Procedure

5-Fluoro-1H-indole-2,3-dione (956 mg, 5.79 mmol, 1 eq) was added as a solution in dry DMF to a stirred slurry of sodium hydride (278 mg, 11.6 mmol, 2 eq) in dry DMF drop wise over 15 minutes under an inert atmosphere with adequate pressure release to accommodate H2 evolution. The resulting mixture was stirred for 1 hour and p-methoxybenzyl chloride was added via syringe to the reaction. The solution was then stirred ca 2 hours and worked up by addition of water followed by extraction into ethyl acetate. The organic layer was washed twice with water and then dried over MgSO4. Column chromatography with ethyl acetate/hexane afforded 5-Fluoro-1-(4-methoxy-benzyl)-1H-indole-2,3-dione as a red solid (1.3 g, 80% yield). 1H NMR (CDCl3) δ (ppm): 7.3-7.24 (m, 3H), 7.20 (td, J=8.7, 2.7 Hz, 1H), 6.9-6.86 (m, 2H), 6.76 (dd, J=8.6, 3.6 Hz, 1H), 3.81 (s, 2H), 3.78 (s, 3H). LC/MS=286.1 (M+1).

Source