Ethyl Bromide → 1-Ethyl-4-fluoro-5-nitroindoline

Participants

Reaction Conditions

Reaction Steps

Anhydrous potassium carbonate (0.83 g, 6 mmol) was added to a solution of 4-fluoro-5-nitro-indoline (0.54 g, 3 mmol) in acetone (20 mL). The mixture was stirred at 60° C. for 10 min and ethyl bromide (0.33 mL, 4.50 mmol) added dropwise and the mixture was refluxed for a further 12 h. The mixture was concentrated in vacuo and the residue partitioned between ethyl acetate (50 mL) and water (50 mL). The organic layer was separated and the aqueous layer extracted with ethyl acetate (5×10 mL). The combined organic layers were washed with water (3×10 mL), brine (3×10 mL) and then dried over anhydrous sodium sulphate. Concentration of the organic layer afforded the crude product which was purified by column chromatography over silica gel neutral alumina mesh using 5-8% ethyl acetate in hexane as eluent to afford 1-ethyl-4-fluoro-5-nitro-indoline (0.47 g, 75%) as a yellow solid.

Provenance & Evidence