Preparation
Add 2.5 equal volumes of phosphorus oxychloride dropwise to dimethylformamide (5 ml per 1 ml POCl3), and cool in an ice bath. Stir the mixture for 5 minutes. Add the selected indole (1 equal volume) as a dimethylformamide solution (10 ml per 1 g indole). Heat the mixture to room temperature. Stir the mixture for 3 hours. When the reaction becomes a heavy suspension requiring vigorous stirring, add 10 equal volumes of 3.8 M potassium hydroxide aqueous solution through a dropping funnel. Heat the mixture under reflux overnight. Cool the mixture to room temperature. Add saturated sodium bicarbonate and ethyl acetate until the mixture becomes clear. Separate the organic layer. Extract the aqueous layer with ethyl acetate. Dry the combined organic layer on sodium sulfate. Filter the combined organic layer. Concentrate the combined organic layer under vacuum to give the title compound 5-Bromo-2-oxindole.
Chemical Properties
White to brown crytalline powder
Uses
5-Bromooxindole is an important raw material and intermediate used in organic synthesis, pharmaceuticals, agrochemicals and dyestuff.
