Potassium Iodide → 6-Methyl-4-iodo-indole-3-carboxaldehyde

Participants

Reaction Conditions

Reaction Steps

A solution of thallium (III) trifluoroacetate (1 g, 1.84 mmol) in trifluoroacetic acid (15 mL) was added to 6-methyl-indole-3-carboxaldehyde (200 mg, 1.25 mmol) and the resulting mixture was stirred at 30° C. for 2 h. The solvent was removed under vacuum (rotary evaporator). To the residue was added an aqueous solution of potassium iodide (2 g, 12 mmol, in 20 mL of water) and the mixture was stirred at room temperature overnight. Solid sodium meta-bisulfite was added to the reaction mixture until it turned yellow. The mixture was basified with aqueous NaOH solution and was extracted repeatedly from diethyl ether. The combined organic was washed with brine and was dried over magnesium sulfate. Evaporation of solvent gave the crude product, which was purified by flash chromatography by using EtOAc as eluent. The product, 6-methyl-4-iodo-indole-3-carboxaldehyde was isolated as solid to yield 283 mg (79%) of the desired product. MS: 286.

Provenance & Evidence