Citric Acid → 2-Chloro-1-methyl-1H-indole-3-carbaldehyde

Participants

Reaction Steps

2-Chloroindole-3-carboxaldehyde (2.69 g) and methyl iodide (4.26 g) were dissolved in a mixed solvent of tetrahydrofuran (25 ml) and dimethylsulfoxide (25 ml), and sodium hydride (0.66 g, 60% mineral oil dispersion) was added thereto at 0° C. A 10% aqueous solution of citric acid was added to the reaction solution, and the mixture was extracted with ethyl acetate. The organic layer was washed with water and then a saturated saline, and dried over anhydrous magnesium sulfate. After concentration under reduced pressure, the residue was washed with hexane (30 ml) to give 2-chloro-1-methylindole-3-carboxaldehyde (2.54 g).

Provenance & Evidence