Indole → Indole-3-Carboxaldehyde

Participants

Reaction Steps

[a-2H; a-13C]-DMF (7.52 mmol) was dissolved in THF (4 ml), phosphorus oxychloride (3.76 mmol) was added to the resulting solution with stirring in an ice bath, a solution (50 ml) of the indole (35) (3.76 mmol) in THF was further added to the resulting mixture, followed by stirring of the mixture at room temperature for 3 hours. After the confirmation of the completion of the reaction using the TLC method, the reaction system was cooled in an ice bath, water (30 ml) and 2M NaOH aqueous solution were added till an alkaline solution was obtained, the resulting alkaline solution was extracted with methylene chloride-methanol (95:5) mixed solvent (100 ml×3), the extract was washed with a saturated sodium chloride aqueous solution (100 ml×3) and then dried over anhydrous magnesium sulfate. After filtration under reduced pressure, the solvent was distilled off from the filtrate and the resulting residue was purified by silica gel chromatography (developing solvent: methylene chloride/methanol=94/6) to thus give an aldehyde (36) in a yield of 2.68 mmol (71%).

Provenance & Evidence