Dimethylformamide → 3-Formyl-7-methyl-6-nitroindole

Participants

Reaction Conditions

Reaction Steps

Phosphorus oxychloride (0.878 mL, 9.42 mmol) is added to a stirred solution of dimethylformamide (5 mL). A solution of 7-methyl-6-nitroindole (1.5 g, 8.56 mmol) in dimethylformamide (2 mL) is added dropwise at room temperature at a rate so as to keep the temperature of the reaction mixture below 35° C. The solidified mixture is heated to 35° C. and stirred for 30 minutes. The reaction mixture is allowed to cool to room temperature and is treated with 25 mL of 5 N aqueous sodium hydroxide solution. This addition produces an exothermic reaction. This reaction mixture is extracted with ethyl acetate. The ethyl acetate is dried over magnesium sulfate, filtered and the solvents removed by rotary evaporation. The crude residue is recrystallized from ethyl alcohol to yield 1.3 g of 3-formyl-7-methyl-6-nitroindole as a yellow solid (74% yield).

Provenance & Evidence