Dimethylformamide → 1-Methyl-6-nitro-1H-indole

Participants

Reaction Conditions

Reaction Steps

A 1L, three-necked flask equipped with a thermocouple, condenser, and addition funnel was charged with 6-nitroindole (60.0 g, 0.37 mol), potassium carbonate (12.0 g, 87 mmol), N,N-dimethylformamide (240 mL) and dimethyl carbonate (66 mL, 0.784 mol) and the resulting stirred mixture was heated to 126±3° C. The progress of the reaction was monitored by HPLC or TLC (solvent system: 30% ethyl acetate in heptane). After 1 h at this temperature, residual 6-nitroindole could not be detected. Then, the reaction mixture was cooled to 10±5° C. and slowly diluted with water (480 mL). As the water was added, a yellow precipitate formed. The resulting mixture was stirred at room temperature for 2 h, then the solid was recovered by filtration, washed with water (250 mL) and dried under high vacuum at 60-65° C. for 24 h to give 62.6 g of 1-methyl6-nitroindole (96.1% yield) as a yellow solid.

Provenance & Evidence