Sulfuric Acid → 2,4,5-Trifluoro-3-methoxyaniline

Participants

Reaction Conditions

Reaction Steps

50 ml of water and 200 ml of concentrated sulfuric acid were added to 84.4 g (0.42 mole) of 2-amino-4-methoxy-3,5,6-trifluorobenzonitrile (XX) [prepared as described in Step (E2) above]. The mixture was then stirred at 100° C. for 1 hour, after which 150 ml of water were added thereto, and the mixture was stirred at 110°-120° C. for a further 2 hours. The reaction mixture was then allowed to stand to cool to room temperature, after which it was poured into ice-water and neutralized with potassium carbonate. The crystalline substance which precipitated was extracted with ethyl acetate; the extract was washed with water and dried over anhydrous sodium sulfate; and the solvent was removed by evaporation under reduced pressure to afford 57.6 g of 3-methoxy-2,4,5-trifluoroaniline (XXIII) as colorless needles melting at 45°-47° C.

Provenance & Evidence