Sulfuric Acid → 2-Tert-butyl-5-nitroaniline

Participants

Reaction Steps

Concentrated sulfuric acid (1 L) was cooled to −10° C. with a dry ice-isopropanol bath in a 2 L 3-necked round bottom flask fitted with a mechanical stirrer and temperature probe. The 2-t-butylaniline (109 g, 730 mmol) was added, giving a clumpy solid. Once the temperature of the mixture was stabilized at −10° C., the potassium nitrate (101 g, 1001 mmol) was added portion wise, as a solid, over a 4-hour period, maintaining the temperature between −20 and −5° C. Once all of the potassium nitrate was added, the reaction was left to stir overnight with gradual warming to room temperature. The reaction was quenched by diluting with water and then extracting three times with EtOAc. Each of the EtOAc extracts was washed multiple times with saturated NaHCO3, until gas evolution ceased, and with brine. The ethyl acetate extracts were combined, dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure giving a black oil. The oil was eluted through a 36× & cm column of silica gel with EtOAc: hexanes gradient 5-50%. Solvent evaporation afforded 2-tert-butyl-5-nitrobenzenamine as a red solid.

Provenance & Evidence