873055-58-4

5-Amino-2,4-di-tert-butylphenol is an intermediate used in the preparation of ivacaftor via condensation of oxo dihydroquinoline carboxylic acid with amino ditert butylphenol.

To a refluxing solution of 2,4-di-tert-butyl-5-nitro-phenol (1.86 g, 7.40 mmol) and ammonium formate (1.86 g) in ethanol (75 mL) was added Pd-5% wt on activated carbon (900 mg). The reaction mixture was stirred at reflux for 2 h, cooled to room temperature, and filtered through Celite. The Celite was washed with methanol, and the combined filtrates were concentrated to yield 5-amino-2,4-di-tert-butyl-phenol as a grey solid (1.66 g, quant.).