The general procedure for the synthesis of 4-amino-3-trifluoromethylphenol from 3-trifluoromethyl-4-nitrophenol was as follows: 10% palladium/carbon (Pd/C, 100 mg) was added to a 10 mL methanol (MeOH) solution of 4-nitro-3-(trifluoromethyl)phenol (Aldrich, 414 mg, 2.0 mmol). The reaction suspension was stirred under hydrogen (H2) atmosphere for 12 hours. Upon completion of the reaction, the catalyst was removed by filtration and the filtrate was concentrated under vacuum to afford 4-amino-3-(trifluoromethyl)phenol (350 mg, 95% yield), which was pure enough to be used in the subsequent reaction. Mass spectrum (ESI+): m/z 178.02 ([M + H]+).
[1] Journal of Heterocyclic Chemistry, 2011, vol. 48, # 3, p. 733 - 736
[2] Patent: US2005/245530, 2005, A1. Location in patent: Page/Page column 91
[3] Journal of Medicinal Chemistry, 2009, vol. 52, # 13, p. 3881 - 3891
[4] RSC Advances, 2013, vol. 3, # 11, p. 3697 - 3706
[5] Journal of the Chemical Society, 1949, p. 3016,3019