Ethyl Acetate → 4-(5-Amino-3-tert-butyl-pyrazol-1-yl)phenol

Participants

Reaction Steps

To a stirred solution of 5-tert-butyl-2-(4-methoxyphenyl)-2H-pyrazol-3-ylamine (5.3 g, 21.6 mmol) in anhydrous DCM (43.2 mL) was added aluminum trichloride (14.4 g, 108.0 mmol, 5.0 eq) proportion wise, and the reaction was stirred at reflux for 18 h. The cooled reaction was poured into ethyl acetate, and the organic layer was washed with water and brine, dried over Na2SO4, filtered, and concentrated at reduced pressure. Crystallization from DCM/ether afforded the title compound (2.71 g, 54%) as a white solid. 1H-NMR (DMSO-d6) δ 9.47 (s, 1H), 7.21 (d, J=9.0 Hz, 2H), 6.75 (d, J=8.7 Hz, 2H), 5.25 (s, 1H), 4.91 (broad s, 2H), 1.13 (s, 9H); MS LC-MS [M+H]+=232, RT=1.13 min; TLC (35% EtOAc/hex), Rf=0.13.

Provenance & Evidence