To a solution of 5-tert-butyl-2-(4-nitrophenyl)-2H-pyrazol-3-ylamine (5.0 g, 19.2 mmol) in anhydrous DCE (2 mL) was added CDI (3.5 g, 21.1 mmol), and the reaction was stirred under N2 at room temperature for 18 h. 4-(Pyridin-4-yloxy)phenylamine (3.3 g, 17.7 mmol, Dumas et al., U.S. pat. appl. US2002065296 (2002)) in DCE (12 mL) was added to the reaction, and the solution was stirred under N2 at room temperature for 7 h. The reaction mixture was partitioned between EtOAc (100 mL) and water (100 mL). The organic layer was washed with brine, dried over Na2SO4, and concentrated at reduced pressure. The crude residue was purified by MPLC (1:1 hexanes/EtOAc) to give 5.6 g (68%) of the desired product. 1H-NMR (DMSO-d6) δ 9.21 (s, 1H), 8.68 (s, 1H), 8.43 (d, J=6.3 Hz, 2H), 8.36 (d, J=7.2 Hz, 2H), 7.90 (d, J=6.9 Hz, 2H), 7.50 (d, J=6.9 Hz, 2H), 7.09 (d, J=6.6 Hz, 2H), 6.86 (d, J=5.7 Hz, 2H), 6.44 (s, 1H), 1.29 (s, 9H); MS LC-MS [M+H]+=473, RT=2.60 min.
