3-Tert-butyl-isoxazole-5-carboxylic acid [3-nitro-4-trifluoromethyl-6-(2-trifluoromethyl-phenyl)-pyridin-2-yl]-amide → 2-(3-tert-butyl-isoxazol-5-yl)-7-trifluoromethyl-5-(2-trifluoromethyl-phenyl)-1H-imidazo[4,5-b]pyridine

Participants

Reaction Conditions

Reaction Steps

A solution of 3-tert-butyl-isoxazole-5-carboxylic acid [3-nitro-4-trifluoromethyl-6-(2-trifluoromethyl-phenyl)-pyridin-2-yl]-amide (14.6 mg, 0.029 mmol, prepared as described in STEP E above) in AcOH (3 mL) was treated with iron powder (8.12 mg, 0.145 mmol), and the resulting mixture was stirred at 100° C. for 2 h and concentrated in vacuo. The residue was taken up in saturated aqueous NaHCO3 (30 mL) and extracted twice with EtOAc (25 mL). The combined organic extracts were dried over MgSO4 and concentrated in vacuo. The residue was purified on a 4-g SEPRA Si 50 SPE column (Flow rate=10 mL/min; Eluent=EtOAc-hexanes, 1:99 for 10 min, then 1:99 to 1:4 over 40 min) to yield 2-(3-tert-butyl-isoxazol-5-yl)-7-trifluoromethyl-5-(2-trifluoromethyl-phenyl)-1H-imidazo[4,5-b]pyridine as a white solid. 1H-NMR (400 MHz, CD3OD) δ: 7.77 (d, J=7.6 Hz, 1H), 7.63-7.69 (m, 1H), 7.58-7.62 (m, 2H), 7.52-7.58 (m, 1H), 7.26 (s, 1H), 1.33 (s, 9H). Mass Spectrum (LCMS, APCI pos.): Calculated for C21H16N4OF6: 455.1 (M+H); Measured: 455.1.

Provenance & Evidence