Triethylamine → 3-(3-(4-(Pyridin-3-yloxy)-benzyl)-isoxazol-5-yl)-pyridin-2-ylamine

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Reaction Steps

To a methanol (10.0 mL) solution of 3-(4-(2-nitro-ethyl)-phenoxy)-pyridine (819 mg, 3.35 mmol) described in Manufacturing Example 76-1-3 was added lithium methoxide (254 mg, 6.70 mmol) under nitrogen atmosphere at room temperature, which was stirred for 30 minutes at room temperature. The solvent was evaporated from the reaction mixture under a reduced pressure, and anhydrous dichloromethane (15.0 ml) and anhydrous tetrahydrofuran (7.00 mL) were added to the residue. Titanium (IV) chloride (1.18 mL, 10.7 mmol) was added dropwise to the reaction mixture on a dry ice-ethanol bath (−78° C.), and stirred for 30 minutes at room temperature. Sodium bicarbonate solution and ethyl acetate were added to the reaction mixture on an ice bath (0° C.), which was then filtered through a Celite pad. The organic layer of the filtrate was extracted with ethyl acetate, and that organic layer was washed with water and saturated aqueous sodium chloride, dried over anhydrous magnesium sulfate, and filtered. The filtrate was concentrated under a reduced pressure to obtain a crude product (400 mg). To a tetrahydrofuran (5.00 mL) solution of this crude product (250 mg) and 3-ethynyl-pyridin-2-ylamine described in Manufacturing Example 1-2-3 (40.0 mg, 0.339 mmol) was added triethylamine (142 μL, 1.02 mmol) at room temperature, which was stirred for 3 hours at 60° C. Water was added to the reaction solution at room temperature, which was then extracted with ethyl acetate. The organic layer was washed with saturated aqueous sodium chloride and dried over anhydrous magnesium sulfate, and the solvent was evaporated under a reduced pressure. The residue was purified by NH silica gel column chromatography (ethyl acetate:heptane=1:1), the mixture was further purified by reverse-phase high-performance liquid chromatography (using an acetonitrile-water mobile phase containing 0.1% trifluoracetic acid) to obtain the title compound (11.7 mg, 10.0%) as a ditrifluoracetic acid salt.

Provenance & Evidence