Cesium carbonate → 4-chloro-6-(1,3-dimethyl-1H-pyrazol-4-ylamino)nicotinonitrile

関与物質

反応条件

反応手順

4,6-Dichloropyridine-3-carbonitrile (9.60 g, 55.49 mmol), N-(1,3-dimethylpyrazol-4-yl)acetamide (8.5 g, 55.49 mmol, see Example 2.02), palladium(II) acetate (0.374 g, 1.66 mmol), 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (1.926 g, 3.33 mmol) and cesium carbonate (27.1 g, 83.23 mmol) were weighed out in a flask. Dioxane (110 mL) was added and argon was bubbled through the reaction mixture for 5 minutes at room temperature. The resulting suspension was stirred at 90° C. for 2 hours. The reaction mixture was allowed to cool to room temperature with stirring, water (275 mL) was added followed by the portionwise addition of lithium hydroxide hydrate (6.99 g, 166.47 mmol). The solution was left to stir at room temperature for 30 minutes. The resulting precipitate was collected by filtration, washed with water and dried. The crude product was purified by flash chromatography on silica gel eluting with 0 to 5% MeOH in EtOAc/DCM (1:1). The solvent was evaporated to dryness. The residue was triturated in Et2O, and the resulting precipitate was collected by filtration, washed with Et2O and dried to a constant weight to afford 4-chloro-6-(1,3-dimethylpyrazol-4-ylamino)pyridine-3-carbonitrile (6 g, 43.7%) as a pale yellow solid. 1H NMR spectrum (500 MHz, CDCl3): δ 2.15 (s, 3H), 2.88 (s, 3H), 6.43 (s, 1H), 6.45 (s, 1H), 7.44 (s, 1H), 8.36 (s, 1H); Mass spectrum: m/z (ESI+) (M+H)+=248.

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