2,4-Dichloropyridine → 4-chloro-N-(2-methylpyrazol-3-yl)pyridin-2-amine

참여 물질

반응 조건

반응 단계

TRIS(DIBENZYLIDENEACETONE)DIPALLADIUM(0) (1.238 g, 1.35 mmol) was added in one portion to 2,4-dichloropyridine (10g, 67.57 mmol), 1-methyl-1H-pyrazol-5-amine (7.22 g, 74.33 mmol), (9,9-dimethyl-9H-xanthene-4,5-diyl)bis(diphenylphosphine) (2.346 g, 4.05 mmol) and cesium carbonate (33.0 g, 101.36 mmol) in 1,4-dioxane (350 mL) warmed to 105ºC over a period of 20 hours under nitrogen. The reaction mixture was evaporated to dryness and redissolved in DCM (250 mL), and washed with water (200 mL) The organic layer was filtered using phase separating paper and evaporated to afford crude product. The crude product was purified by flash silica chromatography, elution gradient 0 to 3% MeOH in DCM. Relavent fractions were repurified by flash silica chromatography, elution gradient 0 to 5% MeOH in EtOAc. Pure fractions were evaporated to dryness to afford 4-chloro-N-(1-methyl-1H-pyrazol-5-yl)pyridin-2-amine (2.91 g, 20.66 %) as a yellow crystalline solid.

출처 및 근거