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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

TRIS(DIBENZYLIDENEACETONE)DIPALLADIUM(0) (251 mg, 0.27 mmol) was added in one portion to 2,4-dichloropyridine (1000mg, 6.76 mmol), 1,3-dimethyl-1H-pyrazol-5-amine (826 mg, 7.43 mmol), (9,9-dimethyl-9H-xanthene-4,5-diyl)bis(diphenylphosphine) (461 mg, 0.80 mmol) and sodium tert-butoxide (974 mg, 10.14 mmol) in 1,4-dioxane (60 mL) warmed to 130ºC over a period of 10 minutes under nitrogen. The resulting mixture was stirred at 130°C for 20 hours. The reaction mixture was evaporated to dryness and redissolved in DCM (150 mL). Solids were filtered off by suction and the filtrate subsequently washed with water (100 mL). The organic layer was dried over MgSO4, filtered and evaporated to afford crude product. The crude product was purified by flash silica chromatography, elution gradient 0 to 4% MeOH in DCM. Pure fractions were evaporated to dryness to afford 4-chloro-N-(1-methyl-1H-pyrazol-5-yl)pyridin-2-amine (802 mg, 56.9 %) as a yellow oil which crystallised on standing.

Herkunft & Nachweise