Cesium carbonate → 5-Bromo-3-(1-ethyl-5-methyl-1H-pyrazol-3-ylamino)-1-methylpyridin-2(1H)-one

Participants

Reaction Conditions

Reaction Steps

A sealed tube was equipped with a magnetic stirrer and charged with 1-ethyl-5-methyl-1H-pyrazol-3-amine (870 mg, 7 mmol), 3,5-dibromo-1-methylpyridin-2(1H)-one (1.9 g, 7 mmol) and cesium carbonate (5 g, 15 mmol) in 1,4-dioxane (69 mL). After bubbling nitrogen through the solution for 30 min, Xantphos (480 mg, 0.8 mmol) and tris(dibenzylideneacetone) dipalladium(0) (450 mg, 0.5 mmol) were added, and the reaction mixture was heated to 100° C. for 16 h. After this time, water (50 mL) and ethyl acetate (50 mL) were added. The aqueous layer was separated and extracted with ethyl acetate (2×50 mL). The combined organic extracts were washed with brine (100 mL) and dried over sodium sulfate. The mixture was concentrated under reduced pressure to near dryness when the desired product crashed out and was filtered. Washing with diethyl ether (10 mL) afforded a 40% yield (870 mg) of 302a.

Provenance & Evidence