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

Participants

Reaction Conditions

Reaction Steps

A 250 ml sealed tube with a magnetic stirrer was charged with 5-methyl-1H-pyrazol-3-amine (0.91 g, 9.36 mmol), 3,5-dibromo-1-methyl-1H-pyridin-2-one (2.1 g, 7.87 mmol), cesium carbonate (7.6 g, 23.56 mmol) and 1,4-dioxane (78 mL). After degassing for 10 minutes, tris(dibenzylideneacetone)dipalladium(0) (0.72 g, 0.8 mmol) and Xantphos (0.91 g, 1.57 mmol) were added. The reaction mixture was heated at 115° C. for 48 hours. Then the mixture was cooled to room temperature and partitioned between dichloro-methane (50 mL) and water (30 mL). The organic phase was separated, and the aqueous layer was extracted with dichloromethane (3×30 mL). The combined organic phases were dried over sodium sulfate and concentrated under reduced pressure. The residue was purified by flash column chromatography (silica, 9:1 methylene chloride/methanol) to give 85% yield (1.88 g) of 112a as a solid: MS (ESI+) m/z 285.0 (M+H).

Provenance & Evidence