Cesium carbonate → (R)-tert-Butyl 4-(6-(5-Bromo-1-methyl-2-oxo-1,2-dihydropyridin-3-ylamino)pyridin-3-yl)-3-methylpiperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser was charged with 1,4-dioxane (40 mL), 151b (1.0 g, 3.4 mmol), 3,5-dibromo-1-methylpyridin-2(1H)-one (2.7 g, 10.2 mmol), and cesium carbonate (2.2 g, 6.8 mmol). After bubbling nitrogen through the resulting mixture for 10 minutes, XantPhos (198 mg, 0.34 mmol) and tris(dibenzylideneacetone)dipalladium(0) (313 mg, 0.34 mmol) were added. The reaction mixture was subjected to three cycles of vacuum/argon flush and heated at 100° C. for 5 h. After this time the reaction was cooled to room temperature and filtered. The filtrate was partitioned between ethyl acetate (50 mL) and water (50 mL). The aqueous layer was separated and extracted with ethyl acetate (3×30 mL). The combined organic layer was washed with brine (50 mL) and dried over sodium sulfate. The drying agent was removed by filtration and the filtrate was concentrated under reduced pressure. The residue was purified by silica-gel column chromatography eluting with 30:1 dichloromethane/methanol to afford 151c as yellow solid (1.1 g, 63%). MS-ESI: [M+H]+ 478.

Provenance & Evidence