Cesium carbonate → (S)-3-[[5-(4-Boc-2-methyl-1-piperazinyl)-2-pyridyl]amino]-5-bromo-1-methylpyridin-2(1H)-one

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Reaction Steps

A 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer and reflux condenser was charged with 1,4-dioxane (50 mL), 105b (4.0 g, 13.7 mmol), 3,5-dibromo-1-methylpyridin-2(1H)-one (5.5 g, 20.8 mmol), and cesium carbonate (11 g, 35 mmol). After bubbling nitrogen through the resulting mixture for 30 minutes, XantPhos (272 mg, 0.47 mmol) and tris(dibenzylideneacetone)dipalladium(0) (430 mg, 0.47 mmol) were added, and the reaction mixture was heated at reflux for 3 h. After this time the reaction was cooled to room temperature, partitioned between ethyl acetate (300 mL) and water (300 mL), and filtered. The aqueous layer was separated and extracted with ethyl acetate (150 mL×2). The organic layers were combined, washed with brine (150 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 on flash column eluting with 50:1 CH2Cl2/methanol to afford 105c as a yellow solid (5.4 g, 83%). LCMS: [M+H]+ 478

Provenance & Evidence