Cesium carbonate → HCID 86683763, compound

Participants

Reaction Steps

A 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser was charged with tert-butyl 4-(6-aminopyridin-3-yl)-3,3-dimethylpiperazine-1-carboxylate 190b (950 mg, 3.1 mmol), 3,5-dibromo-1-methylpyridin-2(1H)-one (1240 mg, 4.6 mmol), 1,4-dioxane (30 mL), and cesium carbonate (2015 mg, 6.2 mmol). After bubbling nitrogen through the resulting solution for 5 min, Xantphos (179 mg, 0.31 mmol) and tris(dibenzylideneacetone)dipalladium(0) (283 mg, 0.31 mmol) were added. The reaction mixture was subjected to three cycles of vacuum/argon flush and heated at reflux for 10 h. After this time the reaction was cooled to room temperature and filtered. The filtrate was partitioned between ethyl acetate (50 mL) and water (10 mL). The aqueous layer was separated and extracted with ethyl acetate (3×20 mL). The combined organic layer was washed with brine (30 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 4:1 petroleum ether/ethyl acetate to afford 190c (1.21 g, 79%). LCMS: [M+H]+ 492.1.

Provenance & Evidence