Cesium carbonate → HCID 86683761, compound

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 5-bromo-2-nitropyridine (5.6 g, 28.0 mmol), tert-butyl 3,3-dimethyl-piperazine-1-carboxylate (3.0 g, 14.0 mmol), cesium carbonate (9.1 g, 28 mmol), and 1,4-dioxane (50 mL). After bubbling nitrogen through the resulting solution for 30 min, Binap (870 mg, 1.4 mmol) and tris(dibenzylideneacetone)dipalladium(0) (1.2 g, 1.4 mmol) were added. The reaction mixture was subjected to three cycles of vacuum/argon flush and stirred at 120° C. for 24 h. After this time the reaction was cooled to room temperature it was filtered and the filtrate was partitioned between ethyl acetate (200 mL) and water (50 mL). The aqueous layer was separated and extracted with ethyl acetate (3×50 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 5:1 petroleum ether/ethyl acetate to afford 125a (1.27 g, 27%). LCMS: [M+H]+ 337.2.

Provenance & Evidence