Potassium Carbonate → (R)-tert-Butyl 2-Methyl-4-(6-nitropyridin-3-yl)piperazine-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 methylsulfinylmethane (50 mL), 5-bromo-2-nitropyridine (2.2 g, 11 mmol), (R)-tert-butyl 2-methylpiperazine-1-carboxylate (2.2 g, 11 mmol), and potassium carbonate (3.08 g, 22 mmol). See FIG. 8. The system was subjected to three cycles of vacuum/nitrogen flush and heated at 65° C. for 15 h. It was then cooled to room temperature, and partitioned between ethyl acetate (100 mL) and water (20 mL). The aqueous layer was separated and extracted with ethyl acetate (50 mL×2). The combined organic layer was washed with brine (50 mL) and dried over anhydrous sodium sulfate. The drying agent was removed by filtration and the filtrate was concentrated under reduced pressure. The residue was purified on flash column chromatography eluting with 2:1 (UV) petroleum/ethyl acetate to afford 108a as a yellow solid (1.75 g, 50%). LCMS: [M+H]+ 323

Provenance & Evidence