2-Aminopyridine → 5-Bromo-1-methyl-3-(pyridin-2-ylamino)-1h-pyridin-2-one

Participants

Reaction Conditions

Reaction Steps

A 250-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser was charged with 1,4-dioxane (60 mL), 5-bromo-2-nitropyridine (8.0 g, 31.8 mmol), pyridin-2-amine (1.0 g, 10.6 mmol), and cesium carbonate (7.0 g, 21.2 mmol). After bubbling nitrogen through the resulting mixture for 30 minutes, XantPhos (616 mg, 1.0 mmol) and tris(dibenzylideneacetone)dipalladium(0) (973 mg, 1.0 mmol) were added. The reaction mixture was subjected to three cycles of vacuum/argon flush and heated at 100° C. for 12 h. After this time the reaction was cooled to room temperature and filtered. The filtrate was partitioned between ethyl acetate (100 mL) and water (100 mL). The aqueous layer was separated and extracted with ethyl acetate (3×150 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 on silica-gel column eluting with 30:1 dichloromethane/methanol to afford 178a (1.5 g, 51%) as yellow solid. MS: [M+H]+ 280

Provenance & Evidence