Cesium carbonate → HCID 178479983, compound

Participants

Reaction Steps

A 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser was charged with 1,4-dioxane (15 mL), 126c (455 mg, 1.95 mmol), 3,5-dibromo-1-methylpyridin-2(1H)-one (0.40 g, 1.5 mmol), and cesium carbonate (1.22 g, 3.75 mmol). After bubbling nitrogen through the resulting mixture for 30 minutes, XantPhos (87 mg, 0.15 mmol) and tris(dibenzylideneacetone)dipalladium(0) (70 mg, 0.075 mmol) were added. The reaction mixture was refluxed for 15 h. After this time the reaction was cooled to room temperature and filtered. The filtrate was partitioned between ethyl acetate (30 mL) and water (30 mL). The aqueous layer was separated and extracted with ethyl acetate (2×50 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 on silica-gel column eluting with 50:1 dichloromethane/methanol to afford 126d as a yellow solid (320 mg, 70%). MS: [M+H]+ 309. 1H NMR (500 MHz, DMSO-d6) δ 11.85 (s, 1H), 8.23 (s, 1H), 8.02 (d, J=2.5 Hz, 1H), 7.35 (d, J=2.5 Hz, 1H), 5.77 (d, J=2.0 Hz, 1H), 3.46 (s, 3H), 1.84-1.82 (m, 1H), 0.92-0.90 (m, 2H), 0.65-0.64 (m, 2H).

Provenance & Evidence