Cesium carbonate → HCID 67016555, compound

Participants

Reaction Steps

A 100-mL three-neck round-bottomed flask equipped with a reflux condenser, magnetic stirrer and nitrogen inlet was charged with 116b (400 mg, 1.66 mmol), 3,5-dibromo-1-methyl pyrazin-2(1H)-one (443 mg, 1.66 mmol), cesium carbonate (1.19 g, 3.65 mmol), and 1,4-dioxane (20 mL). After bubbling nitrogen through the resulting suspension for 30 min, Xantphos (144 mg, 0.249 mmol) and tris(dibenzylideneacetone)-dipalladium(0) (152 mg, 0.166 mmol) were added, and the reaction mixture was heated at reflux for 4 h. After this time, the mixture was cooled to room temperature and filtered, and the filter cake was washed with methylene chloride (2×20 mL). The filtrates were combined and concentrated under reduced pressure, and the resulting residue was purified by column chromatography to afford a 51% yield (353 mg) of 116c as a yellow solid: mp 172-173° C.; 1H NMR (500 MHz, CDCl3) d 8.17 (s, 1H), 8.06 (s, 1H), 7.65 (s, 1H), 6.70 (s, 1H), 4.28 (t, 2H, J=5.0 Hz), 3.97 (t, 2H, J=5.5 Hz), 3.51 (s, 3H), 0.85 (s, 9H), −0.79 (s, 6H); MS (APCI+) m/z 428.3 (M+H).

Provenance & Evidence