Dimethylformamide → 5-bromo-1-methyl-3-(pyrimidin-4-ylamino)pyridin-2(1H)-one

Participants

Reaction Conditions

Reaction Steps

A 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer and nitrogen inlet was charged with 3,5-dibromo-1-methylpyridin-2(1H)-one (2.00 g, 21.0 mmol), 2-aminopyrimidine (5.61 g, 21.0 mmol), cesium carbonate (13.7 g, 42.1 mmol), DMF (5 mL) and 1,4-dioxane (70 mL). After bubbling nitrogen through the resulting suspension for 30 min, Xantphos (1.10 g, 1.89 mmol) and tris(dibenzylideneacetone)dipalladium(0) (963 mg, 1.05 mmol) were added. A reflux condenser was attached to the flask, and the reaction mixture was heated at 100° C. for 4 h. After this time, the mixture was cooled to room temperature and diluted with 90:10 methylene chloride/methanol (150 mL) and water (100 mL), and the layers were separated. The aqueous layer was extracted with 90:10 methylene chloride/methanol (50 mL), and the combined organic layers were washed with brine and dried over sodium sulfate. The drying agent was removed by filtration. The filtrate was concentrated under reduced pressure, and the resulting residue was purified by flash column chromatography (silica, 90:10 methylene chloride/methanol) to afford 142a in 58% yield (3.42 g) as an amorphous light green solid: mp 217-219° C.; 1H NMR (500 MHz, CDCl3) δ 9.29 (s, 1H), 8.77 (s, 1H), 8.72 (d, J=2.5 Hz, 1H), 8.36 (d, J=6.0 Hz, 1H), 7.69 (d, J=2.5 Hz, 1H), 7.37 (dd, J=5.5, 1.0 Hz, 1H), 3.53 (s, 3H); LCMS (ESI+) m/z 281.0 (M+H).

Provenance & Evidence