Cesium carbonate → 5-Bromo-3-(1,5-dimethyl-1H-pyrazol-3-ylamino)-1-methylpyridin-2(1H)-one

Participants

Reaction Steps

A 250-mL single-necked round-bottomed flask equipped with a magnetic stirrer and reflux condenser was charged with 3,5-dibromo-1-methylpyridin-2(1H)-one (1.50 g, 5.62 mmol), 1,5-dimethyl-3-amino-1H-pyrazole (625 mg, 5.62 mmol), cesium carbonate (5.48 g, 16.8 mmol) and 1,4-dioxane (36 mL). After bubbling nitrogen through the resulting solution for 30 min, Xantphos (553 mg, 0.955 mmol) and tris(dibenzylideneacetone)dipalladium(0) (625 mg, 0.562 mmol) were added and the reaction mixture was heated at reflux for 16 h. The reaction mixture was cooled to room temperature and the resulting precipitate was filtered off. The filter cake was washed with methylene chloride (approximately 20 mL). The resulting filtrate was then concentrated under reduced pressure and purified by column chromatography to afford 105a (935 mg, 56%) as a yellow solid: 1H NMR (300 MHz, CDCl3) δ 7.84 (s, 1H), 7.31 (s, 1H), 6.86 (s, 1H), 5.65 (s, 1H), 3.71 (s, 3H), 3.57 (s, 3H), 2.23 (s, 3H); MS (ESI+) m/z 297.0 (M+H).

Provenance & Evidence