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

Participants

Reaction Conditions

Reaction Steps

A 350-mL sealed tube equipped with a magnetic stirring bar was charged with 3,5-dibromo-1-methyl-1H-pyridin-2-one (3.2 g, 0.012 mol), 5-ethyl-1H-pyrazol-3-amine (2.0 g, 0.018 mol), Pd2(dba)3 (0.55 g, 0.60 mmol), 9,9-dimethyl-4,5-bis(diphenyl-phosphino)xanthene (0.49 g, 0.00084 mol), Cs2CO3 (7.8 g, 0.024 mol), and 1,4-dioxane (80 mL). After the reaction mixture was stirred at 105° C. for 16 h, it was cooled to room temperature, partitioned between dichloromethane (50 mL) and water (30 mL), and the organic phases were extracted with dichloromethane (30 mL×3). The combined organic phases were washed with water (30 mL×2) and brine (20 mL×1), dried (Na2SO4), and filtered through a pad of Celite, and the resulting filtrated was concentrated. To the crude product were added dichloromethane (20 mL) and ether (100 mL). The mixture was sonicated for 10 min., and the resulting precipitates were filtered to give 42% yield (1.5 g) of 5-bromo-3-(5-ethyl-1H-pyrazol-3-ylamino)-1-methylpyridin-2(1H)-one (125a) as a solid.

Provenance & Evidence