Cesium carbonate → 5-Bromo-3-(5-ethyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazin-2-ylamino)-1-methylpyridin-2(1H)-one

Participants

Reaction Conditions

Reaction Steps

A 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser was charged with 208b (1.0 g, 6.0 mmol), 3,5-dibromo-1-methylpyridin-2(1H)-one (1.6 g, 6.0 mmol), Pd2(dba)3 (274 mg, 0.30 mmol), XantPhos (347 mg, 0.60 mmol), cesium carbonate (3.9 g, 12.0 mmol), and 1,4-dioxane (50 mL). After three cycles of vacuum/argon flush, the mixture was stirred at 100° C. for 3 h. It was then filtered and the filtrate was evaporated in vacuo. The residue was purified by silica-gel column chromatography eluting with 40:1 dichloromethane/methanol to afford 208c (630 mg, 29%) as a yellow solid. MS-ESI: [M+H]+ 352

Provenance & Evidence