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

Participants

Reaction Conditions

Reaction Steps

A 100-mL round-bottomed flask equipped with a magnetic stirrer and a reflux condenser was charged with 304b (230 mg, 1.17 mmol), 3,5-dibromo-1-methylpyridin-2(1H)-one (468.4 mg, 1.76 mmol), Pd2(dba)3 (53.5 mg, 0.0585 mmol), Xantphos (67.6 mg, 0.117 mmol), Cs2CO3 (762.8 mg, 2.34 mmol), and dioxane (20 mL). After three cycles of vacuum/N2 flush, the mixture was heated at 100° C. for 3 h. Analysis of the reaction mixture by LCMS showed complete conversion to the desired product. It was cooled to room temperature and filtered. The filtrate was concentrated under reduced pressure. The residue was purified by silica-gel column chromatography eluting with 40:1 dichloromethane/methanol to afford 304c as a dark solid (380 mg, 85%). MS-ESI: [M+H]+ 382.2

Provenance & Evidence