Cesium carbonate → 2-(5-Bromo-1-methyl-2-oxo-1,2-dihydropyridin-3-ylamino)-5-isopropyl-4,5-dihydropyrazolo[1,5-a]pyrazin-6(7H)-one

Participants

Reaction Conditions

Reaction Steps

A 100-mL round-bottomed flask equipped with a reflux condenser was charged with 151e (200 mg, 1.0 mmol), 3,5-dibromo-1-methylpyridin-2(1H)-one (268 mg, 1.0 mmol), Pd2(dba)3 (50 mg, 0.050 mmol), xantphos (58 mg, 0.10 mmol), Cs2CO3 (652 mg, 2.0 mmol) and 1,4-dioxane (20 mL). The system was subjected to three cycles of vacuum/argon flush and heated at 100° C. for 2 h. It was then cooled to room temperature and filtered. The solid was washed with dichloromethane (2×10 mL). The combined filtrate was concentrated under reduced pressure. The residue was purified by silica-gel column chromatography eluting with dichloromethane/methanol (80:1 to 30:1) to afford 151f (300 mg, 79%) as a yellow solid. MS-ESI: [M+H]+ 380.2

Provenance & Evidence