Cesium carbonate → 5-Bromo-3-(6,6-dimethyl-6,7-dihydro-4H-pyrazolo[5,1-c][1,4]oxazin-2-ylamino)-1-methylpyridin-2(1H)-one

Participants

Reaction Conditions

Reaction Steps

A 100-mL round-bottomed flask equipped with a reflux condenser was charged with 1,4-dioxane (10 mL), 6,6-dimethyl-6,7-dihydro-4H-pyrazolo[5,1-c][1,4]oxazin-2-amine 330g (167 mg, 1.0 mmol), 3,5-dibromo-1-methylpyridin-2(1H)-one (320 mg, 1.2 mmol), Pd2(dba)3 (91 mg, 0.10 mmol), XantPhos (116 mg, 0.20 mmol), and cesium carbonate (652 mg, 2.0 mmol). After three cycles of vacuum/argon flush, the mixture was heated at 100° C. for 3 h. It was then filtered and the filtrate was evaporated under reduced pressure. The residue was purified by silica-gel column chromatography eluting with 100:1 dichloromethane/methanol to afford 335a (210 mg, 60%) as a yellow solid. MS-ESI: [M+H]+ 352.9

Provenance & Evidence