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

Participants

Reaction Conditions

Reaction Steps

A sealed tube was equipped with a magnetic stirrer and charged with 1-(2-amino-6,7-dihydropyrazolo[1,5-a]pyrazin-5(4H)-yl)ethanone 108c (860 mg, 4.8 mmol), 3,5-dibromo-1-methylpyridin-2(1H)-one (1.8 g, 6.7 mmol), and cesium carbonate (3.4 g, 10.5 mmol) in 1,4-dioxane (67 mL). After bubbling nitrogen through the solution for 30 min, Xantphos (330 mg, 0.6 mmol) and tris(dibenzylideneacetone) dipalladium(0) (300 mg, 0.3 mmol) were added, and the reaction mixture was heated to 100° C. for 16 h. After this time, H2O (50 mL) and EtOAc (50 mL) were added. The aqueous layer was separated and extracted with EtOAc (2×50 mL). The combined organic extracts were washed with brine (100 mL) and dried over sodium sulfate. The resulting residue was purified by column chromatography eluting with a gradient of CH2Cl2-60:35:5 CH2Cl2:Et2O:MeOH to afford a 41% yield (720 mg) of 3-(5-acetyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazin-2-ylamino)-5-bromo-1-methylpyridin-2(1H)-one 108d.

Provenance & Evidence