Cesium carbonate → 6-Chloro-2-methyl-4-(pyrimidin-4-ylamino)pyridazin-3(2H)-one

Participants

Reaction Steps

A 250-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser was charged with 1,4-dioxane (150 mL), pyrimidin-4-amine (1.7 g, 18.0 mmol), 4-bromo-6-chloro-2-methylpyridazin-3(2H)-one (4.0 g, 18.0 mmol), and cesium carbonate (11.74 g, 36.0 mmol). After bubbling nitrogen through the suspension for 30 minutes, Xantphos (1.04 g, 1.8 mmol) and tris(dibenzylideneacetone)dipalladium(0) (823 mg, 0.9 mmol) were added. The system was subjected to three cycles of vacuum/argon flush and heated at reflux for 15 h. It was then cooled to room temperature and filtered. The solid was washed with dichloromethane (2×50 mL). The combined filtrate was concentrated and the residue was washed with acetonitrile (5 mL) to afford 263a (2.99 g, 70%) as a yellow solid. MS: [M+H]+ 238

Provenance & Evidence