Cesium carbonate → (S)-tert-Butyl 4-(6-(6-Chloro-3-oxo-2-((2-(trimethylsilyl)ethoxy)-methyl)-2,3-dihydropyridazin-4-ylamino)pyridin-3-yl)-3-methylpiperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A 50-mL round-bottomed flask equipped with a reflux condenser was charged with (S)-tert-butyl 4-(6-aminopyridin-3-yl)-3-methylpiperazine-1-carboxylate 191f (580 mg, 2.0 mmol), 253a (1.36 g, 4.0 mmol), Pd2(dba)3 (180 mg, 0.20 mmol), Xantphos (230 mg, 0.40 mmol), Cs2CO3 (1.3 g, 4.0 mmol), and dioxane (20 mL). After three cycles of vacuum/argon flush, the mixture was heated at 100° C. for 2 h. It was then cooled to room temperature and filtered. The filtrate was evaporated under reduced pressure and the resulting residue was purified by silica-gel column chromatography eluting with 4:1 petroleum ether/ethyl acetate to afford 253b (1.0 g, 91%) as yellow solid. MS-ESI: [M+H]+ 551.2

Provenance & Evidence