Cesium carbonate → Tert-Butyl 4-(6-(5-Bromo-1-methyl-2-oxo-1,2-dihydropyridin-3-ylamino)pyridin-3-yl)-3-oxopiperazine-1-carboxylate

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Reaction Steps

A 100-mL three-neck round-bottomed flask equipped with a magnetic stirrer, nitrogen inlet and reflux condenser was charged with 3,5-dibromo-1-methylpyridin-2(1H)-one (530 mg, 1.99 mmol), 121b (580 mg, 1.99 mmol), cesium carbonate (1.43 g, 4.40 mmol) and 1,4-dioxane (30 mL). After bubbling nitrogen through the resulting mixture for 20 minutes, Xantphos (98.4 mg, 0.170 mmol) and tris(dibenzylideneacetone)dipalladium(0) (91.6 mg, 0.100 mmol) were added, and the reaction mixture was heated at reflux for 4 h. After this time, the reaction was cooled to room temperature, filtered and concentrated under reduced pressure. The resulting residue was purified by flash chromatography to afford an 84% yield (802 mg) of 121c as a yellow solid: mp 130-132° C.; 1H NMR (500 MHz, CDCl3) δ 8.68 (d, 1H, J=2.5 Hz), 8.24 (d, 1H, J=2.5 Hz), 7.98 (s, 1H), 7.52 (dd, 1H, J=9.0, 2.5 Hz), 7.00 (d, 1H, J=2.5 Hz), 6.82 (d, 1H, J=8.5 Hz), 4.26 (s, 2H), 3.81 (m, 2H), 3.73 (m, 2H), 3.60 (s, 3H), 1.50 (s, 9H); MS (ESI+) m/z 478.2 (M+H).

Provenance & Evidence