Cesium carbonate → 5-Morpholin-4-yl-1-[4-(2-oxopiperidin-1-yl)phenyl]-2,3-dihydropyridin-6-one

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Reaction Conditions

Reaction Steps

Part B. Soluble copper(I)-catalyzed Ullmann coupling reaction. A suspension of 1-(4-iodo-phenyl)-3-morpholin-4-yl-5,6-dihydro-1H-pyridin-2-one (10, 2.2 g, 5.73 mmol), piperidin-2-one (42, 851 mg, 8.59 mmol, 1.5 equiv), and Cs2CO3 (3.73 g, 11.46 mmol, 2.0 equiv) in toluene (15 mL) was treated with Cu(PPh3)3Br (1.065 g, 1.146 mmol, 20% equiv) at room temperature under N2, and the resulting reaction mixture was degassed three times under a steady stream of nitrogen. The reaction mixture was warmed up to reflux for 6 h. When HPLC showed the Ullmann coupling reaction was complete, the reaction mixture was cooled down to 5–10° C. before being quenched with 14% of ammonium hydroxide aqueous solution (20 mL) and EtOAc (30 mL) at 5–10° C. The mixture was stirred for an additional 4 h at 25° C. The two layers were then separated, and the aqueous layer was extracted with EtOAc (3×20 mL). The combined organic extracts were washed with saturated NaCl aqueous solution (10 mL), dried over MgSO4, and concentrated in vacuo. The residue was directly purified by flash column chromatography (SiO2, 15–40% EtOAc/hexane gradient elution) to afford the desired 3-morpholin-4-yl-1-[4-(2-oxo-piperidin-1-yl)-phenyl]-5,6-dihydro-1H-pyridin-2-one (63, 1.568 g, 2.036 g theoretical, 77%) as a pale-yellow oil, which solidified upon standing at room temperature in vacuo. For 63, CIMS m/z 356 (M++H, C20H25N3O3).

Provenance & Evidence