Morpholine → 3-(Morpholin-4-yl)-1,2,5,6-tetrahydropyridin-2-one

Participants

Reaction Steps

A solution of 3-chloro-5,6-dihydro-1H-pyridin-2-one (44, 1.0 g, 7.6 mmol) in THF (4 mL) was treated with morpholine (663 mg, 0.67 mL, 7.6 mmol, 1.0 equiv) and triethylamine (TEA, 1.54 g, 2.1 mL, 15.2 mmol, 2.0 equiv) at room temperature, and the resulting reaction mixture was warmed up to reflux for 6 h. When HPLC and TLC showed the reaction was deemed complete, the reaction mixture was quenched with water (10 mL) and EtOAc (20 mL), and the resulting mixture was stirred at room temperature for 10 min. The two layers were separated, and the aqueous layer was extracted with EtOAc (3×20 mL). The combined organic extracts were washed with saturated NaCl aqueous solution (5 mL), dried over MgSO4, and concentrated in vacuo. The residue was then purified by flash column chromatography (SiO2, 15-40% EtOAc/hexane gradient elution) to afford the desired 3-morpholin-4-yl-5,6-dihydro-1H-pyridin-2-one (45, 595 mg, 1.384 g theoretical, 43%) as pale-yellow oil, which solidified upon standing at room temperature in vacuo and was found to be essentially pure to do the following reaction without further purification. For 45, CIMS m/z 181 (M+−H, C9H14N2O2).

Provenance & Evidence