Synthesis
The general procedure for the synthesis of 5,6-dihydro-3-(4-morpholinyl)-2(1H)-pyridinone from morpholine and 3,3-dichloro-2-piperidinone was as follows: 100 g (0.60 mmol) of 3,3-dichloro-2-piperidinone was dissolved in 400 mL of 1,4-dioxane at room temperature, followed by the addition of 60 mL (0.66 mmol) morpholine and 210 mL (1.50 mmol) of triethylamine. The reaction mixture was heated to 110°C and the progress of the reaction was monitored by thin layer chromatography (TLC). The reaction was completed after about 4.5 h. The reaction mixture was cooled to room temperature, during which time a solid precipitated. The solid was separated by filtration and the filtrate was distilled under reduced pressure to remove the solvent to give a yellow solid. The solid was washed sequentially with ether (2 x 400 mL) and water (2 x 200 mL) and dried to give a white solid powder 5,6-dihydro-3-(4-morpholinyl)-2(1H)-pyridinone 100.5 g (theoretical yield 108.5 g) in 92% yield.
References
[1] Patent: CN104513239, 2017, B. Location in patent: Paragraph 0197; 0238; 0241; 0242
[2] Monatshefte fur Chemie, 2017, vol. 148, # 8, p. 1477 - 1482
[3] Patent: CN104327074, 2016, B. Location in patent: Paragraph 0151; 0152; 0153
[4] Patent: CN104311558, 2016, B. Location in patent: Paragraph 0150; 0151; 0152
[5] Patent: CN104277041, 2016, B. Location in patent: Paragraph 0155; 0156; 0157
