Synthesis
General procedure: 2,4-Dichloropyrimidine (1.0 g, 6.7 mmol) was suspended in ethanol (20 ml) under inert atmosphere, cooled to 0°C and stirred. To this suspension triethylamine (1.4 ml, 10.1 mmol) and morpholine (0.59 ml, 6.7 mmol) were added sequentially. The reaction mixture was stirred at 0°C for 3 hours. After completion of the reaction, the mixture was concentrated in vacuum, diluted with 1 M NaOH solution (20 ml) and extracted with ethyl acetate (3 x 20 ml). The organic phases were combined, dried with anhydrous sodium sulfate, filtered and concentrated in vacuum to give a colorless solid. The crude product was recrystallized by ethyl acetate/hexane to give 2-chloro-4-morpholino pyrimidine (1.21 g, 90% yield) as a colorless solid, which did not require further purification.LC-MS (ESP) analysis showed m/z 200 [M+H]+ and retention time (R/T) = 3.26 min.
References
[1] Patent: US2006/199804, 2006, A1. Location in patent: Page/Page column 27
[2] Tetrahedron, 2015, vol. 71, # 29, p. 4859 - 4867
[3] Organic Letters, 2018, vol. 20, # 2, p. 473 - 476
[4] Patent: WO2017/58503, 2017, A1. Location in patent: Page/Page column 419-421
[5] European Journal of Medicinal Chemistry, 1991, vol. 26, # 7, p. 729 - 733