Synthesis
GENERAL METHOD: In a 50 mL round-bottomed flask, 2,4-dichloropyrimidine (3.36 mmol) was dissolved in anhydrous ethanol (5 mL), followed by the addition of triethylamine (5.03 mmol) and tetrandrine (5.03 mmol). For the reaction of 2,4-dichloropyrimidine, the mixture was stirred at room temperature; while for the other dichlorodiazines, it was carried out under ethanol reflux conditions. The reaction progress was monitored by gas chromatography (GC). After the starting material 2,4-dichloropyrimidine was completely consumed, the reaction mixture was poured into saturated ammonium chloride solution (20 mL) and extracted with dichloromethane (3 x 20 mL). The organic layers were combined, dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The crude product was ground with petroleum ether and filtered through a Büchner funnel to give the pure 2-chloro-4-(pyrrolin-1-yl)pyrimidine.
References
[1] Organic Letters, 2018, vol. 20, # 2, p. 473 - 476
[2] Tetrahedron, 2015, vol. 71, # 29, p. 4859 - 4867
[3] Bioorganic and Medicinal Chemistry Letters, 2018,
[4] European Journal of Medicinal Chemistry, 1991, vol. 26, # 7, p. 729 - 733
[5] Patent: WO2009/29617, 2009, A1. Location in patent: Page/Page column 86-87
