Synthesis
The general procedure for the synthesis of ethyl 4-methyl-2-chloropyrimidine-5-carboxylate from ethyl 4-methyl-2-hydroxypyrimidine-5-carboxylate was as follows: ethyl 4-methyl-2-hydroxypyrimidine-5-carboxylate (10 mmol) was dissolved in phosphorochloride (10 mL), and heated and refluxed for 30 min. Upon completion of the reaction, the excess phosphorus trichloride was removed by distillation under reduced pressure. Subsequently, residual phosphorous trichloride was removed by azeotropic distillation with dried benzene. Finally, the crude product was purified by column chromatography to afford pure ethyl 4-methyl-2-chloropyrimidine-5-carboxylate.
References
[1] European Journal of Medicinal Chemistry, 2011, vol. 46, # 6, p. 2290 - 2294
[2] Patent: WO2016/37578, 2016, A1. Location in patent: Page/Page column 70
[3] European Journal of Medicinal Chemistry, 2013, vol. 66, p. 314 - 323