Synthesis
(b) Synthesis of 5-bromo-4-chloro-2,6-dimethylpyrimidine. 5-Bromo-2,6-dimethylpyrimidin-4-ol (3.95 g, 19.45 mmol) was mixed with phosphorochloridic acid (6 mL, 64.4 mmol) and heated to reflux for 3 h at 110 °C. The reaction was carried out at a pressure of 1.5 °F. Upon completion of the reaction, the reaction solution was concentrated under reduced pressure, followed by the slow and careful addition of ice water to precipitate a white precipitate. The solid was collected by filtration, washed thoroughly with cold water and dried to afford the target product 5-bromo-4-chloro-2,6-dimethylpyrimidine (2.73 g, 63% yield). The product was analyzed by LCMS (ES+), m/e 221 [M+H]+.
References
[1] Patent: WO2013/96151, 2013, A1. Location in patent: Page/Page column 131
[2] Patent: US2016/176882, 2016, A1. Location in patent: Paragraph 0346; 0348
[3] Patent: WO2017/221092, 2017, A1. Location in patent: Paragraph 00202
[4] Patent: WO2017/221100, 2017, A1. Location in patent: Paragraph 00160
