Synthesis
3-Bromo-6-methyl-5-nitropyridin-2-ol (9.2 g, 36.7 mmol) was used as starting material, which was dissolved in phosphorus oxychloride (POCl3, 56.2 g, 366.7 mmol). The reaction mixture was stirred and reacted at 80 °C overnight. Upon completion of the reaction, the mixture was slowly poured into water (800 mL) and the solid product was precipitated. The solid was collected by filtration and dried to afford the target compound 3-bromo-2-chloro-5-nitro-6-methylpyridine (7.5 g, 81.4% yield).
References
[1] Patent: US2018/170909, 2018, A1. Location in patent: Paragraph 1925; 1926
[2] Patent: WO2015/89192, 2015, A1. Location in patent: Paragraph 00275; 00276
[3] Patent: WO2016/37005, 2016, A1. Location in patent: Paragraph 00259-00260
[4] Patent: WO2008/101682, 2008, A2. Location in patent: Page/Page column 42-43
