Synthesis
Step 2: 26.8 g (0.195 mol) of SOCl2 was slowly added dropwise to 100 mL of methanol at a low temperature of -10 °C while stirring was continued. After the dropwise addition, the reaction mixture was gradually warmed up to room temperature and stirring was continued for 1 hour. Subsequently, 10 g of 6-methyl-2-pyridinecarboxylic acid (Compound 2) was added to the reaction system and the reaction was refluxed at 80 °C for 5 hours. Upon completion of the reaction, 10.2 g of methyl 6-methyl-2-pyridinecarboxylate (Compound 3) was obtained in 93% yield.
References
[1] Patent: CN105294552, 2016, A. Location in patent: Paragraph 0047; 0051
[2] Patent: WO2004/48383, 2004, A1. Location in patent: Page 40
[3] Patent: WO2004/48382, 2004, A1. Location in patent: Page 8
[4] Patent: WO2016/187308, 2016, A1. Location in patent: Paragraph 0349
[5] Patent: WO2012/80221, 2012, A1. Location in patent: Page/Page column 98
