Synthesis
General procedure for the synthesis of methyl 6-formyl-2-pyridinecarboxylate from methyl 6-hydroxymethyl-2-pyridinecarboxylate: the product of Example 17A (8 g, 48 mmol) was dissolved in dichloromethane (200 mL) and electrolytic manganese dioxide (41.67 g, 0.48 mol) was added. The reaction mixture was stirred at 25 °C for 4 days and filtered through diatomaceous earth after completion of the reaction. The filtrate was concentrated under reduced pressure and the residue was purified by silica gel column chromatography to afford methyl 6-formyl-2-pyridinecarboxylate as a white solid (6.9 g, 87% yield) using a 5% dichloromethane solution of methanol as eluent.
References
[1] Patent: US2005/131017, 2005, A1. Location in patent: Page/Page column 106
[2] Patent: US6020345, 2000, A
[3] Bioorganic and Medicinal Chemistry Letters, 2003, vol. 13, # 4, p. 609 - 612
[4] Patent: WO2004/37808, 2004, A1. Location in patent: Page 9-10
[5] Chemistry of Heterocyclic Compounds, 2009, vol. 45, # 2, p. 161 - 168
