General procedure for the synthesis of tert-butyl (4-formylpyridin-2-yl)carbamate from (4-(hydroxymethyl)pyridin-2-yl)carbamate:
Synthesis of compound 2G: tert-butyl (4-formylpyridin-2-yl)carbamate
Compound 2F ((tert-butyl (4-(hydroxymethyl)pyridin-2-yl)carbamate, 2.5 g, 11.15 mmol, 1.00 eq.) was dissolved in dichloroethane (DCE, 25 mL) followed by addition of manganese dioxide (MnO2, 19.4 g, 223.14 mmol, 20.02 eq.). The reaction mixture was stirred at 70 °C overnight. Upon completion of the reaction, the solid catalyst was removed by filtration. The filtrate was concentrated to dryness under reduced pressure to afford 1.4 g (57% yield) of the target product compound 2G as a white solid.
[1] Synthesis, 2007, # 16, p. 2529 - 2533
[2] Patent: WO2003/103669, 2003, A1. Location in patent: Page 21
[3] Patent: WO2008/108958, 2008, A2. Location in patent: Page/Page column 32
[4] Patent: WO2008/108957, 2008, A2. Location in patent: Page/Page column 30
[5] Patent: WO2018/209132, 2018, A1. Location in patent: Paragraph 0526