Synthesis
5-Methylpyrazine-2-carboxylic acid (13.81 g, 0.1 mol), tert-butanol (95 mL, 1 mol), triethylamine (27.9 mL, 0.2 mol) and diphenylphosphoryl azide (30.27 g, 0.11 mol) were dissolved in 300 mL of toluene. The reaction mixture was heated to reflux temperature for 8 hours. Upon completion of the reaction, the product was purified by silica gel column chromatography with petroleum ether-ethyl acetate (20:1, v/v) as eluent to afford 15.2 g of N-Boc-2-amino-5-methylpyrazine as a pale yellow solid in 72.7% yield.
References
[1] Bioorganic and Medicinal Chemistry Letters, 2006, vol. 16, # 14, p. 3751 - 3754
[2] Bioorganic and Medicinal Chemistry Letters, 2005, vol. 15, # 18, p. 4136 - 4142
[3] Patent: EP2781508, 2014, A1. Location in patent: Paragraph 0153
[4] Bioorganic and Medicinal Chemistry Letters, 2002, vol. 12, # 8, p. 1203 - 1208
[5] Patent: WO2011/90738, 2011, A2. Location in patent: Page/Page column 45
