Synthesis
The general procedure for the synthesis of 3-(Boc-amino)-6-methoxypyridine from 5-amino-2-methoxypyridine and di-tert-butyl dicarbonate was as follows: 1.0 g of 5-amino-2-methoxypyridine was placed in a single-neck flask and dissolved in 40 mL of dioxane. Subsequently 1.79 g of di-tert-butyl dicarbonate was added and the reaction mixture was heated to reflux overnight. After completion of the reaction, it was cooled to room temperature and the solvent was removed by evaporation under reduced pressure. The resulting residue was purified by silica gel column chromatography using a solvent mixture of heptane and ethyl acetate (the volume ratio was tapered from 90/10 to 70/30) as eluent for gradient elution. Finally, 1.58 g of the target product 3-(Boc-amino)-6-methoxypyridine was obtained in 97% yield.
References
[1] Patent: US2011/178053, 2011, A1. Location in patent: Page/Page column 46
[2] Bioorganic and Medicinal Chemistry Letters, 2004, vol. 14, # 12, p. 3303 - 3306
[3] Journal of the Chemical Society - Perkin Transactions 1, 1996, # 18, p. 2221 - 2226
[4] Tetrahedron Letters, 2011, vol. 52, # 41, p. 5292 - 5296
[5] Journal of Medicinal Chemistry, 2015, vol. 58, # 12, p. 5053 - 5074
