220731-04-4

General procedure for the synthesis of tert-butyl (5-aminopyridin-2-yl)carbamate from tert-butyl (5-nitropyridin-2-yl)carbamate: tert-butyl (5-nitropyridin-2-yl)carbamate (1 eq.), 10% palladium carbon by weight of the raw material and ethyl acetate were added to a reaction flask under hydrogen atmosphere. The reaction mixture was stirred and reacted at room temperature overnight. Upon completion of the reaction, the mixture was filtered through a diatomaceous earth pad and the filtrate was concentrated under reduced pressure to give the target product tert-butyl (5-aminopyridin-2-yl)carbamate. The product was analyzed by HPLC-MS (Method A): retention time Rt = 1.50 min, molecular ion peak [M + H]+ m/z: 210. The reaction yield was quantitative.

[1] Patent: WO2016/120808, 2016, A1. Location in patent: Page/Page column 104
[2] Patent: US2010/249099, 2010, A1. Location in patent: Page/Page column 96
[3] Patent: US2011/9405, 2011, A1. Location in patent: Page/Page column 54
[4] Patent: EP2518071, 2012, A1. Location in patent: Page/Page column 41-42
[5] Patent: WO2012/146667, 2012, A1. Location in patent: Page/Page column 95-96