General procedure for the synthesis of 2-amino-5-bromo-3-(hydroxymethyl)pyridine hydrobromide from 2-amino-3-(hydroxymethyl)pyridine: (2-amino-pyridin-3-yl)methanol (22.1 g, 178 mmol) was dissolved in acetic acid (350 mL) at room temperature, and bromine (9.0 mL, 178 mmol) was added slowly and dropwise over a period of 1 h under stirring. The reaction mixture was continued to stir overnight at room temperature. Upon completion of the reaction, the mixture was filtered and the solid product was collected. The filter cake was washed with methyl tert-butyl ether (MTBE, 50 mL) and subsequently dried under vacuum at 60 °C for 2 h to afford the target compound 2-amino-5-bromo-3-(hydroxymethyl)pyridine hydrobromide as a yellow solid (37.9 g, 75% yield). Mass spectrum (ESI, positive ion mode) m/z: 203.0 ([M-80]+).
