Synthesis
The general procedure for the synthesis of 2-amino-5-hydroxypyridine from 5-(benzyloxy)pyridin-2-amine was as follows: 2-amino-5-benzyloxypyridine, ethanol (217 g) and a toluene solution (331 g) of 10% Pd/C (2.28 g, 53% moisture content) were added to an autoclave and the reaction was carried out at 25 °C. During the reaction, hydrogen was introduced into the autoclave, maintaining an absolute pressure of 0.2 MPa, and the reaction lasted for several hours. Upon completion of the reaction, the Pd/C catalyst was removed by filtration and the residue was washed with ethanol (76 g). The filtrate was dried under reduced pressure to give 2-amino-5-hydroxypyridine (25.6 g, 0.23 mol) in 92% yield.