Compound can be prepared in several different ways: 1) By treatment of pyridine-4-sulfonic acid (I) with NH4OH and ZnCl2 in an autoclave at 160 C. 2) By reduction of 4-nitropyridine (II) with SO2 in hot water or diluted H2SO4. 3) By treatment of pyridine-4-carboxylic acid (III) with NH3 at high temperature using CuO as catalyst. 4) By treatment of 4-chloropyridine (IV) or 3-chloropyridine (V) with KNH2 in liquid NH3. 5) By treatment of 4-iodopyridine (VI) or 3-iodopyridine (VII) with KNH2 in liquid NH3.