A Simple and Efficient Route for Preparing 2,3,5,6-Tetraaminopyridine Hydrochloride Salt

A simple and efficient route for preparing 2,3,5,6-tetraaminopyridine hydrochloride salt (TAP·3HCl·H2O) was introduced in this paper. The title compound was synthesized, as usual, in two steps (nitration and hydrogenation) with a total yield of 90%. The use of an oleum and fuming nitric acid mixture in the nitration step improved the yield and purity of the intermediate product. A highly efficient hydrogenation using a H2/Pd/C/C2H5OH system was developed. The products were characterized by TG, IR, 1H-NMR, 13C-NMR, HPLC and elemental analysis.