Electrochemical synthesis of 2,4,5,6-tetraaminopyrimidine in acid media

2,4,5,6-Tetraaminopyrimidine (AP), which is an intermediate product in the synthesis of methotrexate intended for medical treatment of acute leucosis, can be produced by electrochemical reduction of 2,4,6-tetramino-5-nitrosopyrimidine in alkaline and acid media. The advantage of using the latter is the absence of sodium sulfate waste formed during AP isolation from alkaline solutions. The conditions of the AP electrosynthesis in sulfate medium are elaborated. The process is found to be catalyzed by Sn 2+ ions