One-pot synthesis of fused 2-thiouracils: Pyrimidopyrimidines, pyridopyrimidines and imidazolopyrimidines

Abstract

Several 6-substitued-1-methyl-2,5,7,8-tetrahydro-2-thiopyrimido[4,5-d] pyrimidine-4-ones and ethyl 7-amino-5-aryl-1-methyl-4-oxo-1,2,3,4-tetrahydro-2- thiopyrido[2,3-d]pyrimidines-6-carboxylates were synthesized by treatment of 6-amino-1-methyl-2-thiouracil with primary amines and formalin (40%), and with ethyl 3-aryl-2-cyanoacrylate respectively. 8-Substituted-7-hydroxy-3-methyl-2- thioxanthines were synthesized by the treatment of 6-amino-1-methyl-5-nitroso-2- thiouracil with benzylidene-anilines. Elemental and spectral analyses were performed for the new compounds. © 2008 Verlag der Zeitschrift für Naturforschung, Tübingen.