10.1515/znb-2008-0709
The research focuses on the one-pot synthesis of fused 2-thiouracils, including pyrimidopyrimidines, pyridopyrimidines, and imidazolopyrimidines, which are potentially significant as chemotherapeutic agents. The study aims to expand the knowledge of 2-thiopyrimido[4,5-d]pyrimidines, a class of compounds not previously reported in the literature, and to contribute to the synthesis of biologically active compounds with potential applications in various therapeutic areas. The researchers synthesized several 6-substituted-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 by treating 6-amino-1-methyl-2-thiouracil with primary amines and formalin, and with ethyl 3-aryl-2-cyanoacrylate, respectively. Additionally, 8-substituted-7-hydroxy-3methyl-2-thioxanthines were synthesized by treating 6-amino-1-methyl-5-nitroso-2-thiouracil with benzylidene-anilines. The newly synthesized compounds were subjected to elemental and spectral analyses to confirm their structures and properties. The chemicals used in the process include various primary amines, formalin, ethyl 3-aryl-2-cyanoacrylates, and benzylidene-anilines, among others. The study successfully yielded a series of new compounds with potential biological activities, contributing to the development of novel therapeutic agents.
10.1002/ejoc.200900216
The research presents a novel and efficient method for synthesizing pyrimido[5,4-d]pyrimidine N-oxides, which are of significant interest in drug development due to their structural similarity to purines and their potential biological activities. The study explores the reaction of benzylhydroxylamine with 6-cyanopurines to form 7-benzyloxy-8-imino-7,8-dihydropyrimido[5,4-d]pyrimidines, which upon treatment with hydrochloric acid, yield the desired N-oxides. The study concludes that the solubility of the hydrochloride of the intermediate pyrimido-pyrimidines in the reaction solvent plays a crucial role in determining the final product, with soluble hydrochlorides leading to the rearranged product and insoluble ones yielding the N-oxides. This work provides a mild and selective approach to synthesizing these heterocyclic compounds, which could have implications for the development of new pharmaceutical agents.
