Collect. Czech. Chem. Commun. 2005, 70, 350-360

Some Aspects of Reaction of 6-Aminouracil and 6-Amino-2-Thiouracil with α,β-Unsaturated Ketones

Valentin A. Chebanov*, Vyacheslav E. Saraev, Ekaterina A. Gura, Sergey M. Desenko and Vladimir I. Musatov

Department of Photoactive Heterocyclic Compounds, Scientific and Technological Corporation "Institute for Single Crystals", Institute for Scintillation Materials of National Academy of Science of Ukraine, Lenin Ave 60, 61001 Kharkiv, Ukraine


A number of 5,7-diaryl-5,8-dihydropyrido[2,3-d]pyrimidines and 5,7-diarylpyrido[2,3-d]- pyrimidines were obtained by the reaction of 6-aminouracil derivatives with α,β-unsaturated ketones. Basic catalysts decrease yields of the dihydro derivatives whereas acids increase it. In the reactions of ketones containing the dimethylamino group, elimination of the aryl substituent from position 5 of the pyridopyrimidine system was observed. Some aspects of oxidation of 5,8-dihydropyrido[2,3-d]pyrimidines and synthesis of pyrido[2,3-d]pyrimidines were also investigated.

Keywords: Nitrogen heterocycles; Pyrido[2,3-d]pyrimidines; Pyrimidines; Oxidation; NMR spectroscopy; Cyclizations; α,β-Unsaturated ketones; Heteroannulations.

References: 23 live references.