Synthesis of 2,4-Dimethoxy-5-(3-oxo-1-alkynyl)pyrimidines, 2,4-Dimethoxy-5-(3-oxoalkyl)pyrimidines, and 5-(3-Oxoalkyl)uracils by a Highly Convenient Procedure

Article abstract of DOI:10.1055/s-1990-26843

A simple synthesis of 2,4-dimethoxy-5-(3-oxoalkynyl)pyrimidines from the readily available 5-ethynyl-2,4-dimethoxypyrimidine is described.The sequence proceeds via an ethynylboron intermediate which is acylated with carboxylic anhydrides.The 5-(3-oxo-1-alkynyl)products are hydrogenated to the saturated analogs and these are O-dealkylated with chlorotrimethylsilane/sodium iodide to give 5-(3-oxoalkyl)uracils, e.g., 5-(3-oxobutyl)-, 5-(3-oxopentyl)-, and 5-(3-oxohexyl)uracil.These compounds and the nucleosides derived therefrom are of interest as anticancer and antiviral agents.