Abstract
5-Alkylbarbituric acids (1b-f) were converted to 5-alkyl-2, 4, 6-trichloropyrimidines (2b-f) by using phosphoryl chloride in refluxing n-butyl acetate in the presence of N, N-diethylaniline hydrochloride. Treatment of 2 with sodium methoxide in dry acetonitrile followed by reaction with potassium ethyl mercaptide and desulfurization with Raney Ni afforded 5-alkyl-2, 4-dimethoxypyrimidines (5b-f), as key intermediates in the present study. Coupling of 5 with 1-O-acetyl-2, 3, 5-tri-O-benzoyl-β-D-ribofuranose in the presence of stannic chloride in acetonitrile afforded 5-alkyl-1-(2, 3, 5-tri-O-benzoyl)-β-D-ribofuranosyl-1, 2-dihydro-4-methoxypyrimidin-2-ones (6a-f) in quantitative yields. Ammonolysis of 6 with methanolic ammonia afforded the title 5-alkylcytidines (7a-f). Compounds 6 were also easily converted to their uridine counterparts by treatment with hydrochloric acid. Growth-inhibitory effects of 7 on cultured mouse leukemia L5178Y cells, antiviral activity against a rhabdovirus, infectious hematopoietic necrosis virus (IHNV), in cultured CHSE-214 cells and properties as a substrate of human cytidine deaminase were also examined.
