title: Reaction of diazoalkanes with 1-substituted 2, 4-dioxopyrimidines. Formation of O2, N-3 and O4-alkyl products.
abstract: In non-aqueous solution, diazomethane and diazoethane react with the O2, O4 and N-3 sites of uridine, thymidine, 1-methyluracil and 1-methylthymine. Diazoethane has a higher affinity for alkylating oxygens than does diazomethane. The relative ratio of O2:O4:N-3 methyl products is 1:2:16 and of ethyl products the ratio is 1:1:2. When the diazoethane reaction is performed in neutral buffered solution, the same proportion of O2:O4:N-3 ethyl products is found, but the extent of reaction is very low. O2-alkylation greatly labilizes the glycosidic bond of thymidine and uridine toward acid hydrolysis. All O2 and O4 alkyl 1-substituted 2,4-dioxopyrimidines are dealkylated in weak acid but the O2 alkyl group is the more stable.
mesh_terms: D000473:Alkanes; D001665:Binding Sites; D055598:Chemical Phenomena; D002621:Chemistry; D002854:Chromatography, Paper; D002855:Chromatography, Thin Layer; D003979:Diazonium Compounds; D011743:Pyrimidines; D013056:Spectrophotometry, Ultraviolet; D014529:Uridine / Q000031:analogs & derivatives
chemical_list: D000473:Alkanes; D003979:Diazonium Compounds; D011743:Pyrimidines; D014529:Uridine