New Highly Fluorescent Derivatives of Cytidine and Cytosine

Article abstract of DOI:10.1021/jo00163a009

Cytidine and Cytosine react with 1'-methylthiaminium ion in methanol containing 2,4,6-trimethylpyridine catalyst.Products contain a tricyclic dipyrimido<1,6-a:4',5'-d>pyrimidine ring which is highly fluorescent, having emission bands at 414 and 433 nm (shoulder) with the main excitation peak at 390 nm in water.The nucleosides ionosine, guanosine, and xanthosine under the same conditions only alkylate, the fist two at N-1 and N-7 and the latter at N-7.Uracil similarly gives the 1,3-dialkylated product.The alkyl group is the (4-amino-1,2-dimethyl-5-pyrimidinio)methyl porti on of the thiamin.