An Efficient Method for the Synthesis of [4–15N]Cytidine, 2′-Deoxy[4–15N]Cytidine, [6–15N]adenosine, and 2′-Deoxy [6–15N]adenosine Derivatives

Nucleophilic substitution reactions of 4-azolyl-1 β-P-D-ribofuranosylpyrimidin-2(1H)-one and 6-azolyl-9-β-D-ribofuranosyl-9H-purine derivatives, which were converted from uridine and inosine, with [15N]phthalimide in the presence of triethylamine or DBU gave N 4-phthaloyl[4-15N]cytidine and N 6-phthaloyl[6-15N]- adenosine derivatives, respectively, in high yields. Similar reactions of those azolyl derivatives with succinimide afforded N 4-succinylcytidine and N 6-succinyladenosine derivatives in high yields. The corresponding 2′-deoxyribonucleosides were also synthesized efficiently through the same procedure. 1. Partial Protection of Carbohydrate Derivatives. Part 31. For Part 30, see Aoyama, Y.; Sekine, T.; Iwamoto, Y.; Kawashima, E.; Ishido, Y. Nucleosides Nucleotides, submitted. The present work has partly been communicated (cf. Kamaike, K.; Takahashi, M.; Utsugi, K.; Tomizuka, K.;Ishido, Y. Tetrahedron Lett. 1995, 36, 91–94.). #This paper is dedicated to Dr. Yoshihisa Mizuno on the occasion ...