title: Design and synthesis of 1-(beta-D-ribofuranosyl)imidazo[4,5-c]pyrazoles as 5:5 bicyclic analogs of purine nucleosides.
abstract: 5-Alkylaminopyrazole nucleosides underwent nitrosation to give the corresponding N1-ribosylated 5-alkyl-amino-4-nitrosopyrazoles. The intramolecular cyclo-dehydration reactions of these 5-alkylamino-4-nitrosopyrazoles were carried out in pyridine at reflux temperature to afford the ring-closure N-1 ribosylated imidazo[4,5-c]pyrazoles in good yields.
authors.affiliation: Department of Chemistry, College of Science, National Taiwan Normal University, Taipei 11677, Taiwan. tcchien@ntnu.edu.tw
authors.forename: Tun-Cheng
authors.initials: TC
authors.lastname: Chien
authors.forename: John C
authors.initials: JC
authors.lastname: Drach
authors.forename: Leroy B
authors.initials: LB
authors.lastname: Townsend
mesh_terms: D001643:Bridged Bicyclo Compounds / Q000138:chemical synthesis / Q000737:chemistry; D011684:Purine Nucleosides / Q000138:chemical synthesis* / Q000737:chemistry; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D001643:Bridged Bicyclo Compounds; D011684:Purine Nucleosides; D011720:Pyrazoles