title: Synthesis of imidazo[4,5-e][1,4]diazepine and 3-substituted 3-deazapurine nucleosides from 1-substituted inosines.
abstract: New synthetic methods of imidazo[4,5-e][1,4]diazepine nucleosides 8-11 and 3-substituted 3-deazainosines 14 from inosine have been reported. Treatment of N1-substituted inosines 1-3 with aqueous NaOH gave 5-amino-4-(N-substituted carbamoyl)imidazole ribosides 5-7, followed by appropriate manipulations to afford ring-expanded guanosine, inosine, and xanthosine analogues. Additionally, the 5-amino group of 4-N-allylcarbamoyl derivative 12 was converted into corresponding 5-iodo nucleoside 13. We found that 13 was cyclized to form 3-deaza-3-methylinosine (14) in the presence of Pd catalysts.
authors.affiliation: Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Aoyagi
authors.forename: N
authors.initials: N
authors.lastname: Minakawa
authors.forename: A
authors.initials: A
authors.lastname: Matsuda
mesh_terms: D007093:Imidazoles / Q000138:chemical synthesis; D007288:Inosine / Q000737:chemistry*; D015394:Molecular Structure; D011687:Purines / Q000737:chemistry*; D012263:Ribonucleosides / Q000737:chemistry*
chemical_list: D007093:Imidazoles; D011687:Purines; D012263:Ribonucleosides; D007288:Inosine