5334-33-8Relevant articles and documents
Novel xanthine oxidase inhibitor studies. Part 3. Convenient and general syntheses of 3-substituted 7H-pyrazolo[4,3-e]-1,2,4-triazolo[4,3-c]pyrimidin-5(6H)-ones as a new class of potential xanthine oxidase inhibitors
Nagamatsu, Tomohisa,Fujita, Takayuki,Endo, Kazuki
, p. 33 - 42 (2007/10/03)
Convenient and general syntheses of 3-substituted 7H-pyrazolo[4,3-e]-1,2,4-triazolo[4,3-c]pyrimidin-5(6H)-ones (12), a new class of potent xanthine oxidase inhibitors, involving the oxidative cyclisation of 6-substituted 4-alkylidenehydrazino- or 4-arylmethylidenehydrazino-1H-pyrazolo[3,4-d]pyrimidines (3 and 11) with 70% nitric acid as the key step, are reported. The hydrazones 3 and 11 were obtained by a versatile synthetic route via the key intermediates, 6-chloro-4-hydrazino-1H-pyrazolo[3,4-d]pyrimidine 2 or oxypurinol 4, starting from 2,4,6-trichloropyrimidine-5-carbaldehyde 1. Their inhibitory activities against bovine milk xanthine oxidase in vitro are also described; i.e. the pyrazolotriazolopyrimidines 12 were several hundred times more potent than allopurinol.
A General Route for the Facile Synthesis of 4-Thioxopyrimidin-2-one Derivatives via the Annulation of Cyclic o-Aminonitriles Using Carbonyl Sulfide
Hernandez, Maria A.,Chung, Fung-Lung,Earl, Robert A.,Townsend, Leroy B.
, p. 3941 - 3945 (2007/10/02)
A facile synthesis of 4,5-diamino-9-(β-D-ribofuranosyl)pyrrolodipyrimidin-7-one (6) from an appropriately substituted pyrrolopyrimidine has been accomplished.A key reaction in this synthesis involves the ring closure of a cyclic o-aminonitrile precursor by using carbonyl sulfide to obtain the versatile 4-thioxopyrimidin-2-one intermediate 3.A study involving the generality of this reagent for the annulation of cyclic o-aminonitriles under different reaction conditions is also discussed.