RESUMO
The photolytic decomposition of the insecticide imidacloprid (1) in HPLC grade water and of imidacloprid as the formulated product Confidor insecticide in tap water was studied using HPLC methodology. The structures of several degradates have been determined in aquatic medium, and the DT(50) values of imidacloprid and Confidor have been measured. In addition, the influence of TiO(2) on the photodegradation of Confidor was studied. The photoproduct 1-(6-chloro-3-pyridinyl)methyl-2-imidazolidinone (5) has been identified as the main degradate in each of the three series of experiments by several analytical techniques. The photolytic half-lives for imidacloprid under the conditions of this study were 43 min in HPLC grade water, 126 min formulated as Confidor in tap water, and 144 min formulated as Confidor in tap water in the presence of TiO(2).
Assuntos
Imidazóis/química , Cromatografia Líquida de Alta Pressão/métodos , Imidazóis/efeitos da radiação , Inseticidas/química , Inseticidas/efeitos da radiação , Espectrometria de Massas , Neonicotinoides , Nitrocompostos , Fotólise , ÁguaRESUMO
The Divakar-Reese procedure has been successfully applied for transforming 7-oxo-isothiazolo[4,5-d]pyrimidine C-nucleosides (4a,b, 5a,b, 6a) via 1,2,4-triazol-1-yl intermediates (7a,b, 8a,b) into various 7-substituted C-nucleosides 15a,b, 16a,b, 17a, 18a, 19a,b, 20a,b; their subsequent deprotection provides novel types of unusual C-glycosides 22b, 23a, 24a,b, 25b, 26b. C-Nucleosides, possessing on its heterocyclic base other than naturally occuring oxo- or amino substituents, are important model compounds for biological or medicinal studies (2,3). We want to report on the synthesis of novel 7-substituted isothiazolo = [4,5-d]pyrimidine C-nucleosides. As we could show in previous papers (1,4), there exists a simple approach to the protected C-glycosides 4-6.
Assuntos
Nucleosídeos de Pirimidina/síntese química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Nucleosídeos de Pirimidina/químicaRESUMO
[reaction: see text] Synthetic approaches to a variety of thioisomunchnones derived from uracils and uridine are described, as well as their properties and cycloaddition tendencies. The anhydro-3-hydrocy-2-phenyl-6-(2',3',5'-tri-O-benzoyl-beta-D-ribofuranosyl)thiazolo[3,2-c]pyrimidine-5(6H)-on-4-ium hydroxide represents a novel class of mesoionic nucleosides.