D 62 Direct modification of benzoannelated crown ethers with 1,2,4-triazin-5(2H)-one moieties [Text] / G. L. Rusinov, D. G. Beresnev, N. A. Itsikson, O. N. Chupakhin // Heterocycles. - 2001. - Т. 55, № 12. - P2349-2359 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: A convenient method for one-step coupling of benzoannelated crown ethers with 1,2,4-triazinones based on the reaction of nucleophilic addition to unsubstituted carbon atom of the triazine ring has been worked out. It has been shown that the reaction of 3-substituted 1,2,4-triazin-5(2H)-ones (1) with benzocrown ethers (benzo-12-crown-4, benzo-15-crown-5, benzo-18-crown-6) in the presence of acetic or trifluoroacetic anhydride is accompanied by acylation of triazine ring and results in formation of 3-(1-acyl-5-oxo-1,4,5,6-tetrahydro-1,2,4-triazin-6-yl)benzocrown ethers (7-12). The latters were converted to 3-(5-oxo-2,5-dihydro-1,2,4-triazin-6-yl)benzocrown ethers (18-20) using two alternative routes: the elimination of acetic or trifluoroacetaldehyde or the deacylation followed by the oxidation of the 1,4,5,6-tetrahydro derivatives (13-15). |