title: Route to benzo- and pyrido-fused 1,2,4-triazinyl radicals via N'-(het)aryl-N'-[2-nitro(het)aryl]hydrazides.
abstract: A two-step route to 1,3-disubstituted benzo- and pyrido-fused 1,2,4-triazinyl radicals is presented. The route involves the N'-(2-nitroarylation) of easily prepared N'-(het)arylhydrazides via nucleophilic aromatic substitution of 1-halo-2-nitroarenes, which in most cases gives N'-(het)aryl-N'-[2-nitro(het)aryl]hydrazides in good yields. Mild reduction of the nitro group followed by an acid-mediated cyclodehydration gives the fused triazines, which upon alkali treatment afford the desired radicals. Fifteen examples of radicals are presented bearing a range of substituents at N-1, C-3, and C-7, including the pyrid-2-yl and 8-aza analogues. This route to the N'-(het)aryl-N'-[2-nitro(het)aryl]hydrazides, which works well with benzo- and picolinohydrazides, required a modification for aceto- and trifluoroacetohydrazides that involved a multistep synthesis of asymmetrically 1,1-diaryl-substituted hydrazines.
authors.affiliation: Department of Chemistry, University of Cyprus , P.O. Box 20537, 1678 Nicosia, Cyprus.
authors.forename: Andrey A
authors.initials: AA
authors.lastname: Berezin
authors.forename: Georgia
authors.initials: G
authors.lastname: Zissimou
authors.forename: Christos P
authors.initials: CP
authors.lastname: Constantinides
authors.forename: Yassine
authors.initials: Y
authors.lastname: Beldjoudi
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Rawson
authors.forename: Panayiotis A
authors.initials: PA
authors.lastname: Koutentis