146850-06-8Relevant articles and documents
Photochemical Nitration by Tetranitromethane. Part VI. Predominant Nitro/trinitromethyl Addition to Naphthalene in Dichloromethane and Acetonitrile
Eberson, Lennart,Hartshorn, Michael P.,Radner, Finn
, p. 1793 - 1798 (2007/10/02)
The photochemical reaction between naphthalene and tetranitromethane in dichloromethane or acetonitrile gave predominantly (85-95percent) products of nitro/trinitromethyl addition to the aromatic system, namely cis- and trans-1-nitro-4-trinitromethyl-1,4-dihydronaphthalene and trans-2-nitro-1-trinitromethyl-1,2-dihydronaphthalene.A small amount of trans-2-hydroxy-1-trinitromethyl adduct was also formed, presumably originating from an initial nitrito/trinitromethyl adduct.The minor reaction pathway directly gave product(s) of nitro substitution, the ratio of 1- to 2-nitronaphthalene being high (25) in dichloromethane and in the beginning of the acetonitrile runs (up to ca. 40percent conversion).The temperature dependence of this process suggests that coupling between (naphthalene)cation radical and nitrogen dioxide is the major pathway leading directly to nitro products. 2-Nitronaphthalene, formed after long reaction periods in acetonitrile runs, was presumably formed via elimination of nitroform from the 1,2-adduct. cis-1-Nitro-4-trinitromethyl-1,4-dihydronaphthalene was isolated in pure form and shown to undergo facile base-catalysed elimination of nitroform in dichloromethane and acetonitrile to give 1-nitronaphthalene.It also underwent a slow spontaneous elimination in acetonitrile.It was stable under acidic conditions.GLC of the pure adduct gave exclusively 1-nitronaphthalene at a low injector-port temperature, whereas at higher temperatures a mixture of products was formed (naphthalene, 1- and 2-nitronaphthalene and 1-naphthonitrile).
Light-initiated and thermal nitration reactions during photolysis of naphthalene/tetranitromethane or 1-methoxynaphthalene/tetranitromethane in dichloromethane
Eberson, Lennart,Radner, Finn
, p. 5825 - 5834 (2007/10/02)
The photolysis of naphthalene or 1-methoxynaphthalene together with tetranitromethane in dichloromethane, using light with a cutoff at λ 2-promoted nitration (α/β ratio ca. 20). The adducts are formed by photochemical excitation of the CT complex between naphthalene and tetranitromethane, resulting in formation of the triad [ArH?+ NO2 (NO2)3C-] from which the observed chemistry develops by attack of trinitromethanide upon the radical cation. For 1-methoxynaphthalene, a representative of more highly reactive aromatics, the reaction is again photochemically initiated and again adducts seem to be responsible for the further development of thermal nitration reactions, apart from the NO2-induced reaction. Elimination of HNO2 from one of the 1,4-adducts induces a novel HNO2/tetranitromethane-dependent nitration process, shown separately to operate in the dark on reactive substrates. The aryltrinitromethane formed in this step is "hydrolyzed" to the corresponding carboxylic acid, 4-methoxy-1-naphthoic acid, under the anhydrous conditions prevailing during photolysis. Nitrous acid is a likely candidate as the proton source for this reaction. With an alcohol present, moderate yields (up to ≈50%) of alkyl 4-methoxy-1-naphthoates are obtained. From other adducts, nitro compounds are formed by elimination of nitroform. Trinitromethanide ion was shown to possess greatly differing reactivity (ratio >103) toward a model radical cation, tris(4-bromophenyl)aminium ion, in dichloromethane and acetonitrile, respectively.
