Nitrations aromatic rings, ozone

A mixture of NO2 and ozone has also been used. " Clays, such as clay-supported cupric nitrate (Claycop), " " or MontmorUlonite KSF—Bi(N03) can be used to nitrate aromatic rings. Nitration of styrene poses a problem since addition occurs to the C=C unit to give a 1-nitroethyl aryl. " Heterocycles, such as pyridine, are nitrated with N2O5 and S02. " Deactivated aromatic rings, as in acetophenone, were nitrated with N2O5 and Fe(acac)2. " ... 

Other processes in which the aromatic ring is modified via electrophilic substitution reactions are nitration and ozonation. The electrophilic substitution of nitro groups on the aromatic moiety of lignin and accompanying reactions have been reviewed by Dence (1971). A nitration process consisting of the pretreatment of chemical pulp with nitrogen dioxide followed by treatment... 

Aromatic cyclic acetals can be successfully nitrated on the aromatic ring with NO in ice-cooled dichloromethane in the presence of ozone to give mainly o- and p-nitro derivatives in good combined yields (90-95%) [28] ... 

Gasoline hydrocarbons volatilized to the atmosphere quickly undergo photochemical oxidation. The hydrocarbons are oxidized by reaction with molecular oxygen (which attacks the ring structure of aromatics), ozone (which reacts rapidly with alkenes but slowly with aromatics), and hydroxyl and nitrate radicals (which initiate side-chain oxidation reactions) (Stephens 1973). Alkanes, isoalkanes, and cycloalkanes have half-lives on the order of 1-10 days, whereas alkenes, cycloalkenes, and substituted benzenes have half- lives of less than 1 day (EPA 1979a). Photochemical oxidation products include aldehydes, hydroxy compounds, nitro compounds, and peroxyacyl nitrates (Cupitt 1980 EPA 1979a Stephens 1973). 

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