Nitration of styrenes by dinitrogen pentoxide in dichloromethane

Abstract

The reaction of 4-R-substituted styrenes (R = H, Me, Cl, CF₃, NO₂) with N₂O₅ in dichloromethane gives several products including 1-aryl-2-mtroethyl nitrate 1,1,2-dinitro-1-arylethane 2,1,2-dinitrato-1-arylethane 3 and 2-aryl-2-nitroethyl nitrate 4. When R = CF₃ or NO₂, 1–4 are the only products and 1 predominates at low temperature and/or high concentrations of N₂O₅. All are formed in part by radical pathways, as is shown by ¹⁵N CIDNP effects. Evidence for ionic pathways is also presented. The kinetics of formation of 1 from 4-nitrostyrene at –45 °C are of high order in N₂O₅.