Hydro peroxides /NaNO2/KHSO4 mediated synthesis, kinetics and mechanistic study of nitration of aromatic compounds in aqueous acetonitrile

Abstract

Abstract In this study, the authors employed hydrogen peroxide (HP) and tetrabutyl hydrogen peroxide (TBHP) as efficient green reagents for the nitration of aromatic compounds using NaNO2/ KHSO4. Kinetics of the reactions revealed first order dependence on [Phenol] as well as [hydro peroxide] (i.e. [HP] or [TBHP]) under the conditions [NaNO2] >> [hydro peroxide] and [Phenol]. Introduction of the electron donating groups accelerated the rate, while electron withdrawing groups retarded the rate: m-Me >p-MeO >-H>p-Me > m-OH >≈ p-Br ≈ p-OH>p-Cl. On the other hand, ortho substituted phenols indicated a sequence: o-OH> o-Me> -H. The Hammett's quantitative structure activity plots (log k versus σ) deviated from linearity. These deviations were explained due to mesomeric para interaction energy (ΔΔGp) parameters arising from the exalted sigma (σ or σeff) values, and Yukawa–Tsuno parameter (r).