Decomposition of 2-isopropylnaphthalenehydroperoxide into 2-naphthol and acetone: reactor operation parameters Original Research Article

Reactor operation parameters for the liquid-phase acid-catalyzed decomposition of 2-isopropylnaphthalenehydroperoxide (2-IPNHP) were investigated to produce simultaneously 2-naphthol and acetone with a high yield. The 2-naphthol and acetone are produced from 2-IPNHP by ionic reactions, nevertheless, dimethyl-2-naphthylcarbinol (DMNC) and 2-acetonaphthone (AN) formations through radical reactions cannot be avoided because of the induced decomposition effects but can be decreased. The decomposition of 2-IPNHP was carried out in the presence of two different aprotic solvents of low dielectric (DE) constant, i.e. 2-isopropylnapthalene (IPN) and acetone (AC), and the protogenic solvent acetic acid (AcOH), with two different oxyacid catalysts, i.e. HClO4 and H2SO4. The production rate of 2-naphthol increases with the increase in the dipole moment (DM) of aprotic solvents. The increase in the initial 2-IPNHP concentration increases 2-IPNHP decomposition and 2-naphthol production rates. 2-Naphthol production rate decreases and the radical by-product AN formation rate increases with increasing temperature. The presence of the impurities DMNC and AN of the reactant mixture and a radical scavenger in the decomposition reaction medium decreased the 2-naphthol production rate. A 70% yield of 2-naphthol was obtained in the presence of IPN by 0.047 mol dm−3 HClO4 with the initial concentrations of 1.155 mol dm−3 2-IPNHP, 0.470 mol dm−3 DMNC and 0.011 mol dm−3 AN at T=22 °C and N=1000 rpm. The reaction rate equations for the decomposition reaction of 2-IPNHP and production of 2-naphthol are also presented.