GB1120256A - Process for the production of oxirane compounds and phthalic anhydride or alpha-naphthol - Google Patents

Abstract

Oxirane compounds and either phthalic anhydride or a -naphthol are prepared by catalytic epoxidation of an olefinically unsaturated compound by reaction with tetralin a -hydroperoxide in the liquid phase to form an oxirane and a -tetralol and subsequent oxidation of a -tetralol to phthalic anhydride or dehydrogenation to a -naphthol. Tetralin a -hydroperoxide may be obtained by liquid phase oxidation of tetralin with molecular oxygen. Specified unsaturated compounds include hydrocarbons, alcohols, ethers, esters, ketones and chlorides. Suitable epoxidation catalysts include compounds of Ti, V, Cr, Se, Zr, Nb, Mo, Te, Ta, W, Re and U. It is preferred to use the catalyst in a form which is soluble in the reaction mixture, e.g. naphthenates and carbonyls of Mo, V and W. A basic substance may be included in the epoxidation reaction mixture. The oxirane may be separated, e.g. by distillation, from the product mixture before the subsequent reaction of the a -tetralol. a -Tetralol is preferably oxidized using molecular oxygen in the vapour phase, optionally in the presence of a V2O5 or Co, Mo or Cu oxidation catalyst. Dehydrogenation of a -tetralol is preferably effected in the presence of hydrogen and a dehydrogenation catalyst, preferably Pt on carbon. Examples relate to the preparation of propylene oxide and phthalic anhydride or a -naphthol.