Process for the production of hydroperoxides of partly-hydrogenated polynuclear, aromatic hydrocarbons

摘要

Hydroperoxides of partly - hydrogenated, polynuclear, aromatic hydrocarbons are prepared by oxidation of the hydrocarbons in the liquid phase with oxygen or oxygen-containing gases at raised temperatures and normal or increased pressures under exposure to light and in the presence of an organic colouring matter which absorbs light in the red to yellow spectral range, and separating the resulting hydroperoxide in known manner from the reaction mixture. Hydrocarbons which may be oxidized are tetrahydronaphthalene, octahydronaphthalene, ar-alkyl-tetrahydronaphthalenes, tetrahydroanthracene, octahydroanthracene, tetrahydrophenanthrene, octahydrophenanthrene, and tetrahydroacenaphthene. Organic colouring matters specified are chlorophyll, metal complexes of phthalocyanines, fluorescein, dinaphthylene dioxide (2:81; 8:21 - dioxidodinaph-thyl - 1:11), 2 - phenyl - benzimidazole and 9-phenyl - 3:7 - dimethylacridine. Both sunlight and artificial light may be used. The oxidation may be conducted by passing the oxidizing gas in a finely divided state through the hydrocarbon at reaction temperature, by trickling the hydrocarbon over Raschig or porcelain rings or pumice in countercurrent to the heated oxidizing gas, or the hydrocarbon may be sprayed or atomized and contacted with the oxidizing gas. The hydroperoxide is isolated by precipitation of its salt with caustic soda solution, liberation of the free hydroperoxide by treatment with acetic acid and recrystallization from ether, or by distilling off the unreacted tetrahydronaphthalene in vacuo and recrystallization. In an example, the oxidation of tetrahydronaphthalene in the presence of chlorophyll and light is compared with a similar but uncatalysed reaction, and a similar oxidation catalysed by manganese stearate.