PURPOSE: To improve yield in obtaining the titled compound useful as a synthetic raw material for weather-resistant pigment by acylating a 6-alkyltetralin, dehydrogenating and oxidizing, by hydrogenating an acyl group introduced in acylating process before oxidizing process to completely convert the acyl group to a hydroxyalkyl group and/or an alkyl group.
CONSTITUTION: A 6-alkyltetralin is acylated in the presence of Friedel-Crafts catalyst and then the reaction product is dehydrogenated. In the operation, before or after the dehydrogenating process or simultaneously in dehydrogenation, an acyl group introduced in the acylating process is hydrogenated and stabilized. The hydrogenation is carried out in the presence or absence of an alcohol solvent by using a noble metallic catalyst such as platinum at normal temperature W 250°C under 5W100kg/cm2 hydrogen pressure so that the acyl group is substantially completely converted into a hydroxyalkyl group and/or an alkyl group. Then the resulting substance is oxidized, preferably in a gas phase to give the aimed compound. A catalyst of hydrogen fluoride/boron trifluoride type is preferable as the catalyst.
TANAKA YASUSHI
SAKURAI TOKIO
