Method for producing arylethylenes.

摘要

A method for producing arylethylene comprising four steps : (I) bringing 1,1-diarylethane into contact with an acid catalyst in the presence of an inert gas to crack said compound to form arylethylenes and alkylbenzenes; (II) separating the reaction mixture obtained in the above cracking step (I) into at least a fraction mainly containing 1,1-diarylethane; (III) bringing said fraction mainly containing 1,1-diarylethane into contact with hydrogen gas in the presence of a hydrogenation catalyst; and (IV) recracking the hydrogenated fraction obtained in the preceding hydrogenation step (III) by recycling it into said cracking step (I). This method is particularly useful for producing p-isobutylstyrene which is a starting material for preparing ibuprofen, a valuable medicine.