| 摘要 |
Alkenylaromatic and alkylaromatic hydrocarbons are made by dehydration or hydrogenation, respectively, of aralkyl alcohols obtained as by-products in the epoxidation of olefinic compounds using aralkyl hydroperoxides. Prefered aralkyl hydroperoxides are those derived from alkylaromatic compounds having at least one hydrogen atom on the carbon adjacent to the aromatic ring; reduction to the corresponding aralkyl alcohol and subsequent dehydration yields styrene type hydrocarbons, the preferred hydroperoxides of ethylbenzene and cumene yielding styrene and a -methylstyrene. Dehydration may be effected in the vapour phase at 180-280 DEG C. over a dehydration catalyst, e.g. silica, alumina or, particularly, titania. Hydrogenation of the aralkyl alcohol to the corresponding alkylaromatic hydrocarbon is carried out in a known manner.ALSO:Olefinically unsaturated compounds are epoxidized by reaction in the liquid phase with an aralkyl hydroperoxide in the presence of a metal epoxidation catalyst which contains at least one metal other than alkali metals or alkaline earth metals. The epoxidation proceeds with reduction of the hydroperoxide to the corresponding aralkyl alcohol which is subsequently dehydrated or hydrogenated to the corresponding aralkenyl or aralkyl compounds (see Division C5). Specified unsaturated compounds include C2- 30 aliphatic and alicyclic olefins, esters, alcohols, ketones, ethers, mercaptans and alkenyl chlorides. Preferred hydroperoxides are those derived from alkyl-aromatic compounds having at least one hydrogen atom on a carbon adjacent to the ring, particularly cumene and ethylbenzene. Specified catalysts are those containing compounds of Mo, W or V. It is preferred to add the catalyst in the form of a compound which is at least partially soluble in the reaction medium, e.g. as a carboxylate or carbonyl. The epoxidation may be effected at -20 DEG to +200 DEG C., preferably in the presence of a solvent. Examples describe the epoxidation of propylene, 4-vinyl cyclohexene, octene-1, dodecene-1 or hexadecene-1. |
