GB1114563A - Epoxidation process - Google Patents

Abstract

Epoxy compounds are prepared by reacting an olefinically unsaturated compound with a hydroperoxide of an aralkane, having at least one hydrogen atom on a carbon atom adjacent to the aromatic ring, in the liquid phase in the presence of a metal epoxidation catalyst, the amount of hydroperoxide employed being 0.1-1.0 mol per mol olefinic groups and the reaction being continued until hydroperoxide conversion is at least 95%. It is preferred to continue the reaction until hydroperoxide conversion is at least 98%. The preferred epoxidation catalysts are V, W, Mo and Se, particularly compounds thereof which are soluble in the reaction mixture, e.g. carboxylates. Preferred hydroperoxides are those of cumene and ethyl-benzene. Specified olefinic reactants include olefins, alcohols, esters, ethers, ketones and organic halides. The preferred olefinic group: hydroperoxide ratios are in the range 2:1 to 5:1. It is preferred to operate at - 10 DEG C. to 175 DEG C. in the presence of an organic solvent. In the course of the reaction, the hydroperoxide is reduced to an alcohol having the same carbon skeleton. This alcohol can be recovered and reacted with hydrogen to effect reduction to the corresponding hydrocarbon which on reaction with molecular oxygen yields the hydroperoxide which may be recycled. Examples relate to the preparation of propylene oxide using cumene hydroperoxide, which is prepared by oxidation of cumene. Cumyl alcohol is obtained as a by-product.