GB837464A - Improvements in and relating to epoxides - Google Patents

Abstract

An epoxide is formed from a liquid medium containing an olefinically unsaturated compound, hydrogen peroxide, a catalytic concentration of a peracid of an oxide of a metal of Group IV, V, VI or VIII of the Periodic Table or a peracid of a heteropolyacid, and an inorganic or organic alkaline-reacting substance in quantity sufficient to alter the pH of the medium to a value of below 7 and at least 3. Preferably the medium is an aqueous liquid medium maintained at a pH from 4 to 6. The alkaline substance may be an aliphatic, cycloaliphatic, aromatic or heterocyclic, primary, secondary or tertiary amine in an amount of 0.005 to 2% by weight of the reaction medium. Alternatively ammonia or alkali metal or alkaline earth metal carbonates, hydroxides or phosphates may be employed. Per acids of oxides of Ti, Zr, V, Ta, Cr, Mo, W, U and Ru are suitable. Per acids of heteropolyacids include those of S, Se or Te with Mo or W. Per acids of molybdotungstic and chromotungstic acids are also suitable. The per acid may be added as such or formed in situ, an amount of 0.01 to 2% of per acid by weight of the reaction medium being suitable. Aqueous hydrogen peroxide solutions may contain 3 to 90% H2O2 by weight. Reaction temperatures are generally in the range from 0 DEG to 100 DEG C. The epoxidations may be performed in a medium in which water is the sole inert diluent but other diluents such as alcohols, ketones, ethers and halogenated hydrocarbons may be used. The compound epoxidized may be an olefinically unsaturated mono or polyhydric alcohol which may be aliphatic, cycloaliphatic, aromatic or heterocyclic containing from 3 to 15 carbon atoms or a halogenated, particularly chlorinated alcohol. 1 : 2-Epoxycyclopentanol-3 and 1 : 2-epoxybutanediol-3 : 4 are novel compounds. Epoxides of methyloleate and similar esters, butadiene and cyclohexene may also be prepared. The epoxy alcohols are useful as intermediates in the preparation of epoxy-substituted esters of silicon acids and for the formation of epoxy resins. The epoxides or their hydrolysis products may be esterified with acetic or propionic acid to form esters which are useful plasticizers for polyvinyl chloride. Specification 754,359 is referred to.ALSO:Epoxy alcohols, such as 1 : 2-epoxycyclopentanol-3 (for preparation see Group IV (b)), are polymerized by virtue of the epoxy group by heating in the presence of stannic chloride or other epoxy-polymerization catalyst; 1 : 2-epoxy-cyclopentanol-may also be heated with phthalic anhydride to form a resin. The epoxy alcohols may be hydrolysed under mildly aqueous acidic conditions to obtain polyols. In the case of monohydric epoxy alcohols, triols are obtained which are esterifiable with acetic acid or propionic acid to produce polyesters which are plasticizers for polyvinyl chloride and like materials. Specification 754,359 is referred to.