GB634118A - A process for the catalytic hydroxylation of olefinic compounds - Google Patents

Abstract

A compound containing an olefinic bond between two carbon atoms, each of which has the other two valencies linked to separate atoms, the compound containing no other elements than carbon, hydrogen, oxygen and halogen, is hydroxylated by treatment with hydrogen peroxide in the presence of formic acid. In place of hydrogen peroxide, any peroxidic compound capable of yielding free hydroxyl radicals or active peroxidic oxygen under the reaction conditions may be employed as the hydroxylating agent, e.g. hydrocarbon peroxides such as "propane peroxide" resulting from the incomplete oxidation of hydrocarbons. Many unsaturated compounds are specified, representative examples being:-ethylene, propylene, cetene, cyclopentene, cyclohexene, butadiene, cyclohexadiene, vinyl chloride, allyl chloride, allyl bromide, crotonyl chloride, methallyl alcohol and chloride, allyl alcohol, methyl vinyl carbinol, diallyl ether, and allyl, glyceryl ethers. Preferred products, i.e. glycerols and chlorohydrins, are obtained from olefins of the type <FORM:0634118/IV (b)/1> where R1-5 is hydrogen, hydrocarbon, or halogen-substituted hydrocarbon, e.g. methyl to amyl, cyclohexyl, benzyl, phenyl, and radicals containing a carbinol, chloro- or bromomethyl or chloroethyl group, and X is hydroxy or halogen. The reaction is preferably performed in dilute aqueous solution, but a heterogeneous medium with or without water may be used. When a non-aqueous medium is required, solvents such as inert ethers, nitriles and tertiary alcohols are employed, in conjunction with a solution of hydrogen peroxide in, e.g. tertiary butyl alcohol. Esters formed as by-products may be removed by known methods. With a gaseous olefin, pressure may be used, or a counter-current process employed. The preferred conditions comprise 1 mol. of catalyst to each mol. of olefin with an excess of peroxide at moderate temperatures, i.e. 0-80 DEG C., in dilute solution, preferably dilute aqueous solution. Excess peroxide may be decomposed in known manner. In the examples, allyl alcohol is oxidized to glycerol in the presence of formic acid with (1) propane peroxides, and (2) and (3) hydrogen peroxide. In addition, the following are representative of other conversions effected: crotonic acid to dihydroxybutyric acid, ethyl crotonate to ethyl dihydroxybutyrate, diethyl maleate to diethyl mesotartrate, vinyl bromide and divinyl ether to glycolaldehyde and oleic acid to 9 : 10-dihydroxystearic acid. Specifications 540,534, [Group III], and 541,110 are referred to. A sample has been furnished under Sect. 2 (5) of octane-1 : 2-diol, prepared by the oxidation of octene-1 with hydrogen peroxide in the presence of formic acid. The Specification as open to inspection under Sect. 91 includes further extensive lists of suitable olefinic compounds, e.g. buten-1-ol-3, diallyl, dilimonene, fumaric acid, anethole, eugenol, chlolesterol, acrylic acid, cinnamic aldehyde, acrolein, and mesityl oxide. Additional oxidizing agents specified include diacyl peroxides (e.g. diacetyl), acyl peracids (e.g. peracetic acid), ditertiary butyl peroxide, tertiary butyl hydroperoxide, lauryl and acetone peroxides. Examples are given of the oxidation of vinyl acetate and C10 olefines. This subject-matter does not appear in the Specification as accepted.