GB969018A - A process for the preparation of alkenyl esters of carboxylic acids - Google Patents

Abstract

a , b -Alkenyl esters of carboxylic acids are prepared by reacting olefines under superatmospheric pressure with salts of metals of the palladium and platinum group with non-carboxylic acids, and salts of alkali or alkaline earth metals with carboxylic acids, in a substantially non-aqueous liquid medium. Ethylene, propylene, 1- and 2-butylene, 1-pentene, olefines from the polymerization of ethylene and/or propylene, olefines from the cracking of paraffins, butadiene and isoprene may be the starting materials and the platinum group salts may be halides, sulphates, nitrates or sulphonates, e.g. palladium dichloride. The carboxylates of the alkali or alkaline earth metals may be acetates, propionates, butyrates, pivalates, palmitates, stearates, benzoates, succinates, adipates, phthalates, terephthalates and those derived from higher boiling acids formed by the reaction of olefinic hydrocarbons with formic acid or carbon monoxide and water. The anhydrous medium may be the carboxylic acids and/or liquid sulphur dioxide, thiocyclopentane-1, 1-dioxide, acetone, methyl ethyl ketone, iso-octane, halogenated hydrocarbons, dimethyl formamide, acetonitriles, 1,2-dimethoxy ethane, tetrahydrofurane, ethyl acetate, and nitro ethane, and temperatures of 0 DEG to 150 DEG C. are employed. The metal compounds may be reoxidised preferably in the presence of a promotor nitrogen dioxide or of metallic salts comprising redox systems such as copper, iron or cobalt salts under oxygen pressure and the water formed is removed before recirculation. An example describes the preparation of a vinyl ester of a carboxylic acid branched at the a -carbon atom obtained by the reaction of a mixture of olefines (8-10C.) with carbon monoxide and water with an acid catalyst, using palladium dichloride, ethylene and sodium salts of the above acid. Specification 969,017 is referred to.