Ethyl fumarate

The addition of active methylene compounds (ethyl malonate, ethyl aoeto-acetate, ethyl plienylacetate, nltromethane, acrylonitrile, etc.) to the aP-double bond of a conjugated unsaturated ketone, ester or nitrile In the presence of a basic catalyst (sodium ethoxide, piperidine, diethylamiiie, etc.) is known as the Michael reaction or Michael addition. The reaction may be illustrated by the addition of ethyl malonate to ethyl fumarate in the presence of sodium ethoxide hydrolysis and decarboxylation of the addendum (ethyl propane-1 1 2 3-tetracarboxylate) yields trlcarballylic acid ... 

Ethyl fumarate has been prepared from fumaric acid and ethyl alcohol, with or without sulfuric acid as catalyst,4 from silver fumarate and ethyl iodide,5 from silver maleate and ethyl iodide plus a trace of iodine,6 from ethyl maleate by the action of iodine,6 from ethyl maleate and phosphorus pentachloride,7 and by passing hydrogen chloride into a boiling absolute alcohol solution of malic acid.8... 

If 99 per cent alcohol is used instead of 96 per cent, the yield of ethyl fumarate is 87 per cent of the theoretical instead of 80 per cent. When large quantities of ester are being prepared it is easy to use dry alcohol, since the alcohol-water distillate can be dehydrated over quicklime and used again. The wet alcohol is conveniently dehydrated by refluxing six hours over quicklime in a 12-I. flask and then distilling. 

Neises, B. and W. Steglich, Esterification ofcarboxyic acids with dicyclohexylcarbodiimide/4-dimethylaminopyridine tert-butyl ethyl fumarate. Organic Syntheses, 1990.7 p. 93-94. 

The Nature of the Condensation Produkt from Ethyl Benzylmalonate and Ethyl Fumarate. J. chem. Soc. (London) 193, 42. 

Ethyl maleate from Commercial Solvents Corporation, Terre Haute, Indiana, was distilled before use. Ethyl fumarate can be used also, but the yield of product is lower since a much greater proportion of high-boiling compounds is obtained. Aldehydes do not undergo free-radical addition to maleic anhydride under these conditions. 

Among the polyesters that are used for PVC, the copolymers of butadiene with ethyl fumarates and ethyl acrylates deserve mention. They have been produced by Badische Anilin-und Sodafabrik (BASF) under the commercial name Palamoll. Palamoll I consists of 75% diethyl fumarate and 25% butadiene Palamoll II contains equal parts of butadiene and ethyl acrylate. In combination with the same amount of liquid plasticizers (such as DOP), films with cold resistance down to — 60°C. can be produced. These products are especially important for cable insulation because of their good dielectric properties. The Palamoll products are produced by emulsion polymerization and can be directly combined with emulsions of PVC. 

Ethylene bromide Ethyl ether Ethyl fumarate 2-Ethylhexanol Ethylidine diacetate Ethyl maleate Ethyl valerate Eugenol methyl ether... 

The ethyl malonate and ethyl fumarate should be redistilled under reduced pressure, and the material boiling over a 2-degree range should be collected. 

Heat is developed during the reaction, and the mixture may be kept boiling by adding the ethyl fumarate at a suitable rate. 

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