ChEBI: Diethyl maleate is a maleate ester resulting from the formal condensation of both carboxy groups of maleic acid with ethanol. A colourless liquid at room temperature (m.p. -10###) with boiling point 220### at 1 atm., it is commonly used as a dienophile for Diels-Alder-type cycloaddition reactions in organic synthesis. It has a role as a glutathione depleting agent. It is a maleate ester and an ethyl ester. It derives from an ethanol.