Process for producing phosphonomaleic acid esters

Abstract

Novel phosphonomaleic acid esters of the formula ##STR1## in which R.sup.1 is an optionally substituted alkyl radical containing from 1 to 6 carbon atoms and, where n=0, may also be an optionally substituted aryl radical, R.sup.2, R.sup.3 and R.sup.4 each independently is an optionally substituted alkyl radical containing from 1 to 16 carbon atoms, R.sup.5 is hydrogen, an alkyl or aryl radical containing from 1 to 7 carbon atoms, and n=0 or 1, are produced by reacting a base with a 1-halogen-1-phosphonosuccinic acid ester of the formula ##STR2## in which Hal is chlorine or bromine. The esters are useful as intermediates in the synthesis of sequestrants, corrosion inhibitors, stabilizers, flameproofing agents, pharmaceuticals and pesticides.

Dependencies are inferred from the claim text.