| 摘要 |
Oligocarboxyalkanephosphonic acids of the general formulae <IMAGE> in which R denotes hydrogen, alkyl or the carboxyl group and R<1> denotes hydrogen or alkyl are prepared. These compounds are obtained by reacting a corresponding dialkyl carbalkoxymethanephosphonate with compounds having an activated olefinic double bond at 0 to 140 DEG C in the presence of strong basic catalysts, purifying the reaction products by distillation, and then subjecting them to hydrolysis or acidolysis with aqueous mineral acids at temperatures between 80 and 120 DEG C or with anhydrous hydrogen chloride at temperatures from 130 to 180 DEG C. The abovementioned oligocarboxyalkanephosphonic acids can be used as sequestering agents. |
