Hydroxyacetonitrile diphosphonic acid, a process for its production, and
申请人:Henkel Kommanditgesellschaft auf Aktien
公开号:US04908138A1
公开(公告)日:1990-03-13
Hydroxyacetonitrile diphosphonic acid corresponding to the following general formula ##STR1## in which M represents H or a cation of a base, and salts thereof; to a process for their preparation comprising reacting 3-R.sup.1 -3-oxo-1-aminopropane-1,1-diphosphonic acids corresponding to the following general formula ##STR2## in which R.sup.1 is a tertiary substituted alkyl group, an optionally substituted cycloalkyl group or an optionally substituted aryl or heteroaryl radical, with nitrous acid, the secondary product R.sup.1 -COOH and unreacted starting material are separated off from the reaction mixture and the hydroxyacetonitrile diphosphonic acid is obtained in the form of a salt by addition of a base; and to the use of the above compounds as complexing agents and as thresholders.