1-aminoalkane-1,1-diphosphonic acids and their salts

Abstract

A process for the production of 1-aminoalkane-1,1-diphosphonates of the formula ##SPC1## Wherein R.sub.1 is a member selected from the group consisting of hydrogen, lower alkyl and phenyl, R.sub.2 and R.sub. 3 are members selected from the group consisting of hydrogen, alkyl having 1 to 22 carbon atoms, cycloalkyl having 5 to 6 carbon atoms, phenyl, alkylphenyl having 7 to 18 carbon atoms, phenylalkyl having 7 to 18 carbon atoms and together with the nitrogen atom, piperidino, pyrrolidino and morpholino, and X is a member selected from the group consisting of hydrogen, alkali metal, ammonium, pyridinium, guanidinium and mono-, di-, and tri-lower-alkanol-ammonium with the proviso that at least one of R.sub.1, R.sub.2 and R.sub.3 is other than hydrogen, which consists essentially in reacting a phosphorus trihalide selected from the group consisting of phosphosus trichloride and phosphorus tribromide with a monocarboxylic acid amide of the formula ##SPC2## wherein the molecular weight of said carboxylic acid amide is over 46 and R.sub.1, R.sub.2 and R.sub. 3 have the above assigned meanings, at a temperature of from 0.degree. to 75.degree.C, subjecting the resultant reaction product to hydrolysis, and recovering said 1-aminoalkane-1,1-diphosphonates. The 1-aminoalkane-1,1-diphosphonates, some of which are novel, are capable of forming complexes with heavy metals.