摘要:
A process for the preparation of .alpha.- or .alpha.,.alpha.'-substituted derivatives of the bis(aminomethyl)phosphinic acid of the formula I and their acid or basic salts, ##STR1## in which R.sup.1, R.sup.2 and R.sup.3 are defined as in the description, wherein a bis(aminomethyl)phosphinate is converted into the corresponding bisimine, which is alkylated by R.sup.2 and R.sup.3 in the .alpha.- and/or .alpha.,.alpha.'-position after reaction with a base, and is converted into a compound of the formula I by subsequent treatment with an acid.