Abstract: The invention relates to a process for the preparation of phosphorus-containing compounds of the formula (I) ##STR1## where R.sup.1 and R.sup.2 are identical or different and are a straight-chain or branched alkyl radical having 1 to 8 carbon atoms, a cyclohexyl-, cyclopentyl-, aryl-, halogen-, (C.sub.1 -C.sub.6)-alkyl- or (C.sub.1 -C.sub.6)-alkoxy-substituted aryl radical, where R.sup.1 and R.sup.2, together with the phosphorus atom and the oxygen atom, can also form a ring, in particular an oxaphosphorin ring, which comprises metering acrylonitrile at elevated temperature into a compound of the formula (II) ##STR2## where R.sup.1 and R.sup.2 are as defined above.

Abstract: The present invention relates to a hydrophilic, highly swellable hydrogel based on (co)polymerized hydrophilic monomers or based on graft (co)polymers, characterized in that it has been surface-modified by means of a mixture ofA) one or more diglycidyl phosphonates andB) one or more other reactive compounds which are capable of reacting with the functional groups in the polymer, to a process for the preparation thereof, to the use thereof, and to diglycidyl phosphonate-containing crosslinking agent mixtures.

Abstract: The present invention relates to the use of compounds of the general formula I ##STR1## in which R denotes alkyl, alkenyl or aryl, which can be optionally substituted, as crosslinkers in the preparation of hydrogels, and to the hydrogels thus prepared and their use.

Abstract: In order to prepare N-acylphosphinothricin diesters, acetals of methyl-(3-oxopropyl)phosphinic acid esters of the formula ##STR1## are reacted in a dipolar aprotic solvent with a carboxylic acid amide and carbon monoxide in the presence of hydrogen gas using a cobalt compound as a catalyst, where the radical R' is alkyl or aryl or aralkyl.