Revisiting the synthesis of 1-phosphonomethylhydantoins and phosphonates alike

The synthesis of various 1-phosphonomethylhydantoins and diethyl 1-phosphonomethyl-2-thiohydantoins, which share similar structural moiety with glyphosate, was reviewed and accomplished by two different synthetic routes: from glyphosate or hydantoins directly or from <i>N</i>-benzylglycine ethyl ester in a four-step sequence.