Abstract Substituted phenylammonium chlorides react with cyanamide to give the corresponding phenylguanidines which on treatment with chloroformate esters give N-subst. phenyl-N, N"-guanidinedicarboxylic acid esters. All substances prepared have been tested for their anthelmintic activity against the model helminths Nippostrongylus brasilienses and Hymenolepis nana var. fraterna. The most significant activity has been found with diethyl ...