Potent dopamine-.beta.-hydroxylase inhibitors having the Formula ##STR1## that are useful to inhibit dopamine-.beta.-hydroxylase activity, pharmaceutical compositions including these inhibitors, and methods of using these inhibitors to inhibit dopamine-.beta.-hydroxylase activity in mammals. Also disclosed are novel intermediates useful in preparing the presently invented inhibitors.
2-(N-Phenylakyl-N-formyl)amino-3-hydroxy-2-propenoic acids are intermediates for mercaptoimidazolecarboxylic acids which are dopamine-.beta.-hydroxylase inhibitors.