Synthesis and calcium antagonistic activity of a series of diethyl benzofuryl, benzothienyl and benzogammapyronyl benzylphosphonates

Abstract In this work we present about 15 original heterocyclic diethyl benzylphosphonate analogues of fostedil, in which we have varied the nature of the heterocycle, the substituents or the phosphonic group, or even the position of this latter. Three diethyl 4-(2-benzofuryl) benzyl phosphonates exhibited slightly higher calcium antagonism than the control. Solely substitution with a fluorine atom was able to maintain activity, whereas the other modifications always decreased it.