Guanylation of thiosemicarbazones: a new synthetic route to polysubstituted guanylhydrazones with antimicrobial activity

thiosemicarbazones were employed for the first time as electrophiles in the guanylation reaction promoted by hgcl2, affording polysubstituted guanylhydrazones, with regioselective introduction of each nitrogen substituent. the antibacterial and antifungal activities of guanylhydrazones were evaluated by determination of minimal inhibitory concentrations. some of them exhibited very low minimal inhibitory concentrations (mic) and broad-spectrum activities. the configurations of two guanylhydrazones were assigned by x-ray analysis that also revealed intramolecular interactions of the type n-h...n and c-h...n.