Abstract
An efficient ferric citrate catalyzed Biginelli reaction is reported to synthesize novel dihydropyrimidin-(1H)-ones with free amino group. Diversifying this free amino element provides an access to new and interesting DHMPs for pharmacological profiling. A series of novel dihydropyrimidin-(1H)-ones-sulphonamide conjugates were synthesized and evaluated against a panel of Gram positive as well as Gram negative bacteria and fungi. Among the series, the DHMP conjugate 6a with a 2-napthyl sulphonamide moiety exhibited excellent antibacterial activity with potency at least four times higher than the standard drugs such as ciprofloxacin, ampicillin and chloramphenicol against the tested bacterial strains.