In search for novel anti-cancer and antimicrobial agents with promising pharmacotoxicological profile, the synthesis of some substituted 4-halofuran-2(5H)-ones (8a–l, 9, 11) and derived halogenated quinoxalin-2(1H)-ones (12a–d) is described. Some of the halogenated furanones were readily oxidized to the corresponding 2-bromo-2-propenoic acids (13a–c) with hydrogen peroxide in alkaline medium. Twenty-two compounds were preliminary tested for their in vitro activity against three bacteria and one fungus and revealed encouraging activity. On the other hand, three compounds were screened as anti-cancer agents using cell line panel protocol and 22 compounds were subjected to cycline-dependent kinases (CDKs) inhibition screening program but were inactive.