Eight novel analogues of Nifurtimox, 4-[(5-nitrofurfurylidene) amino]-3-methylthiomorpholine- 1, 1-dioxide, containing alfa–beta unsaturated amides, were synthesized and evaluated for their in vitro activity against Trypanosoma cruzi epimastigotes. Four derivatives bearing a nitro group at the 5-position of the furan ring were the most active in inhibiting culture growth and provoking cell death, showing trypanocidal activity more than threefold the potency of ...