We report herein the synthesis and the in vitro antileishmanial evaluation of a series of 6- substituted purines. The most active compounds against Leishmania amazonensis promastigotes were 6-(3′-chloropropylthio) purine 2 (DA Benson, I. Karsch-Mizrachi, DJ Lipman, J. Ostell, BA Rapp, DL Wheeler, Genbank. Nucleic Acids Res. 28 (2000) 15–18; EV Aleksandrova, PMIE Valashek, J. Med. Pharm. Chem. 35 (2001) 172–173), 6-(3′-( ...