7-(CH3)3N-4-{2,4-(NO2)2C6H3S}-nido-7-CB10H11 has been synthesized through a Friedel-Crafts substitution reaction on 7-(CH3)3N-nido-7- CB10H12. A biodistribution study in mice with implanted B16 melanoma indicates that the compound locates in neoplastic tissue at concentrations which suggest that its use in 10B neutron capture therapy may be feasible.