Synthesis of (Aminoalkylamine)-N-aminoalkyl)azanonaborane(11) Derivatives for Boron Neutron Capture Therapy

New boron-containing polyamine have been synthesized: (aminoalkylamine)-N-(aminoalkyl)azanonaborane(11) derivatives [H(2)N(CH(2))(n)H(2)NB(8)H(11)NH(CH(2))(n)NH(2)], where n = 4-6 and 12, and [H(2)N(CH(2))(3)H(2)NB(8)H(11)NH(CH(2))(4)NH(2)]. (4-Aminobutylamine)-N-(4-aminobutyl)azanonaborane and (3-aminopropylamine)-N-(4-aminobutyl)azanonaborane were less toxic in vitro (LD(50) of approximately 700 and approximately 1100 microM, respectively) than spermine, while (4-aminobutylamine)-N-isopropylazanonaborane with its hydrophobic isopropyl group and those with n = 5, 6, and 12 were already toxic under similar conditions (LD(50) << 500 microM). These compounds may be useful as delivery agents for boron neutron capture therapy.