SYNTHESIS, CHARACTERIZATION, AND REACTIVITY OF ISOCYANATO DICARBABORANES OBTAINED FROM O-CARBORANE

The functionalization of o-carborane with (bromoalkyl)phthalimides or propargylphthalimide, their subsequent transformation into isocyanate- substituted o-carborane, and their reactivity toward amino-and alcohol -containing molecules are reported. The preparation of these functiona lized ureas and carbamates could potentially lead to the utilization o f these molecules as suitable precursors for drugs to be used in boron neutron capture therapy (BNCT). The compounds 1-RNHC(O)NH(CH2)(n)-1,2 -C2B10H11 and 1-ROC(O)NH-1,2-C2B10H11 (n = 1, 2, and 3) were prepared by reaction of 1-0=C=N(CH2)(n)-1,2-C2B10H11, (n = 1, 2, and 3) with th e corresponding amino-or alcohol-containing substrate. Experimental de tails and analytical data leading to the identification of the reporte d compounds are provided Additionally the X-ray diffraction structures of 1-C6H4(CO)(2)NCH2CH2CH2-1 2-C2B10H11 (1c) and 1 -(C6H5)(2)C=N-CH2- 1,2-C2B10H11 (20) are reported. Compound Ic crystallizes in the P (1) over bar space group, a = 10.791(1) Angstrom, b = 13.104(1) Angstrom, c = 7.1816(9) Angstrom, alpha =97.389(8)degrees, beta = 90.416(5)degre es, gamma = 66.462(6)degrees, Z = 2, R = 0.0512 for 2140 reflections w ith F-2 > 3.0 sigma(F-2). Compound 20 crystallizes in the P2(1)/n spac e group, a= 16.5560(7) Angstrom, b = 7.0173(4) Angstrom, c = 16.9750(6 ) Angstrom, beta = 97.932(2)degrees, Z = 4, R = 0.0843 for 2755 reflec tions with F > 4.0 sigma(F).