title: Structures of the anticancer compounds N-(2-hydroxyethyl)-2-(3-nitro-1,2,4-triazol-1-yl)-acetamide (RB-6110) and 5-(1-aziridinyl)-3-nitro-1-(3-oxo-1-butyl)-1,2,4- triazole (RB-6162).
abstract: RB-6110: C6H9N5O4, Mr = 215.17, monoclinic, C2/c, a = 20.595 (3), b = 4.713 (1), c = 19.914 (4) A, beta = 110.69 (1) degree, V = 1808.3 A3, Z = 8, Dx = 1.588 Mg m-3, lambda(Cu K alpha) = 1.54178 A, mu = 0.838 mm-1, F(000) = 675, T = 298 K, final R = 0.042 for 1219 observed reflections with I greater than or equal to 1.5 sigma (I). RB-6162: C8H11N5O3, Mr = 225.21, monoclinic, P2(1)/c, a = 7.515 (1), b = 14.758 (2), c = 9.813 (1) A, beta = 108.49 (1) degree, V = 1032.1 A3, Z = 4, Dx = 1.450 Mg m-3, lambda(Cu K alpha) = 1.54178 A, mu = 0.927 mm-1, F(000) = 472, T = 298 K, final R = 0.042 for 1113 observed reflections with I greater than or equal to 1.5 sigma (I). RB-6110 and RB-6162 are 3-nitro-1,2,4-triazoles with potential application as anticancer agents. The nitro groups are in the plane of the aromatic triazole ring with dihedral angles of 1.2 (4) and 4.6 (4) degrees, respectively. The arizidine substituent of RB-6162 is almost perpendicular [dihedral angle 80.1 (4) degrees] to the triazole plane. Molecular-orbital calculations on RB-6162 have confirmed that this geometry is energetically favoured. The energy barrier to rotation about the triazole-aziridine bond has been determined as 51.5 (5) kJ mol-1 by the dynamic NMR method.
authors.affiliation: Biomolecular Structure Unit, Institute of Cancer Research, Sutton, Surrey, England.
authors.forename: R
authors.initials: R
authors.lastname: McKenna
authors.forename: T C
authors.initials: TC
authors.lastname: Jenkins
authors.forename: S
authors.initials: S
authors.lastname: Neidle
mesh_terms: D000970:Antineoplastic Agents; D001388:Aziridines; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D008968:Molecular Conformation; D013816:Thermodynamics; D014230:Triazoles; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D000970:Antineoplastic Agents; D001388:Aziridines; D014230:Triazoles; C063021:RB 6110; C063022:5-(1-aziridinyl)-3-nitro-1-(3-oxo-1-butyl)-1,2,4-triazole