SYNTHESIS AND CHARACTERIZATION OF 2,2-DIPHENYL-1-(5-ACETONYL-2,4,6-TRINITRO-1,3-CYCLOHEXADIENYL)HYDRAZINE, C21H19N5O7

The reaction of 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazine with the enolate of acetone, followed by acidification, yields the title compound 2,2-diphenyl-1-(5-acetonyl-2,4,6-trinitro-1,3-cyclohexadienyl)hydrazine, C21H19N5O7. The identity of the latter was confirmed by a combination of mass spectrometry, FTIR, elemental analysis, and H-1 NMR. Crystals were grown from dichloromethane -95% ethanol and the structure was determined by X-ray diffraction. Crystals are monoclinic, P2(1)/c, a = 9.254(3), b = 13.531(3), c = 17.39(5) angstrom, beta = 106.18(2)degrees at 225 K. R = 0.073, R(omega) = 0.038 for reflections with I > 2sigma(I). The Zachariasen extinction factor, g, refined to 18(3) x 10(-4). The cyclohexadiene ring is puckered with a primarily twist-boat conformation. Atoms C(1) to C(3), C(6), the nitro group on C(2), and the hydrazine moiety (N(8)-N(7)-H(7) attached to C(l)) all lie close to a common plane. The planes of the two phenyl rings, the acetonyl substituent, and the C(6) nitro group are each roughly perpendicular to this plane. The C(5) acetonyl and C(6) nitro groups are trans to each other.