Synthesis and Crystal Structure of 7,8-Dihydroquinolino[2,3-a]acridine Derivatives

Abstract Novel 9-amino-3-substituted-1,2,3,4-acridin-1-one derivatives and 9,14-diamino-7-substituted-7,8-dihydroquinolino[2,3-a]acridine derivatives were synthesized by the condensation reaction of 5-substituted-1,3-cyclohexanedione with 2-aminobenzonitrile and substituted 2-aminobenzonitrile using p-toluenesulfonic acid, K2CO3, and Cu2Cl2 as catalysts. The structures of all compounds were characterized by elemental analysis, infrared, mass spectrometry, and 1H and 13C NMR spectra. The crystal and molecular structures of 6, 14-diamino-3,4,11,12-tetramethoxy-7-phenyl-7,8-dihydroquinolino[2,3-a]acridine 5a have been determined by single-crystal x-ray diffraction analysis. The crystal of compound 5a belongs to triclinic with space group P-1, a = 1.06168(15) nm, b = 1.16951(17) nm, c = 1.6020(2) nm, α = 71.380(3)°, β = 77.686(3)°, γ = 66.743(3)°, Z = 2, V = 1.7231(4) nm3, R 1 = 0.1060, and wR 2 = 0.2192.