Synthesis and Crystal Structure of 12-(2,4-Dichlorophenyl)-7,8,9,10,11,12-hexahydrobenzo[f]pyrimido [4,5-b]quinoline-9,11-dione DMF Solvate

The title compound 12-(2,4-dichloropheny1)-7,8,9,10,11,12-hexahydrobenzo[f]pyrimido[4,5-b]quinoline-9,11-dione DMF solvate 1 (C24H20Cl2N4O3, M-r = 483.34) was synthesized and crystallized. The crystal belongs to the monoclinic system, space group P2(1)/n with a = 6.4798(16), b = 20.595(5), c = 16.723(4) angstrom, beta=95.267(7)degrees, Z = 4, V = 2222.3(9) angstrom(3), D-c = 1.445 g/cm(3), mu(MoK alpha) = 0.328 mm(-1), F(000) = 1000, the final R = 0.0530 and wR = 0.1388 for 3484 observed reflections (I> 2 sigma(I)). X-ray analysis reveals that the central 1,4-dihydropyridine ring is slightly distorted, adopting a half-chair conformation, which is obviously different from the boat conformations of other similar compounds. In addition, the classical hydrogen bonds of N(2)-H(2A)center dot center dot center dot O(2) are presented in the crystals, and link the adjacent molecules to form dimmers. Atom 0(3) in the MAT solvent forms two hydrogen bonds of O(3)center dot center dot center dot H(1H) N(1) and O(3)center dot center dot center dot H(3H)-N(3) with a pyrimidoquinoline moiety, forming an interesting half-chair-like conformation. The hydrogen bonds link the molecules to form dimmers, while intermolecular pi-pi interaction connects the above-mentioned dimmers to yield a one-dimensional structure.