SYNTHESIS AND STRUCTURE OF 1-METHYL-4-(3-THIOCARBAMOYL-3-CYANOPROPENYLIDENE)-1,4-DIHYDROQUINOLINE

1,4-Dimethylquinolinium iodide reacts with (2-nitrophenyl)aminomethylenecyanothioacetamide in the presence of triethylamine to give 1-methyl-4-(3-thiocarbamoyl-3-cyanopropylidene)-1,4-dihydroquinoline, the structure of which has been established by x-ray crystallography. The molecule is virtually planar, the dihedral angle between the dihydroquinoline nucleus and the 3-thiocarbamoyl-3-cyanopropylidene group being 3.39-degrees. The bond lengths found indicate considerable transfer of charge between the dihydroquinoline ring and the cyanothioacetamide group. The crystal contains stacks of molecules with an interplanar spacing of 3.351 angstrom, which could also facilitate charge transfer.