Synthesis, Structure, and Reactions of Substituted 2-Aminotetrahydroquinoline-3-carbonitriles

A series of substituted 2-aminotetrahydroquinolinecarbonitriles have been synthesized by the three-component condensation of diaryl(hetaryl)methylidenecyclohexanones, malononitrile, and ammonium acetate. Factors responsible for the reaction selectivity and product formation pathway have been revealed. The reaction of aminoquinolinecarbonitriles with acetic anhydride under acidic conditions afforded substituted hexahydro­pyrimido[4,5-b]quinolinones. The structure of the synthesized compounds has been determined by IR and ¹H and ¹³C NMR spectroscopy, including HSQC two-dimensional correlation technique.