The synthesis of iminothiophenone-fused quinolines and evaluation of their serendipitous reactions

The novel synthesis of tricyclic 2-(cyclohexylimino)thieno[2,3-b]quinolin-3(2H)-ones from the reaction of 2mercaptoquinoline-3-carbaldehydes and isocyanides in methanol without using any additive is described. This protocol proceeds with high atom economy through the formation of C–S and C–C bond and then oxidation via tandem reaction. Moreover, some other remarkable aspects of this reaction such like the hydrolysis and a three-component reaction with aromatic amine to afford a highly conjugated schiff base is also investigated