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