Chemistry of 2-(Pipridin-1-yl) and/ or 2-(Morpholin-1-yl) Quinolines (Part II): Synthesis, Reactivity and Biological Activities

Background: Vilsmeier-Haack formylation of N-arylacetamides and used them as a key intermediate for preparation of 2-(piperidin-1-yl) and/ or 2-(morpholin-1-yl) quinoline-3- carbaldehydes. these used as precursors for the synthesis of 2-(piperidin-1-yl) and/ or 2-(morpholin- 1-yl) quinoline derivatives through the reaction with active methyl and/ or methylene component, Claisen-Schmidt condensation, one-pot multicomponent reactions (MCRs), reductive amination, Grignard reaction, etc. Methods: This review demonstrates the synthesis of 2-chloroquinoline-3-carbaldehyde derivatives, through Vilsmeier-Haack formylation of N-arylacetamides that used as a precursor for preparation of 2-(piperidin-1-yl) and/ or 2-(morpholin-1-yl) quinoline- 3-carbaldehydes and reacted them with various reagents to form the 2-(piperidin-1-yl) and/ or 2-(morpholin-1-yl) quinolines derivatives. Results: Many 2-(piperidin-1-yl) and/ or 2-(morpholin-1-yl) quinolines derivatives were achived through the reaction with active methyl and/ or methylene component, Claisen-Schmidt condensation, one-pot multicomponent reactions (MCRs), reductive amination, Grignard reaction, etc…. Conclusion: Many quinoline ring systems, specifically concerning medicinal chemistry, had been published over the past decade. During this review, we have outlined the synthetic routes and reactions of 2-(piperidin-1-yl) and/ or 2-(morpholin-1-yl) quinoline-3-carbaldehydes. This review implies a section of the synthesis of 2-(piperidin-1-yl) and/ or 2-(morpholin-1-yl) quinoline-3-carbaldehydes which can be prepared via Vilsmeier formylation of N-arylacetamides followed by heating of the formed aldehydes with piperidine or morpholine and two sections on its reactions with different reagents were presented. Eventually, this review focus upon 2-(piperidin-1-yl) and/ or 2-(morpholin-1- yl) quinoline-3-carbaldehydes as an interesting heterocyclic compound that can be utilized as a precursor and building block for the synthesis of an extended range of heterocyclic systems which have a potent pharmacological interest.