Synthesis of Thieno[2,3-b]quinolin-2-yl methanone Derivatives via Sequential Multi-component Reaction

Thienoquinolines are substantial structural units in the domain of medicinal chemistry due to their myriad bioactivities. This class of compounds exhibits a wide array ofbiological properties including analgesic and anti-inflammatory activities. Some of them are useful as antagonist and antioxidant, memory enhancers, antipyretics, antianaphylactic, high affinity selective 5-HT1A receptor ligands, molluscicidal and larvicidal, and potential antihypertensive agents. Accordingly, the development of convenient synthetic methods to access such heterocycles prompts us to examine the three-component reaction between 2- chloroquinoline-3-carbaldehyde, phenacyl bromide 1 and sodium sulfide. We used a one-pot sequential three-component procedure for the synthesis of thieno[2,3- b]quinolin-2-yl methanones 2 in DMF at room temperature which resulted in the products with excellent yields (85-95%) in short reaction times.