Thieno[3,2-c]pyran-4-one based novel small molecules: Their synthesis, crystal structure analysis and in vitro evaluation as potential anticancer agents

Novel thieno[3,2-c]pyran-4-one based small molecules were designed as potential anticancer agents. Expeditious synthesis of these compounds was carried out via a multi-step sequence consisting of few steps such as Gewald reaction, Sandmeyer type iodination, Sonogashira type coupling followed by iodocyclization and then Pd-mediated various C-C bond forming reactions. The overall strategy involved the construction of thiophene ring followed by the fused pyranone moiety and then functionalization at C-7 position of the resultant thieno[3,2-c]pyran-4-one framework. Some of the compounds synthesized showed selective growth inhibition of cancer cells in vitro among which two compounds for example, 5d and 6c showed IC50 values in the range of 2.0-2.5 μM. The crystal structure analysis of an active compound along with hydrogen bonding patterns and molecular arrangement present within the molecule is described.