Copper(I) Iodide Nanoparticles Catalyzed Solvent-Free Synthesis of 4-arylacridinediones and 6-aryldiindeno[1,2-b:2,1-e]pyridinediones

The importance of acridine core structure and other heterocycles containing its framework is well known, as they are found in numerous compounds with a variety of biological effects such as, antibacterial, antifungal, antimalarial, and anticancer properties. Many members of these compounds are used as chemotherapeutic agents against cancer cells [1]. Pyridine is also an important solvent and heterocyclic nucleusfor the design and synthesis of novel molecules with biological activities and properties. It occurs in several natural compounds which are used as a precursor in agrochemicals and pharmaceuticals [2]. The utility of nanostructured metal salts as catalysts in organic synthesis has drawn special attention due to their better properties compared to the bulk size. Nanosized copper iodide is one reusable Lewis acid catalyst which has revealed several catalytic activities for the synthesis of organic compounds and others [3]. I wish to report herein a solvent-free condensation between aromatic aldehydes 1, ammonium acetate (2) and active methylene compounds including dimedone (3), or 1,3-indanedione (5), in the presence of CuI nanoparticles (CuI NPs) as an efficient and recyclable catalyst leads to 4-arylacridinediones 4, and 6-aryldiindeno[1,2-b:2,1- e]pyridinediones 6. The avoidance of using harmful organic solvents, production of pure products in high to excellent yields without any by-products, reusability of catalyst, and very simple operation are the advanteges of this novel and practical approach.