Summary: Considering the fact that they are dealing with environmentally acceptable processes, in order to decrease utilization and generation of harmful substances. Microwave and ultrasound mediated synthesis have been determined as green technologies for some time now, but there is still a tendency to minimize the use of harmful and toxic organic solvents in organic synthesis. Deep eutectic solvent became popular in recent years, since their potency to be used in these kinds of processes is immense. Deep eutectic solvents are characterized as nontoxic and environmentally acceptable solvents, easily synthesized from biodegradable components. As such, they are an excellent tool for green chemistry concept, especially since they can be combined with microwaves and ultrasound. Therefore, due to their advantages compared to conventional synthesis, emphasising the environment safety and ecological issues, those methods will be employed in synthesis of some coumarin, quinazolinone and pyridine heterocyclic compounds with potential biological activity. Heterocyclic compounds have been of interest for many researchers in the last few decades due to their wide spectrum of biological properties. Such compounds have found their application in agriculture, food industry, pharmacology and medicine. A tendency today is not only design and synthesis of heterocyclic compounds, but finding new ways of simplifying the reactions, gaining higher yields, shortening reaction times and implementation of ecologically acceptable synthetic methods.

The main goal of this project is to develop procedures for synthesis of various biologically active and important heterocycles using green technologies. This project will be performed considering three (3) aspects; 1) Synthesis of quinazolinone derivatives, 2)     Knoevenagel condensation and 3) Synthesis of pyridine derivatives. All of these reactions are very common in chemical laboratories, utilized in every day work of many researchers, whether for synthesis of important chemical intermediates or final biologically active products, for different purposes. Quinazolinone derivatives that are going to be synthesized within this project are very potent and important chemical intermediates (quinazolin-4(3H)-one derivatives, 2-methylquinazolin-4(3H)-one derivatives, 2-mercapto-3-substituted-quinazolin-4(3H)-one derivatives) for synthesis of various drugs and medications on a daily basis, often used in pharmaceutical industry. Thus it is of great importance to find an ecologically acceptable process for their synthesis. Knoevenagel condensation is also one of very commonly used reactions in many laboratories employed in formation of C-C bond. Optimization of this reaction and further synthesis of novel compounds based on optimal conditions is also of great importance for every synthetic chemist. Also, the same will be done with pyridine derivatives and oximes, compounds known for their biological activity. All of compounds or their derivatives have a potency to be used in food or agricultural industry as food additives, fungicides, herbicides, etc., or in pharmaceutical industry for various drug applications. Since there are so many possibilities in formation of deep eutectic solvents which are visible through a great number of components which can be combined or the ratios in which they can be combined, a great amount of work and time will be invested in these investigations. Also, all reactions will be performed with stirring and heating, with microwaves and ultrasound. For that reason two doctoral students will be working on this project, each one of them dealing with specific type of compounds or reactions and it is expected that they gain their PhD diploma within this project. Results will serve all the scientists working with synthesis of heterocyclic compounds and also will set a good base for their production scale up and possible application in various industries aiming the ecologically friendly approach.