New synthetic approach to DMI

More and more substances used by chemists are found to be carcinogenic, mutagenic, explosive or flammable, and this not only endangers the health and safety of those who work directly or indirectly with these substances, but it also pollutes the environment around us. In order to tackle this problem, in recent times, chemists has increasingly adopted more sustainable and safe synthetic approaches following the guideline the 12 principles of Green Chemistry. One of these principles involves the use of safer solvent and auxiliary substances which should be made unnecessary wherever possible and innocuous when used. In this view, since it is well known that solvents are the most widely used chemicals, numerous investigation have been devoted to develop and/or employ new environmentally friendly and safer solvents. From these premises, the aim of this thesis project is to develop new synthetic approaches to dimetil isosorbide (DMI), one of the most promising green polar high-boiling media. Herein the synthesis of DMI have been studied by reaction of isosorbide, its precursor, with dimethyl carbonate employed as green solvent and reagent. Various heterogeneous catalysts have been investigated including zeolites and hydrotalcites in order to identify the best performing one for the selective synthesis of DMI reducing or completely avoiding the formation of the numerous by -products. In addition, in order to minimize waste, the catalyst that offers the best performance, will be recovered and recycled to evaluate its reuse cycle. Alternative reaction conditions will be also explored i.e., via microwave apparatus. Green metrics will be evaluated so to assess the sustainability of the reaction.