Green Synthesis of Copper Triflusalate and Pyridine Adducts

© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Conventional organic solvents are the preferred media to prepare and crystallize metallorganic materials, since the wide diversity of organic solvents allows the control of solubility parameters and precipitation kinetics. However, they are the largest waste input in fine chemical synthesis; and moreover, in the processing of materials with ester containing groups, which have a significant tendency to hydrolysis, the use of organic solvents can be too aggressive to keep the structure of labile molecules. In this context, milder methods to prepare crystalline metallorganic derivatives of triflusal (HTrf), a drug bearing an ester group, are here described. HTrf molecule itself and its derivatives have important applications in the pharmaceutical industry. In this work, copper triflusalate complexes and derived pyridine adducts are prepared via an environmentally friendly supercritical CO2 method, preserving the ester group from hydrolysis. For comparison, some intricate conventional solvent liquid methods are also envisaged. Products are fully characterized in regard of composition, structure and magnetic properties.