Microwave assisted synthesis of new β-diketo derivatives ligands

The metal complexes of β-diketo derivatives and especially those of acetylacetone are well known and have been extensively studied. To improve the chelating ability of this molecule, we have introduced a further coordinative group. The designed compounds, which include a carboxylic group and the β-diketo moiety, are promising candidates as new metal ligands for pharmaceutical applications. Classical synthetic strategy for the obtainment of these adducts requires a two step procedure consisting first in the SN2 reaction of methylenic group and second deprotection of ester derivatives in order to set the carboxylic function free. Concerning the first step, traditional approach requires long reaction times and long work up procedures that lead to very poor product yields. Microwave (MW) irradiation at 2.45 GHz in closed vessels was exploited in this first synthetic step to take advantages from rapid heating rates thanks to the intrinsic volumetric and selectivity nature of MW heating. Results in terms of reaction times and yields as well as possible future developments, will be discussed.