A scale-up procedure to Dialkyl Carbonates: purification, chemical physical properties, biodegradability and cytotoxicity tests

Among the different dimethyl carbonate (DMC) derivatives, dialkyl carbonates DACs are extensively investigated as safe alternatives to chlorine reagents. In fact, they can replace alkyl halides and dimethyl sulfate in alkylation and carbonylation reactions as well as phosgene and its derivatives in the alkoxycarbonylation ones. In this work we explored the high yielding scale-up synthesis of non-commercially available or expensive dialkyl carbonates (DACs) via transcarbonylation reactions of an alcohol with dimethyl carbonate (DMC) promoted by a nitrogen-based organocatalyst. Compared to previously published works, the proposed procedure has been customized for DACs large scale production (up to 70 mL of product obtained). Purification of these compounds has been achieved by fractional distillation and the exceeding reagents have been recovered and recycled. The selected DACs for this study include both symmetrical and unsymmetrical compounds, incorporating several alkyl, alkoxyalkyl, alkylamino and alkylthio functional groups. The chemical-physical properties of the new DACs have been also evaluated, as well as their water solubility. Furthermore, both biodegradability and cytotoxicity tests have been carried out to investigate the effects of the different substituents on the greenness of these potential solvents and reagents.