Mechanochemical 1,1′-Carbonyldiimidazole-Mediated Synthesis of Carbamates

Abstract

1,1′-Carbonyldiimidazole (CDI) was used as an eco-friendly acylation agent for the mechanochemical preparation of carbamates. The anticonvulsant N-methyl-O-benzyl carbamate was obtained in a vibrational ball-mill, while planetary ball-mill was suitable to develop a new sustainable method to access N-protected amino esters with no racemization. Compared to the synthesis in solution, mechanochemistry proved to be a powerful tool enhancing the reactivity of both alcohol and carbamoyl-imidazole intermediate, under mild conditions, without the need of activation as usually reported for solution synthesis. This new technology provides a sustainable method for the synthesis of carbamates using 1,1′-carbonyldiimidazole.