Reactive deep eutectic solvents for EDC-mediated amide synthesis.

The sustainability of amide bond formation is an ever-present topic in the pharmaceutical industry, as it represents the common motif in many clinically approved drugs. Despite many procedures for accomplishing eco-friendly amide synthesis having been developed, this transformation still remains a contemporary challenge. Herein, we report a greener approach for amide synthesis by using Reactive Deep Eutectic Solvents (RDESs) acting as both the reaction medium and reactants. The procedure not only avoids the use of hazardous solvents but also provides operationally simple product recovery with high purity and efficiency, without chromatographic purification. This approach was efficiently applied to the synthesis of a key intermediate in the production of an active pharmaceutical ingredient like atenolol. The green metrics of the gram-scale procedure were compared to the conventional industrial strategy showing an advancement in the greening of amide synthesis.