Safe and Sustainable by Design (SSbD) Synthesis of Food and Personal Care Ingredients by Mechanochemistry

The preparation of perillartine, a potent marketed sweetener, and N-tert-butyl-α-phenylnitrone (PBN), a most commonly used free-radical spin-trap used in personal care formulation, endowed with antioxidant, neuroprotective, and anti-aging properties, was studied by vibrating and planetary ball-milling. The reactivity in polymeric jars, such as PTFE and in-house made polyoxymethylene (POM), was evaluated and compared to the most commonly used stainless steel and zirconium oxide milling media. This investigation revealed an insightful correlation while also accounting for the energy involved in each transformation. Assessment of the processes by green chemistry metrics and tools (e.g., Chem21, DOZN 3.0 and EcoScale) showed that mechanochemical approaches offer a Safe and Sustainable by Design (SSbD) approach also complying with the IUPAC guiding principles of a responsible chemistry. The reduced solvent consumption, the simplified purification procedures, and lower associated environmental and safety hazards are strongly aligned with the green chemistry principles.