Green synthesis of Azachalcones: an evaluation based on chemical greenness metrics

The syntheses of azachalcones were performed using Conventional Synthesis (CS) and Green Synthesis (GS) methodologies. This study evaluated the chemical greenness of the processes through mass and energy metrics, alongside the Green Star (GSt) metric. GS showed significant improvements, with compounds 1 l and 1 m exhibiting yield increases of 143.72% and 79.67%, respectively, and a 94.58% reduction in waste production, as indicated by the E-Factor. Energy metrics, including Energy Intensity (EI) and Time Intensity (TI), highlighted the GS efficiency, with EI values decreasing from 85.714 kWh·g−1 in CS to under 1.00 kWh·g−1 in GS, and TI values reducing by over 99.0%. The GSt analysis demonstrated enhanced compliance with green chemistry principles, particularly P1 (Prevention), P2 (Atom Economy), and P6 (Energy Efficiency). These results support GS as a sustainable alternative for azachalcone synthesis, with potential industrial applications. The synthesis of azachalcones demonstrated promising results, fulfilling the Zero Pass and First Pass criteria, thus representing a potentially valuable methodology for pharmaceutical applications.