The mass-based metrics were calculated considering all steps of the respective preparation route (see ESI for the details). In terms of total yield (86%), the mechanochemical approach delivered comparable or superior results as the benchmark solution-state approaches. Atom economy (AE), which reflects the theoretical efficiency of reactant utilization, is lower in the mechanochemical route (AE = 39.1) because of the higher molecular weight of the reagents involved. However, reaction mass efficiency (RME), which represents the actual maximum efficiency of reactant utilization, is noticeably higher (RME = 17.0) than those of the solution-based protocols, in which a greater excess of chemicals was used. Finally, total process mass intensity (total PMI), which reflects the amount of waste generated per unit of product, is approximately 2.5 times lower than in a similar early-stage development solution route (PMI = 563.5 vs.