TECHNOLOGICAL PROCESSES OF ORGANIC SYNTHESIS: PROCESS-LEVEL STRUCTURE, GREEN METRICS AND ENABLING TECHNOLOGIES

This article examines the technological processes of organic synthesis as an integrated system of chemical transformation, separation, purification and waste-management operations rather than as a single reaction step. The aim is to identify, on the basis of published evidence and transparent calculations, the technological decisions that most strongly determine the material efficiency, safety and scalability of organic synthesis. A structured analytical review of peer-reviewed literature (1991–2023) was combined with quantitative evaluation of atom economy for representative reaction types and with a comparative analysis of two industrial case studies: the manufacture of ibuprofen (Boots and BHC routes) and of sitagliptin (rhodium-catalysed asymmetric hydrogenation versus transaminase biocatalysis). The calculations show that atom economy ranges from 100% for addition reactions such as the Diels–Alder reaction and catalytic hydrogenation to 25.7% for the Wittig methylenation of cyclohexanone, and that the change from a stoichiometric six-step route to a catalytic three-step route raises the atom economy of ibuprofen synthesis from about 40% to 77.5%. Published data further indicate that solvents account for the largest share of process mass in fine-chemical and pharmaceutical manufacture, and that continuous-flow, microwave-assisted and biocatalytic technologies improve heat transfer, selectivity or safety under defined conditions. A five-stage decision framework for designing technological processes of organic synthesis is proposed. The results can be used in process development and in teaching organic technology.