A Practical and Convenient Synthesis of the Essential Antibiotic Drug Cefazolin under Sequential One-Flow Conditions

A sequential continuous-flow synthesis of cefazolin, which is a vital first-choice drug used for the prevention of primary infection in most surgeries, was investigated. Rapid flow and efficient mixing of substrates in suitable flow reactors enabled the target compound to be obtained in a short period without any intermediate isolation. A flexible system design that can be applied from a small-scale to medium-scale synthesis was demonstrated, and optimal parameters were established to realize the synthesis. A 0.3 mol/h scale synthesis was achieved in 54% isolated yield with 13.75 g/h dL space–time–yield of cefazolin. The obtained material had an acceptable impurity profile and could be purified by simple acid–base extraction and precipitation.