Developing a Multistep Continuous Manufacturing Process for (1R,2R)‑2-Amino-1-methylcyclopentan-1-ol

A multistep continuous manufacturing process to synthesize (1R,2R)-2-amino-1-methylcyclopentan-1-ol (2) was developed. The step 1/2 flow process mitigated the safety hazard associated with high exothermicity during epoxidation, the epoxide-opening reaction, and the low onset of the epoxide intermediate. Process improvements included a hybrid plug flow reactor (PFR)/continuous stirred tank reactor (CSTR) reaction and a continuous quench/work-up process in step 1; a continuous reaction, extraction, washing, and thin-film distillation work-up in step 2; and a continuous trickle bed hydrogenation in step 3, which provided the desired product with high purity and high ee. The end-to-end continuous process provided significant advantages of cost-saving, minimization of manufacturing space and utilities, and reduction of the cycle time.