1120335-14-9Relevant articles and documents
The continuous flow Barbier reaction: An improved environmental alternative to the Grignard reaction?
Kopach, Michael E.,Roberts, Dilwyn J.,Johnson, Martin D.,McClary Groh, Jennifer,Adler, Jonathan J.,Schafer, John P.,Kobierski, Michael E.,Trankle, William G.
, p. 1524 - 1536 (2012/06/04)
A key pharmaceutical intermediate (1) for production of edivoxetine·HCl was prepared in >99% ee via a continuous Barbier reaction, which improves the greenness of the process relative to a traditional Grignard batch process. The Barbier flow process was run optimally by Eli Lilly and Company in a series of continuous stirred tank reactors (CSTR) where residence times, solvent composition, stoichiometry, and operations temperature were optimized to produce 12 g h-1 crude ketone 6 with 98% ee and 88% in situ yield for 47 hours total flow time. Continuous salt formation and isolation of intermediate 1 from the ketone solution was demonstrated at 89% yield, >99% purity, and 22 g h-1 production rates using MSMPRs in series for 18 hours total flow time. Key benefits to this continuous approach include greater than 30% reduced process mass intensity and magnesium usage relative to a traditional batch process. In addition, the flow process imparts significant process safety benefits for Barbier/Grignard processes including >100× less excess magnesium to quench, >100× less diisobutylaluminum hydride to initiate, and in this system, maximum long-term scale is expected to be 50 L which replaces 4000-6000 L batch reactors.
