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Relationships Between Step and Cumulative PMI and E-factors: Implications on Estimating Material Efficiency With Respect to Charting Synthesis Optimization Strategies

preprint
submitted on 26.06.2018 and posted on 27.06.2018 by John Andraos
This report describes mathematical relationships between step and cumulative process mass intensities (PMIs) for synthesis plans, and analogous parameters applied to Efactors. It is shown that both step E-factors and step PMIs are not additive for synthesis plans. It is also shown that a recursive calculation of cumulative PMIs from step PMIs is
a rapid method of determining overall PMIs for synthesis plans, though cumulative PMIs are not sufficiently informative as step PMIs or step E-factors to identify bottlenecks in
synthesis plans. Illustrations on the use of these metrics to track the material efficiency of published synthesis plans for the pharmaceutical, apixaban, are given as a template
example. Advantages and disadvantages of each metric are discussed. A general algorithm to select the most promising candidate synthesis plans considered at the design
stage for a given molecular target that most likely satisfy “green” material efficiency criteria is also presented.

History

Email Address of Submitting Author

c1000@careerchem.com

Institution

CareerChem

Country

Canada

ORCID For Submitting Author

0000-0002-2982-2708

Declaration of Conflict of Interest

No conflict of interest.

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