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Updated: Jan 23, 2026

Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
Structural elucidation of a dimeric impurity in the process development of ceftolozane using LC/HRMS and 2D-NMR
Jing Liao1, Huaming Sheng1, Josep Saurí1
1Analytical Research & Development, Merck & Co., Inc., Rahway, NJ 07065, USA.
Abstract:
Ceftolozane is MSD's 5th generation cephalosporin antibiotic with broad-spectrum gram-negative activity. While refining the synthetic route to the drug substance, a dimeric impurity was observed in the final active pharmaceutical ingredient (API) of ceftolozane. Through impurity enrichment and preparative isolation, the structure of the impurity was subsequently established through LC/HRMS, HRMSMS, H/D exchange and 2D-NMR studies. A kinetic study of the impurity formation was conducted to determine the best conditions to control it in the final chemical process.
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