ABSTRACT
Verubecestat is an inhibitor of ß-site amyloid precursor protein cleaving enzyme 1 (BACE1) being evaluated in clinical trials for the treatment of Alzheimer's disease. Synthetic route development involves diastereoselective transformations with a need for enantiomeric excess (ee) determination of each intermediate and final active pharmaceutical ingredient (API). The analytical technical package of validated methods relies on enantioselective SFC and RPLC separations using multiple 3 and 5⯵m coated polysaccharide-based chiral stationary phases (CSPs) and mobile phases combinations. Evaluation of recently developed chiral columns revealed a single chiral selector (Teicoplanin) bonded to 2.7⯵m core-shell particles using H3PO4 in H2O/ACN and triethylammonium acetate: methanol based eluents at different isocratic compositions allowed good enatioseparation of all verubecestat intermediates. EE determination of verubecestat is easily performed on NicoShell, another macrocyclic glycopeptide chiral selector bonded to 2.7⯵m superficially porous particles. This approach enables fast and reliable enantiopurity analysis of the entire verubecestat synthetic route using only two chiral columns and mobile phases on a conventional HPLC system, simplifying technical package preparation, method validation and transfer to manufacturing facilities.
Subject(s)
Chemistry Techniques, Analytical/methods , Cyclic S-Oxides/chemical synthesis , Glycopeptides/chemistry , Thiadiazines/chemical synthesis , Chromatography, High Pressure Liquid , Polysaccharides/chemistry , Porosity , Stereoisomerism , Teicoplanin/chemistryABSTRACT
Verubecestat is an inhibitor of ß-secretase being evaluated for the treatment of Alzheimer's disease. The first-generation route relies on an amide coupling with a functionalized aniline, the preparation of which introduces synthetic inefficiencies. The second-generation route replaces this with a copper-catalyzed C-N coupling, allowing for more direct access to the target. Other features of the new route include a diastereoselective Mannich-type addition into an Ellman sulfinyl ketimine and a late-stage guanidinylation.
Subject(s)
Alzheimer Disease/drug therapy , Amyloid Precursor Protein Secretases/antagonists & inhibitors , Aspartic Acid Endopeptidases/antagonists & inhibitors , Cyclic S-Oxides/chemical synthesis , Thiadiazines/chemical synthesis , Alzheimer Disease/metabolism , Catalysis , Chemistry Techniques, Synthetic , Copper/chemistry , Cyclic S-Oxides/chemistry , Humans , Molecular Structure , Thiadiazines/chemistryABSTRACT
The key structural feature in Boceprevir, Merck's new drug treatment for hepatitis C, is the bicyclic [3.1.0]proline moiety "P2". During the discovery and development stages, the P2 fragment was produced by a classical resolution approach. As the drug candidate advanced through clinical trials and approached regulatory approval and commercialization, Codexis and Schering-Plough (now Merck) jointly developed a chemoenzymatic asymmetric synthesis of P2 where the net reaction was an oxidative Strecker reaction. The key part of this reaction sequence is an enzymatic oxidative desymmetrization of the prochiral amine substrate.
