Thiazole-Based σ1 Receptor Ligands: Diversity by Late-Stage C−H Arylation of Thiazoles, Structure–Affinity and Selectivity Relationships, and Molecular Interactions

Artur K. Kokornaczyk, Dirk Schepmann, Junichiro Yamaguchi, Kenichiro Itami, Erik Laurini, Maurizio Fermeglia, Sabrina Pricl, Bernhard Wünsch

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    3 Citations (Scopus)


    Spirocyclic thiophene derivatives represent promising σ1 ligands with high σ1 affinity and selectivity over the σ2 subtype. To increase ligand efficiency, the thiophene ring was replaced bioisosterically by a thiazole ring, and the pyran ring was opened. Late-stage diversification by regioselective C−H arylation of thiazoles 9 a–c resulted in a set of 53 compounds with high diversity. This set of compounds was analyzed with respect to σ1 affinity, σ12 selectivity, lipophilicity (logD7.4), lipophilicity-corrected ligand efficiency (LELP), and molecular target interactions. The most promising candidates were pyridyl-substituted thiazole derivatives 33 c (2-(1-benzyl-4-ethoxypiperidin-4-yl)-5-(pyridin-3-yl)thiazole) and 34 c (2-(1-benzyl-4-ethoxypiperidin-4-yl)-5-(pyridin-4-yl)thiazole), possessing low-nanomolar σ1 affinity (Ki=1.3 and 1.9 nm), high σ12 selectivity (>1500-fold), low lipophilicity (logD7.4=1.8) and very good ligand efficiency (LELP=5.5), indicating promising pharmacodynamics and pharmacokinetics. Molecular simulation studies, including docking and deconvolution of the free binding energy into its major components, led to decreased hydrophobic stabilization of pyridyl derivatives 33 c and 34 c, which was compensated by lower desolvation energy.

    Original languageEnglish
    Pages (from-to)1070-1080
    Number of pages11
    Issue number13
    Publication statusPublished - 2017



    • C−H arylation
    • molecular dynamics
    • structure–affinity relationships
    • thiazoles
    • σ receptors

    ASJC Scopus subject areas

    • Molecular Medicine
    • Pharmacology, Toxicology and Pharmaceutics(all)
    • Organic Chemistry

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