Metabotropic glutamate receptor 5 negative allosteric modulators: discovery of 2-chloro-4-[1-(4-fluorophenyl)-2,5-dimethyl-1H-imidazol-4-ylethynyl]pyridine (basimglurant, RO4917523), a promising novel medicine for psychiatric diseases.

Abstract

Negative allosteric modulators (NAMs) of metabotropic glutamate receptor 5 (mGlu5) have potential for the treatment of psychiatric diseases including depression, fragile X syndrome (FXS), anxiety, obsessive-compulsive disorders, and levodopa induced dyskinesia in Parkinson's disease. Herein we report the optimization of a weakly active screening hit 1 to the potent and selective compounds chloro-4-[1-(4-fluorophenyl)-2,5-dimethyl-1H-imidazol-4-ylethynyl]pyridine (basimglurant, 2) and 2-chloro-4-((2,5-dimethyl-1-(4-(trifluoromethoxy)phenyl)-1H-imidazol-4-yl)ethynyl)pyridine (CTEP, 3). Compound 2 is active in a broad range of anxiety tests reaching the same efficacy but at a 10- to 100-fold lower dose compared to diazepam and is characterized by favorable DMPK properties in rat and monkey as well as an excellent preclinical safety profile and is currently in phase II clinical studies for the treatment of depression and fragile X syndrome. Analogue 3 is the first reported mGlu5 NAM with a long half-life in rodents and is therefore an ideal tool compound for chronic studies in mice and rats.

• Authors: Georg Jaeschke, Sabine Kolczewski, Will Spooren, Eric Vieira, Nadia Bitter-Stoll, Patrick Boissin, Edilio Borroni, Bernd Büttelmann, Simona Ceccarelli, Nicole Clemann, Beatrice David, Christoph Funk, Wolfgang Guba, Anthony Harrison, Thomas Hartung, Michael Honer, Jörg Huwyler, Martin Kuratli, Urs Niederhauser, Axel Pähler, Jens-Uwe Peters, Ann Petersen, Eric Prinssen, Antonio Ricci, Daniel Rueher, Marianne Rueher, Manfred Schneider, Paul Spurr, Theodor Stoll, Daniel Tännler, Jürgen Wichmann, Richard H Porter, Joseph G Wettstein, Lothar Lindemann
• Journal: Journal of medicinal chemistry (J Med Chem) Vol. 58 Issue 3 Pg. 1358-71 (Feb 12 2015) ISSN: 1520-4804 [Electronic] United States
• PMID: 25565255 (Publication Type: Journal Article)

Chemical References

• 2-chloro-4-((2,5-dimethyl-1-(4-(trifluoromethoxy)phenyl)-1H-imidazol-4-yl)ethynyl)pyridine
• 2-chloro-4-(1-(4-fluorophenyl)-2,5-dimethyl-1H-imidazol-4-ylethynyl)pyridine
• Imidazoles
• Pyridines
• Receptor, Metabotropic Glutamate 5

Topics

• Allosteric Regulation (drug effects)
• Animals
• Depression (drug therapy)
• Dose-Response Relationship, Drug
• Drug Discovery
• Fragile X Syndrome (drug therapy)
• Humans
• Imidazoles (chemical synthesis, chemistry, pharmacology)
• Macaca mulatta
• Male
• Mice
• Mice, Inbred Strains
• Molecular Structure
• Pyridines (chemical synthesis, chemistry, pharmacology)
• Rats
• Rats, Sprague-Dawley
• Rats, Wistar
• Receptor, Metabotropic Glutamate 5 (antagonists & inhibitors)
• Structure-Activity Relationship