Syntheses of 2-Amino and 2-Halothiazole Derivatives as High-Affinity Metabotropic Glutamate Receptor Subtype 5 Ligands and Potential Radioligands for in Vivo Imaging
摘要:
The structure of the potent selective mGlu(5) ligand, SP203 (1, 3-fluoro-5-[[2-(fluoromethyl)thiazol-4-yl]ethynyl]benzonitrile), was modified by replacing the 2-fluoromethyl substituent with an amino or halo substituent and by variation of substituents in the distal aromatic ring to provide a series of new high-affinity mGlu(5) ligands. In this series, among the most potent ligands obtained, the 2-chlorothiazoles 7a and 7b and the 2-fluorothiazole 10b showed subnanomolar mGlu(5) affinity. 10b also displayed > 10000-fold selectivity over all other metabotropic receptor subtypes plus a wide range of other receptors and binding sites. The 2-fluorothiazoles 10a and 10b were labeled using [F-18]fluoride ion (t(1/2) = 109.7 min) in moderately high radiochemical yield to provide potential radioligands that may resist troublesome radiodefluorination during the imaging of brain mGlu(5) with position emission tomography. The iodo compound 9b has nanomolar affinity for mGlu(5) and may also serve as a lead to a potential I-123-labeled ligand for imaging brain mGlu(5) with single photon emission computed tomography.
Syntheses of 2-Amino and 2-Halothiazole Derivatives as High-Affinity Metabotropic Glutamate Receptor Subtype 5 Ligands and Potential Radioligands for in Vivo Imaging
摘要:
The structure of the potent selective mGlu(5) ligand, SP203 (1, 3-fluoro-5-[[2-(fluoromethyl)thiazol-4-yl]ethynyl]benzonitrile), was modified by replacing the 2-fluoromethyl substituent with an amino or halo substituent and by variation of substituents in the distal aromatic ring to provide a series of new high-affinity mGlu(5) ligands. In this series, among the most potent ligands obtained, the 2-chlorothiazoles 7a and 7b and the 2-fluorothiazole 10b showed subnanomolar mGlu(5) affinity. 10b also displayed > 10000-fold selectivity over all other metabotropic receptor subtypes plus a wide range of other receptors and binding sites. The 2-fluorothiazoles 10a and 10b were labeled using [F-18]fluoride ion (t(1/2) = 109.7 min) in moderately high radiochemical yield to provide potential radioligands that may resist troublesome radiodefluorination during the imaging of brain mGlu(5) with position emission tomography. The iodo compound 9b has nanomolar affinity for mGlu(5) and may also serve as a lead to a potential I-123-labeled ligand for imaging brain mGlu(5) with single photon emission computed tomography.
Efficient and Regioselective Halogenations of 2-Amino-1,3-thiazoles with Copper Salts
作者:Fabrice G. Siméon、Matthew T. Wendahl、Victor W. Pike
DOI:10.1021/jo802799c
日期:2009.3.20
dihalo 1,3-thiazole derivatives can be efficiently and selectively prepared under mild conditions from 2-amino-1,3-thiazoles. Halogenations proceed easily in the presence of copper(I) or copper(II) chlorides, bromides, or iodides directly in solution or with supportedcopper halides.
单卤和二卤 1,3-噻唑衍生物可以在温和条件下由 2-氨基-1,3-噻唑高效且选择性地制备。在铜 (I) 或铜 (II) 氯化物、溴化物或碘化物直接存在于溶液中或与负载的卤化铜一起存在时,卤化很容易进行。