Abstract: The present invention is directed to compounds of Formulas (I, IIa and IIb): The invention also relates to pharmaceutical compositions comprising compounds of Formulas (I, IIa and IIb). Methods of making and using the compounds of Formulas (I, IIa and IIb) are also within the scope of the invention.

Abstract: The present invention is directed to compounds of Formula (I), which includes enantiomer and diasteromers thereof: The invention also relates to pharmaceutical compositions comprising compounds of Formula (I). Methods of making and using the compounds of Formula (I) are also within the scope of the invention.

Abstract: The present invention is directed to compounds of Formulas (I, IIa and IIb): The invention also relates to pharmaceutical compositions comprising compounds of Formulas (I, IIa and IIb). Methods of making and using the compounds of Formulas (I, IIa and IIb) are also within the scope of the invention.

Abstract: The present invention relates to novel, selective radiolabelled tau ligands which are useful for imaging and quantifying tau aggregates, using positron-emission tomography (PET). The invention is also directed to compositions comprising such compounds, to processes for preparing such compounds and compositions, to the use of such compounds and compositions for imaging a tissue or a subject, in vitro or in vivo, and to precursors of said compounds.

Abstract: The present invention is directed to compounds of Formulas (I, IIa and IIb): The invention also relates to pharmaceutical compositions comprising compounds of Formulas (I, IIa and IIb). Methods of making and using the compounds of Formulas (I, IIa and IIb) are also within the scope of the invention.

Abstract: The present invention relates to novel, selective radiolabelled tau ligands which are useful for imaging and quantifying tau aggregates, using positron-emission tomography (PET). The invention is also directed to compositions comprising such compounds, to processes for preparing such compounds and compositions, to the use of such compounds and compositions for imaging a tissue or a subject, in vitro or in vivo, and to precursors of said compounds.

Abstract: The present invention relates to novel, selective radiolabelled tau ligands which are useful for imaging and quantifying tau aggregates, using positron-emission tomography (PET). The invention is also directed to compositions comprising such compounds, to processes for preparing such compounds and compositions, to the use of such compounds and compositions for imaging a tissue or a subject, in vitro or in vivo, and to precursors of said compounds.

Abstract: The present invention relates to novel, radiolabeled mGluR2/3 ligands, selective versus other mGlu receptors which are useful for imaging and quantifying the metabotropic glutamate receptor mGlu2 and 3 in tissues, using positron-emission tomography (PET). The invention is also directed to compositions comprising such compounds, to processes for preparing such compounds and compositions, to the use of such compounds and compositions for imaging a tissue, cells or a mammal, in vitro or in vivo and to precursors of said compounds.

Abstract: The present invention relates to novel, selective, radiolabelled mGluR2 ligands which are useful for imaging and quantifying the metabotropic glutamate receptor mGluR2 in tissues, using positron-emission tomography (PET). The invention is also directed to compositions comprising such compounds, to processes for preparing such compounds and compositions, to the use of such compounds and compositions for imaging a tissue, cells or a mammal, in vitro or in vivo and to precursors of said compounds.

Abstract: The present invention relates to novel, radiolabelled mGluR2/3 ligands, selective 5 versus other mGlu receptors, which are useful for imaging and quantifying the metabotropic glutamate receptors mGlu2 and 3 in tissues, using positron-emission tomography (PET). The invention is also directed to compositions comprising such compounds, to processes for preparing such compounds and compositions, to the use of such compounds and compositions for imaging a tissue, cells or a mammal, in vitro or 10 in vivo and to precursors of said compounds.

Abstract: The present invention relates to novel, selective, radiolabelled mGluR2 ligands which are useful for imaging and quantifying the metabotropic glutamate receptor mGluR2 in tissues, using positron-emission tomography (PET). The invention is also directed to compositions comprising such compounds, to processes for preparing such compounds and compositions, to the use of such compounds and compositions for imaging a tissue, cells or a mammal, in vitro or in vivo and to precursors of said compounds.

Abstract: The present invention is directed to compounds of Formulas (I, IIa and IIb): The invention also relates to pharmaceutical compositions comprising compounds of Formulas (I, IIa and IIb). Methods of making and using the compounds of Formulas (I, IIa and IIb) are also within the scope of the invention.

Abstract: The present invention relates to novel, radiolabelled mGluR2/3 ligands, selective 5 versus other mGlu receptors, which are useful for imaging and quantifying the metabotropic glutamate receptors mGlu2 and 3 in tissues, using positron-emission tomography (PET). The invention is also directed to compositions comprising such compounds, to processes for preparing such compounds and compositions, to the use of such compounds and compositions for imaging a tissue, cells or a mammal, in vitro or 10 in vivo and to precursors of said compounds.

Abstract: The present invention is directed to compounds of Formulas (I, IIa and IIb): The invention also relates to pharmaceutical compositions comprising compounds of Formulas (I, IIa and IIb). Methods of making and using the compounds of Formulas (I, IIa and IIb) are also within the scope of the invention.

Abstract: The present invention relates to novel 6,7-dihydropyrazolo[1,5-a]pyrazin-4(5H)-one derivatives as negative allosteric modulators (NAMs) of the metabotropic glutamate receptor subtype 2 (“mGluR2”). The invention is also directed to pharmaceutical compositions comprising such compounds, to processes for preparing such compounds and compositions, and to the use of such compounds and compositions for the prevention or treatment of disorders in which the mGluR2 subtype of metabotropic receptors is involved.

Abstract: The present invention relates to novel 1-aryl-4-methyl-[1,2,4]triazolo[4,3-a]-quinoxaline derivatives as inhibitors of phosphodiesterase 2 (PDE2) and to a lesser extent of phosphodiesterase 10 (PDE10) or as inhibitors of both, phosphodiesterases 2 and 10. The invention is also directed to pharmaceutical compositions comprising such compounds, to processes for preparing such compounds and compositions, and to the use of such compounds and compositions for the prevention and treatment of disorders in which PDE2 is involved, or disorders in which both PDE2 and PDE10 are involved, such as neurological and psychiatric disorders, and endocrinological or metabolic diseases. The present invention also relates to radiolabelled compounds which may be useful for imaging and quantifying the PDE2 enzyme in tissues, using positron-emission tomography (PET).

Abstract: The present invention relates to novel 6,7-dihydropyrazolo[1,5-a]pyrazin-4(5H)-one derivatives as negative allosteric modulators (NAMs) of the metabotropic glutamate receptor subtype 2 (“mGluR2”). The invention is also directed to pharmaceutical compositions comprising such compounds, to processes for preparing such compounds and compositions, and to the use of such compounds and compositions for the prevention or treatment of disorders in which the mGluR2 subtype of metabotropic receptors is involved.

Abstract: The present invention relates to novel 6,7-dihydropyrazolo[1,5-a]pyrazin-4(5H)-one derivatives of Formula (I) as negative allosteric modulators (NAMs) of the metabotropic glutamate receptor subtype 2 (“mGluR2”). The invention is also directed to pharmaceutical compositions comprising such compounds, to processes for preparing such compounds and compositions, and to the use of such compounds and compositions for the prevention or treatment of disorders in which the mGluR2 subtype of metabotropic receptors is involved.

Abstract: The present invention relates to novel 6,7-dihydropyrazolo[1,5-a]pyrazin-4(5H)-one derivatives of Formula (I) as negative allosteric modulators (NAMs) of the metabotropic glutamate receptor subtype 2 (“mGluR2”). The invention is also directed to pharmaceutical compositions comprising such compounds, to processes for preparing such compounds and compositions, and to the use of such compounds and compositions for the prevention or treatment of disorders in which the mGluR2 subtype of metabotropic receptors is involved.

Abstract: The present invention is directed to a compound of Formula (I) or (Ia) The invention also relates to pharmaceutical compositions comprising compounds of Formula (I) or (Ia). Methods of making and using the compounds of Formula (I) or (Ia) are also within the scope of the invention.