The present invention provides quinoline carboxamide and quinoline carbonitrile compounds of formula (I) or a pharmaceutically acceptable salt thereof, wherein R1, R2, L, X1, X2, and X3, are as defined herein. The compounds of the invention, and pharmaceutically acceptable salts thereof, and pharmaceutical compositions comprising them, are useful as non-competitive mGluR2 antagonists, or mGluR2 negative allosteric modulators (NAMs), and may be useful in methods of treating a person in need thereof for diseases or disorders in which the mGluR2-NAM receptor plays a causative role, such as Alzheimer's disease, cognitive impairment, schizophrenia and other mood disorders, pain disorders and sleep disorders.